earthquake disaster

71
05/09/22 05/09/22 Let’s adopt the Update Service

Upload: fr-khan

Post on 12-Aug-2015

60 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Earthquake Disaster

04/15/2304/15/23

Let’s adopt the Update Service

Page 2: Earthquake Disaster

04/15/2304/15/23

The Pain of The Pain of ChangeChange

Page 3: Earthquake Disaster

04/15/2304/15/23

• The Composite Cement

• The High Strength Re-inforcement STEEL

• Use of CPVC Pipe & fittings for Plumbing

• Use of Admixture for Damp & Repair

• Painting

• Utility Equipments

• Outsource

Topic to be PresentedTopic to be Presented

Page 4: Earthquake Disaster

04/15/2304/15/23

Severe Weather ConditionSevere Weather Condition

Page 5: Earthquake Disaster

04/15/2304/15/23

Present Day LossPresent Day Loss

Page 6: Earthquake Disaster

04/15/2304/15/23

Bhuj DisasterBhuj Disaster

Page 7: Earthquake Disaster

04/15/2304/15/23

Bangladesh is among the most densely populated Bangladesh is among the most densely populated country in the world. Much of in active seismic zones country in the world. Much of in active seismic zones making the occurrence of deadly earth quakes a making the occurrence of deadly earth quakes a frighten scenario. Many of the earthquakes have frighten scenario. Many of the earthquakes have occurred in the north-eastern part of the country and occurred in the north-eastern part of the country and south-eastern area. The Madhupur Fault runs in south-eastern area. The Madhupur Fault runs in Dhaka division. The border with the Indian state of Dhaka division. The border with the Indian state of Meghalaya is also a fault. Dhaka Division have both Meghalaya is also a fault. Dhaka Division have both suffered severe earth quakes in the past. Tsunamis suffered severe earth quakes in the past. Tsunamis have also effected many tiny nationshave also effected many tiny nations..

Page 8: Earthquake Disaster

04/15/2304/15/23

Largest InstrumentedLargest Instrumented

Earthquakes in Earthquakes in

BangladeshBangladesh

Page 9: Earthquake Disaster

04/15/2304/15/23

Largest Instrumented Earthquake in BangladeshLargest Instrumented Earthquake in Bangladesh8 July 1918 – Near Kishorgaj (Dhaka Div.), 8 July 1918 – Near Kishorgaj (Dhaka Div.), Bangladesh, Mw 7.4Bangladesh, Mw 7.410:22:07 UTC, 24.50 N, 91.00 E10:22:07 UTC, 24.50 N, 91.00 E

Often referred to as the Srimangal earthquake, this Often referred to as the Srimangal earthquake, this massive quake was centered of Mymensingh, in the massive quake was centered of Mymensingh, in the northern part of Dhaka Division near Kishorganj, northern part of Dhaka Division near Kishorganj, Bangladesh has suffered some major Earthquake Bangladesh has suffered some major Earthquake preceded by a series of light to moderate preceded by a series of light to moderate foreshocks.foreshocks.

Page 10: Earthquake Disaster

04/15/2304/15/23

• 2 April 1762 – Near Chamble, (Sorthern Chittagong Division)

• 30 June 1868 – Near Sylhet, (Northern Chittagong Division)

• 14 July - 1885 – Near Dhaka, (Dhaka Division)

• 8 July - 1885 – Near Kishorganj, (Dhaka Division)

• 9 September 1923 – West of Durgapur, (Dhaka Division)

• 24 December 1944 – Near Sylhet, (Northern Chittagong Division)

• 19 May 1945 – Near Mohangonj, (Dhaka-Chittagong Division)

• 10 December 1949 – North of Saidpur, (Rajshahi Division)

• 24 December 1950 – Near Baniyachung, (Northern Chittagong Division)

• 12 June 1956 – Near Netrakona, (Northern Dhaka Division)Continue………

Large Earthquakes in Bangladesh

Page 11: Earthquake Disaster

04/15/2304/15/23

• 21 June 1963 – Near Netrakona, (Northern Dhaka Division)

• 12 May 1977 – Bangladesh-Myanmar border region

• 6 February 1988 – Near Sylhet, (Northern Chittagong Division)

• 12 June 1989 – Bay of Bengal, Off Khulna Division

• 8 May 1997 – Indo-Bangladesh border region

• 21 November 1997 – Southern Mizoram

• 22 July 1999 – Moheskhali Island, (Chittagong Division)

• 31 December 1999 – Off Kutubdia Island, (Chittagong Division)

• 19 December 2001 – Dhaka Area, (Dhaka Division)

• 26 July 2003 – Harina Bazar-Daluchari area, (Chittagong Division)

