基于文克尔假定的土工格室加筋体受力分析

Deformation analysis of geocell reinforcement based on Winkler model

针对土工格室加筋体的受力变形特性,将格室体视为置于弹性地基上的梁,基于文克尔假定,建立考虑水平摩阻力影响的土工格室加筋体的挠曲变形微分方程,从而得到了土工格室加筋体在集中荷载和均布荷载共同作用下的挠曲变形幂级数半解析解。在此基础上,分析了格室体长度、格室体刚度、地基反力系数及筋土界面水平摩阻力等因素对格室体挠曲变形及内力的影响。结果表明,格室体的设置可有效地减小路基沉降,但也存在着尺寸效应;地基土体地基的反力系数对路基沉降有较大的影响,该系数越大路基沉降越小;筋土界面水平摩阻力对格室体的挠曲变形及弯矩有一定程度的削弱作用,在工程设计中值得考虑。

The geocell for reinforcement of subgrade was regarded as a beam placed on elastic foundation under vertical load. On the basis of Winkler model, a deformation control differential equation of this reinforcement with the effect of horizontal resistance at the interface between geocell reinforcement and foundation soil taken into account was proposed. A power-series semi analytical solution for this equation was deduced. Consequently, the methods for calculating the bending deflection and internal force of the geocell reinforcement under both point load and uniform distributed load were proposed. The factors influencing the stress-deformation characteristics of the geocell reinforcement such as length and stiffness of geocell reinforcement, coefficient of subgrade reaction force and the horizontal resistance at the interface between the geocell reinforcement and soil were discussed. The results show that the geocell reinforcement can reduce the settlement of the subgrade, but a size effect is existed. The coefficient of subgrade reaction may influence the settlement and the settlement is smaller while the coefficient is higher. The horizontal resistance at the interface may weaken the bending deflection and bending moment of geocell reinforcement which must be considered in engineering design.