Coefficient Analysis of Soft Soil Consolidation Based on Measurement of Stratified Settlement

Abstract

The coefficient of consolidation is an important parameter for calculating and predicting the consolidation settlement of soft soil. In this study, a back analysis method for the coefficient of consolidation is established based on field monitoring results of stratified settlement; the method can calculate both the coefficients of vertical consolidation, cv, and horizontal consolidation, ch, of soft soil at different moments. This new method overcomes the problems of traditional methods, which can calculate only one coefficient at a time. The use of the proposed method to determine cv and ch for the drainage consolidation of a thick layer of soft soil can compensate for the drawbacks of laboratory testing, which include insufficient consideration of the environmental factors affecting field consolidation, the distortion of experimental results with changes in these factors, and the inability to reasonably determine ch for soil layers. The new method is theoretically rigorous and reasonable as well as practically feasible in engineering. It is reasonable to use the coefficients of consolidation, back-calculated from the settlement observation data of earlier loading levels (not including the first level of loading), as parameters for consolidation prediction in later stages. In preloading drainage consolidation fields of soft soil, which are structurally strong and where obtaining suitable soil samples is difficult, it is necessary to set a certain number of stratified settlement observation points and use the back analysis of the field monitoring results of stratified settlement to determine the coefficient of soft soil consolidation.