Page 12: Earthquake Disaster

04/15/2304/15/23

Seismic Detailing Seismic Detailing RequirementsRequirements

Page 13: Earthquake Disaster

04/15/2304/15/23

Full Collapse of StructureFull Collapse of Structure

Page 14: Earthquake Disaster

04/15/2304/15/23

The key objective of earthquake-resistant design is to The key objective of earthquake-resistant design is to

make a structure with adequate strength and ductile to make a structure with adequate strength and ductile to

assure life safety, specifically, to avoid collapse under assure life safety, specifically, to avoid collapse under

the most intense probable earthquake at a site during the most intense probable earthquake at a site during

the whole life of structure. Economy is one of the key the whole life of structure. Economy is one of the key

objectives by allowing yielding in some structural objectives by allowing yielding in some structural

members subjected to moderate-to-strong members subjected to moderate-to-strong

earthquakes.earthquakes.

Traditionally, seismic risk levels have been classified as Traditionally, seismic risk levels have been classified as

low, moderate, and high. Similarly Bangladesh National low, moderate, and high. Similarly Bangladesh National

Building code classifies three seismic zones; these are Building code classifies three seismic zones; these are

Zone 1, Zone 2 and Zone 3 with being the most severe.Zone 1, Zone 2 and Zone 3 with being the most severe.Continue………..Continue………..

A. Introduction

Page 15: Earthquake Disaster

04/15/2304/15/23

There are five basic structural There are five basic structural systems for reinforced concrete systems for reinforced concrete

buildings are :buildings are :

• Bearing wall system

• Building frame system

• Moment resisting frame system

• Dual system and

• Special structural systems.

Page 16: Earthquake Disaster

04/15/2304/15/23

Load Bearing Brick StructureLoad Bearing Brick Structure

Page 17: Earthquake Disaster

04/15/2304/15/23

Extreme Rescue DifficultyExtreme Rescue Difficulty

Page 18: Earthquake Disaster

04/15/2304/15/23

Concerned moment resisting Concerned moment resisting frame system is three types frame system is three types

which are as follows :which are as follows :

• Special Moment Resisting Frames (SMRF)

• Intermediate Moment Resisting Frame (IMRF)

• Ordinary Moment Resisting Frame (OMRF)

Continue……….

Page 19: Earthquake Disaster

04/15/2304/15/23

For continued existence of buildings from For continued existence of buildings from earthquake some configuration scarcity earthquake some configuration scarcity (Fig. I) we may avoid. we may avoid.

These are:These are:

Partial load paths Vertical and horizontal irregularities Weak column-strong beam soft story at any level

Page 20: Earthquake Disaster

04/15/2304/15/23

Geometric ScarcityGeometric Scarcity

Page 21: Earthquake Disaster

04/15/2304/15/23

Failure of Soft StoreyFailure of Soft Storey

Page 22: Earthquake Disaster

04/15/2304/15/23

Also detailing be free from Also detailing be free from

deficiencydeficiency Poor anchorage and splices of longitudinal rebar

in beams and columns Inappropriate locations of splices of longitudinal

rebar Inadequate shear reinforcement in beams and

columns Inadequate reinforcement (ties) in beam-column

joint regions

Page 23: Earthquake Disaster

04/15/2304/15/23

Result of DeficiencyResult of Deficiency

Page 24: Earthquake Disaster

04/15/2304/15/23

B. General Requirements of Concrete and B. General Requirements of Concrete and Reinforcement in Earthquake – Resisting Reinforcement in Earthquake – Resisting ConstructionConstruction

1. Compressive strength fc' of the concrete shall be not less than 20 MPa.

2. Compressive strength of light weight aggregate used in design shall not exceed 30 MPa.

3. Rebar shall confirm with ASTM A706, ASTM A6 1 5 and BDS 1 3 .3

4. No welded splices in the critical regions (twice member\depth from column or beam face) (Fig. 3 & Fig.7)

Continue ………….

Page 25: Earthquake Disaster

04/15/2304/15/23

Beam Splice DetailBeam Splice Detail

Page 26: Earthquake Disaster

04/15/2304/15/23

• Column Tie Detail

Page 27: Earthquake Disaster

04/15/2304/15/23

Joint FailureJoint Failure

Page 28: Earthquake Disaster

04/15/2304/15/23

5. Welded splices and mechanical connection shall not more than alternate bars in each layer of longitudinal bar are spliced at a section and the center to center distance between splices of adjacent bars is 600 mm or more measured along the longitudinal axis of the member (Fig. 7).

