SEMINAR ON PROJECT MONITORING FOR NON-ENGINEERS

MODULE II: OVERVIEW OF DETAILED ENGINEERING DESIGN

Part I: Building Design Data And Requirements

A. Background Information

a.1 The Philippines is the most Disaster Prone Country in the World in the Previous 100 years. The Center for Research on the Epidemiology of Disasters (CRED), based in Belgium, compiles a database of natural and technological disasters worldwide. The CRED database period 1901-2013 shows that the Philippines suffered possibly the worst combination of disasters among all countries. (see www.em-dat.net)

In order for an event to be entered into the CRED list, at least one of the following criteria has to be fulfilled:

- 10 or more people reported killed. - 100 or more people reported affected - A call for international assistance - Declaration of a state of emergency

For a list of the highest natural disaster events,(see for example, Table 2.1 and Table 2.2)

TABLE 1.0 - TOP 10 NATURAL DISASTER EVENTS ACCORDING TO NUMBER OF PEOPLE KILLED

DISASTER TYPE YEAR LOCATION PEOPLE KILLED

Storm 2013 Samar, Leyte, Cebu, Iloilo, Capiz, Aklan, Palawan Provinces

7,354

Earthquake 1976 Gulf of Moro, Sulu 6,000

Wind Storm 1991 Bago, La Cariota, Bacolod, (Negros) and Leyte 5,956

Storm 2012 Davao Oriental, Compostela Valley 1,901

Earthquake 1990 Cabanatuan, Baguio, Dagupan (Luzon Isl.) 1,621

Wind Storm 1970 (1) Bicol area, (2) Mindanao 1,551

Storm 2011

CDO, Negros Oriental, Cebu, Zambaonga Del Norte, Misamis Oriental, Lanao Del Norte, Bukidnon, Compostela Valley, Surigao Del Sur, Lanao del Norte 1,439

Wind Storm 1984 Surigao del Norte, Bohol Isl., Mindanao, Negros Occidental, Cebu Provinces 1,399

Storm 2006 Bicol Region, Catanduanes, Sorsogon, Mindoro, Marinduque, Batangas, Laguna 1,399

Volacano 1911 Manila Region 1,335

Wind Storm 1984 Capiz, Iloilo, Aklan, Antique, Leyte, Eastern Samar, Roxas, Tacloban 1,079

TABLE 2.0 - TOP 10 NATURAL DISASTER EVENTS ACCORDING TO AMOUNT OF DAMAGE

DISASTER TYPE YEAR LOCATION DAMAGE

U$$1,000

Storm 2013 Samar, Leyte, Cebu, Iloilo, Capiz, Aklan, Palawan

Provinces 1,000,000

Earthquake 1990 Cabanatuan, Baguio, Dagupan (Luzon Isl.) 920,000

Storm 2012 Davao Oriental, Compostela Valley 898,352

Wind Storm 1995 Pampanga, Sultan Kudarat provinces 709,000

Storm 2009 Region I, Region II, Region III, Region IV-A, Region V,

Region VI 585,379

Wind Storm 1991 Regions IV and XII 435,000

Wind Storm 1990 Samar , Masbate provinces, Palawan, Iloilo, Negros

Occidental, Cebu 388,500

Storm 2011 NCR, Ilocos Region, Region III, Region IV-b (Mimaropa),

Region V-Bicol, Region VI 344,173

Wind Storm 1998 Albay, Catanduanes Prov. 319,176

Wind Storm 1991 Luzon Isl. 311,000

Meanwhile, the Asian Disaster Reduction Center (ADRC), which is based in Japan,

analyzed a very similar database of disasters from 1901 to 2013

(www.adrc.or.jp/databook_20th/). Nationwide, 35 natural disasters were listed; the sum of

people killed reached 57,280; and the sum of the material damage exceeded US$8-Billion.

Both the CRED and ADRC databases list many types of natural disaster, which are listed

below in alphabetical order.

