LATERAL LOAD BEHAVIOR OF DRILLED SHAFTS

Abstract

DRILLED SHAFT FOUNDATIONS, USED EXTENSIVELY TO SUPPORT HIGHWAY STRUCTURES, ARE OFTEN SUBJECTED TO BOTH AXIAL AND LATERAL LOADS. TO OBTAIN A SAFE AND ECONOMICAL DESIGN, THE RESPONSE OF THE SOIL TO THE APPLIED LOADS MUST BE KNOWN. IN THIS STUDY, CURRENTLY AVAILABLE CRITERIA FOR PREDICTING THE RESPONSE OF SAFT CLAYS AND SANDS TO LATERAL LOADS ARE SUMMARIZED AND NEW CRITERIA ARE DEVELOPED FOR THE LATERAL LOAD RESPONSE OF STIFF CLAYS. A FULL-SCALE INSTRUMENTED SHAFT WAS SUBJECTED TO REPEATED APPLICATIONS OF LATERAL LOADS AND THE SOIL RESPONSE WAS OBSERVED. UNDISTURBED SAMPLES OF THE SOIL AT THE TEST SITE WERE SUBJECTED TO REPETITIVE LOADING IN LABORATORY TRIAXIAL COMPRESSION TESTS. THE RESULTS OF THE FIELD TEST AND THE LABORATORY TESTS WERE CORRELATED AND A PROCEDURE FOR PREDICTING THE RESPONE OF A STILL CLAY TO SHORT-TERM STATIC LOADING OR REPEATED LOADING WAS DEVELOPED.