coc bridges and structures design guidelines 2015 - rev 2

7/25/2019 CoC Bridges and Structures Design Guidelines 2015 - Rev 2

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CITY OF CALGARY

DESIGN GUIDELINES FOR BRIDGES AND STRUCTURES

FIFTH EDITION, 2015


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THE CITY OF CALGARY PAGE iDESIGN GUIDELINES FOR BRIDGES AND STRUCTURES 2015

TABLE OF CONTENTS

DISCLAIMER..1

1.0 INTRODUCTION ___________________________________________________________ 1

1.1 Purpose ___________________________________________________________________ 1

1.2 Modifications and Revisions ___________________________________________________ 1

1.3 Consultant Terms of Reference ________________________________________________ 2

1.4 Definitions _________________________________________________________________ 2

2.0 QUALITY AND STANDARDS _______________________________________________ 3

2.1 General ___________________________________________________________________ 3

2.2 Codes and Standards ________________________________________________________ 3

3.0 GENERAL DESIGN CRITERIA _______________________________________________ 4

3.1

Design Life

_________________________________________________________________ 43.2 Safety _____________________________________________________________________ 4

3.3 Function ___________________________________________________________________ 4

3.4 Efficiency and Economy ______________________________________________________ 5

3.5 Aesthetics of Structures ______________________________________________________ 5

3.6 Environmental Considerations _________________________________________________ 6

3.7 Special Considerations for Pedestrian Bridges and Structures ________________________ 6

4.0 BRIDGE GEOMETRY _____________________________________________________ 7

4.1 Vertical Clearance ___________________________________________________________ 74.2 Horizontal Clearances ________________________________________________________ 8

4.3 Grades and Slopes ___________________________________________________________ 9

4.4 Approach Slabs _____________________________________________________________ 9

4.6 Other Requirements ________________________________________________________ 10

4.7 Camber and Deflections _____________________________________________________ 11

5.0 LOADS AND LOAD EFFECTS ______________________________________________ 12

5.1 General __________________________________________________________________ 12

5.2 Live Load _________________________________________________________________ 12

5.3 Pedestrian Load ___________________________________________________________ 12

5.4 Maintenance Vehicle Load ___________________________________________________ 12

5.5 Multiple Use Structure Loads _________________________________________________ 13

5.6 Vehicle Collision Load _______________________________________________________ 13

5.7 Construction Loads _________________________________________________________ 13


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THE CITY OF CALGARY PAGE iiDESIGN GUIDELINES FOR BRIDGES AND STRUCTURES 2015

5.8 Seismic Loads _____________________________________________________________ 13

5.9 Methods of Analysis ________________________________________________________ 13

5.10 Diaphragms _______________________________________________________________ 14

5.11 Construction and Temporary Load Conditions ___________________________________ 14

6.0 DURABILITY ___________________________________________________________ 14

6.1 General __________________________________________________________________ 14

6.2 Concrete Structures ________________________________________________________ 14

6.3 Concrete Cover ____________________________________________________________ 15

6.4 High Performance Concrete (HPC) _____________________________________________ 16

6.5 Protective Coatings _________________________________________________________ 16

6.6 Structural Details __________________________________________________________ 18

6.7 Drainage _________________________________________________________________ 19

6.8 Bridge Deck Drainage _______________________________________________________ 19

6.9 Deck Drains _______________________________________________________________ 20

6.10 Drip Grooves ______________________________________________________________ 20

6.11 Utilities on Bridges _________________________________________________________ 20

6.12 Steel Structures ____________________________________________________________ 21

6.13 Uncoated Weathering Steel __________________________________________________ 21

6.14 Corrosion Protection ________________________________________________________ 21

6.17

Masonry Structures

________________________________________________________ 236.18 Other Materials ____________________________________________________________ 24

6.19 Inspection and Maintenance Access ___________________________________________ 24

6.20 Approach Slabs ____________________________________________________________ 24

6.22 Construction ______________________________________________________________ 24

7.0 SERVICEABILITY LIMIT STATES ____________________________________________ 25

7.1 General __________________________________________________________________ 25

7.2 Crack Control ______________________________________________________________ 25

7.3 Stress Limits ______________________________________________________________ 277.4 Deformation ______________________________________________________________ 27

7.5 Vibration _________________________________________________________________ 27

8.0 FATIGUE LIMIT STATE ___________________________________________________ 28

8.1 Reinforced and Pre-stressed Concrete __________________________________________ 28

8.2 Structural Steel ____________________________________________________________ 28


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THE CITY OF CALGARY PAGE ii iDESIGN GUIDELINES FOR BRIDGES AND STRUCTURES 2015

9.0 DESIGN OF FOUNDATIONS AND EARTH RETAINING STRUCTURES _______________ 28

9.2 Codes and Specifications ____________________________________________________ 29

9.3 Geotechnical Report ________________________________________________________ 29

9.4 Design ___________________________________________________________________ 29

9.5 Loads ____________________________________________________________________ 29

9.7 Construction Methods ______________________________________________________ 31

9.8 Proprietary Walls __________________________________________________________ 32

9.9 Inspection and Quality Assurance _____________________________________________ 32

10.0 CABLE STAYED BRIDGES _________________________________________________ 32

10.1 General __________________________________________________________________ 32

10.2 Reference Publications ______________________________________________________ 32

10.3

Limitations

________________________________________________________________ 3310.4 Design ___________________________________________________________________ 33

10.5 Corrosion Protection ________________________________________________________ 35

10.6 Construction Considerations _________________________________________________ 35

10.7 Quality Assurance __________________________________________________________ 35

10.8 Maintenance ______________________________________________________________ 36

11.0 INTEGRAL ABUTMENT BRIDGES __________________________________________ 36

11.1 Characteristics of Integral Abutment Bridges ____________________________________ 36

11.2 Limitations ________________________________________________________________ 3611.3 Design ___________________________________________________________________ 37

12.0 SEMI-INTEGRAL ABUTMENT BRIDGES ______________________________________ 39

12.1 Characteristics of Semi-Integral Bridges ________________________________________ 39

12.2 Limitations ________________________________________________________________ 39

12.3 Design ___________________________________________________________________ 40

12.4 Details ___________________________________________________________________ 40

13.0 BRIDGE DECK JOINTS AND BEARINGS ______________________________________ 41

13.1 General __________________________________________________________________ 41

13.2 Design Requirements _______________________________________________________ 41

13.3 Temperature Variation Effects on Deck Joints and Bearings ________________________ 41

13.4 General Policy for Deck Joints ________________________________________________ 41

13.5 Deck Joints - Functional Requirements _________________________________________ 41

13.6 Deck Joints - Design and Detailing _____________________________________________ 42


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THE CITY OF CALGARY PAGE ivDESIGN GUIDELINES FOR BRIDGES AND STRUCTURES 2015

13.7 General Design Policy for Bridge Bearings _______________________________________ 43

13.8 Bearing Types and Specifications ______________________________________________ 43

13.9 Bearing Design ____________________________________________________________ 43

13.10 Bearing Detailing ________________________________________________________ 44

14.0 TRAFFIC BARRIERS _____________________________________________________ 44

14.1 Barrier Selection and Detailing Criteria _________________________________________ 45

14.2 Traffic Barrier Joints ________________________________________________________ 45

15.0 HIGHWAY ACCESSORY SUPPORTS _________________________________________ 46

15.1 General Considerations _____________________________________________________ 46

15.2 Design and Construction _____________________________________________________ 46

16.0 NOISE BARRIERS _______________________________________________________ 46

16.1

Design

___________________________________________________________________ 4616.2 Durability and Maintenance Requirements ______________________________________ 47

16.3 Functional Requirements ____________________________________________________ 48

16.4 Construction ______________________________________________________________ 48

17.0 CONTRACT DOCUMENTS ________________________________________________ 49

17.1 Drawings _________________________________________________________________ 49

17.2 Specifications _____________________________________________________________ 51

17.3 Preliminary Design Report ___________________________________________________ 51

17.4 Quality Control and Quality Assurance _________________________________________ 5217.5 Project Closure Documentation _______________________________________________ 53


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THE CITY OF CALGARY PAGE vDESIGN GUIDELINES FOR BRIDGES AND STRUCTURES 2015

