SIMULATED GROUND RESPONSE USING NON-LINEAR ELASTIC MODULI

THE PROPOSED RESEARCH IS RELATED TO A LONG STANDING NEED FOR THE KNOWLEDGE OF MODULI VALUES OF EARTH MATERIALS AS THEY EXIST AT LARGE STRAIN LEVELS SUCH AS DURING EARTHQUAKE LOADINGS. THE DETERMINATIONS OF SUCH MODULI AT LOW STRAIN LEVELS ARE THE OBJECTIVES OF NUMEROUS WESTON GEOPHYSICAL PROJECTS BY THE DESIGNATED PRINCIPAL INVESTIGATOR FOR MANY YEARS; IN ADDITION, AND ON NUMEROUS OCCURRENCE, SUCH LOW STRAIN DATA WERE COMPARED TO STATICALLY DETERMINED MODULI VALUES. ATTEMPTS TO RECONCILE DIFFERENCES BETWEEN LOW LEVEL AND HIGH LEVEL DATA HAVE GENERALLY LED TO ONLY "RULE-OF-THUMB" RELATIONSHIP WHOSE RELIABILITY IS UNCERTAN. THE NEED FOR RESEARCH AND DEVELOPMENT OF SUCH A RELATIONSHIP, BETWEEN LOW STRAIN LEVEL MODULI AND HIGH STRAIN LEVEL MODULI IS THEREFORE APPARENT IN ORDER TO CORRECTLY PREDICT THE EFFECTS OF EARTHQUAKES ON MAN MADE STRUCTURES, SUCH AS TALL BUILDINGS, SILOS OF VARIOUS TYPES, AND OTHR ABOVE-GROUND AND IN-GROUND FACILITIES OF A CRITICAL NATURE WHOSE FUNCTION MUST BE ASSURED DURING EVENTS OF STRONG SHAKING. THE WORK EFFORTS OF THIS PHASE I RESEARCH PROPOSAL WILL THEREFORE CONSTITUTE THE INITIAL TASKS LEADING TO THE DEVELOPMENT OF SUCH A RELATIONSHIP FOR MODULI VALUES AT THE DIFFERENT STRAIN LEVELS.