LIMITATIONS OF CONVENTIONAL ANALYSIS OF CONSOLIDATION SETTLEMENT

Consolidation settlements are often large and potentially damaging to structures. Estimating their magnitudes, and the rates at which they will occur, plays an important part in many civil engineering projects. At Bay Farm Island in San Francisco Bay, and Kansai International Airport in Japan, settlement magnitudes and settlement rates were of great importance for design. In these and similar cases it is important to understand what factors control the accuracy with which settlement magnitudes and settlement rates can be estimated. Accurate predictions of settlement magnitudes require accurate evaluations of clay compressibility and preconsolidation pressure. Accurate prediction, of settlement rates require improved methods of anticipating whether embedded sand strata will or will not provide internal drainage: use of computer analyses to take into account important factors such as variations in c(v) within clay layers, nonlinear stress-strain behavior, and nonuniform strain profile effects; and research to develop an improved model of clay compressibility that includes the effects of strain rate.