LIST OF APPENDICES

APPENDIX A : SUPPL EMENTARY GUIDELINES

A1 HIGHWAY ACCESSORY SUPPORTS GUIDELINES FOR STRUCTURALDESIGN AND CONSTRUCTION

APPENDIX B : DESIGN SUBMITTALS

B1 TITLEBLOCKB2 DESIGN BRIEF FORMATB3 ASSURANCE OF ENGINEERING FIELD REVIEW AND COMPLIANCE

FORM

APPENDIX C : STANDARD CITY SPECIFICATIONS

02510 (a) BRIDGE DECK ASPHALTIC CONCRETE PAVING SINGLE LIFT02510 (b) BRIDGE DECK ASPHALTIC CONCRETE PAVING MULTIPLE LIFTS02510 (c) BRIDGE DECK ASPHALTIC CONCRETE PAVING REHABILITATION02850 NOISE BARRIERS03200 CONCRETE REINFORCEMENT03300 CAST IN PLACE CONCRETE03301 HIGH PERFORMANCE CONCRETE03483 MECHANICALLY STABILIZED EARTH RETAINING WALLS05210 STRUCTURAL STEEL SUPPLY AND FABRICATION07100 BRIDGE DECK WATERPROOFING

APPENDIX D : WARRANTY FORMS

D1 BEARINGSD2 EXPANSION JOINTSD3 GALVANIZINGD4 COATINGS (PAINTING included)

APPENDIX E : TYPICAL DETAILS

DG01 BRIDGE BARRIER SECTION TYPICALDG02 INTEGRAL/ SEMI INTEGRAL ABUTMENT Approach Slab End DetailDG03 SEMI INTEGRAL ABUTMENT Wingwall DetailDG04 SEMI INTEGRAL ABUTMENT Wingwall DetailDG05 INTEGRAL/ SEMI INTEGRAL ABUTMENT APPROACH Slab Interface DetailDG06 DECK WATERPROOFING SYSTEM with 80mm Two-course Hot Mix Asphalt

Concrete PavementDG07 DECK WATERPROOFING SYSTEM with 80mm Two-course Hot Mix Asphalt

Concrete Pavement


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THE CITY OF CALGARY PAGE viDESIGN GUIDELINES FOR BRIDGES AND STRUCTURES 2015

LIS T OF TABLES

TABLE 6.3.1 Surfaces exposed to de-icing chemicals, Cover to Principal Reinforcing

TABLE 10.4.4 Standard Classification for Pre-stressing Steels for Cable Stays

TABLE 17.1.4 Typical List of Drawings


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THE CITY OF CALGARY PAGE 1DESIGN GUIDELINES FOR BRIDGES AND STRUCTURES 2015

CITY OF CALGARYDESIGN GUIDELINES FOR BRIDGES AND STRUCTURES

2015

DISCLAIMER:

The City is providing these Design Guidelines for use in the design of bridges and structuresowned by The City of Calgary. The City does not undertake any duty of care or obligationwhatsoever; and receipt of these documents does not in any way relieve the Consultant of hisresponsibility or liability for his own work and obligations.

1.0 INTRODUCTION

1.1 Purpose

This Document sets forth The City of Calgary design criteria that govern design of newbridges and structures, as well as evaluation and rehabilitation of existing structures. The

Guidelines apply to the structures including, but not limited to, the following:

i. Vehicular bridgesii. Pedestrian bridgesiii. Large culverts and tunnelsiv. Light Rail Transit platforms and stationsv. Retaining wallsvi. Highway Accessory Supportsvii. Noise barriers

This document reflects the current City of Calgary policies governing planning, design,construction and rehabilitation of structures owned and managed by The City of Calgary.

This document provides basic design considerations and any unique applications, issues, ordeparture from the Guidelines shall be referred to The City of Calgary, TransportationInfrastructure, Bridges and Structures for review and acceptance at the early stage of designor construction as applicable.

This document supersedes City of Calgary Design Guidelines for Bridges and Structures,Fourth Edition, 2013 Revision 3.

1.2 Modifications and Revis ions

1.2.1 Revisions to Guidelines:

Revisions to the Guidelines occur periodically upon changes of reference codes,modifications to the policies governing structures management or due to anongoing process of improving the document due to recent experience gainedfrom designs, construction, maintenance, and as a result of most currentresearch and new technologies available.

Other City of Calgary Business Units, at their discretion, may consider


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alternatives to or relaxations of the Guidelines and Specifications when theDeveloper or their agent, or the contractor or their agent, provides a writtensubmission identifying the reasons for special considerations.

Comments and suggestions to improve the Guidelines are welcome and should

be referred to:Ms. Jadwiga Kroman, P.Eng.Manager, Bridges and StructuresTransportation InfrastructureCity of CalgaryP.O. Box 2100, Stn. M, #8481Calgary, Alberta T2P 2M5E-mail: [email protected]

City of Calgary, Transportation Infrastructure, Bridges and Structures, willconduct necessary research, review or analysis of the proposed modificationsand, if the proposed modification is deemed appropriate, the implementation ofthe revision will follow.

1.2.2 Revisions to Specifications:

Specifications included in the Appendices of this Document shall not be alteredwhen used as part of Contract Documents. Modifications to the specifications asapplied to the specific projects may be made through the use of the Modificationsto Technical Specifications section of the project specifications. Suchmodifications shall be made only upon the prior review by the authorized Citypersonnel.

1.3 Cons ultant Terms of Referen ce

Consultants should refer to the Consultant Terms of Reference for project-specificrequirements pertaining to planning, design, and construction review and project closure.

1.4 Definitions

The following are the administrative definitions that shall be used in conjunction with theGuidelines as well as with codes and standards referenced herein:

i. Approved or Approval - means approved or approval, in writingby The City of Calgary.

ii. Engineer of Record- means an Engineer licensed in the Provinceof Alberta that, through a contract with The City of Calgary, isresponsible for design and verification of construction compliancewith the Contract Documents.

iii. For the purpose of these Guidelines, the terms Engineer andEngineer of Record are used interchangeably.

iv. Owner - means The City of Calgary or its representative(s),agent(s) or assignee(s).


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v. Reviewed or Review means planning, design or constructionwork is accepted by The City without detailed checking ofcalculations and application of engineering principles.

vi. The City - means The City of Calgary.

2.0 QUALITY AND STANDARDS

2.1 General

2.1.1 This document takes precedence over all other applicable codes and/orstandards, unless Approved otherwise.

2.1.2 Expertise: New design and evaluations of existing bridges and structures shall beperformed by a Professional Engineer employed by a firm pre-qualified by TheCity of Calgary. The design shall be independently checked by an experiencedbridge engineer or structural engineer, as applicable to the scope of the design.

2.1.3 Design requirements assigned to construction contractors or suppliers shall beclearly outlined in construction contract documents.

2.1.4 Wherever standards (e.g., CSA, ASTM and others) are referred to in thisdocument, the current edition, including supplements, shall apply.

2.2 Codes and Standards

2.2.1 Permanent and Existing Structures

The Design Standard shall be Canadian Highway Bridge Design Code (CHBDC)CAN/CSAS6, latest edition, except as noted otherwise in this Document.

Section 14 of the CAN/CSA-S6, latest edition shall be used for load limitrestrictions of the existing bridges and for assessment of serviceability or fatiguelife of the existing bridge elements. It should not be used for justification of adesign that does not meet the requirements of other Clauses of the CHBDC.

References to American Association of State Highway and TransportationOfficials (AASHTO) have been made for selected aspects of bridge andstructures design.

Use of loads and strength formulas from other codes in conjunction with theCHBDC requires an investigation; Approved by The City, into compatibility and

safety levels with appropriate calibration of load and resistance factors.

2.2.2 Temporary Structures

Temporary structures shall be designed in accordance with CAN/CSA-S6, latestedition, except for Falsework and temporary access scaffolding which shall bedesigned to CSA Standards S269.1 and S269.2.


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Falsework and temporary access scaffolding shall be designed andindependently checked by a professional engineer.

Design loads and load combinations shall be described and accounted for. Anote regarding exclusions of certain loads from the original design, i.e.

construction-specific loads, shall be included on the drawings.2.2.3 Buildings and Parkades

Building structural components shall conform to the Alberta Building Code,current edition and all of its supplements.

Parkade structure design shall conform to CAN/CSA-S413, latest edition. Theupgrade and repair procedures for existing structures shall conform to CAN/CSA-S448.1, latest edition.

2.2.4 Plus 15 and Plus 30 Elevated Walkways

Design of Plus 15 Elevated Walkway System, connecting two buildings shallconform to the Alberta Building Code, current edition, unless specified otherwise.

3.0 GENERAL DESIGN CRITERIA

3.1 Design Life

Unless Approved otherwise, the design life of new structures shall be 75 years with theannual target reliability index of 3.75.

Design life of retaining walls, river crossings, railway or light rail transit (LRT) crossings and

tunnels shall be 100 years.

3.2 Safety

Safety of the structures shall be assured through application of design methodology basedon Limit States in accordance with CAN/CSA-S6, latest edition, choice of multiple-load-pathstructural systems (unless Approved otherwise), assurance of clear and continuous flow offorces and detailing that enhances durability and facilitates maintainability of the structures.

