考虑蠕变性状的港区软土地基参数反演和长期沉降预测

Back analysis of parameters and long-term settlement prediction of harbor soft ground considering its creep behavior

结合上海某集装箱码头建设项目,针对本工程深厚淤泥质黏土的场地条件,引入Mesri蠕变模型考虑堆场地基的长期蠕变变形。利用施工期和工后短期实测分层沉降资料,由最小二乘法建立目标函数,运用分层迭代反演方法反演得到各软土层的黏弹性参数;将反演得到的土层参数代入自行编制的沉降计算软件,计算得到地基沉降量,并将计算值与实测值进行对比,对比结果证明了参数反演的可靠性;利用反演得到的土层参数对工后的长期沉降进行了预测,为本工程的安全运营提供了指导。

Based on a harbor construction project in Shanghai, the Mesri creep model is introduced to depict the creep deformation behavior of the soft ground. The viscoelastic parameters of Mesri model are determined by back analysis of field monitoring data. The objective function is established by least square method, and the variables are optimized. Taking into account the layered property of soft ground, iterative back analysis layer by layer method is used. Back analyzed parameters are substituted into the self-programmed software to calculate the settlement. The comparison between calculated result and measured result confirms the reliability of back analysis. At last, the long-term ground settlement after construction is predicted on the basis of the results of back analysis.