SHEAR WALL, ITS STIFFNESS , ADVANTAGES , DISADVANTAGES, TYPES OF SHEAR WALL

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1PRESENTED BY
UMA MULLAPUDI

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WHAT IS A SHEAR WALL
 S H EA R WA L L I S A V ER TI C A L S TR U C T U RAL
E L E ME N T U S ED T O R ES I S T TH E H O RI ZO N TA L
F O R C E S S U C H A S WI N D FO R C E , S E I S M I C
F O R C E . T H E S E F O R C ES A C TS PA R A L L E L TO
TH E P L A N E O F T H E WA L L . S H E A R WA L L S AR E
G E N E RA LL Y U S E D I N H I G H R I SE B U I L D I N G S
WH E R E E F FE C T O F WI N D FO R C E S A N D
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WH E R E E F FE C T O F WI N D FO R C E S A N D
S E I S M I C F O R C E S I S MO R E.
 WA L L TH I C K C A N V A R Y F R O M 150M M TO
40 0 MM .
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WHAT IS A SHEAR WALL BUILDING?
REINFORCED CONCRETE BUILDINGS OFTEN HAVE VERTICAL PLATE-LIKE RC
WALLS CALLED SHEAR WALLS IN ADDITION TO SLABS, BEAMS AND
COLUMNS. THESE WALLS GENERALLY START AT FOUNDATION LEVEL AND
ARE CONTINUOUS THROUGHOUT THE BUILDING HEIGHT. THEIR THICKNESS
CAN BE AS LOW AS 150MM, OR AS HIGH AS 400MM IN HIGH RISE
BUILDINGS. SHEAR WALLS ARE USUALLY PROVIDED ALONG BOTH LENGTH
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BUILDINGS. SHEAR WALLS ARE USUALLY PROVIDED ALONG BOTH LENGTH
AND WIDTH OF BUILDINGS. SHEAR WALLS ARE LIKE VERTICALLY-ORIENTED
WIDE BEAMS THAT CARRY EARTHQUAKE LOADS DOWNWARDS TO THE
FOUNDATION.

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PLACEMENT OF SHEAR WALLS
• LOCATED SYMMETRICALLY TO AVOID ILL EFFECTS
OF TWISTING
• SYMMETRY CAN BE ALONG ONE OR BOTH THE
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• SYMMETRY CAN BE ALONG ONE OR BOTH THE
DIRECTIONS.
• CAN BE LOCATED AT BOTH EXTERIOR OR INTERIOR
• MORE EFFECTIVE WHEN LOCATED ALONG EXTERIOR
(PERIMETER OF BUILDING).

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WHAT ARE THE FUNCTIONS OF A SHEAR WALL?
• SHEAR WALLS MUST PROVIDE THE NECESSARY LATERAL STRENGTH TO RESIST
HORIZONTAL EARTHQUAKE FORCES. WHEN SHEAR WALLS ARE STRONG
ENOUGH, THEY WILL TRANSFER THESE HORIZONTAL FORCES TO THE NEXT
ELEMENT IN THE LOAD PATH BELOW THEM. THESE OTHER COMPONENTS IN THE
LOAD PATH MAY BE OTHER SHEAR WALLS, FLOORS, FOUNDATION WALLS,
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LOAD PATH MAY BE OTHER SHEAR WALLS, FLOORS, FOUNDATION WALLS,
SLABS OR FOOTINGS.
• SHEAR WALLS ALSO PROVIDE LATERAL STIFFNESS TO PREVENT THE ROOF OR
FLOOR ABOVE FROM EXCESSIVE SIDE-SWAY. WHEN SHEAR WALLS ARE STIFF
ENOUGH, THEY WILL PREVENT FLOOR AND ROOF FRAMING MEMBERS FROM
MOVING OFF THEIR SUPPORTS. ALSO, BUILDINGS THAT ARE SUFFICIENTLY STIFF
WILL USUALLY SUFFER LESS NONSTRUCTURAL DAMAGE.
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HOW SHEAR WALLS PROVIDE
STIFFNESS?
THE STIFFNESS OF THE SHEAR WALL, JUST LIKE ITS
STRENGTH, DEPENDS ON THE COMBINED STIFFNESS OF ITS
THREE COMPONENTS: LUMBER, SHEATHING AND FASTENERS.
 THE SIZE AND GRADE OF END STUD(S), THICKNESS AND
GRADE OF SHEATHING, AND THE SHEATHING FASTENER
DIAMETER DETERMINE HOW FLEXIBLE
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A WOOD SHEAR WALL WILL BE. WHEN PRESENT, HOLDOWN
DEVICES ALSO CONTRIBUTE TO THE OVERALL STIFFNESS OF
THE SHEAR WALL. IF HOLDOWN DEVICES STRETCH OR SLIP,
THE TOP OF
THE SHEAR WALL WILL MOVE HORIZONTALLY. THIS
HORIZONTAL MOVEMENT ADDS TO THE MOVEMENT ALLOWED
BY THE LUMBER, SHEATHING AND FASTENERS.
 ANY ADDITI ONAL MOVEMENT FROM THE HOLDOWN WILL
REDUCE THE EFFECTIVE STIFFNESS OF THE SHEAR WALL. 10