3.3 Function

Functional requirements for a structure shall be established or reviewed and Approved byThe City. The design may proceed upon Approval of the functional criteria. Functionalrequirements include purpose, use, location, environmental and socio-economic impactsand any other applicable terms of reference. Provisions for, or impact on ALL users (i.e.motorists, cyclists, pedestrians, wheelchair) shall be considered in the project functionaldefinition.


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3.4 Efficiency an d Econo my

The efficient structural design shall result in minimum use of structural materials ascontrolled by safety.

The design shall result in an economical structure. The economy of the design shall bebased on minimum cost controlled by safety, serviceability and lifetime maintenance. Unless Approved otherwise, life-cycle costs shall be used along with initial construction costs in thecost analysis of alternative structure types.

3.5 Aes thetics of Structures

Aesthetic considerations, appropriate to function and location shall be included in the designof bridges and structures.

The majority of City of Calgary structures will be constructed in the urban environment andthe visual impact of the structures on the environment shall be considered in the design.

The proportion and configuration of the bridge elements shall be compatible with the contextof the space and the immediate environment. In the selection of the bridge type and itscomponents, the following essentials shall be considered:

3.5.1 Good visibility achieved through provision of large under-span openings andavoidance of vertical lines of piers and walls close to the driving lanes.

3.5.2 Visual continuity of the bridge form with topography of the environment.

3.5.3 Superstructure geometry: an overall pleasing bridge line achieved throughbalanced span-to-depth proportion, smooth horizontal and vertical alignment and

camber or vertical crest curve of the bridge spans.

3.5.4 Substructure geometry: shape and location of piers, placement, height and shapeof abutments.

3.5.5 Clarity of function expressed by form.

3.5.6 Harmony of all elements of the bridge expressed by compatibility, contrast andrhythm of shapes, weight, and materials used.

3.5.7 Proper design of details is essential to producing aesthetic design of structures.The following elements shall be considered:

i. High quality surface finishes.ii. Consistent and compatible color and shape of all structure

components.iii. Careful detailing of joints. In particular, expansion joints shall be

designed to prevent the uncontrolled flow of water over concretesurfaces and to prevent staining.

iv. Control of surface water runoff from the structures.


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v. Use of hidden pier caps, diaphragms and screen walls.vi. Signage, lighting, and landscaping shall be carefully planned to

complement the appearance of the structure and avoid clutter.vii. Construction joints in exposed concrete surfaces shall be concealed

by reveals or other architectural details.

3.5.8 Aesthetic design shall be submitted for Approval by The City prior to proceedingto the detailed design phase.

3.6 Environmental Considerations

3.6.1 General

Bridges and structures shall be designed to comply with all environmentalrequirements established for the project site. The design shall includeassessment of possible environmental impacts and measures proposed tomitigate or minimize any adverse effects.

The design shall consider optimization of the project footprint, elements oflandscaping, and methods of conservation of natural environment.

3.6.2 Sustainable Products and Materials

Use of environmentally sustainable materials and methods of construction isencouraged. Materials and products shall be specified through conscientiouschoices of the following characteristics:

i. Durability, thus enhancement of bridges and structures life-cycleii. Minimum use of natural non-renewable resourcesiii. Use of recyclable and recycled materials

iv. Minimum wastage of space, materials and energyv. Energy-efficient processes and productsvi. Innovative materials, systems and solutions promoting sustainable

solutions

3.6.3 Noise Control

Where stipulated in the project scope, structure design shall incorporate featuresthat tend to minimize the generation and propagation of noise.

3.6.4 Drainage

Refer to Section 4.0 BRIDGE GEOMETRY for minimum slopes and grades andto Section 6.2.5 Bridge Deck Drainage for drainage criteria. Sustainabledrainage solutions, such as bio-swales, are encouraged.

3.7 Special Cons iderations for Pede s trian Bridges and Structures

3.7.1 Types of Structures


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Conceptual design of pedestrian bridges and other pedestrian grade separationsshall consider functional requirements such as safety, connectivity with adjacentpathways, recreational, public transportation and other facilities, community fitand local context.

3.7.2 Pedestrian UnderpassesNarrow and/ or long pedestrian underpasses and tunnels should be avoidedunless justified for a specific location and require an Approval from the City priorto proceeding with the design.

Should a pedestrian underpass be warranted, consideration should be given to:

i. Visibility and Security of users (Crime Prevention ThroughEnvironmental Design: CPTED)

ii. Geometry (see Section 4.0 for allowable length and width) Length isto be minimized and width and clearance are to be maximizedwhenever possible.

iii. Adequate lightingiv. Drainagev. Maintenancevi. Aestheticsvii. Signage

3.7.3 Bridge Approaches

Considerations shall be given to provision of safe access and exit areas forpedestrian structures. Good visibility at entrance and exit approaches as well asacross the structure, safe connection to pathway/walkway systems, directionalrailings, grab rails if applicable, fence, signage or other means of directingpedestrian and cyclist traffic shall be included in the design.

3.7.4 Lighting

Street lighting and/or pathway lighting shall be utilized for the illumination ofpedestrian overpasses. In areas of transit oriented design or underpasses, aminimum lighting level is required.

Light standards shall not be located on the pedestrian overpasses, except forriver crossings or where Approved otherwise.

4.0 BRIDGE GEOMETRY

4.1 Vertical Clea ran ce

4.1.1 Vehicular Bridges

Vertical clearance over roadways shall be minimum 5.4 m (posted) plus 0.1m toaccount for construction tolerance, long term deformations and future paving.


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Vertical clearance over the Federal Railways shall be minimum 7.16 m (or 23feet, 6 inches) above the base of rail.

Vertical clearance over light rail transit (LRT) tracks shall be minimum 6.0 mabove the top of rail.

4.1.2 Pedestrian Bridges, Underpass and Sidewalks

Over roadways: minimum 5.7 m (posted), plus 0.1m to account for constructiontolerance, long term deformations and future paving.

Over pedestrian pathways/bikeways: minimum 2.5 m, measured from thepathways/bikeways to the underside of the structure.

Over pedestrian pathways/bikeways located in tunnels* and underpasses*:minimum 3.6 m.

*See Section 3.7.2: Pedestrian Underpasses

4.2 Horizontal Clearan ces


Horizontal clearances shall include considerations for any future widening plansof the roadway below.

Horizontal clearances shall include substructure protection by traffic barriers,unless the clear zone requirements can be met.

4.2.2 Pedestrian Bridges, Underpass and SidewalksMinimum clear widths are outlined as follows. Some locations may require awider structure, based on site-specific analysis (land use, expected volumes,etc.)

Land crossings

Pathways and sidewalks integrated with interchange bridge structures.

i. Part of regional pathway system 3.0 mii. Part of pathway system 2.5 m

iii. Part of sidewalk system 2.0 miv. Stand alone pathway underpasses 3.0 mv. Stand alone pathway overpasses 3.0 m

River crossings

Pathways and sidewalks integrated with bridge structures.


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i. Part of pathway system 3.0 mii. Part of sidewalk system 2.5 miii. Stand-alone bridges 4.0 m

4.3 Grades and Slopes


Vehicular bridges shall have a minimum grade of 1%, unless otherwise Approved.

Roadway cross slopes shall be 2%, except on super-elevated road alignments,where special assessment of safety and drainage may be required.

Construction of bridges on spiral horizontal alignments shall be avoided unless Approved. Safety and drainage analyses shall be required to justify exceptions.


Longitudinal grade shall be:

i. Max 5% orii. Max 1:12 (8.33%) over a 9 m horizontal distance with landings of

minimum 1.5 m long and a 1% longitudinal slope

Pedestrian bridge decks shall have a centered crown, unless otherwise Approved. Crown on ramps are not required, provided 1% longitudinal grade isprovided.

Sidewalks and pedestrian bridge decks shall be provided with a 2% cross-fall,sloping towards the roadway and a minimum 1% longitudinal grade.

4.4 Approach Slabs

4.4.1 Vehicular Bridge

Vehicular bridges shall be provided with reinforced concrete approach slabsanchored to the abutments. The minimum length of slabs shall be 6.0 m, exceptfor integral or semi-integral bridges, unless otherwise Approved. The approachslab shall extend to the lateral limits of the roadway, but shall not be integral with

the curbs or barriers to allow differential settlement to occur, except for integral orsemi-integral bridges. Longitudinally, the slab shall not extend into theintersecting roadway.

4.5 Horizon tal Layou t



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Tight switch-back alignment of ramps should be avoided. Switch-back landingsshould be round-shaped and should allow for unobstructed sight lines for bothdownward and upward traffic.

