INDUCED PORE PRESSURES DURING PILE-DRIVING OPERATIONS

Abstract

A THEORY FOR ESTIMATING THE MAXIMUM PORE PRESSURES INDUCED BY PILE DRIVING IS PRESENTED. THEORETICAL RESULTS ARE COMPARED WITH MEASUREMENTS CARRIED OUT AT THREE SITES, AND SOME PUBLISHED DATA. THE MAXIMUM PORE PRESSURES MAY BE ESTIMATED WITH REASONABLE ACCURACY BY THE METHOD PROPOSED. ITS MAGNITUDE DEPENDS ON STRESS HISTORY AND PORE-PRESSURE CHARACTERISTICS OF THE CLAY, BUT IS INDEPENDENT OF PILE DIMENSIONS. WITHIN A RADIAL FAILURE ZONE OF THE SOIL SURROUNDING THE PILE, THE PORE PRESSURES ARE CONSTANT; OUTSIDE THIS ZONE THEY DECREASE RAPIDLY WITH DISTANCE FROM THE PILE. THE PORE PRESSURE GENERALLY INCREASES WITH DEPTH RESULTING FROM INCREASE IN EFFECTIVE OVERBURDEN STRESS. THERE IS NO DIRECT SUMMATION OF PORE PRESSURES WITHIN THE FAILURE ZONE OF A PILE OWING TO THE DRIVING OF ADJACENT PILES. /A/LCPC/RRL/