考虑上覆水综合作用的水下真空预压沉降分析

上覆水问题是水下真空预压与陆上真空预压的一大不同点。在水下真空预压中,上覆水会对地基固结和沉降产生一定的影响。通过有限元模拟研究了上覆水对加固区土体的沉降所产生的两方面影响,即荷载作用方面和边界渗透方面。基于有限元结果,结合固结理论和渗流理论,提出一种考虑上覆水综合作用效果的地基沉降计算方法,并通过一则案例分析对该方法进行了验证,同时与传统计算方法进行了对比分析。结果显示,与传统方法相比所得结果与实测数据更加吻合,说明了考虑上覆水对地基沉降的综合影响是可靠的。最后对工程实际中的应用提出了一定的建议。

Settlement analysis by considering combined effect of covering water in underwater vacuum preloading

Covering water is one of the factors that make the underwater vacuum preloading different from the onshore one. It affects the behaviors of consolidation and settlement of the foundation to some degree. FEM analysis is adopted to investigate the loading and the boundary seepage effects of the covering water on the foundation settlement. An analysis method is proposed with the theories of consolidation and seepage to consider the combined effect of the covering water on the settlement on the basis of the FEM results, which is proved to be reasonable and valid with a case study. Comparison is also made between the conventional and the proposed methods. The research results show that the prediction by the proposed method is better in fitting with the measured data than the conventional one, suggesting the reasonability and validity of the proposed method in considering the effect of the covering water. Advices are also given to the application of the method in engineering practice.