Spiral ramps, if Approved, shall have a minimum radius of 25 m and shall

conform to vertical clearance requirements.Landings at entry/exit locations shall facilitate the anticipated traffic to and fromthe bridge and shall safely direct the traffic to connecting pathways.

Way finding features, landscaping, public art and viewing features areencouraged within the approaches and pedestrian crossing facilities.

4.6 Other Requirements

4.6.1 Accessibility

Design of access ramps for overpasses should take into consideration The Cityof Calgary Access Design Standards and CAN/CSA -B651 Accessible Design forthe Built Environment. Access via stairs only requires Approval by the City.

4.6.2 Grab Rails and Railing

Pedestrian railings shall be 1050 mm high; bicycle or mixed use bridge railingsshall be 1400 mm high.

Pedestrian railings shall be constructed such that maximum space between solidelements (i.e. vertical pickets) of the railing shall not exceed 100 mm, within theheight of 1050 mm.

Pickets shall not be required between the top pedestrian rail and horizontalbicycle rail.

In some locations, railings higher than 1400 mm may be required. Please consultproject manager for project specific requirements.

Grab rail at the height of 865 mm to 965 mm (from wearing surface to top of rail)shall be required on all sloped ramps and the intermittent landings. Grab railsection diameter should be between 30 mm to 43 mm.

Grab rails are required for pedestrian bridges unless otherwise Approved.

Exceptions may be considered for bridges with 5% or less longitudinal gradeupon Approval.

Design of railings should discourage climbing.

4.6.3 Light Rail Transit (LRT)

For bridges located over LRT tracks, railings shall be grounded as per The City of


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Calgary LRT Design Guidelines Manual.For bridges located over LRT tracks, protective shrouds shall be required overthe centenary wires.

Additional design considerations may be provided by Calgary Transit for specific

project items.4.6.4 Crash Walls

Structure elements located within the LRT or Canadian Pacific Railway (CPR)clear zone shall be protected by a suitably designed crash wall.

4.6.5 Finishes, Curbs, and Joints

Deck surface shall be broom finished or shall have an Approved non-slip finish.Pedestrian overpass curbs shall be minimum 75 mm high unless otherwise

Approved.

Construction joints in bridge barriers shall be positioned over the drains fromsidewalk to roadway.

Expansion joint cover plates shall be coated with PPG Protective & MarineCoatings SFT675 (grey) non-slip coating or Approved equivalent.

4.7 Cambe r and Deflections

4.7.1 Bridges shall be built to match the profile grade after permanent Dead Load hasbeen applied.

4.7.2 Steel girders typically are cambered for 100% of dead load effects. Self weight,superimposed dead loads and final roadway grade line shall be considered. Datashall be presented on a camber diagram on the drawings that shows overallcamber as well as net camber values for individual camber segments.

4.7.3 For precast girders, camber and deflection diagram(s), including effects of pre-stressing, post-tensioning and stages of construction, shall be shown on thedrawings. Camber should be designed to take into account the effects of creepand shrinkage. The design height of haunches shall be shown on camberdiagrams. Verification and adjustment, of the height of haunches shall be madeat all applicable stages of construction.

4.7.4 Cast-in-place superstructure shall be shown on the drawings with elevationsshown for setting of forms. The deflection and camber data shall be shown on thedrawings.

4.7.5 Deflections on Pedestrian Bridges

The following maximum limits of Live Load (LL) deflections shall apply:


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i. Pedestrian Load Span/500ii. Maintenance vehicle Load Span/500iii. Cantilever arm due to pedestrian LL Cantilever Length/300iv. Horizontal deflection due to wind Span/500

The above limits are not to replace other serviceability criteria, provided inCAN/CSA-S6, latest edition, which may govern the design as being morestringent.

5.0 LOADS AND LOAD EFFECTS

5.1 General

Bridge and structure design shall be based on Limit States philosophy, with equal emphasisbeing given to Ultimate Limit States (ULS), Serviceability Limit States (SLS) and FatigueLimit State (FLS), in accordance with CAN/CSA-S6 (latest edition).

5.2 Live Load

5.2.1 The design live load for new highway bridge structures shall be a CL-800 TruckLoad increased by dynamic load allowance, or CL-800 Lane Load. The uniformly-distributed portion of the CL-800 Lane Load shall be 9 kN/m and shall have awidth of 3.0 m.

5.2.2 Overload Trucks shall not be used for new bridge design.

5.2.3 Evaluation of existing bridges shall be done using Load Evaluation Trucks CL1-800, CL2-800, and CL3-800.

5.3 Pedes tr ian Load

5.3.1 Pedestrian Load shall be included in the design for all designated occupancyareas such as sidewalks /pathways on bridges, or pedestrian bridges and ramps,in accordance with CAN/CSA-S6 (latest edition).

5.3.2 Pedestrian/bicycle bridges and ramps shall be designed for a maintenancevehicle as specified in CAN/CSA-S6 (latest edition).

5.4 Mainten an ce Veh icle Loa d

5.4.1 Maintenance Vehicle Load shall be considered along with Snow Load on thebridge where the geometry of the facility warrants entry of small snow removalvehicles.

5.4.2 Maintenance Vehicle Loads for sidewalks on bridges shall be included at the ULSonly.

5.4.3 Maintenance Vehicle Loads for pedestrian bridges shall be considered at ULS


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and SLS.

5.5 Multiple Use Structure Load s

For bridges that carry Light Rail Transit (LRT) in addition to vehicular traffic, the City and

Calgary Transit will specify the live loads and load factors for particular bridge sites.

5.6 Veh icle Collision Loa d

5.6.1 Bridge piers located within 10 m from the edge of the road pavement shall bedesigned for a Collision Load, regardless of the presence of guardrail. Themagnitude and application of the equivalent horizontal static force shall be inaccordance with Clause 3.15 of CAN/CSA-S6 (latest edition).

5.6.2 LRT underpasses shall be designed for a Collision Load as specified in The Cityof Calgary LRT Design Guidelines; however, in no case shall the total factoredload effect of Collision Load and the relevant load combination be less than that

specified herein.

5.7 Construction Loads

5.7.1 Construction Dead Load shall include weight of materials, formwork, falsework,stationary lifting devices and equipment.

5.7.2 Construction Live Load shall include weight of workers, equipment and otherelements subject to movement during construction at the construction stageconsidered.

5.7.3 Concurrent Loads due to wind, ice, stream flow, temperature change shall beconsidered at a ten (10) year return period, as applicable.

5.8 Seismic Loads

Seismic analysis and design shall be based on requirements pertinent to SeismicPerformance Zone 1.

5.9 Metho ds of Analysis

5.9.1 For short and medium span bridges conforming to the conditions stated inCAN/CSA-S6 (latest edition), a simplified method of analysis may be used.

5.9.2 Regardless of the method of analysis load distribution factors used for girderdesign shall be shown on the Drawings.

5.9.3 All relevant structural responses including deformation shall be analyzed. Refinedmethods of analysis shall be selected based on the criteria outlined in CAN/CSA-S6 (latest edition).


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5.10 Diaphragms

Intermediate diaphragms are required in bridges with steel or concrete girders and concretedecks, unless Approved otherwise.

5.11 Construction and Temporary Load Conditions

During design, evaluation of the structure for the following temporary construction loadconditions shall be performed:

i. Prior to superstructure installationii. During all stages of superstructure installation and deck casting.

The assumed magnitude of construction loads, methodology and sequence shall beincluded in the Drawing Notes. Any deviation from these assumptions shall be re-evaluatedprior to construction and shall be based on the Contractors proposed constructionmethodology.

6.0 DURABILITY

6.1 General

6.1.1 Consideration shall be given in all aspects of design to minimizing thedeterioration of the appearance, and to maximizing structural capacity as well asperformance of the structures during the design lifetime.

6.1.2 Structural design and detailing shall focus on minimizing the impacts of suchenvironmental factors as temperature variations, snow, ice, salt, rain, wind andsolar radiation. Structural site investigation shall include testing of soils,groundwater, local runoff water, and atmospheric pollution level and, whererelevant, drainage system discharge to detect corrosive substances.

6.1.3 Durability shall be enhanced by selection of the proper structural systems,adequate design for strength and serviceability, choice of materials, as well asadequate Quality Control and Quality Assurance during design, fabrication andconstruction.

6.2 Concrete Structures

Standard Specifications are included in this document for concrete elements (see AppendixC):

003300 Cast In Place Concrete003301 High Performance Concrete003200 Concrete Reinforcement003483 Mechanically Stabilized Earth Retaining Walls

Durability of concrete structures shall be assured through design and detailing, application of


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high performance materials, protection of reinforcing steel and application of concretesealers.

6.3 Concrete Cover

6.3.1 The requirements for concrete cover over reinforcing steel shall be as shown inTable 8.5 of CAN/CSA-S6 (latest edition), except as specified in Table 6.2.1herein.