• Drought (ex. El Niňo

• Volcano(ex. Explosion, Lahar Flow)

• Wave/Surge (ex. Tsunami)

• Wild Fire

• Wind Storm

• Slide (ex. Landslide)

• Earthquake

• Epidemic(ex. Malaria, Dengue Fever)

• Flood

• Insect Infestation

The ADRC analysis of the natural disasters indicates the following historical trends.

1. Wind storms lead, in terms of frequency, in total number of people killed, injured, or

otherwise affected, and in value of damage.

2. Earthquakes rank second, in terms of total number of people killed or injured, and in

monetary value of damage. Floods place second, too, in terms of frequency, in total number of

people affected and in monetary value of damage.

3. Volcano eruptions rank third, in terms of number of people killed and in monetary value of

damage.

In summary, the hazards that caused the most disasters were, and still are, as

listed below in the order of overall significance:

• Wind storms

• Earthquakes

• Floods, and

• Volcano eruptions

2.2 The Philippines is No.1 Country Visited by Wind Storm

The geographical location of the Philippines is prone to be subjected to wind storm. Fig

2.1 is the wind zone map of the Philippines, while Table 2.3 also presented the basic wind speed

for the Provinces of the Philippines.

Fig. 1.0 Wind Zone Map of the Philippines

2.3 The Philippines belongs to the Earthquake Belt of the World

Fig. 2.2 shows the Epicenter of the Past World Earthquakes while Fig. 2.3 is Seismic Source: Active Faults and Trenches in the Philippines.

The Philippines is divided into two Earthquake zones: Zone 4 – covers areas that have active faults and trenches are capable of generating

large magnitude earthquakes. All the provinces except Palawan and Tawi-Tawi fall under Zone 4.

Zone 2 – covers areas that do not have earthquake.

Fig. 2.2 Seismicity of the Philippines – Epicenter of Past World Earthquakes

Fig. 2.3 Seismic Sources: Active Faults & Trenches

Fig.2.4 Referenced Seismic Map of the Philippines

MODULE II: OVERVIEW OF DETAILED ENGINEERING DESIGN Part I: Building Design Data and Requirements b. MATERIALS COMMONLY USED IN BUILDING CONSTRUCTION Basic Construction Materials:

1. CEMENT 2. SAND 3. GRAVEL 4. REINFORCING STEEL BARS 5. STANDARD WIRE REINFORCEMENT (WELDED WIRE MESH) 6. STRUCTURAL STEEL

b.1 To produce concrete, mix cement, sand and gravel with measured quantity of clean water. Depending upon the mixture and used of the concrete, the strength produced may varies. (The figure below shows the stress strain diagram for concrete. b.2 The reinforcing steel bar commonly used in the Philippines is subdivided into three (3) according to properties:

1. Philippine Standard Structural Grade, Grade 230 fy = 230 MPa (33,000 psi)

2. Philippine Standard International Grade, Grade 275 -fy = 275 MPa (40,000 psi) 3. Philippine Standard Hard Grade, Grade 414 -fy = 414 Mpa (60,000 psi)

Reinforced Concrete – is a term when concrete is reinforced with reinforcing steel bar. TABLE b.3- STEEL REINFORCEMENT INFORMATION ON SIZES, AREAS AND WEIGHTS

PHILIPPINE STANDARD (SI)

