逐级改变有限元计算参数分析软土地基的稳定性

目的提出综合处理后的软土地基在分级加载作用下逐级改变有限元计算参数，分析软土地基稳定性的计算方法和模型参数．方法利用理论计算或现场监测结果确定下一级荷载加栽前软土地基相对于最终沉降量所达到的固结度，根据固结压力与固结度，利用室内试验结果获得计算参数，输入有限元计算软件中相应的施工步骤中，作为评价下一级荷载时软土地基的稳定性．结果将逐级改变计算参数和采用固定不变计算参数的计算结果与实测结果比较，逐级改变计算参数的计算结果表明，竖向位移、侧向位移与实测结果很接近．而采用固定不变的计算参数计算结果竖向位移最大差值达42．5cm，侧向位移最大差值达8cm，与实际工程不符．结论逐级改变计算参数时更接近工程中的实际情况．所提出的计算方法和试验所确定的模型参数为今后类似工程的设计、计算提供参考依据．

Stability of Soft Soil Foundation Analyzed by Change of Finite Element Parameters Stage by Stage

The article puts forward how to change finite element parameters of soft soil foundation disposed synthetically stage by stage and analyzes calculation methods and model parameters of soft soil foundation stability. The degree of consolidation of soft soil foundation relative to ultimate settlement is determined before the next loading, with the theoretical calculation or on - site monitoring. According to consolidation pressure, degree of consolidation and the test results in laboratory, calculation parameters are acquired and input into corresponding construction steps of finite element Computing software to evaluate soft soil foundation stability at next loading. By comparing calculated results of changing parameters stage by stage and the calculated results of fixed parameters with the practical measured results, the calculated results of changing parameters stage by stage are similar to the measured results including vertical displacement and horizontal displacement. The calculated results of fixed parameters show that the maximal difference of vertical and horizontal displacement is 42.5 cm and 8 cm, which doesnt tally with the practical projects. Therefore, the changing parameters stage by stage are closer to practical situation in project. The proposed calculation method and model parameters determined by test provide a reliable basis for the design and calculation of similar projects in future.