FIELD ADAPTATION AND EVALUATION OF PROTOTYPE OF IN SITU GEOTECHNICAL TORSIONAL CYLINDRICAL SHEAR TESTING SYSTEM FOR EARTHQUAKE RESISTANT DESIGN

Period of Performance: 01/01/1993 - 12/31/1993

$50K

Phase 1 SBIR

Recipient Firm

Dynamic In Situ Geotechnical
7 Wyndam Ct
Lutherville, MD 21093
Principal Investigator

Abstract

THE RESEARCH IS TO ADVANCE THE ABILITY TO EFFECTIVELY ENGINEER CRITICAL CONSTRUCTED FACILITIES TO RESIST EARTHQUAKES IN ORDER TO REDUCE LOSSES AND ENVIRONMENTAL DAMAGE. A FIELD ADAPTATION AND EVALUATION OF A PROTOTYPE IN SITU GEOTECHNICAL TESTING SYSTEM IS TO BE CARRIED OUT. THE SYSTEM IS TO PROVIDE ESTIMATES FOR SOIL DEPOSITS OF THE IN SITU CYCLIC SHEAR STRESS VS. STRAIN CHARACTERISTICS NEEDED BY DYNAMIC EARTHQUAKE ANALYSES (LIQUEFACTION, CYCLIC DEGRADATION AND DEFORMATION, AND UNDERGRADED NON-LINEAR INELASTIC CHARACTERISTICS). THE PROJECT ADDRESSES THE CONCERN OF RELIABLY PREDICTING AMPLIFIED MOTIONS, LIQUEFACTION, AND DEFORMATIONS OF SOIL DEPOSITS. FUNDAMENTAL IMPROVEMENTS IN ESTIMATING SOIL CHARACTERISTICS ARE STILL GREATLY NEEDED. EXISTING PROCEDURES CAN SEVERELY LIMIT POTENTIALLY POWERFUL ANALYSES LEADING TO EITHER UNCONSERVATIVE OR COSTLY, EXCESSIVELY CONSERVATIVE DESIGNS. THE PROCEDURE IS TO COMBINE ATTRACTIVE FEATURES OF EXISTING PROCEDURES. EARTHQUAKE-LIKE CYCLIC LOADS ARE TO BE APPLIED. TESTS, HOWEVER, ARE TO BE CONDUCTED IN SITU WITH MANY STEPS TO PRESERVE IN SITU CONDITIONS. AN ECONOMIC FEASIBILITY STUDY IS PLANNED.