Bar Size Designation Area, mm2 Mass, kg/m

10 79 0.618

12 113 0.890

16 201 1.580

20 314 2.465

25 491 3.851

28 616 4.831

32 804 6.310

36 1019 7.986

42 1385 10.870

58 2642 20.729

b.3 STANDARD WIRE REINFORCEMENT Table –b.4 WRI Standard Wire Reinforcement

MW and MD SIZE Diameter, mm

Mass, kg/m

Area, mm² / m of width for various spacings

PLAIN DEFORMED CENTER-TO-CENTER SPACING, mm

50 75 100 150 200 250 300

MW290 MD290 19.22 2.270 5800 3900 2900 1900 1450 1160 970

MW200 MD200 15.95 1.570 4000 2700 2000 1300 1000 800 670

MW130 MD130 12.90 1.020 2600 1700 1300 870 650 520 430

MW120 MD120 12.40 0.942 2400 1600 1200 800 600 480 400

MW100 MD100 11.30 0.785 2000 1300 1000 670 500 400 330

MW90 MD90 10.70 0.706 1800 1200 900 600 450 360 300

MW80 MD80 10.10 0.628 1600 1100 800 530 400 320 270

MW70 MD70 9.40 0.549 1400 930 7100 470 350 280 230

MW65 MD65 9.10 0.510 1300 870 650 430 325 260 220

MW60 MD60 8.70 0.471 1200 800 600 400 300 240 200

MW55 MD55 8.44 0.432 1100 730 550 370 275 220 180

MW50 MD50 8.00 0.393 1000 670 500 330 250 200 170

MW45 MD45 7.60 0.353 900 600 450 300 225 180 150

MW40 MD40 7.10 0.314 800 530 400 270 200 160 130

MW35 MD35 6.70 0.275 700 470 350 230 175 140 120

MW30 MD30 6.20 0.236 600 400 300 200 150 120 100

MW25 MD25 5.60 0.196 500 330 250 170 125 100 83

MW20 5.00 0.157 400 270 200 130 100 80 67

MW15 4.40 0.118 300 200 150 100 75 60 50

MW10 3.60 0.079 200 130 100 70 50 40 33

MW5 2.50 0.039 100 67 50 33 25 20 17

b.4 STRUCTURAL STEEL b.4.1 Structural Steel - construction material formed with a specific cross-section and certain standards of chemical composition. It is used in the construction of frames for industrial buildings, bridges and other structures. b.4.2 Different type of structural steel are subdivided into two(2), as follows: ROLLED – SHAPE SECTION

COLD – FORMED SECTION

These sections are available in the market with the corresponding strength: ASTM A7 – fy = 33 ksi ASTM A36 – fy = 36 ksi C. COMPONENTS OF A BUILDING STRUCTURES c.1 Components of a Building Structures:

1. Substructure – All parts that are embedded to the ground such as footing and footing tie beam

2. Superstructure – All parts that are exposed to the ground such as columns, beams and suspended slab.

c.2 SUBSTRUCTURE c.2.1 Footing - is a structural member that carries the loads induced reactions and moments from columns or walls, and transfer it to the supporting soil.

c.2.2 TYPES OF FOOTING

c.2.3 Footing Tie Beam (FTB) Footing Tie Beam – is a flexural member that is commonly used to interconnect columns. It is used to support masonry wall and reduce the effect of differential settlement of footing. c.3 SUPERSTRUCTURE c.3.1 Column – is a compression member carrying loads from beams and transmitting it to the footing. It is also a part of special moment frame subjected to bending and axial load.

Under Zone 4, the column, as a member of moment resisting frame must satisfy the following requirements:

1. Size or Section - The shortest cross-sectional dimension measured on a straight line passing through the geometric centroid, shall not be less than 300 mm except for buildings or structures regulated by NSCP Volume 3 and BP 220. The ratio of the shortest cross-sectional dimension to the perpendicular dimension shall not be less than 0.40

2. Longitudinal Reinforcement or main bar shall have an area Ast not less than 0.01Ag or more than 0.06Ag. .

SINGLE SPREAD FOOTING

STRAP FOOTING

COMBINED FOOTING

MAT FOOTING

PILE FOOTING - DRIVEN PILE - BORED PILE

where Ag = gross concrete area = 300 x 300 (see Fig. 4.3)

Fig. 4.3 – Typical Column Rebar Arrangement

3. Transverse reinforcement or column ties (seeFig.4.3) is reinforcing steel bars that is used to enclose the main unprestressed reinforcement throughout the column length.

