Simplified method for nonlinear settlement calculation in soft soils considering lateral deformation
YANG Guang-hua1, 2, 3, HUANG Zhi-xing2, LI Zi-yun2, JIANG Yan1, 3, LI De-ji1
1. Guangdong Research Institute of Water Resources and Hydropower, Guangzhou 510610, China; 2. School of Civil Engineering and Transportation, South China University of Technology, Guangzhou 510641, China; 3. Geotechnical Engineering Technology Center of Guangdong Province, Guangzhou 510610, China
Abstract：The common method for computing settlement of soft soils is the layer-wise summation method using compression modulus under the confined condition. But the lateral deformation makes a large part of the whole settlement. To eliminate the calculation error, the method in the national specifications or codes is that the results are multiplied by an empirical coefficient from 1.1 to 1.7. Since the empirical coefficient is not sure, a new method considering the lateral deformation is proposed. This method divides the settlement of soft soil into two parts. One is the settlement Sc caused by 1 D confined compression using the layer-wise summation and e-p curve to compute, the other is the settlement Sd caused by lateral deformation using the same way but the parameter is secant modulus Ep from the e-p curve and Duncan-Chang model. So the e-p curve is the core for computing the settlement. In practical engineering, the initial void ratio e0 and compression modulus Es1-2 are frequently used and can reflect the characteristics of the soils well. The two parameters are combined with compression index Cc, thus we can use e-lgp curve to get the compression modulus Esi under different stress states. Since Esi, Sc, Sd are easy to get, it brings a big convenience to engineering computation. Finally, the applicability of the proposed method is validated through an engineering case.
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