Table 6.3.1

Surfaces exposed to de-icing chemicals, Cover to Principal Reinforcing:

Structure Element Concrete Cover*** andTolerancesConcrete decks and sidewalksTop Surface 70+5/-10 mmSoffit: 5010 mm

Precast LRT Platform Top Surface 60 + 10 mmPrecast LRT Platform Soffit 40 + 10 mmTraffic Barriers:Front Surface 70 5 mmBack Surface 70 5 mmMedians, Curbs 60 10 mmSubstructures and Retaining Walls** 70 10 mmPrecast T, I and Box Girders****Soffit 40 + 10 mmExterior Surface 35 5 mmPrecast Panels for Retaining Walls 60+10 mm

** Front surface within splash zone.

*** Average concrete cover as placed shall conform to the specified values,excluding the tolerances. (I.e. tolerances shall apply to construction only).

**** Girders of bridges spanning over the roadways shall be considered exposedto de-icing chemicals.

6.3.2 The applicable concrete covers shall be shown on the Drawings.

6.3.3 For bundled bars, the concrete cover shall be the smaller of the diameter of asingle bar having area equal to that of the bundle and 50 mm, but not less thanthat given for single bars. Bundled bars shall not be specified for use within 100mm of surfaces exposed to moisture containing de-icing chemicals.

6.3.4 Anchorages and mechanical connections for bars shall have concrete cover of atleast that specified for reinforcing bars.

6.3.5 Anchorages and mechanical connections for post-tensioning tendons shall have


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methods such as galvanizing or the use of stainless steel material.

6.5.3 Corrosion Protection for Reinforcement

The following alternatives of the reinforcing material and/or protection against

corrosion may be included in the design of the corrosion protection systems forthe bridge superstructure components exposed to severe conditions as describedin section 6.4.1 of this Document. Approval of the corrosion protection system isrequired.

Hot dip galvanized steel is a preferred protection system. Top and bottom matsof bridge deck, suspended slab and sidewalk reinforcing, front and backreinforcing of traffic barriers or walls, reinforcing of curbs and medians shall be ofgrade 400W, if galvanized reinforcing steel is used.

Use of non-corrosive concrete reinforcing material such as FRP (FibreReinforced Polymer) is encouraged.

Stainless steel bars and stainless steel-cladded reinforcing may be used upon Approval.

Epoxy coated reinforcing steel is not to be used except in special cases upon Approval.

Detailing of reinforcing steel shall reflect the type of protection system used.Special care during handling, installation and concrete placement will benecessary to avoid abrasion of coating.

Galvanized reinforcing shall be fabricated, galvanized, handled and placed inaccordance with the City of Calgary Specification Section -03200 ConcreteReinforcement, included in Appendix C. The ASTM A767/A767M-97, StandardSpecification For Zinc Coated (Galvanized) Steel Bars For ConcreteReinforcement shall be used for galvanizing reinforcing steel, as modified by theSection 03200 of The City of Calgary Specification.

Chairs, tie wires, nuts, bolts, washers, other devices and incidental hardware thatis to be used to support, position or fasten the galvanized reinforcement shall behot dip galvanized.

Plastic chairs or plastic coated metal hardware, in lieu of galvanized components,may be used.

6.5.4 Sealers

Only Approved sealers shall be used. Please refer to Cast In Place ConcreteSpecification (Appendix C)

Penetrating sealers shall be used in the following structure elements, unlessotherwise specified for a particular project:


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i. Exposed (i.e. not paved over with Polymer Modified Asphalt or notprotected by a pavement membrane system) surface of bridge deck;

ii. All surfaces of exposed medians, walls and curbs;iii. Sidewalks and pedestrian walking surface;

iv. Bearing seats.For new concrete surfaces Type 1c penetrating sealers shall be used. Thesealers shall be applied in accordance with the manufacturers recommendation.

For existing/repaired concrete Type 1b penetrating sealers shall be used.

Pigmented sealers (Type 3) shall be applied to the following structure elements:

i. Exterior (side) surface of superstructure;ii. Substructure of pedestrian bridges and highway bridges (unless

specified otherwise by the City);iii. Soffit of superstructure of pedestrian bridges;iv. Soffit of exterior girders;v. Deck fascia including soffit of cantilevered deck;vi. Concrete railing balustrades;vii. Traffic barriers, all surfaces;viii. Other structural installations and elements, such as retaining walls

or noise walls, as required by site-specific design considerationsand as Approved.

Banff Beige and Concrete Gray pigmented (Type 3) sealers have beentypically used for the above applications, unless Approved otherwise.

6.6 Structural Details

6.6.1 Structural detailing shall include provision of free air circulation for the above-ground components. All formwork material shall be removed from thesuperstructure elements, such as box girders.

6.6.2 Steel stay-in-place forms shall not be used. Concrete stay in place forms may beused, subject to Approval.

6.6.3 Voids, drain holes and other structure discontinuities shall be detailed so as toprevent entry of birds, insects or animals.

6.6.4 Surfaces that are susceptible to nesting of birds should be protected by use ofbird deterrent. Proposed system is to be submitted for Approval.

6.6.5 Bearing seats shall be designed so that contact with salt-laden water runoff,debris or leakage is prevented. The bearing seats shall be sloped at 3% awayfrom the bearing assemblies. Level areas for jacking of the superstructure forbearing replacement shall be provided.


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6.6.6 Elements shall be detailed to minimize the number of pockets, recesses andother means of water and debris traps. Pockets or recesses in the top surface ofbridge decks are not permitted.

6.6.7 Precast concrete element connections using steel hardware exposed to

environmental conditions are not permitted. Continuity of elements shall beprovided through post-tensioning.

6.6.8 Acceptable locations of construction joints and construction details of the jointsshall be shown on the Drawings.

6.6.9 Bridge deck joints may be a source of structural deterioration, thereby giving riseto a major bridge maintenance demand. Consideration shall be given tominimizing the use of expansion joints by providing deck slab continuity atintermediate supports and, where feasible, integral or semi-integral abutmentsystem (see Chapters 11 and 12).

6.6.10 Joints between bridge abutment back wall and approach slab, or betweenintegral superstructure and approach slab, shall be sealed.

6.7 Drainage

6.7.1 In general, a nominal slope should be provided on the surfaces of concreteelements to facilitate drainage away from the structure. Water should be directedto appropriate catch basins or settling areas.

6.7.2 The use of swales is recommended adjacent walls to help direct water away fromthe structure.

6.7.3 Drainage measures should be clearly outlined on the Drawings. Preliminarydesign of the drainage system shall be submitted for review by the City at the30% Design review stage.

6.8 Bridge Deck Drainage

6.8.1 Slopes and Grades

Refer to Section 4.0 BRIDGE GEOMETRY for minimum cross slopes andgrades.

6.8.2 Vertical curves on bridge decks should provide a minimum grade of 1% percent,

unless Approved otherwise. If the longitudinal grade is less than 1% percent,additional drains or special sloping of the gutters may be required.

6.8.3 Deck drainage shall not be discharged on unprotected embankments or anytravelled way (either vehicular, railroad or pedestrian). When applicable andfeasible, drain pipe shall be hidden from the view of oncoming traffic.

6.8.4 Long term deformations, such as creep should be taken to the consideration in


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design of bridge deck drainage.

6.9 Dec k Drains

6.9.1 Bridge deck drainage requirements shall be determined based on project-specific

design and drainage volume analysis. Bridge drains are generally notrecommended on bridge structures less than 100 meters long if they have fullwidth shoulders, adequate cross slopes and have adequate catch basins on thebridge approaches.

6.9.2 Drains shall be located in the areas of maximum flow. Drains shall be of minimum200 mm diameter for roadway bridges and 100 mm diameter for pedestrianbridges. For the protection of pedestrians, one dimension of every opening shallnot be greater than 50 mm. The grate inlet top surface shall be set slightly lowerthan the surface of pavement, and the pavement shall be slightly dished aroundthe inlet. The dishing shall not be deeper than 20 mm.

6.9.3 Bridge drainage systems shall avoid horizontal runs of drain pipe if a reasonablemodification to the design of scupper spacing permits the placement of drainsadjacent to piers at the low end of spans. Where horizontal runs of drain pipecannot be avoided, the minimum slope shall be 8% or unless other means ofprotection against freezing and clogging are used.

6.9.4 The use of scuppers for deck drainage shall be minimized. Scuppers or deckdrains shall pipe the drainage to the storm water drainage system. All drainagehardware shall be galvanized.

6.9.5 Deck waterproofing membranes shall be adequately detailed around deck drainsand along the gutter lines to disallow water penetration underside the membrane.