Recommended sizes to be used are: for main bar– Φ32mm and smaller – …..............................................................................use Φ10 for main bar – Φ36mm, Φ42mm, Φ58mm and bundled longitudinal bars – ……...............use Φ12

The location and recommended spacing of column ties are: At Confined region – with a length of Lo

– ¼ of the minimum of dimension of the member. – 6x diameter of the smallest longitudinal bar – So = 100 + (350 – hx) 3 The value of the So shall not exceed 150mm and need not be taken less than 100mm. hx = the dimension perpendicular to the axis of bending

c.3.2 Beam The length Lo shall be the longest among:

- depth of the member at the joint face or at the section where flexural yielding is likely to occur,

- 1/6 of the clear span of the member - 450mm

At unconfined region – beyond Lo Column ties spacing shall be the smallest among:

- 6x dia. of the smallest longitudinal column bar - 150mm

At joint reinforcement – column ties shall be same spacing at confined region. Beam - is a structural element that is capable of withstanding load primarily by resisting bending. The bending force induced into the material of the beam as a result of the external loads, own weight, span and external reactions to these loads is called a bending moment. Under Zone 4, beams to be used as flexural members of special moment frames shall satisfy the following requirements: (see Fig. 4.4)

1. Clear span shall not be less than 4 times its effective depth. clear span L1 > 4d

2. Width of member shall not be less than the smaller of 0.3h and 250mm where: h = overall depth of beam bw 0.30h

250

3. Width of member shall not exceed the width of the supporting member bw Width of column 4. The minimum overall depth of the beam unless deflections are computed is given in Table 4.1

5. Reinforcing Steel Bars Longitudinal reinforcement: minimum, Asmin √fc’ bwd 4fy 1.40 bwd fy

max As 0.25 bwd At least 2 bars shall be provided continuously both top and bottom.

Fig. 4.4 – Rebar Arrangement for Beam 6. Transverse Steel Bars

• Transverse steel Bars are sometimes called hoops, stirrup ties, stirrups or ties. maximum spacing at distance 2h from column = d 4 = 8 x diameter of the smallest longitudinal bars (db) = 24 x diameter of hoop bars (dh) = 300 mm Where hoops are not required, stirrups with seismic hooks at both ends shall be spaced at a distance not more than d/2 throughout the length of the member Table c.1 Minimum Thickness of Non-prestressed Beams or One-Way Slabs Unless Deflections

are Computed

Member

Minimum Thickness, h

Simply Supported

One end continuous

Both ends continuous

Cantilever

Members not supporting or attached to partitions or other construction likely to be damaged by large deflections

Solid one-way slabs

l/20 l/24 l/28 l/10

Beams or ribbed one-way slabs l/16 l/18.5 l/21 l/8

c.3.3 SLAB a. ONE WAY SLAB

- The ratio of longer span to the shorter span is greater than 2.0 and due to the huge difference in lengths, load is not transferred to the shorter beams.

- Reinforcement for shrinkage and temperature stressed normal to flexural reinforcement shall be provided in structural slabs where the flexural reinforcement extends in one

direction only.

Fig. 4.5 – Types of Truss

b. TWO WAY SLAB

- -The ratio of the longer span to shorter span is less than 2.0 and the load is transferred/carried in both directions.

The minimum thickness of one-way slab is given in Table c.1

COMPONENTS OF A BUILDING STRUCTURES

The proposed 2-Storey Office Building to be used by as office of a local government agency. It is located in a buildable area as indicated in the geohazard map. The building is made of reinforced concrete and to be designed as moment resisting space frame, under Zone 4 category.

a. Design Loads - weight of concrete …………………………………………………………………………….24 kn/m³ - trusses, purlins, sag rods, etc……………………………………………………………0.24 kn/m² - 100 CHB……………………………………………………………………………………………2.48 kn/m² - 150 CHB……………………………………………………………………………………………2.80 kn/m² - G.I roofing……………………………………………………………………………………..-0.072 kn/m² - Floor topping & live load ceiling, electical, piping, fixtures,etc.………..0.20 kn/m²

Live Load

- Roof construction live load………………………………………………………………-0.96 kn/m² - office…………………………………………………………………………………………………1.92 kn/m²

- finishes……………………………………………………………………………………………..0.61 kn/m² - partitions……………………………………………………………………………………………1.0 kn/m² - hailway, stairs…………………………………………………………………………………..3.84 kn/m² b. Material Properties Concrete 28th day Compressive strength –fc=20.68mPa