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TYPES
REINFORCED CONCRETE SHEAR WALL
• CONCRETE BLOCK SHEAR WALL
• STEEL SHEAR WALL
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• STEEL SHEAR WALL
• PLYWOOD SHEAR WALL
• MID-PLY SHEAR WALL
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• REINFORCED CONCRETE SHEAR WALLS ARE WIDELY USED
SHEAR WALLS FOR RESIDENTIAL BUILDINGS.
• THE REINFORCEMENT IS PROVIDED IN BOTH HORIZONTAL AND
VERTICAL DIRECTIONS. BUT AT THE END OF EACH WALL, BARS
ARE CLOSELY SPACED AND ANCHORED. SO, THE END ZONES OF
RC SHEAR WALL IS CALLED AS BOUNDARY ELEMENTS OR
BARBELLS.
1.REINFORCED CONCRETE SHEAR WALL
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BARBELLS.
• THE WALL THICKNESS OF RC SHEAR WALL IS VARIED
DEPENDING UPON MANY FACTORS LIKE THERMAL INSULATION
REQUIREMENTS OF BUILDING, AGE OF BUILDING, NUMBER OF
FLOORS OF BUILDING ETC. IT VARIES FROM 150 MM TO 500 MM.
IN GENERAL, THE PROVISION OF SHEAR WALL IS CONTINUOUS
THROUGHOUT THE HEIGHT OF BUILDING. BUT SOMETIMES IT IS
DISCONTINUED WHERE THERE IS A BUILDING ENTRANCE OR
PARKING SPACE ETC.

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CONCRETE BLOCK SHEAR WALLS ARE CONSTRUCTED USING
HOLLOW CONCRETE BLOCKS ALONG WITH STEEL REINFORCEMENT
BARS. REINFORCEMENT IS GENERALLY USED TO MAXIMIZE THE
EFFECT OF CONCRETE BLOCK MASONRY AGAINST SEISMIC LOADS.
• THE REINFORCEMENT BARS ARE ARRANGED THROUGH SPACES OF
CONCRETE BLOCKS IN BOTH VERTICAL AND HORIZONTAL
2. CONCRETE BLOCK SHEAR WALL
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CONCRETE BLOCKS IN BOTH VERTICAL AND HORIZONTAL
DIRECTIONS. AFTER PLACING BARS IN CONCRETE BLOCK MASONRY,
FRESH CONCRETE GROUT IS POURED INTO THE HOLLOW SPACE AND
IS ALLOWED TO SET.
• THIS TYPE OF WALLS CAN TAKE BOTH GRAVITY LOADS AND
LATERAL LOADS. SO, THEY CAN WORK LIKE SHEAR WALL AS WELL
AS LOAD BEARING WALL.

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3. STEEL SHEAR WALL
•STEEL SHEAR WALL CONSISTS OF A STEEL PLATE WALL,
BOUNDARY COLUMN AND HORIZONTAL FLOOR BEAM. THE
ACTION OF STEEL SHEAR WALL IS MORE LIKE A PLATE
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ACTION OF STEEL SHEAR WALL IS MORE LIKE A PLATE
GIRDER.
•STEEL PLATE WALL ACTS AS WEB OF PLATE GIRDER,
BOUNDARY COLUMNS ACTS AS FLANGES AND
HORIZONTAL BEAMS ACTS AS STIFFENERS OF PLATE
GIRDER.

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4. PLYWOOD SHEAR
WALL
• PLYWOOD SHEAR WALLS ARE TRADITIONAL TYPE WALLS
WHICH ARE ALSO CALLED AS TIMBER SHEAR WALLS. IT
CONSISTS OF PLYWOOD SHEETS AND STUDS.
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CONSISTS OF PLYWOOD SHEETS AND STUDS.
•PLYWOOD SHEETS TRANSFER SHEAR FORCE WHILE STUDS
RESISTS THE TENSION OR COMPRESSION.
• NOW A DAYS PLYWOOD SHEAR WALLS ARE REDESIGNED
USING NEW TECHNICAL ADVANCEMENTS. STEEL SHEETS,
SURE BOARDS ETC. ARE USING IN PLACE OF PLYWOOD.

