针对某地铁车站开挖引起地表沉降较大的问题,基于车站开挖引起地表沉降的实测数据,利用随机介质理论方法反演地铁车站初步开挖引起的地表移动参数,包括沉降槽影响范围以及断面收缩率,并利用所得的参数对该车站下一步开挖进行地表沉降预测;通过类似地层条件的地表沉降实测数据,利用数值模拟正交反分析法确定主要模型参数,预测了该地铁车站各施工阶段引起的地表沉降值。并结合洞内特征点的收敛发展规律,将地表沉降理论预测结果与数值模拟结果进行对比。结果表明:由于2种预测方法的不同导致最终的地表沉降值存在差异.但主要开挖阶段引起的地表沉降基本一致;主要的差异来源于数值模拟方法考虑了更为具体的衬砌施工工序,导致开挖过程中洞内收敛特征与理论预测方法明显不同。
In this paper, the parameters of surface movement and settlement prediction were calculated by using of optimization algorithms according to the problem of comparatively large surface subsidence of a Qingdao metro line -3 subway station excavation. According to the station surface subsidence measured data,, and further excava- tion subsidence prediction has been done using the resulting surface parameters, based on stochastic medium theory inverse analysis parameters of surface movement of the impact scope of the settlement trough and section shrinkage By the results of four sections of surface subsidence was calculated to obtain the mean surface movement parameters of the station layer conditions and predict the final settlement value after the completion of all excavation. The actual site construction works would be guided using surface subsidence prediction methods.