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International Journal of Civil Engineering and Technology (IJCIET)

Volume 9, Issue 1, January 2018, pp. 639–651, Article ID: IJCIET_09_01_062

Available online at http://http://www.iaeme.com/ijciet/issues.asp?JType=IJCIET&VType=9&IType=1

ISSN Print: 0976-6308 and ISSN Online: 0976-6316

© IAEME Publication Scopus Indexed

DESIGN AND ANALYSIS OF FOOT OVER

BRIDE USING STADD PRO

T. Prashanth

BE Student, Department of Civil Engineering,

Saveetha School of Engineering, Chennai, Tamilnadu, India

V. Gokulnath

Assitant Professor, Department of Civil Engineering,

Saveetha School of Engineering, Chennai, Tamilnadu, India

ABSTRACT

Footbridges are needed where there is a separate pathway must be supplied for

human beings to move site visitors flows or some physical impediment, along with a

river. The masses they convey are, with regards to toll road or railway bridges, pretty

modest, and in most circumstances a reasonably light structure is needed. They are,

but, often required to give a protracted clear span, and stiffness then becomes an

crucial consideration. The bridges are frequently required very virtually on view to

the general public and consequently the advent deserves careful attention.

Steel offers financial and appealing kinds of creation which suit all of the

requirements demanded of a footbridge. Due to fast creation of a massive quantity of

foot over bridges, many existing bridges placed in seismic zones are poor to face up to

earthquakes. In order fulfil the requirement of this improved visitors in the limited

land the length of bridge will become medium to large. During an earthquake, failure

of shape starts at factors of weak spot. Generally, weak spot is due to geometry, mass

discontinuity and stiffness of shape. In this undertaking we can layout for a most

appropriate foot over bridge together with connection details and additionally

estimation of structural components at the side of foundation detailing for the foot

over bridge structure.

Key words: Foot over bridge, stiffness, earthquake, foundation etc..

Cite this Article: T. Prashanth and V. Gokulnath, Design and Analysis of Foot Over

Bride Using Stadd Pro. International Journal of Civil Engineering and Technology,

9(1), 2018, pp. 639-651.

http://www.iaeme.com/IJCIET/issues.asp?JType=IJCIET&VType=9&IType=1

1. INTRODUCTION

A steel truss footbridge was chosen as the best alternative for ranges of 10 to 20m, and

conceivably up to 25m, when it is unrealistic to build wharfs for transitional backings for

pillar sort footbridges. It ought to likewise be considered for ranges more than 10m when

docks are conceivable. The points of interest are thought to be:

T. Prashanth and V. Gokulnath


The steel areas required ought to be accessible in principle asset focuses - The segments

are probably going to be more uniform fit as a fiddle and size than timber segments,

permitting clear development of standard truss plans - Joints are less demanding to make than

in timber trusses .

It ought to be conceivable to develop a standard outline in a medium measured workshop

in advantageous estimated parts for transport to site. Get together on location includes darting

the parts together and fitting a timber deck, errands that can be done under supervision of a

capable expert by neighborhood craftsmen and others talented in utilizing their hands.

There are 3 levels at which the scaffold might be separated into parts for transportation:

i. Singular individuals that are predrilled in the workshop, transported and catapulted together

on location. For this situation each piece must be conveyed 24km starting from the road a

precarious track to the footbridge site. This technique requires extensive exact penetrating of

openings in the workshop and cautious get together on location.

ii. The steel individuals are cut and welded up into boards in the workshop and the boards

penetrated for catapulting together. Boards are transported to site and darted together on

location. This fundamentally lessens pre-penetrating and get together work. Boards may

weigh up to around 100kg.

iii. Boards are shot together in the workshop into modules that are transported to site. The

modules are shot together on location. This will require the slightest get together work nearby.

Modules are probably going to weigh up to 300 to 400kg and will be very massive to

transport. This technique is just liable to be conceivable if there is access for trucks

specifically to the footbridge site.

2. LITERATURE REVIEW

Synthesis of quantitative and qualitative evidence for accident analysis in risk based highway

planning, states the quantitative and qualitative evidence for the accident analysis road space

is a scarce resource so accumulation of future volume traffic is taken into account. The

forecasting for the future volume traffic is calculated and appropriate junctions are provided

(Ref.2)

Physical method of traffic control, states the designing and control of signals at the various

junctions on the basis of traffic flow and time period for the particular junction (Ref.3)

Signal control at intersections, states the different methods of signal design and provides

information about trial cycle method in which traffic volume count for every 15 minutes is

taken into consideration for each junction (Ref.4)

Road safety management using Weight-age analysis, states the method of weight-age

analysis in which accident severity index is calculated and design criteria is decided based on

the accident cost ratio (Ref.5)

Necessity

People are unaware about traffic at junctions. While crossing the road this may lead to loss of

life or injury, in order to reduce this effect there is a necessity for foot over bridge at most

critical junctions:

Regulation of the traffic flow and time delay.