6. Welding of stirrups, ties or other similar elements to longitudinal reinforcement required by design shall not be permitted

Page 29: Earthquake Disaster

04/15/2304/15/23

Column FailureColumn Failure

Page 30: Earthquake Disaster

04/15/2304/15/23

C. Flexural Members of Frames C. Flexural Members of Frames (Beam) (Beam)

in Earthquake-resisting in Earthquake-resisting ConstructionConstruction

Page 31: Earthquake Disaster

04/15/2304/15/23

Geometry General RequirementsGeometry General Requirements

1. Members shall be flexure dominated component i.e. lower axial load

2. Factored axial Compressive force on the member shall not exceed Ag fc'/10

3. Clear span for the member shall not be less than four times is effective depth i.e. if span is less, ln ≥ 4d (Fig. 9)

4. The width-to-depth ratio (b/d) shall not be less than 0.3 (Fig. 12)

5. The width of beam shall not be less than 250 mm (Fig. 13)

6 The width shall not be more than the width of the supporting member (measured on a plane perpendicular to the longitudinal axis of the flexural member) plus distances on each of the supporting member not exceeding three-fourths of the depth of the flexural member, i.e. b < bcol + 2(3/4 db)

Contd………..

Page 32: Earthquake Disaster

04/15/2304/15/23

Beam Depth SpanBeam Depth Span

Page 33: Earthquake Disaster

04/15/2304/15/23

Max Width/DepthMax Width/Depth

Page 34: Earthquake Disaster

04/15/2304/15/23

Min Beam DimensionMin Beam Dimension

Page 35: Earthquake Disaster

04/15/2304/15/23

7. Lap splices of flexural reinforcement shall be permitted only if hoop or spiral reinforcement is provided over the lap length.

8. Welded splices and mechanical connections conforming to sec 8.2.12.3(a) through 8.2.I2.3(d) of BNBC/93 are allowed for splicing provided not more than alternate bars in each layer of longitudinal reinforcement are spliced at a section and the center to center distance between splices of adjacent bard is 600 mm or more measured along the longitudinal axis of the frame member.

9. Maximum spacing of the transverse reinforcement enclosing the lapped bars shall not exceed d/4 or 100mm. (Fig. 2)

10. Lap splices shall not be used (Fig. 3}

• Within the joints

• Within a distance of twice the member depth from the face of the joint

• At locations where analysis indicates flexural yielding caused by inelastic lateral displacements of the frame.

Main/Longitudinal Reinforcement RequirementMain/Longitudinal Reinforcement Requirement

Page 36: Earthquake Disaster

04/15/2304/15/23

Beam Hoop DetailBeam Hoop Detail

Page 37: Earthquake Disaster

04/15/2304/15/23

Beam Splice AreaBeam Splice Area

Page 38: Earthquake Disaster

04/15/2304/15/23

11. At least two longitudinal bars shall be provided continuously both top and bottom. (Fig. 2)

12. Lap splices only permitted outside yielding regions and beam- column joints, i.e. Splices shall be in the middle third must be enclosed by hoop or spiral reinforcement (Fig. 2)

13. Mechanical splices or welded splices are preferred.

Page 39: Earthquake Disaster

04/15/2304/15/23

Displacement FailureDisplacement Failure

Page 40: Earthquake Disaster

04/15/2304/15/23

TRANAVERSE REINFORCEMENT GUIDELINETRANAVERSE REINFORCEMENT GUIDELINE

14. Hoops shall be provided in the following regions (Fig. 2)

* At both ends of the flexural member, over a length equal to twice the member depth measured from the face of the supporting member toward mid-span at both ends

* Locate the first hoop not more than 2 in. from the face of support

* The hoop spacing, Sh shall also fulfill the following

Sh ≤ d/4

≤ 8-times the diameter of the smallest longitudinal bars

≤ 24-times the diameter of hoop bars and

≤ 300 mm

15. Elsewhere through the span hoop spacing shall not more than d/2 (Fig.2)

Page 41: Earthquake Disaster

04/15/2304/15/23

D.D. Frame Members Subjected to Bending and Frame Members Subjected to Bending and Axial Axial

Load (Column) in Earthquake-resisting Load (Column) in Earthquake-resisting ConstructionConstruction

Page 42: Earthquake Disaster

04/15/2304/15/23

Geometry/General RequirementsGeometry/General Requirements

I. Factored axial compressive force on the member shall not less than Pu ≥ Ag fc’/ 10

2. The shortest cross-sectional dimension bmin ≥ 300 mm

(Fig. 16)

3. The ratio of shortest cros-sectional dimension to the perpendicular dimension to the perpendicular dimension

bmin / bmax ≥ 0.4 (Fig. 15)

