考虑蠕变效应的高速铁路桥梁桩基工后沉降计算

Method of Post-construction Settlement Calculation for High-speed Railway Bridge Pile Foundation in Consideration of Creep Effect

使用Mesri蠕变模型建立了考虑蠕变效应的高速铁路桥梁桩基工后沉降计算方法,利用实测工后沉降,使用非线性最小二乘方法建立目标函数,反分析得到桩底持力层Mesri蠕变模型参数。将反分析得到的计算模型用于估算高速铁路桥梁桩基工后长期沉降,估算沉降较好地反映了高速铁路桥梁桩基工后沉降的发展趋势,对高速铁路的安全运营有一定的指导意义。另外,根据桩底土层的监测数据可知,传统计算方法确定的土层压缩厚度远小于实测压缩层厚度,根据传统方法确定的压缩层厚度计算得到的高速铁路桥梁桩基工后沉降会小于实测工后沉降。

The Mesri creep model is used to develop the method of calculating the post-construction settlement of high-speed railway bridge pile foundation in consideration of creep effect. Using the post-construction settlement data of high-speed railway bridge pile foundation, the nonlinear least square method is applied to invert Mesri Creep model parameters of bearing layer. Then the above model is used to compute long-term construction settlement of high-speed railway bridge pile foundation, and it shows that computing result can preferably reflect the post-construction settlement development tendency of highspeed railway bridge pile foundation, which shows that this method is meaningful for safe operation of high-speed railway. In addition, based on monitoring data of soil compressed layer under the pile bottom, it is known that soil compressed layer thickness computed by traditional methods is far less than that measured, so the post-construction settlement computed by soil compressed layer thickness computed by traditional methods is less than that measured.