6.10 Drip Groo ves

Continuous drip grooves underside of outer edge of superstructure shall be provided. Dripgrooves shall be 20 mm deep and min 50 mm wide. Minimum cover to reinforcing shall bemaintained at the drip grooves.

6.11 Utilities on Bridg es

6.11.1 Utilities, if Approved by the City, shall be placed in non-corrosive type conduits,located in non-structural elements or in low stress areas of secondarycomponents. All utilities and attachments shall be of non-corrosive material or

galvanized steel. The attachments to primary structural elements, if Approved,shall not compromise the structural integrity or long term durability of structures.

6.11.2 At transition points, such as expansion joints, couplings and fittings shall becapable of accommodating the bridge translation. An allowance shall be made fora vertical movement due to bridge jacking during bearing replacement.

6.11.3 No fluid-carrying or gas utility lines shall be placed carried under the bridge


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superstructure, unless Approved otherwise.

6.12 Steel Structures

A Standard Specification is included in Appendix C for structural steel elements:

005201 Structural Steel

6.13 Unco ated Weathe ring S teel

6.13.1 General

Generally, the use of weathering steel for bridges will not be aesthetically suitablein most environments within the City of Calgary.

6.13.2 Handling and Cleaning

Weathering steel, if Approved, shall be cleaned and handled in accordance withthe Technical Specifications. Substructures shall be protected from staining byproper detailing of steel girders, and by application of protective coating in theproximity of the substructure. Painting of the exterior girder/fascia may berequired as an aesthetic enhancement.

6.14 Corrosion Protection

6.14.1 Dissimilar Metals

Careful attention shall be given in selecting combinations of metal componentsthat do not promote dissimilar metals corrosion. Provisions shall be made toensure proper separation of dissimilar metals if the use of dissimilar metals is

Approved. Use of separation materials or coatings shall be detailed in Drawingswhere possibility of dissimilar metal contact may occur.

6.14.2 Stainless Steel

Stainless steel is a preferred corrosion protection system. Grade of steel must bespecified.

6.14.3 Structural Steel Paint System

If Approved, steel structures may be painted with an Approved high quality

coating.

All structural steel bridge members that require coatings shall receive a three-coat paint system in accordance with an Approved Specification.

A paint warranty form for the paint system (see Appendix D for Warranty Forms)shall be included with the Specifications.


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6.14.4 Galvanizing

6.14.4.1 Galvanizing of Structural Steel Members

Galvanizing of structural steel shall be performed in accordance with the

Structural Steel Specification 005201(Appendix C).6.14.4.2 Repairs of galvanized elements

Repairs of galvanized elements shall be made using metalizing, unless Approved otherwise.

If Approved, repairs of galvanized elements may be done using zinc richpaint, such as ZINGA. Zinc rich paint should contain a pure zinc contentof at least 95%.

6.14.4.3 Galvanizing of Bolts for Bridges

All anchor bolts, tie-down hardware, and miscellaneous steel (ladders,platforms, grating, etc.) are to be hot-dip galvanized. While ASTM A307(coarse thread) bolts shall be hot-dip galvanized, A325M (fine thread)bolts must be mechanically galvanized when utilized either withgalvanized steel components, or coated with single-coat inorganic paintsystems when slip critical connections are utilized. Other applicationsnot requiring full torque of the bolts may use hot-dip galvanized A325Mbolts.

6.14.4.4 Galvanizing of Bolts for Miscellaneous Structures

Bolts for connections of structural steel members of miscellaneousstructures other than bridges, including overhead sign structures, trafficmast arms, ground-mounted signs, etc., shall be ASTM - A325M, andshall be hot-dip galvanized or stainless steel, unless Approvedotherwise.

6.14.5 Paint Coating of Galvanized Steel Elements

Where specified, galvanized elements may be painted using Approved urethanepaint. Pre-approved systems such as GALVATONE or equal shall be used.

6.15 Design and Detailing

6.15.1 Deck Joints

Generally, steel-girder superstructure should be combined with jointless concretedeck construction and, if feasible, semi-integral or integral abutments.

Deck joints on steel girder superstructures shall be erected by bolting to girders.Bolted connections shall utilize slotted holes to provide adjustment in all


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directions.

6.15.2 Steel Girders

Stiffened girder plate girder webs shall in no case have intermediate transverse

stiffeners spaced farther than 150% of the girder height.Vertical connection plates, such as transverse stiffeners, which are used forconnecting diaphragms or cross frames, shall be rigidly connected to girderflanges.

Diaphragms shall be 30% and preferably 50% of the girder height.Crevice-creating details shall be eliminated when possible; therefore, the use ofstiffeners and bracing should be minimized.

Fracture-critical elements shall be clearly identified on the Drawings.

6.16 Welding

6.16.1 Field welding is not permitted, unless Approved otherwise.

6.16.2 Welding of steel structural elements shall be done using continuous welds,regardless of structural requirements.

6.16.3 Prior to the commencement of steel fabrication, a meeting shall be set up with thefabricator, General Contractor, Engineer, third party testing, and Cityrepresentatives to discuss the fabrication process and quality assuranceprocedures.

6.16.4 Welding components after galvanizing is generally not acceptable. In someexceptional cases, upon submission and Approval of detailed procedure, weldingof components after galvanizing may be allowed.

6.16.5 Quality control and quality assurance of welding shall be project-specific andshall be clearly outlined on the Drawings.

6.17 Mas onry Structures

A Standard Specification addressing masonry structures, such as noise walls, is included in Appendix C:

002850 Noise Barriers

Only pre-approved masonry products and systems shall be used for noise walls andretaining walls. Masonry products shall not be used for highway-loaded ramps or retainingwalls in splash zones (10 m horizontally from the paved traffic lane and 3 m vertically fromthe surface of pavement).


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6.18 Other Materials

The composition, properties, and performance of materials not specifically covered in thisDocument or in the reference Standards, shall be specified by taking into account designloads and environmental degradation during the structure design life.

All new materials and products proposed for application in bridges and structures shall bepre-Approved or submitted for review and Approval.

6.19 Ins pection and Maintenance Acces s

Provisions shall be made in all bridge design and detailing to accommodate routine bridgecondition inspections of all bridge components. Sizes, location and clearances shall bedesigned to enable access to all components for inspection and maintenance activities.

6.20 Approac h Slabs

Bridges on roadways with asphalt wearing surfaces shall be provided with reinforcedconcrete approach slabs anchored to the abutments. The joint between the abutment andapproach slab shall be sealed.

6.21 Overlays

Unless Approved otherwise, vehicular bridge decks shall receive a deck waterproofingmembrane and two layers of asphalt overlay in accordance with the City of CalgarySpecification included in Appendix C.

Polymer Modified Asphalt overlay may be proposed for some specific bridge locations, suchas widening of an existing structure with similar overlay or in deck rehabilitation, inaccordance with City of Calgary Specification included in Appendix C.

6.22 Construction

6.22.1 The quality of materials, construction or performance standards and performanceof final products shall be specified on Drawings or in the Specifications. Qualityassurance standards and methods shall be specified on Drawings or in theSpecifications.

6.22.2 Strict conformance of construction with the technical contract documents is theresponsibility of the Engineer of Record and the Contractor.

6.22.3 Conformance of the construction with contract documents is of paramountimportance as related to durability of structures. Deviation from constructionmethods assumed for design purposes may cause load effects, built-in stressesand component resistances different from those anticipated in the design.

6.22.4 The Engineer of Record shall be responsible for compliance of constructionscope and quality with Contract Documents.


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6.22.5 Alternate methods of construction may be proposed to the Engineer of Record forreview and consideration. A recommendation authenticated by the Engineer ofRecord shall be submitted to the City prior to construction using alternateconstruction methods.

7.0 SERVICEABILITY LIMIT STATES

7.1 General

Structural components shall be designed to satisfy the requirements for:

i. Crack controlii. Stress limitsiii. Deformation controliv. Vibration control*

*Bridges only

Structures shall be designed and constructed as good and as robust as necessary in orderto satisfy the required service life with minimum amount of foreseen maintenance.

7.2 Crack Control

Cracks in reinforced and partially pre-stressed concrete structures are expected to occur,however, crack width and spacing shall be controlled by adequate and well-detailedreinforcement.

Pre-compression of concrete superstructures, thus preventing cracks under tensile stresses

through use of pre-stressed concrete, is required. Partially pre-stressed bridge componentsshall have sufficient amount of pre-stress so that under permanent loads the cracks causedby live load remain closed.

For best crack control detailing, the reinforcing bars should be located closer to the tensileface than the pre-stressing tendons.