Page 43: Earthquake Disaster

04/15/2304/15/23

Max Column RatioMax Column Ratio

Page 44: Earthquake Disaster

04/15/2304/15/23

Min Column DimensionMin Column Dimension

Page 45: Earthquake Disaster

04/15/2304/15/23

Main/Longitudinal Reinforcement NecessitiesMain/Longitudinal Reinforcement Necessities

4. The reinforcement ratio pg shall not be less than 0.01 and shall not exceed 0.06

5. Lap splices are permitted only within the center half of the member length and shall be designed as tension splices. (Fig. 7)

6. Welded splices and mechanical connections (conforming to sec 8.2.12.3[a] through 8.2.12.3[d] of BNBC/93) are allowed for splicing the reinforcement at any section provided not more than alternate longitudinal bars are spliced at a section and the center to center distance between splices of adjacent bard is 600 mm or more along the longitudinal axis of the reinforcement. (Fig. 7)

Page 46: Earthquake Disaster

04/15/2304/15/23

Tranaverse Reinforcement GuidelineTranaverse Reinforcement Guideline

7. Transverse reinforcement shall be provided as specified below (Unless a larger amount is required by see 8.3.8 of BNB/93)

* The Volumetric ratio of circular hoop reinforcement, ρs shall not be less than that

and shall not be less that that required by Eq. (6.3.3)

* The total cross-sectional area of rectangular hoop reinforcement shall not be less than given by the following equations-

Ash = 0.3 (Shcfc’ / fyh) [Ag/Ach)-1] ……………. (8.3.3)

Ash = 0.09 Shcfc’ / fyh ………………………….(8.3.4)

yhf

fc'.Ps

120

Page 47: Earthquake Disaster

04/15/2304/15/23

Importance of TieImportance of Tie

Page 48: Earthquake Disaster

04/15/2304/15/23

TieTie

Page 49: Earthquake Disaster

04/15/2304/15/23

* Transverse reinforcement shall be provided by either single or overlapping hoops. Crossties of the same

bar size and spacing as the hoops shall be permitted to be used, each end of crosstie shall engage a peripheral longitudinal reinforcing bar. Consecutive crossties

shall be alternated end for end along the longitudinal reinforcement.

* If the design strength of member core satisfies the requirement of the specified loading combinations including earthquake effect, Eq. (8.3.3) and (6.3.3) of BNBC/93 need not be satisfied

Page 50: Earthquake Disaster

04/15/2304/15/23

8 Transverse reinforcement spacing are as follows within 10 (Fig.8)

s ≤ 0.25 hmin ≤ 100 mm

9 Crossties or legs of overlapping hoops shall not be spaced more than 350 mm on center in the direction perpendicular to the longitudinal axis of the structure. [Fig. 11(a)]

10 Special transverse reinforcement required along length l0 (Fig. 8G:\Presentatio on earth quack\image\fig.8.gif) from each joint face where

l0 > hmax the depth of the member at the joint face > ln/6 the clear span of the member > 500 mm

Page 51: Earthquake Disaster

04/15/2304/15/23

Tie Detail in ColumnTie Detail in Column

Page 52: Earthquake Disaster

04/15/2304/15/23

11 If the lower end of the column terminates on a wall, transverse reinforcement as specified in D.7 to D.9 shall extended into the wall for at least the

development length of the largest longitudinal reinforcement in the column at the point of termination. (Table 1 to Table 6)

12 If the column terminates on a footing or mat, transverse reinforcement as specified in D.7 to D.9 shall extend at least 300 mm, into the footing or mat. (Fig. 10)

13 Where transverse reinforcement, as specified in D.7 to D.9, is not provided throughout the full length of the column, the remainder of the column length shall contain spiral or hoop reinforcement with the following spacing (Fig. 8)

S ≤ 6db ≤ 150 mm

Page 53: Earthquake Disaster

04/15/2304/15/23

E. Joints Of Frame Structures

Page 54: Earthquake Disaster

04/15/2304/15/23

Failure due to jointFailure due to joint

Page 55: Earthquake Disaster

04/15/2304/15/23

1. Beam longitudinal reinforcement terminated in a column shall be

terminated in a column shall be extended to the far face of the

confined column core and anchored in tension according to S.3..7.4

of BNBC/93 (tension development length) and in compression

according to chapter-6 of BNBC/93 (compression development

length)

2. Where longitudinal beam reinforcement extends through a beam-

column joint, the column dimensions parallel to the beam

reinforcement shall not be less than 20 times (Fig. 5) the diameter of

the largest longitudinal bar for normal weight concrete. For lightweight

concrete, the dimension shall be not less than 26 times the bar

diameter.

