中文摘要：

针对双向增强体加固软土路基的作用特点,分析了筋材—桩—桩间土在路堤荷载作用下荷载传递机理。根据位移和应力连续条件,将路堤填土和加固区作为统一的整体考虑,并将一定厚度水平向加筋垫层视为具有一定刚度的薄板,基于大挠度薄板理论模拟筋材的挠曲变形,同时考虑了路堤土拱效应和路基桩土相互作用,建立了路堤荷载作用下双向增强体复合地基受力模型和桩土应力比的有限差分解法。采用相关文献中的工程试验结果对本文的计算方法进行了验证,与其他计算结果进行比较分析,并综合分析了筋材抗拉模量、桩土差异沉降、桩净间距和路堤填土高度对桩土应力比的影响。结果表明采用本文方法计算出的桩土应力比更接近实测结果,说明该计算方法是合理的,可为工程实践提供理论参考。

英文摘要：

According to the characteristics of the soft soil subgrade reinforced by biaxial reinforcement,the interaction mechanism of geogrids,piles and soil under the embankment loads is analyzed.The embankment and the improved area are treated as a whole with continuous displacements and stresses.The horizontal reinforced mattress is modelled as a thin plate,and the deformation is calculated by the thin plate theory.The arching in embankments and the interaction of pile-soil are also considered.A mechanical model of biaxial reinforcement composite foundation under embankment loads is developed,and a finite difference method is presented to solve the value of pile-soil stress ratio.The present method is validated by comparing the analytical solutions with the test results.The results by the proposed method are compared with the calculated results in the references.It shows that the analytical solutions have better agreement with the measured data than the calculated values from the references.The factors which affect pile-soil stress ratio,such as the tensile elastic modulus,differential settlement,clear spacing between piles and the height of embankment,are systematically analyzed.The present method can be applied in engineering practices.