赵明华 郑玥 刘猛 肖尧

摘   要：针对土工格室加筋体的受力变形特点，将其视为小挠度弹性圆薄板，考虑土工格室与桩土加固区的变形协调、土工格室垫层耦合的水平与竖直变形以及上下界面的摩阻效应，建立此轴对称条件下薄板的挠曲变形控制微分方程，利用 Bessel复变函数构造竖向及水平位移解析表达式，从而得出双向增强复合地基网下桩土应力比、沉降及桩土差异沉降的计算公式.采用某工程试验结果对该计算方法进行了验证，证明本文计算方法的合理性.参数分析表明：在一定范围内改变加筋体的复合弹性模量、桩土刚度比、上下界面摩阻系数比等因素可以起到调节双向增强复合地基网下桩土应力比和降低格室体沉降的作用.

关键词：路基;土工格室;双向增强复合地基;纵横耦合变形;桩土应力比;沉降

中图分类号：U416.1;TU473.1              文献标志码：A

文章编号：1674—2974（2019）09—0089—11

Abstract：This paper regarded the force and deformation characteristics of geocell reinforcement，as a small deflection of an elastic circular thin plate. Taking into account the deformation compatibility between the geocell and pile-soil reinforced area，horizontal-vertical coupling deformation of the geocell-reinforced mattress，as well as the horizontal friction effect of the top and bottom plate-soil interface，the governing differential equations of the geocell flexural deformation were established under symmetric load. The analytic expressions of vertical and horizontal displacement were constructed by the Bessel complex-variable functions，from which the calculation formulas were deduced for pile-soil stress ratio below the net， settlement and differential pile-soil settlement. To verify this method， an existing case was employed. Finally，the effects of various factors were discussed， which show that it is beneficial to modify the pile-soil stress ratio below the net and to reduce the embankment settlement by changing the composite elastic modulus， the pile-soil stiffness ratio and horizontal frictional coefficient ratio to some extent.

Key words：subgrade;geocell;bidirectional reinforced composite foundation;vertical-horizontal coupling distortion;pile-soil stress ratio;settlement

土工格室是一种三维网状结构的高分子聚合物，可通过在格室中充填砂、碎石或粘土等材料，构成一个具有较大抗弯刚度和抗剪强度的复合体[1-3].  土工格室作为一种新型路基处理方法，广泛应用于公路、铁路等软基加固工程. 但由于其受力情况和加固机理的复杂性，格室体的变形计算以及与地基间的荷载传递形式始终没有完善的理论研究，从而影响了格室体在工程中的进一步应用和推广.目前国内外的研究成果中，常用梁、板两种结构模型来模拟格室体并进行计算……