Reducing the number of accidents.

Long sight clearance distance.

Free movement of pedestrians.

Design and Analysis of Foot Over Bride Using Stadd Pro


Scope

Foot-over bridge for most critical junction.

Estimation of structural component of foot-over Bridge.

This project includes accident analysis and design of each junction.

Traffic forecasting for future ten years with signal design.

3. METHODOLOGY

The target of this venture is to outline a Foot over scaffold , alongside association

&foundation points of interest, and to dissect it, beneath said fundamental parameters are

considered:

Broad writing review by alluding books, specialized papers did to comprehend essential

idea of subject.

i. Selection of a suitable model of foot over scaffold.

ii. Computation of burdens and choice of preparatory cross-segments of different auxiliary

individuals.

iii. Geometrical demonstrating and basic investigation of foot over scaffold for different

stacking conditions according to IS Codal arrangements.

iv. Interpretation of results. Following exploration must be completed for meeting the above

destinations:

v. Now foot over bridge are demonstrated and investigated as a three dimensional structure

utilizing STADD.Pro V8

vi. STAAD pro highlights cutting edge UI, perception devices, capable investigation and plan

motors with cutting edge limited component (FEM) and dynamic examination abilities. From

show era, investigation and configuration to representation and result confirmation STAAD

genius is the expert first decision. STAAD expert was created by rehearsing engineers far and

wide. It has advanced more than 20 years and meets the necessities of ISO 9001 confirmation.

STAAD or (STAAD.Pro) is an auxiliary investigation and outline PC program initially

created by Research Engineers International at Yorba Linda, CA in year 1997. In late 2005,

Research Engineers International was purchased a more established adaptation called

STAAD-III for windows is utilized by Iowa State University for instructive purposes for

common and basic specialists. At first it was utilized for DOS-Window framework. The

business form STAAD Pro is a standout amongst the most generally utilized basic

investigation and outline programming. It underpins a few steel, cement and timber

configuration codes.

Configuration of Foot over Bridge

A foot over bridge of 21m high is analyzed and designed.

The configuration of the tower is as follows:

Span of bridge = 21 m

Height of bridge = 8.50 m

Width of pedestrian = 3 m

Spacing between each truss = 3 m

Type of truss = warren truss



4. ANALYSIS AND DESIGN

Analysis and design is done by using STAAD.Pro software, with code book IRC: 24-

2001(Ref.11) .Load coming to the plate is calculated using the Equation 4.1

P=Ṕ-(40L-300/9)

P=Live load per meter.

Ṕ=4000 N/m2

L=Effective span in meters, 21 m.

P=3927 N/m2

The structure model is shown from STAAD.Pro the structure is made by connecting node

to node distance as shown in the Figure 4.1

Figure 4.1 Geometry of the structure

Figure 4.2 Section Property ISA 60*60*6

Figure 4.3 Section Property ISHB 200



Figure 4.4 Section Property Tube 70*70*4.9

5. TRUSS CONNECTION DESIGN

Design of number of bolts required for truss connection is done manually as per Indian

standard code IS: 800-2007 (Ref.12). One truss is considered from entire span and force taken

from design values of software, as shown in the Figure 4.11

Figure 4 11 Truss connection

Assumed Data

Bolts diameter = 16 mm

Gusset plate thickness = 8 mm

Property class is = 4.6

Steel grade = 410

Design Procedure

Nominal diameter of bolts = 18 mm

Ultimate tensile strength of bolt = 400 N/mm2

Edge distance (e) = 1.7 x 18=30.6 mm

Pitch distance (p) = 2.5 x 16=40 mm

Ultimate tensile stress of plate = 410 N/mm2

Shear capacity of bolt as given by Equation 4.2

Vdsp =

(4.2)



Where,

=nominal shear capacity of bolts.

=partial safety factor is 1.25

Nominal shear capacity of bolts as given in the Equation 4.3

=

(4.3)

= 400 N/mm2

= 2

= 157 mm2

By substituting, shear capacity of bolt = 58 kN

Bearing capacity of bolt as given in Equation 4.4

Vnpb =

(4.4)

= 0.50

= 16 mm

= 8 mm

= 400 N/mm2

= 1.25

By substituting, bearing capacity of bolt = 51.2 KN

No of bolts required is force divided by bearing capacity of bolt

Finally the obtained design values for the truss is as shown in the Figure 4.12

Figure 4.12 Number of bolts for truss



Table 4.1 Reactions Summery

6. FOUNDATION DESIGN

After completion of analysis and design by using software the finally obtained maximum

reaction values are taken from Table 6.2 and manually designed Isolated footing, as per

Indian standard code of IS:456-2000 (Ref.13).

