基于载荷试验的群桩沉降计算方法

Calculation method of pile group settlement based on static load test

桩基按现行《建筑地基基础设计规范》(GB50007—2002)计算的沉降量与实测值相差很大,主要是深层土的压缩模量定值由于土的扰动等原因造成实验室与现场实际相差很大。根据试桩数据,分析得出接近于真实的桩底土压缩模量,用此值作为计算依据能较准确预测建筑物沉降量。当计算群桩某点的沉降量时,若每个桩对该点的水平距离已知,根据规范就可算得该点桩底以下中垂线各点土的附加压应力。当计算点离桩距离较远时,距离计算点相近的多个桩,可用多个桩平均距离计算。按文中计算方法得到的沉降计算值与工程实测所得的沉降量符合很好。

There is a large difference between the code calculating settlement and the actual one because the compression modulus is not true due to the soil disturbance. Based on the pile test data, it can come closer to the real soil modulus, and this value can be used to forecast more accurate building settlement. When calculating the settlement of a point among the piles, if the distance of each pile to the calculating point is known, the vertical additional soil stress under the calculating pile can be got. The average distance can be used when the piles are far from the calculating point. The calculating results accord well with the test data.