考虑土拱效应的高路堤桩土复合地基受力分析

Stress analysis of pile-soil composite ground considering soil arching effect of high embankment

根据路堤荷载下复合地基的荷载传递机理及变形特征,综合考虑路堤填土的土拱效应和桩、土的荷载传递性状,采用假定的桩间土位移模式同时考虑桩土界面的相对滑移和同一深度处桩间土沉降的非同步性,基于典型单元体建立考虑路堤—桩土加固区—下卧层三者变形与应力协调的平衡方程,并求解获得表征桩土复合地基工作性状的桩土应力比及沉降变形解析公式。研究结果表明:由本文方法所得结果与工程实测结果较吻合,验证了本文方法的可行性。

According to the load transfer mechanism and deformation characteristics of pile-soil composite foundation under the embankment load, soil arching effect of the embankment and load transfer properties of pile-soil reinforced area were considered. Assuming that relative slip existed in the pile-soil interface and the settlements of foundation soil at the same level plane were different, equilibrium equation was established based on the typical element through considering the stress-deformation coordination of embankment, pile-soil reinforced area and underlying soils. The stress ratio of pile-soil and settlement deformation, which were used to characterize the behaviors of the composite ground were obtained by solving the equation. The results show that the result calculated by the proposed method is in accordance with the observed results of the project, which shows that the proposed method is feasible.