Reactions

Axial load along y-direction is fy =120 kN

Moment along X –direction is Mx = 1.117 kN-m

Assumed data:

Safe bearing capacity of soil is 200 kN/m2

Design Procedure

Moments are considered in both direction corner moments are taken and all corner moments

must be less than safe bearing capacity of soil, the corner moments plan is shown

inFigure4.13

Figure 4.13 Plan showing corner moments



Moment Calculations

Moment along corner according to coordinate 1 is given by Equation 4.5

Corner 1 =

+

+

(4.5)


Corner 2 =

+

-

(4.6)


Corner 3 =

-

-

(4.7)


Corner 4 =

-

+

(4.8)

By substituting this values

= 132 KN (Total load)

= 1.117 KN-m

= 3.131 KN-m

Square footing is adopted of size (b=d)

= 900 mm x 900 mm

By substituting above all values in each corner every value is less than the safe bearing

capacity of soil.

Hence it is safe

So, adopt a square footing size = 900 mm x 900 mm.

Area of footing size = 0.81 m2

Axial load = 120 KN

Add 10% load to it to obtain total load.

Total load = 132 KN.

Net soil pressure with a load factor of 1.5 is given by Equation 4.9

qu =

= 0.22 N/mm

2

Plan of square footing as shown in the below Figure 4.14



Figure 4.14 Plan of Square footing

One Way Shear:

Critical section occurs at distance of d from column face.

Factored shear force is given by Equation 4.10

Vul = 0.222 x 900 (1000-d) (4.10)

= 234(1000-d)

One way shear resistance is given by Equation 4.11

Vcl = 0.36 x 900 x d (4.11)

= 324 d

Vul < Vcl

By substituting in above values, d = 382 mm

Assuming percentage of steel reinforcement as 0.25% for M-20 Grade concrete from table

-19 of IS456 code the permissible Shear stress is calculated.

Tc = 0.36 N/mm2

.

Two Way Shear:

It occurs at a distance of d/2 from column face.

Factored shear force is given by Equation 4.12

Vu2 = 0.222 (9002 – (100 + d)

2 ) (4.12)

= 0.222 (810000 – (482)2

)

= 128244.072 N

One way shear resistance is given by Equation 4.13

Vc2 = Ks Tc (4(100 + d) d) (4.13)

= 1.0 x 1.118 (4(100 + d) d)



Vu2 < Vc2

By substituting in above values, d = 170 mm

From both one and two way shear, one way shear is most

Critical so , adopt d = 382 mm

Clear cover = 40 mm

Total overall depth, D = 460 mm

Reinforcement Details:

Mu = 222 x 1 x 0.40 x 0.40/2

= 17.76 kN-m/m

Steel required is calculated from Equation 4.14

Ast =

(1-√

) (4.14)

b = 1000 mm

d = 382 mm

fck = 20 N/mm2

fy = 415 N/mm2

The stress value is given by Equation 4.15

R =

(4.15)

By substituting in above values Ast =130 mm2

Minimum steel required is given by Equation 4.16

But minimum steel is = 0.12% b x D (4.16)

= 552 mm2

So, adopt minimum steel of Ast = 552 mm2

Diameter of bars = 12 mm.

Spacing between the bars = 1000 x area of one bar/ Ast

= 225 mm c/c

Number of bars = 5

Isolated square footings with five number of 12 mm bars provided in both direction with

Centre to Centre spacing of 225 mm is provided and gusset plate is attached to bars and steel

column is attached to it. The isolated square footing with reinforcement details as shown in

the Figure 4.15



Figure 4.15 Reinforcement details

7. ESTIMATION OF STRUCTURAL COMPONENTS OF FOOT-OVER

BRIDG

Estimation of structural component of Foot-over Bridge is shown in the Table 4.2

Table 4.2 Estimation of structural components

PROFILE LENGTH(m) Weight (kN )

D ISLC75 233.50 26.045

ST ISLC175 15.00 2.581

ST ISLC250 12.00 3.286

ST ISLC300 18.00 5.823

LD ISA100X75X6 11.66 1.817

LD ISA65X45X5 34.99 2.827

LD ISA90X60X6 11.66 1.550

LD ISA65X65X5 11.66 1.120

LD ISA25X25X3 5.83 0.126

LD ISA25X25X4 5.83 0.165

LD ISA40X25X5 5.83 0.271

LD ISA45X45X5 5.83 0.383

ST ISLC75 57.50 3.207

ST ISJC100 12.50 0.712

FR ISLC100 32.00 4.926

D ISLC125 42.25 9.505

ST ISA130X130X8 191.29 29.712

ST ISJC200 1.00 0.137

ST ISA90X90X6 1.00 0.332

ST ISA55X55X5 4.12 0.167

TOTAL N

8. RESULTS

i. A foot over bridge of 21m high is analyzed and designed. The configuration of the tower is

as follows:

Span of bridge = 21 m.

