深圳地区花岗岩残积土的沉降计算及现场测试分析

Settlement Calculation of Granite Residual Soil and Site Test Analysis in Shenzhen Area

结合工程实例,探讨采用堆载预压进行大面积软基处理时,淤泥层下卧花岗岩残积土层固结沉降计算方法。指出室内试验得到的花岗岩残积土压缩指标是失真的,其压缩模量偏小,压缩系数偏大,计算得到的沉降量过大,其原因在于试验方法的局限性。计算分析和现场观测表明:根据原位标准贯入试验所得指标计算花岗岩残积土的沉降量更符合实际。

According to the existing engineering project, the calculation method for analyzing the consolidation and settlement of the granite residual soil under soft clay is discussed with preload method applied to improve soft soil. It is pointed out that the granite residual compression index taken from laboratory test is distorted, the compression modulus on the low side, the compression coefficient on the high side and the calculated settlement are greater than measurement. The reason why that is the test method is limited. The calculation and field observation show that it is feasible to use compression coefficient corrected with the result of in-situ standard penetration test to calculate the settlement of granite residual soil.