7.2.1 Crack Control and Reinforcement

Crack control shall be implemented by limiting the crack widths using one of themethods specified below.

i. Calculated Crack Width

At the Serviceability Limit State, if the tension in concrete exceeds f cr

, the crackwidths shall be calculated using a method proposed in CAN/CSA-S6.

ii. Measuring Crack Width

Cracks shall not be wider than the following:


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Concrete exposed to de-icing chemicals:

0.25 mm for non-pre-stressed concrete0.15 mm for pre-stressed concrete

Concrete not exposed to de-icing chemicals:

0.30 mm for non-pre-stressed concrete0.20 mm for pre-stressed concrete

Note: Concrete decks (with or without Waterproofing Membrane) are consideredsurfaces that are subject to spray or surface runoff containing de-icing chemicals.Girders of bridges spanning over the roadways shall be considered exposed tode-icing chemicals.

7.2.2 Amount and Distribution of Tension Reinforcement

Crack control shall be achieved by proper distribution of tension reinforcement inthe zones of maximum tensile stresses, selection of bar sizes, reinforcementratios and control of stresses at Serviceability Limit States.

The following conditions shall be met in order to satisfy the crack controlrequirements:

i. For Concrete exposed to chlorides:

Maximum tensile stress in reinforcing steel f sMaximum bar spacing 200 mm

shall be 180 MPa

Maximum bar diameter:20M for reinforced concrete15M for pre-stressed concrete

ii. For Concrete exposed to freeze thaw conditions:

Maximum tensile stress in reinforcing steel f sMaximum bar spacing lesser of 20d or 300 mm

shall be 200 MPa

Maximum bar diameter:25M for reinforced concrete20M for pre-stressed concrete

7.2.3 Shrinkage and Temperature Reinforcement

Shrinkage and temperature reinforcement normal to the principal reinforcementshall be provided in each face of concrete structural elements. The shrinkage andtemperature reinforcement shall be provided as required by the analysis, but notless than 15M @ 250 millimeters in each face and each direction, unless

Approved otherwise.


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7.3 Stres s Limits

Under service load conditions the limitation of stresses may be required for:

i. Tensile stresses in concrete Limitation of tensile stresses in

concrete is an adequate measure to reduce probability of cracking.ii. Compressive stresses in concrete Limitation of compressivestress in concrete controls plastic strains and longitudinal cracks.

iii. Tensile stress in steel Limitation of tensile stress in reinforcementprevents uncontrolled cracking.

The stresses at Serviceability Limit State loads shall include any effects of re-distribution ofmoments due to creep, shrinkage and relaxation of pre-stressing steel.

7.4 Deformation

7.4.1 Dimensional changes, deflections and rotations shall be included in the design to

assure proper and safe functioning of the structures, avoidance of damage tonon-structural elements and good appearance. Effect of short and long termdeformations shall be analyzed and included in the design and detailing ofstructures. Structures shall be designed with camber so as to compensate forlong term deformations of concrete.

7.4.2 All flexural members shall have adequate stiffness in order to limit deflections andto control vibration, which may adversely affect the strength or serviceability ofthe structure. Deflections and vibration control shall be designed in accordancewith CAN/CSA S6 (latest edition).

7.5 Vibration

7.5.1 General

Vibrations of structures may affect serviceability as follows:

i. Functional effects (i.e. discomfort of pedestrians)ii. Structural effects on secondary and non-structural elements

The vibration behaviour of structures can be influenced by the followingmeasures:

i. Change of the natural frequency by changing the rigidity of the

structure or vibrating mass.ii. Increase the effectiveness of damping features.

7.5.2 Superstructure Vibration

Design and Construction of New Bridges:

Dynamic design analysis shall be performed for all bridges with spans longer


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than 20 m length, or with first flexural frequency below 6Hz.

Design to control vertical, transverse and longitudinal vibrations of bridges usedby pedestrians shall be done in accordance with CAN/CSA-S6 (latest edition) andthe Commentary. Wind, traffic-induced vibrations as well as load of pedestrian

traversing the superstructure shall be considered.Modifications to the Existing Bridges:

Dynamic analysis shall be performed to assess impacts of superstructuremodifications, particularly where the original first flexural frequency of thestructure is altered as a result of the modifications.

8.0 FATIGUE LIMIT STATE

Refer to Section 5.11 Dynamic Analysis of CAN/CSA-S6.

8.1 Reinforced a nd P re-s tres s ed Concrete

8.1.1 Fatigue design shall be performed for structural elements and the requirementsof Fatigue Limit State shall be satisfied. Special care shall be exercised in areasof complicated load path. In partially pre-stressed concrete members, fatigue isconsidered to be a critical limit state.

8.1.2 Tack welding of reinforcing bars is not permitted. Bends and welded joints ofreinforcing steel shall be avoided in areas of high stress range.

8.2 Structural Stee l

The fatigue criteria for structural steel shall be in accordance with the standard specificationfor Structural Steel Supply and Fabrication (see Appendix C).

9.0 DESIGN OF FOUNDATIONS AND EARTH RETAINING STRUCTURES

9.1 Scope

9.1.1 This section describes the structural design requirements for the following:

i. Foundations;ii. Retaining walls;iii. Buried reinforced concrete and steel structures;iv. Tunnelled structures;v. Portal structures.

9.1.2 A Standard Specification is included in this document for mechanically stabilizedearth retaining walls:

003483 MSE Wall (see Appendix C)


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9.2 Codes and Specifications

The design shall, where applicable, be in accordance with the requirements of:

i. CAN/CSA S6 (latest edition)ii. Canadian Foundation Engineering Manual, latest revision.

9.3 Geotech nical Report

9.3.1 A geotechnical engineer shall provide a Geotechnical Report that shall include allnecessary information for design and construction of foundations and earthretaining structures.

9.3.2 The report shall be based on suitable subsurface investigation and laboratorytests, and shall describe the soils conditions in detail, and providerecommendations for suitable foundation types with consideration for

constructability issues.

9.3.3 The report shall include appropriate design parameters pertaining to permanentconditions and, where applicable, to temporary conditions.

9.3.4 The report shall identify subsurface conditions or seasonal effects that could havea significant impact on construction, such as slope stability or the presence oflarge boulders or artesian ground water. Requirements for casing of foundationsshall be also identified.

9.3.5 Impact of the proposed structure and its construction on adjacent property shallbe addressed.

9.3.6 Consultation between the structural engineer and geotechnical engineer shalltake place during planning, design and construction.

9.4 Design

Foundations and retaining walls shall be designed to satisfy requirements of Ultimate LimitStates and Serviceability Limit States.

9.5 Loads

9.5.1 General

Permanent and temporary loads that require evaluation include:

i. Horizontal and vertical forces from soil pressure;ii. Forces from hydrostatic pressure;iii. Loads from structures adjacent to the designed structureiv. Loads from surface traffic;


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v. Loads from surface storage of materials and equipment;vi. Loads from major underground utility structures;vii. Environmental loads (e.g. snow; ice, frost);viii. Loads arising from differential settlement and soil consolidation;ix. Other site-specific loads.

9.5.2 Lateral Earth Pressure and Vertical Earth Pressure

Vertical pressure from superimposed earth load shall be calculated as perSection 7 of CHDBC, with a mass density as determined by the geotechnicalengineer. For submerged or partially submerged conditions, recommendeddensities of the earth shall be obtained from the geotechnical engineer. Dueconsideration shall be given to temporary loads arising from constructionequipment or from stockpiling of construction material or excavated materials atthe ground surface.

A minimum earth load assuming that one (1) meter of fill may be removed, forexample for road or utility construction, shall also be considered.

Structures which retain earth shall be designed for horizontal earth pressure dueto earth abutting against the structure and load surcharges resting on the abuttingearth. The pressure shall be determined by considering the relevant parametersincluding:

i. Configuration, nature and drainage properties of the backfillmaterial;

ii. Displacement characteristics of the retaining wall or structure;iii. Interface conditions between the wall and the backfill;iv. Method and degree of compaction of the backfill material;v. Location of groundwater (existing/ or future);vi. Artesian conditions;vii. Live and dead loads imposed by adjacent foundations;viii. Location of the wall or structure relative to ground surface.ix. Effect of construction methodology and sequencing.

The earth pressure acting on a retaining wall or structure may range from activeearth pressure to passive earth pressure, depending on the displacementcharacteristics of the wall and the methods of compaction of the backfill.

Values of loads, earth pressure coefficients and relevant assumptions shall beshown on the Drawings. In case of any deviations of the site conditions orconstruction methods from the original assumptions, the design adjustments shallbe made and the changes shall be reflected on Record Drawings.

9.5.3 Water Pressures and Buoyancy

The effects of water pressure and buoyancy shall be considered whenever thepresence of groundwater is indicated. High and low water tables shall beestablished for the life of the structure with due consideration given to the


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possibility of future changes in groundwater elevation.