Reinforcing steel bars – for rebars less than 16mmФ, use Intermediate grade, fy’= 275MPa – for rebars 16mm Ф and above, use hard grade fy=414MPa

Structural Steel – for trusses, purlins, cross bracing sagrods, use A36 steel with fy = 248MPa

c. Seismic Local Zone coefficient Z= 0.40 for Zone 4 Importance factor special occupancy I=1.0 Frame Material Factor…………………….Ct = 0.0731 Seismic Source Type Closest distance to know Seismic fault, = (North Bohol Fault) d. Soil Properties………………allowable bearing capacity - 144 kn/m² (Soil Investigation Report)

E. References

1. National Structural Code of the Philippines

Vol. 1 6th Edition, 4th Printing

Design Computations

The minimum requirements of a moment existing frame under Zone 4 Seismic

conditions are:

a. Single spread footing – 1 500 x 1 500 x 300 with 5-6Фmm O.C BW

b. Footing tie beam – 250 x 350 with 2- Ф20mm top

and bottom reinforcements and

hoops 1@50, 10@70 rest @145 O.C

c. Column 300 x 300 with 8- Ф20mm longitudinal bars and hoops

@ confined region……………….2 sets-Ф10mm@ 75 O.C

@ joint reinforcement…………2 sets- Ф10mm@ 75 O.C

@ unconfined region…………..2 sets- Ф10mm@ 120 O.C

d. Beam

2nd Floor – 250 x 350 with 3-Ф20 top

and bottom bars and hoops 1@50,

10@70, rest@145 O.C

e. Slab

two way slab : 120mm thick with main

reinforcement

short span

continuous: Ф10 @ 200 O.C midspan: Ф10 @ 250 O.C discontinuous: Ф10 @ 200 O.C long span continuous: Ф10 @ 200 O.C midspan: Ф10 @ 250 O.C discontinuous: Ф10 @ 200 O.C

MODULE IV: OVERVIEW OF REHABILITATION OF DAMAGED STRUCTURE

Part I: Building Design

Building Construction – causes of damage/defects

1. Old Capitol Building

2. Capitol Annex Building

3. St. Peter the Apostle Church, Loboc

4. Our Lady of Assumption Church,

Dauis

5. Cong. Natalio Memorial Hospital

6. Clarin Community Hospital

MODULE IV: OVERVIEW OF REHABILITATION OF DAMAGED STRUCTURES

Retrofitting Works

PRACTICAL SOLUTIONS TO SEISMIC

RETROFITTING / REHABILITATION

Jacketing

Post‐tensioning

Carbon fiber wrap

RETROFITTING: STRENGTHENING BY JACKETING

Jacketing - is one of the most frequently used techniques to strengthen reinforced concrete

(RC) members.

RETROFITTING: CONCRETE JACKETING

POST-TENSIONING (AS SEISMIC RETROFITTING)

Post-tensioning is a method of reinforcing (strengthening) concrete or other materials with

high-strength steel strands or bars, typically referred to as tendons.

RETROFITTING: POST‐TENSIONING

RETROFITTING: CARBON FIBER WRAP

Carbon fiber - is the common name used to refer to plastic reinforced by a

graphite textile. Less frequently, the term is used to describe the textile itself, but

it is pretty much useless unless embedded in plastic.

RETROFITTING: CARBON FIBER WRAP

2 - STOREY BUILDING

Perspective

GROUND FLOOR PLAN

SECOND FLOOR PLAN

ROOF PLAN

LONGITUDINAL SECTION

FOUNDATION PLAN

2/f Beam Slab

Column

Footing Footing Tie Beam

Roof Beam

7.05 Parapet Wall Line

0.35 F.F.L

6.15 Roof Deck Line

3.35 2/f Line

0.0 N.G.L

SECOND FLOOR FRAMING

ROOF FRAMING PLAN

ROOF FRAMING PLAN

C-PURLINS

SAGROD CROSS BRACING ROOF BEAM

TRUSS