DIAPHRAGM WALL CONSTRUCTION

1. DIAPHRAGM WALL
CONSTRUCTION
BY:
170020053-M.ANIL KUMAR
DEPT:-CIVIL ENGINEERING

2. DIAPHRAGM WALL:-
• DIAPHRAGM WALL IS A CONTINEOUS WALL CONSTRUCTED
IN GROUND IN TO FACILIATE CERTAIN COSTRUCTION
ACTIVITES,SUCH AS:
A) AS A RETAINING WALL
B) AS A CUT-OFF PROVISION TO SUPPORT DEEP EXCAVATION
C) AS A SEPARATING STRUCTURE BETWEEN MAJOR
UNDERGROUND
FACILITIES
D) AS A FORM OF FOUNDATION (BARRETTE PILE –
RECTANGULAR PILE)

3. DIAPHRAGM WALL:-
• DIAPHRAGM WALL IS A REINFORCED CONCRETE STRUCTURE
CONSTRUCTED IN-SITU PANEL BY PANEL. THE WALL IS USUALLY
DESIGNED TO REACH VERY GREAT DEPTH, SOMETIMES UP TO
50M, MECHANICAL EXCAVATING METHOD IS THUS EMPLOYED.
TYPICAL SEQUENCE OF WORK INCLUDES:
A) CONSTRUCT THE GUIDE WALL
B) EXCAVATION TO FORM THE DIAPHRAGM WALL TRENCH
C) SUPPORT THE TRENCH CUTTING USING BENTONITE SLURRY
D) INERT REINFORCEMENT AND PLACING OF CONCRETE TO
FORM THE
WALL PANEL

4. FURTHER EXPLANATION ON
THE WORK SEQUENCES:-
• FIRST WE HAVE TO BUILD THE
GUIDE WALL FOR THE
DIAPHRAGM WALL
• GUIDE WALL IS A PARALLEL
BEAMCONSTRUCT ALONG THE
SIDE OF THE WALL
• WHICH IS USED FOR
THEEXCAVATION FOR THE
DIAPHRAGM WALL TRENCHES

5. GUIDE WALL:-
• GUIDE WALLS ARE
CONSTRUCTED IN-SITU
TYPICALLY AS LIGHLY
REINFORCED CONCRET
E ELEMENTS. GUIDE
WALLS MAINTAIN THE
HORIZONTAL
ALLIGNMENT AND
WALL CONTINUITY OF
A DIAPHRAGM WALL
WHILE THE PROVIDE
SUPPORT FOR THE
UPPER SOILS DEPTH
DURING PANEL
EXCAVATION

6. TRENCH EXCAVATION
• IN NORMAL SOIL CONDITIONS
EXCAVATION IS DONE USING A
CLAM SHELL OR GRAB
SUSPENDED BY CABLES TO THE
CRANE
• THE GRAB CAN EASILY CUT
THROUGH SOFT GROUND
• IN CASE OF ENCOUNTERING
BOULDERS A GRAVITY
HAMMER(CHISEL) IS USED TO
BREAK THE ROCK AND TAKE THE
SPOIL OUT USING THE GRAB

7. EXCAVATION SUPPORT:-
• THE SIDES INSIDE THE TRENCH CUT CAN COLLAPSE EASILY
• BENTONITE SLURRY IS USED TO PROTECT THE SIDES OF THE SOIL
• BENTONITE IS A SPECIALLY SELECTED FINE CLAY,WHEN ADDED
TO WATER FORMA AN IMPREVIOUS CAKE LIKE SLURRYWITH
VERY LARGE VISCOSITY
• THE SLURRY WILL PRODUCE A GREAT
LATERAL PRESSURE SUFFICENT ENOUGH
TO RETAIN VERTICAL WALL

8. REINFORCEMENT:-
• REINFORCEMENT IS INSERTED IN
THE FORM OF A STEEL CAGE,BUT
MAY BE REQUIRED TO LAP A FEW
SECTIONS IN ORDER TO REACH THE
REQUIRED LENGTH

9. CONCRETING:-
PLACING OF CONCRETE IS DONE USING TREMIEPIPES
TO AVOID THE SEGREGATION OF CONCRETE
AS CONCRETE BEING POURED DOWN, BENTONITE
WILL BE DISPLACED DUE TO ITS LOWER DENSITY THAN
CONCRETE
BENTONITE IS THEN COLLECTED AND REUSED

10. PROCEDURE:-
• THE EXCAVATION IS CARRIED OUT USING A HEAVY SELF GUIDED
MECHANICAL GRAB SUSPENDED FROM A LARGE CRAWLER
CRANE
• THE DIAPHRAGM WALLS WERE EXCAVATED AND CONSTRUCTED
IN DISCRETE PANELS OF BETWEEN 2.8M AND 7.0M LENGTHS
• AS THE EXCAVATION PROCEEDS, SUPPORT FLUID WAS ADDED
INTO THE EXCAVATION TO MAINTAIN THE STABILITY OF THE
SURROUNDING GROUND AND TO PREVENT A COLLAPSE. THIS
FLUID IS CALLED “BENTONITE” OR “SLURRY”, WHICH IS A POSER
MADE OF A SPECIAL TYPE OF SOLUBLE CLAY AND IS MIXED AT
THE MIXING PLANT WITH POTABLE WATER
• WHEN THE EXCAVATION IS COMPLETED, THE REINFORCEMENT
CAGE WILL BE LOWERED AND THE CONCRETE PROCEDURE WILL
BEGIN

