In th e N am e o f A llah ,th e M o st B en e ficen t, th e M ost M erc ifu l

Welcome to HRC Bagh

Workshop on Safer Building Through Improving

Steel Detailing

Objective• To understand the recommended practices

with reference to earthquake resistant techniques to make their houses safe;

• To improve steel detailing in in building construction;

• To sensitize the stakeholders to adopt earthquake safer techniques;

• To ensure the effective technology transfer to the target groups.

WELCOME

Bagh Seismic zone

Destruction In Earthquake

7

RC Frame Buildings

DHQH Bagh

8

RC Frame Buildings

9

RC Frame Buildings

Margalla Tower

Earthquake 2005

Ring Spacing

Ring Problem

Our Practice?

Spacing of StirrupsEffects

Common Practice

New

Recommended Spacing

Ring Spacing= 4″

Recommended Shape of Seismic Stirrup

3″

135°

Such stirrups do not open even during strong shaking

Column “L” AND Base

Deficient Length of “L”

19

Proper Column Base

“L” Should be= 12 inch

Beam To Column Joint

Wrong Practices

Results

Beam To Column Joint at lintel Level

Our Practice

MistakeResult

Interior Beam-Column Joint

Beam long bar should passed from the center of column

0‘-6"

Wrong Practice

Is it ok?

Proper Plinth Corner Joint

Band To Column Joint at corner

Right way at middle/ Junction

Minimum= 2 Feet

OVERLAPPING

31

Length of vertical bar not Length of vertical bar not sufficient for 2sufficient for 2ndnd Storey Storey

Practice still continued

Why column fails?

Proper way of Lapping

Min 4‘-0"

Sufficient lapping lengthSufficient lapping length

Within lapping length, Within lapping length, stirrups at closer spacingstirrups at closer spacing

Location at mid Location at mid heightheight

Not more than 50 % bars Not more than 50 % bars lapped at a sectionlapped at a section

Our Practice (New)

Lap length is 15”

Overlapping in Beam

Recommended Overlap should be equal to= 60 x D

Identify Reasons?

Framing around opening

NewAfter Remedy

Infill Walls Connection With? Before OCT 2005

39

Tie-up of Walls

40

Tie-up of Walls

Why crack develop?Beam bar not bent up near support to overcome negative movement

Why crack develop?

Bent up bars

What is Our Practice

Construct beam and slab togetherConstruct beam and slab together

Commonly used steel reinforcementCommonly used steel reinforcementMild Steel Mild Steel High Strength Deformed Bar High Strength Deformed Bar

Should be free from loose mill scale, loose Should be free from loose mill scale, loose rust, coat of paints and oils, cracks, rust, coat of paints and oils, cracks, surface flaws, laminations etcsurface flaws, laminations etcShould comply with requirement of Should comply with requirement of dimension and weight dimension and weight Should not break while bendingShould not break while bending

Steel ReinforcementSteel Reinforcement

Simple Steel Quality Test

Making close hook 4d and bent the bar at 180 degree then straight it. Good quality bar doesn't break, while bad quality steel breaks.

SpacersConcrete Cover

Column= 1.5″

Beam= 1.5″

Slab=3/4″

Foundation=3″

Thank You!!!