The design shall take into account the effect of water pressures pertaining toconstruction sequence.

9.5.4 FloodingLocal flooding may add load to underground structures or may undermine thestability of superstructures. Design of structures shall make allowance for floodelevations based on the 100 year flood. An allowance of one (1) meter clearancefrom 100 year flood elevation shall be made. The elevations used for design shallbe subject to review by The City.

9.5.5 Loads from Adjacent Building Foundations or Other Structures

Horizontal and vertical distribution of loads from foundations of existing buildingsshall be determined by the Engineer, in consultation with the geotechnicalengineer.

Consideration shall be given to the minimum and maximum loads which can betransferred to the underground structure. Where possible, these loads shall bebased on the actual design loads for the adjacent structure. In the absence of thisinformation, a rational approach should be used by the Engineer to evaluate theprobable loading from the existing structure.

When performing the above analyses, the Engineer shall determine the need forall permanent underpinning of buildings or other structures.

9.6 Structural Eleme nts

Footings, deep foundation components, ground anchors, Mechanically Stabilized Earthstructural systems and other retaining structures shall be considered as structural elementsand shall be designed in accordance with the appropriate sections of the CAN/CSA-S6 by aqualified structural Engineer registered in Alberta.

9.7 Construction Methods

9.7.1 The method(s) and/or sequence of construction influences the behaviour andloading conditions applied to a structural system. Consequently, if a structuralanalysis is based on a particular method or sequence of construction, theseconditions must be defined in the construction documents.

9.7.2 The design and construction of all underground structures, whether temporary orpermanent, must ensure that movements of adjacent structures and ground donot exceed acceptable levels. The effect(s) of movement on adjacent structuresmust be evaluated by a structural engineer. Allowable limits on movement ordifferential settlement must be identified and protective measure taken to ensurethat these limits are not exceeded. Protective measures must be agreed to bythe City and the Owner of the structure under consideration.


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9.7.3 Groundwater inflow shall be controlled during construction in accordance with therelevant technical Specification.

9.8 Pro prietary Walls

9.8.1 The City reserves the right to reject any alternate wall system or details which donot conform to the control plans, pre-approved details, City of Calgary DesignGuidelines or CAN/CSA-S6 Standard.

9.8.2 Investigation shall be done to identify if the location of any underground utilitieswould interfere with the wall systems and their modules or straps in any way.

9.8.3 MSE walls or bin type walls shall not be used in situations in which maintenancecrews of the underground utilities will potentially dig into the straps, mesh ormodules. Conventional retaining walls shall be used in these instances.

9.8.4 Foundations for bridges and overhead sign structures shall not be placed on thereinforced backfill of MSE walls (i.e. separate rigid foundation shall be provided).

9.9 Inspection and Quality Assurance

9.9.1 During construction, installation of foundations, ground anchors, MSE and otherretaining walls, shall be inspected by the geotechnical engineer to confirm thatthe actual soil conditions are consistent with the design assumptions and that thegeotechnical aspects of the project are consistent with the design assumptions.

9.9.2 Any impact of actual site conditions or construction method on the new or existingstructure shall be assessed by both the geotechnical and the structural engineer.

9.9.3 Copies of the Inspection Reports shall be included in the construction recordsand any Approved variance of construction installation or details, from theDrawings or Specifications shall be reflected on Record Drawings.

10.0 CABLE STAYED BRIDGES

10.1 General

The following supplementary requirements to CAN/CSA S6, latest edition shall be met forcable stayed bridges designed and constructed for The City of Calgary, unless Approvedotherwise.

10.2 Reference Publications

Recommended reference publications include:

i. Post-Tensioning Institute (PTI) Recommendations for Stay-CableDesign, Testing and Installation


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ii. Fdration Internationale du bton (Fib) CEB FIP Acceptance ofStay Cable Systems Using Pre-stressing Steels.

10.3 Limitations

Cable stayed structures should be chosen where the context is appropriate. Thesestructures can have very high pylons that may not be suitable for certain urban areas.

10.4 Design

10.4.1 General

Design life of cable stayed bridges shall be 100 years.

10.4.2 System

The Citys preference is to use redundant cable stay systems where systems

consisting of multiple tensile elements rather than systems relying on a singletensile element. However, mono-bar stays may be considered upon Approval ifthe design addresses redundancy.

Analysis of the structure shall include, but not be limited to, elongations andforces during all stages of construction, service, pylon deformations, cablereplacement, etc.

10.4.3 Loads

Transverse loads applied from stay cables to the structure.

Guide deviators shall be installed near the anchorage to protect the stay cableanchorages from the effects of transverse loads caused by:

i. Cable vibrationii. Deformation of the structureiii. Change of cable sagiv. Windv. Temperature changesvi. Live loadvii. Construction toleranceviii. Other transverse loads specific to the conditions

Each component of the cable stay system, from stressing end anchorage,through free length to saddle (if applicable) to next anchorage, etc., shall havethe same safety and durability considerations under Serviceability Limit States,Fatigue Limit States, and Ultimate Limit States.

10.4.4 Materials

Choice of structural steel material for cable stay systems is based on chemical


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and mechanical characteristics as well as on performance-or fatigue criteria.High quality steels shall be specified for stay cable performance.

High strength pre-stressing steels should meet the criteria as outlined in Table10.4.4 for stay cable applications:

Table 10.4.4:

Standard Classification for Pre-stressing Steels for Cable Stays

Cable Stay Bar diameter 26 50 mmCable Stay Tensile strength 1030 1050 MPa

10.4.5 Cable Stay and Anchorages

Cable stay systems should be replaceable either one or several at a time.

Only tested cables and anchorages are acceptable. In the cases wherecommercially available systems are not used, testing of cables and anchorageassembly shall be specified. Testing shall include axial fatigue testing withbending effect and purely axial fatigue test at 2.0 million cycles. A minimumfactor of safety of 1.5 shall be used for fatigue strength values obtained from thetests.

Cable stays and anchorages shall be designed for fatigue and strength withrespect of all applicable loads and deformations.

Minimum length adjustment capacity must be provided at the anchorages of staycables for re-stressing and de-tensioning. Instrumentation capable of verifyingand controlling cable stress forces throughout the construction process must beconsidered when selecting cable stay and anchoring systems.

Cable vibrations, including risk of parametric excitation as well as train traffic,wind and rain induced vibration, shall be evaluated, and based on expectedinternal damping).

10.4.6 Grounding

Lightning protection through grounding shall be included in the design.

10.4.7 Functional Requirements

The design for the specified lifetime shall be satisfied for exposure conditionsdefined as High Corrosion Risk.

A clearly defined corrosion protection system shall be submitted and verified ortested as applicable.

Stay cable design should include protection measures to mitigate against impact,


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vandalism, fire and lightning.

Stay cables shall be located such that they do not pose a climbing hazard.

Design shall take into consideration birds and wildlife that may come in conflict

with the stay cables. If necessary, bird deterrent shall be provided.Connections and clamps shall be designed to avoid transverse forces or effectsthat would be harmful to the fatigue and tensile strength of the stay cable.

10.5 Corrosion Protection

10.5.1 Multi-layer corrosion protection which is adequate for the entire life of the staycables is required.

10.5.2 Materials in cable stay systems shall be designed for the design life of the entiresystem. This includes any planned replacement at predictable intervals. The cost

of such replacements shall be included in the life-cycle cost analysis.

10.5.3 Recommended metallic coating is hot dip galvanizing with zinc or zinc/ aluminumduring the manufacturing process of pre-stressing steel. Stainless steel may alsobe considered, upon Approval.

10.5.4 Recommended soft filling materials include wax with low oil content. Stay pipematerial shall be Approved by The City.

10.5.5 Any exposed metallic surface on anchorage components shall be protectedagainst corrosion. Generally, anchorage components are factory-provided withcorrosion protection.

10.6 Construction Considerations

10.6.1 Specialist contractor responsible for the bridge erection shall prepare a detailederection plan and procedure. Limitations of bridge erection over water bodies,CPR and live lines of LRT shall be discussed with the respective Right of Wayowners or regulatory agencies, as applicable.

10.6.2 Construction tolerances: directional installation tolerance of the bearing platesand guide pipes is +/- 5 mrad (+/- 0.3 degrees) around the theoretical axis of thestay cable and +/- 10 mm in positioning of the anchorage.

10.6.3 Transverse loads on the anchorages must be kept low by appropriate use ofguide deviators. Transverse forces in the transition zone must be absorbed as toavoid fretting corrosion. Any possible effects of angular deviations or fatigue maybe verified by full scale testing.

10.7 Quality As s uran ce

The fatigue and ultimate capacity of the cable stay system must be verified by testing.

7/25/2019 CoC Bridges and Structures Design Guidelines 2