考虑流变特性的软土长时位移分析方法及其应用

Analysis of Displacement of Soft Soil and Its Application Considering the Rheological Property

建立了一种以有限元法瞬态力学状态模型与土体位移时效系数相结合的经验型软土长时位移计算方法,通过有限元数值方法模拟工程施工过程而得到软土的瞬时位移,并采用位移时效系数对软土的扰动位移进行时效性分析,将其瞬时位移转化为考虑流变特性的长时位移.其中,位移时效系数的确定结合了软土的流变试验和现场工程的最不稳定时间,反映了软土的流变状态.同时,以宁波市东环南路地铁站基坑工程为例进行了位移时效性分析,以验证所建方法的有效性.结果表明,计算所得软土的长时位移值与现场的监测结果较吻合.

Based on transient finite element method （FEM） and displacement aging coefficient, a method was proposed to obtain the influence of the rheological properties of soft soil on engineering construction. The transient soil displacement was simulated using the FEM simulation method. According to analysis of soft soil from displacement timeliness, its transient displacement could be changed into long-time displace- ment with rheology. And the displacement aging coefficient was calculated from triaxial rheological test of soft soil and the most negative time in the site. So this coefficient can reflect the rheological unstable condi- tion of soft soil. A case of excavation simulation of the South East Outer Ring Road Station in Ningbo was conducted using this method. The calculated displacement result of soft soil agrees well with the on-site monitoring result