Height of bridge = 8.50 m.



Width of pedestrian =3 m.

Spacing between each truss = 3 m.

Type of truss = warren truss

ii. Wind load is calculated using STADD.Pro V8i using IS: 875(Part 3)1987[3] . The total

wind load acting on the structure is 2719 Kg.

iii. Design has been done according to IS: 802 using STADD.Pro and following results are

obtained:

Total weight of steel required in superstructure = 9758 Kg.

Materials required in Super Structure

Table 5.1 Structure design

S. No Profile Length(m) Weight(Kg)

1 ISA 60*60*6 120.33 2130

2 ISHB 200 170.63 2019

3 TUBE 70*70*4.9 418.69 5609

Total 9758

4) An isolated Foundation of square footings with five number of 12 mm bars provided in

both direction with Centre to Centre spacing of 225 mm is provided and gusset plate is

attached to bars and steel column is attached to it.

5) Estimation of structural components of foot over bridge has been done and total weight id

given as 94.61 KN

9. CONCLUSIONS

In the present era, technology in construction is growing at a rapid phase which require

adequate knowledge in construction and designing for foot over bridge means like structural

components of foot over bridge, columns, beams, loadings on foot over bridge etc. So there is

need for proper estimation while designing and analyzing the foot over bridge.

If we could optimize the design of foot over bridge and use more resources, it will save a

lot of money and resources. In olden day’s angle sections are used in making of truss in

structure of foot over bridge, currently tubular sections are preferred as they are more

economical.

The wind load acting on foot over bridge will be comparatively less in magnitude as it is

open structure with more openings, but failure of the towers is mainly due to High Intensity

Winds and Earthquakes. So high factor of safety should be given to wind loads and seismic

loads.

REFERENCES

[1] IRC: 6-2014 Section –II (Loads and Stresses) standard specifications and code of practice

for road bridges.

[2] Engström, B., (2011). Design and analysis of deep beams, plates and other discontinuity

regions. Department of Civil and Environmental Engineering, Chalmers

UniversityofTechnology, Göteborg



[3] Blaauwendraad, J. (2010) Plates and FEM - Surprises and Pitfalls. Springer, Dordrecht.

[4] Al-Emrani, M., Engström, B., Johansson, M. & Johansson, P. (2008): Bärande

konstruktioner Del 1 (Load bearing structures part 1. In Swedish). Department of Civil

and Environmental Engineering, Chalmers University of Technology, Goteborg.

[5] Sustainable Bridges (2007): Non-Linear Analysis and Remaining Fatigue Life of

Reinforced Concrete Bridges. Sustainable Bridges - Assessment for Future Traffic

Demands and Longer Lives.

[6] Durkee, Jackson, “Steel Bridge Construction”, Bridge Engineering Handbook, Crcpress,

PP 45-58, 2000.

[7] G. Mylonakis and G. Gazetas. “Seismic soil-structure interaction: beneficial or

detrimental”, Journal of Earthquake Engineering, 4(03):277–301, 2000.

[8] Granath, P., “Distribution of Support Reaction Against A Steel Girder On A Launching

Shoe.” Journal of Constructional Steel Research, Vol. 47, No.3, Pp. 245-270, 1998.

[9] Durkee, Jackson L., “Foot Over Bridge Erected By Launching”, Journal Of The Structural

Division, ASCE, Vol. 98, No. ST7, Proc. Paper 9028, Pp. 1443-1463, July,1997

[10] M. Ciampoli and P.E. Pinto. “Effects of soil-structure interaction on inelastic seismic

response of bridge piers”. Journal of structural engineering, 121(5):806–814, 1995.

[11] M.Ciampoli and P.E. Pinto. “Effects of soil-structureinteraction on inelastic seismic

response of bridge piers”. Journal of structural engineering, 121(5):806–814, 1995.

[12] J.C. Wilson and B.S. Tan. “Bridge abutments: assessing their influence on earthquake

response of meloland road overpass.” Journal of Engineering Mechanics, 116(8):1838–

1856, 1990.

[13] S. Rajesh, Design of A Steel Foot Over Bridge In A Railway Station, International Journal

of Civil Engineering and Technology, 8(8), 2017, pp. 1533–1548.

AUTHOR DETAILS

T.PRASHANTH, BE Student, Department of Civil Engineering, Saveetha School of

Engineering, Saveetha University, Chennai-602105.

Mr. V. GOKULNATH, Asst. Professor, Department of Civil Engineering, Saveetha School

of Engineering, Saveetha University, Chennai-602105.

design and analysis of foot over bride … fundamentally lessens pre-penetrating and get together...

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