Title: EARTH RETAINING STRUCTURES INSITU RETAINING WALLS
1EARTH RETAINING STRUCTURES (IN-SITU RETAINING
WALLS)
1- CANTILEVER 2- ANCHORED 3- MULTILEVEL ANCHORED
(STRUTTED)
LIMIT EQUILIBRIUM ANALYSIS IS VALID FOR
CANTILEVER OR ANCHORED (1 LEVEL ONLY) IN-SITU
WALLS. IN OTHER WORDS ACTIVE AND PASSIVE
PRESSURES CALCULATED BY RANKINE THEORY MAY BE
USED FOR THE DETERMINATION OF WALL SHEAR, BENDING
MOMENT AND ANCHOR(PROP) FORCE (IN CASE OF
ANCHORED WALLS). FOR MULTILEVEL ANCHORED
(STRUTTED) WALLS THE WALL SHEAR AND BENDING
MOMENTS MAY BE CALCULATED FROM LIMIT EQUILIBRIUM
ANALYSIS BUT THE ANCHOR(PROP) FORCES SHOULD
STRICTLY BE CALCULATED BY APPARENT EARTH PRESSURE
DIAGRAMS.
2APPARENT EARTH PRESSURE DIAGRAMS
3CALCULATION OF STRUT LOADS
4BRACED CUTS
Braced cuts (braced excavations) are generally
used to support the sides of excavations. Sheet
piling, berlin walls, or timber sheeting may be
used the support the sides of braced excavations.
Narrow excavations are supported by horizontal
struts, where raking (inclined) sturts atteched
to blocks are used for wide excavations. Two
major stability problems may occur in braced
cuts 1- Bottom heave in soft clays 2- Piping in
pervious soils
5ANALYSIS of BOTTOM HEAVE
6IN-SITU WALL TYPES
1- CANTILEVER
7IN-SITU WALL TYPES
2- ANCHORED
8IN-SITU WALL TYPES
3- MULTI-PROPPED
9SHEET PILE WALLS
10PILED WALLS
1- CONTIGUOUS PILE WALLS THERE IS SPACING
BETWEEN PILES (USUALLY APPLIED WHEN THERE IS NO
GROUNDWATER) 2- TANGENT PILE WALLS PILES ARE
TANGENT TO EACH OTHER, APPLIED WHEN THERE IS
WATER 3- SECANT PILE WALLS APPLIED FOR
EXCAVATIONS UNDER GROUNDWATER TABLE, THEY CONSIST
OF PRIMARY AND SECONDARY PILES. PRIMARY PILES ARE
CONSTRUCTED FIRST WITHOUT REINFORCEMENT. THEN
SECONDARY PILES ARE CONSTRUCTED BY CUTTING SOME
PART OF THE PRIMARY PILES (8-15cm). SECONDARY
PILES ARE CONSTRUCTED WITH REINFORCEMENT
11PILED WALLS (Contiguous pile wall)
12PILED WALLS (Tangent pile wall)
13PILED WALLS (Secant pile wall)
14BE CAREFUL DURING DESIGN
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