11. JOINING FOR THE DIAPHRAGM WALL
PANEL
• DIAPHRAGM WALL CANNOT BE CONSTRUCTED CONTINUALLY FOR
A VERY LONG SECTION DUE TO LIMITATION AND SIZE OF THE
MECHANICAL PLANT
• THE WALL IS USUALLY CONSTRUCTED IN ALTERNATIVE SECTION
• TWO STOP END TUBES WILL BE PLACED AT THE ENDS OF THE
EXCAVATED TRENCH BEFORE CONCRETING
• THE TUBES ARE WITHDRAWN AT THE SAME TIME OF CONCRETING
SO THAT A SEMI-CIRCULAR END SECTION IS FORMED
• WALL SECTIONS ARE FORMED ALTERNATIVELY LEAVING AN
INTERMEDIATE SECTION IN BETWEEN. THE IN-BETWEEN SECTIONS
ARE BUILT SIMILARLY AFTERWARD BUT WITHOUT THE END TUBE

12. • AT THE END A CONTINUAL DIAPHRAGM WALL IS
CONSTRUCTED WITH THE PANEL SECTIONS TIGHTLY
JOINED BY THE SEMI-CIRCULAR GROOVE

13. TYPES OF DIAPHRAGM WALLS:-
STRUCTURAL DIAPHRAGM WALLS: THEY ARE USED
AS RETAINING WALLS FOR THE PERIMETER WALLS
OF DEEP BASEMENTS AND UNDERGROUND
PARKING FACILITIES AND SUBWAYS
LOAD BEARING WALLS: THEY ARE USED IN PLACE OF
DRILLED PIERS IN FOUNDATION OF TALL BUILDINGS,
BRIDGE AND PIERS
CUTOFF WALLS: IN HYDRAULIC STRUCTURES DIAPHRAGM
WALLS ARE USED AS IMPERMEABLE CUTOFFS TO PREVENT
SEEPAGE BELOW EARTH DAMS AND WEIRS

14. EQUIPMENT USED FOR
CONSTRUCTION:-
• TERNCH CUTTR
• HYDRUALUIC GRAB
• REVERSE MUD CIRCULATION
RIG

15. CONSTRUCTION SEQUENCE:-
• CONSTRUCTION OF GUIDE WALL
• TRENCH EXCAVATION
• SLURRY CLEANING
• REINFORCEMENT CAGE LOWERING
• CONCRETING

16. SLURRY CLEANING:-
• DURING EXCAVATION PROCESS THE MUD OR SOIL WHICH IS
EXCAVATED OFTEN MIXES WITH THE BENTONITE SLURRY AND
AFFECTS ITS PH, VISCOSITY, DENSITY ETC.
• TO BRING ALL THESE PARAMETERS IN ACCEPTABLE LIMITS THE
BENTONITE SLURRY IS CONTINUOUSLY CIRCULATED THROUGH
BENTONITE PLANT WHICH CLEANS THE SLURRY AND RESTORES
ITS REQUIRED PROPERTIES
• THE SLURRY IS CLEANEDN USING THE MACHINE BY REVERSING
CIRCULATING MUD MACHINE

17. ADVANTAGES OF DIAPHRAGM WALL:-
• SUITABLE FOR UNSTABLE SOIL PROFILES BELOW WATER TABLE
• LIMITED CONSTRUCTION TIME
• WHERE DEEPER THAN NORMAL CANTILEVER SUPPORT MAY
NEEDED.
• DESIGNABLE TO CARRY VERTICAL LOADS
• CONSTRUCTION TIME OF BASEMENT CAN BE LOWER
• MINIMIZE THE SETTLEMENT OF ADJACENT BUILDING
• IT IS THE PERMANENT BASEMENT WALL
• IT IS USED AS A SUPPORTING WALL FOR DAMS
• AND STOPS THE SOIL CREEP

18. • DEEPEST
DIAPHRAG WALL
IN THE WORLD IS
CONSTRUCTED IN
CAIRO IT IS 250
METERS DEEP
AND 30 METERS
WIDE AND 87.3
METERS LONG

19. • LONGEST
DIAPHRAGM WALL IN
THE WORLD IS
CONSTRUCTED FOR
POLAVARAM ITS
LENGTH IS 1750
METERS LONG AND
DEPTH OF 30 METERS
AND WIDTH 1.5
METERS

20. ANIMATION VIDEO

21. VEDIO SHOWING CONSTRUCTION OF
DIAPHRAGM WALL:-

22. THANKING YOU