DEFINITION:
PILE WALL IS A RETAINING WALL, EITHER DESIGNED AS CANTILEVER WALL OR ANCHORED WALL. PILEWALL IS USUALLY MADE OF CAST-IN-PLACE
BORED PILES WITH DIAMETER, LENGTH AND REINFORCEMENT ADEQUATE TO THE HEIGHT OF THE RETAINED SOIL AND THE LATERAL FORCES ACTING
ON THE PILE WALL.
PILEWALLS CAN BE MADE OF CONTIGUOUS PILES, TANGENT PIL ES, SECANT
PILES, OR SIMPLY ALIGNED PILES WITH GAPS BETWEEN THE PILES FORMING THE PILEWALL.
PILES
CAN BE PLACED ON A SINGLE LINE, OR ON TWO OR MORE PARALLEL LINES, DEPENDING UPON SOIL CONDITIONS AND DESIGN REQUIREMENTS.
SOIL ANCHORS, GENERALLY POST-TENSIONED, ARE APPLIED AT ONE OR MORE LEVEL OF THE PILEWALL, IF DESIGN
LOADING CONDITIONS CALL FOR IT.
ANCHORS APPLIED TO PILE WALLS CAN BE OF THE FRICTION
TYPE, DRILLED, INSERTED INTO SUBSOIL, GROUTED AND POST-TENSIONED, WITH THE "ACTIVE" LENGTH OF THE ANCHORS DESIGNED
TO BE BEYOND THE POTENTIAL SLIPPAGE AREA OF THE SOIL FORMATIONS RETAINED BY THE PILE WALL, OR CAN BE ANCHORED TO DEAD-MEN
PLACED AT A DISTANCE FROM THE PILEWALL SUFFICIENT TO MAINTAIN THEM OUTSIDE THE AREA OF POTENTIAL SOIL SLIPPAGE.
PILES FORMING THE PILE WALL CAN HAVE DIAMETERS RANGING FROM 300mm [ 0.3M ] TO 2500mm [ 2.5M ]
AND ABOVE, DEPENDING UPON THE HEIGHT OF THE RETAINED SOIL, THE SOIL TYPE, THE PRESENCE OF WATER TABLE AND THE SEISMIC CONDITIONS
OF THE GEOGRAPHICAL LOCATION OF PILEWALL.
FOR PROPER AND ECONOMICAL DESIGN OF PILE WALLS
AND GENERALLY OF ANY RETAINING WALL, IT IS VERY IMPORTANT TO OBTAIN COMPLETE INFORMATION ON ALL PREVAILING SITE CONDITIONS
THAT WILL AFFECT THE PILEWALL DURING ITS SHORT TERM CONDITIONS [CONSTRUCTION PERIOD] AND DURING LONG TERM CONDITIONS [SERVICE
CONDITIONS].
PILE WALL IS GENERALLY EXECUTED AS A TOP-DOWN TYPE OF CONSTRUCTION, BY
INSTALLING THE PILES AHEAD OF GENERAL EXCAVATION, IN THIS WAY THE PILES THAT WILL EVENTUALLY FORM THE PILEWALL ARE INSTALLED
ON UNDISTURBED SOIL, AND THE EXCAVATION ON ONE SIDE OF THE PILE WALL WILL PROCEED IN STAGES, DESIGNED TO KEEP THE SYSTEM RETAINED
SOIL-PILE-WALL IN EQUILIBRIUM.