Page 56: Earthquake Disaster

04/15/2304/15/23

3. The nominal shear strength of the joint shall not be taken greater than the forces specified below for normal weight aggregate concrete.

For joints confined on all four faces …

For joints confined on all three faces

or two opposite faces……………………

For others ………………………………..

jAfc'7.1

jAfc'25.1

jAfc'0.1

Page 57: Earthquake Disaster

04/15/2304/15/23

F. Development and splices of Reinforcement

Page 58: Earthquake Disaster

04/15/2304/15/23

1. The development length Idh for a bar (sizes No. 10 through No. 36) with a standard 90-deg hook in normal weight aggregate concrete shall not be less than 8db, 150mm and length required by the following equation

Calculated values are in Table–1 (based on 21 Mpa concrete and 414 Mpa steel)

2. For lightweight aggregate concrete the development length for a bar with a standard 90-deg hook shall not be less than 10, 190mm and 1 .25 times that required by (Eq. 8.3.5 of

BNBC/93) Calculated values are in Table - 2 (based on 21 Mpa concrete and 414 Mpa steel)

)5.3.8(..........).........'4.5/( fcdfl bydh

Page 59: Earthquake Disaster

04/15/2304/15/23

3. For bar sizes No. 10 through No. 36 (normal weight aggregate concrete), the development length Id for a straight bar shall not be less than

3.1 Two and a half (2.5) times the length required by (Eq. 8.3.5 of BNBC/93) if the depth of the concrete cast in one lift beneath the bar does not exceed 300 mm. Calculated values are in Table 3 (based on 21 Mpa concrete and 414 Mpa steel)

3.2 Three and a half (3.5) times the length required by (Eq. 8.3.5 of

BNBC/93) if the depth of the concrete cast in one lift beneath the bar exceeds 300 mm. Calculated values are in Table – 4 (based on 21 Mpa concrete and 414 Mpa steel)

4 Straight bars terminated at a joint shall pass through the confined core of a column or of a boundary element. Any portion of the straight embedment length not within the confined core shall be increased by a factor of 1.6. Table - 5 & Table - 6 (based on 21 Mpa concrete and 414 Mpa steel)

Page 60: Earthquake Disaster

04/15/2304/15/23

Table:3Table:3Table-3

Development Length Id for Straight bar concrete cast in one lift beneath the bar does not exeed 300 mm

BAR DIA Idh

8 335

10 418

12 502

16 669

20 837

22 920

25 1046

28 1171

32 1338

* All Calculations are based on 21 Mpa concrete and 414 Mpa reinforcement

Page 61: Earthquake Disaster

04/15/2304/15/23

Table: 4Table: 4Table-4

Development Length Id for Straight bar concrete cast in one lift beneath the bar exceed 300 mm

BAR DIA Idh

8 468

10 586

12 703

16 937

20 1171

22 1288

25 1464

28 1640

32 1874

* All Calculations are based on 21 Mpa concrete and 414 Mpa reinforcement

Page 62: Earthquake Disaster

04/15/2304/15/23

Table:5Table:5Table-5

Development Length Id for Straight embedment length not within the confined core

(Concrete weight concrete)

BAR DIA Idh

8 535

10 669

12 803

16 1071

20 1338

22 1472

25 1673

28 1874

32 2141

* All Calculations are based on 21 Mpa concrete and 414 Mpa reinforcement

Page 63: Earthquake Disaster

04/15/2304/15/23

Table:6Table:6Table-6

Development Length Id for Straight embedment length not within the confined core

(Light weight concrete)

BAR DIA Idh

8 750

10 937

12 1124

16 1499

20 1874

22 2061

25 2342

28 2623

32 2998

* All Calculations are based on 21 Mpa concrete and 414 Mpa reinforcement

Page 64: Earthquake Disaster

04/15/2304/15/23

Post Disaster is SeverePost Disaster is Severe

Page 65: Earthquake Disaster

04/15/2304/15/23

Loss of Life & PropertyLoss of Life & Property

Page 66: Earthquake Disaster

04/15/2304/15/23

Long Term Loss of NationLong Term Loss of Nation

Page 67: Earthquake Disaster

04/15/2304/15/23

Rescue LogisticRescue Logistic

Page 68: Earthquake Disaster

04/15/2304/15/23

Rescue ManagementRescue Management

Page 69: Earthquake Disaster

04/15/2304/15/23

No Definte RescueNo Definte Rescue

Page 70: Earthquake Disaster

04/15/2304/15/23

Future is uncertainFuture is uncertain

Page 71: Earthquake Disaster

04/15/2304/15/23

Thank You