基坑变形时间效应的有限元分析

根据基坑变形监测结果,采用以软土流变粘弹塑性模型(SSC模型)为基础的P laxis有限元软件,建立了考虑施工过程的基坑工程计算模型,在反分析获取SSC模型参数的基础上,开展了模型参数验证和基坑变形规律的研究。计算结果与实测数据间良好的一致性表明:反分析得到的模型参数使得计算结果更趋合理;SSC模型能较好地反映软土中基坑变形随时间变化的流变特性,为信息化施工的实施提供了有效途径。

FEM analysis on time-effects of deep excavations

Two deformation monitoring cases were carried out throughout the excavation with different wall and support system. The one was used for back analysis to determine soil parameters by the FEM code PLAXIS with Soft Soil-Creep model (SSC model), which considered the construction processes of excavation, and the soil parameters were obtained by other case. A good agreement between the measured and predicted deformations shows that the soil parameters determined by back analysis make the result more reasonable, and the SSC model is good for analysis of the time-dependent properties of deformation in excavation.