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• MID-PLY SHEAR WALL IS AN IMPROVED VERSION OF
NORMAL PLYWOOD SHEAR WALL. IN THIS CASE, EXTRA
PLYWOOD SHEET IS ARRANGED AT THE CENTER OF
NORMAL PLYWOOD WALL AND SERIES OF PAIRS OF STUDS
ARE POSITIONED ON
THE BOTH SIDES OF MID-PLY.
5. MID-PLY SHEAR WALL
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• STUDS JOINT THE MID-PLY WITH OUTER PLYWOOD
SHEETS. HERE, STUDS ARE ROTATED TO 90O RELATIVE TO
THOSE IS PLYWOOD SHEAR WALLS.
• THE MID-PLY SHEAR WALL ELIMINATES THE PROBLEMS
CAUSED IN STANDARD SHEAR WALLS AND LATERAL LOAD
CARRYING CAPACITY IS HIGHER FOR MID-PLY SHEAR
WALLS

17. Click to edit Master title style•EFFICIENCY OF A SHEAR WALL IS PURELY DEPENDS UPON ITS RIGIDITY OR ITS
STIFFNESS.
•A SOLID SHEAR WALL IS MORE EFFICIENT THAN A SHEAR WALL WITH OPENINGS.
BUT SOMETIMES IT IS NOT POSSIBLE TO CONSTRUCT A SHEAR WALL WITHOUT
OPENINGS SUCH AS OPENINGS FOR DOORS, WINDOWS ETC.
•IN CASE OF OPENINGS TO IMPROVE THE EFFICIENCY OF SHEAR WALL, CONNECT THE
PIERS OF SHEAR WALLS BY SPANDRELS.
EFFICIENCY OF SHEAR WALLS
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PIERS OF SHEAR WALLS BY SPANDRELS.
• PIER IS NOTHING BUT THE PORTION OF SHEAR WALL BETWEEN TWO OPENINGS
AND SPANDREL IS THE PORTION OF SHEAR WALL ABOVE THE OPENING. THE
RESULTING WALL APPEARED BY INTERCONNECTING SPANDRELS OF PIERS OF SHEAR
WALLS IS KNOWN AS COUPLED SHEAR WALL. PROVISION OF OPENINGS IN
BALANCED PATTERN CAN ALSO MAKE THE SHEAR WALL EFFICIENT.
IN FLANGED SHEAR WALLS, THE WALLS WILL MEET AT RIGHT ANGLES TO EACH
OTHER. THIS TYPE OF SHEAR WALLS ARE LESS EFFICIENT SINCE THEY ARE EFFECTED
BY SEISMIC FORCES IN BOTH PRINCIPAL DIRECTIONS OF THE BUILDING.

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19. Click to edit Master title styleFACTORS GOVERNING SEISMIC BEHAVIOUR
• DUCTILITY – RATIO OF DISPLACEMENT AT MAXIMUM LOAD TO
THAT AT YEILD.
• STIFFNESS – PROPERTY OF ELEMENT TO RESIST
DISPLACEMENT
• SOIL STRUCTURE INTERACTION EFFECTS – STRUCTURAL
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• SOIL STRUCTURE INTERACTION EFFECTS – STRUCTURAL
DAMAGE DIRECTLY RELATED TO DEPTH OF SOIL OVERLYING
THE ROCK AND PERIOD OF VIBRATION OF SOIL
• PERIOD OF STRUCTURE –IMPORTANT INDEX THAT IDENTIFIES
VULNERABILITY OF EXCESSIVE DRIFT

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ADVANTAGES
1) TIDIER AND MORE WORKMANLIKE
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2) SPEED IN ERECTING AND DISMANTLING FORMS

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3) GOOD APPEARANCE
4) GREATER CONTROL OF ACCURACY AND WORKMANSHIP
5) NO PROTRUDED COLUMNS AND BEAM FOR HIGH-RISE
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6) THE STRAIGHTNESS OF RC WALL

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7) EARTHQUAKE RESISTANCE
8) SOUND REDUCING
9) COST SAVING.
10) PROVIDE A POTENTIALLY HIGH-DUCTILE SYSTEM WITH A GOOD DEGREE OF
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10) PROVIDE A POTENTIALLY HIGH-DUCTILE SYSTEM WITH A GOOD DEGREE OF
REDUNDANCY, WHICH CAN ALLOW FREEDOM IN ARCHITECTURAL PLANNING OF
INTERNAL SPACES AND EXTERNAL CLADDING.
11) THEIR FLEXIBILITY AND ASSOCIATED LONG PERIOD MAY SERVE TO DETUNE
THE STRUCTURE FROM THE FORCING MOTIONS ON STIFF SOIL OR ROCK SITES.
12) SIGNIFICANTLY REDUCES LATERAL SWAY
13)EASY CONSTRUCTION AND IMPLEMENTATION.

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DISADVANTAGES
- POORLY DESIGNED, MOMENT RESISTING FRAMES HAVE BEEN OBSERVED TO
FAIL CATASTROPHICALLY IN EARTHQUAKES, MAINLY BY FORMATION OF WEAK
STORIES AND FAILURES AROUND BEAM-COLUMN JOINTS.
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- BEAM COLUMN JOINTS REPRESENT AN AREA OF HIGH STRESS CONCENTRATION,
WHICH NEEDS CONSIDERABLE SKILL TO DESIGN SUCCESSFULLY.
- REQUIRES GOOD FIXING SKILLS AND CONCRETING.

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