格构锚固结构与地基相互作用分析

Analysis on Soil and Lattice Framed Anchor Structure Interaction

为了研究格构锚固结构支挡加固松散土层效果,对格构锚固结构与地基土相互作用进行三维有限元模拟.研究松散土体在格构锚固结构作用下的变形及应力分布的变化规律,分析格构锚固结构的受力特征.结果表明,在格构锚固结构的作用下,滑坡体内部受到较均匀的压应力,土体强度提高,在纵横格构梁交叉的尖点处土体存在拉应力集中,塑性区的范围仅限于表层土;预应力锚索加固变形模量小的松散土层与加固变形模量大的岩体同样有效.格构梁的有限元模拟与解析解结果比较表明,按有限元解进行设计比较安全,若按解析解结果设计,建议乘以系数K=1.3.建议格构梁的纵横梁不论是中间梁还是边梁均采用统一的设计方案.

A three-dimensional finite element method was adopted to model the interaction of soils and lattice frame anchor structure and study the effect of the lattice frame anchor structure in landslide correction. Reacted by the lattice frame anchor structure, loose soil layer's compressure stress was more uniform and soil mass strength was improved, soil tensive stress was concentrated on the peak of cross beam and the plastic zone of soil only appears in topsoil. The numerical results show that the deformation modulus of soil mass does not affect the distribution and stress very much. The prestressed anchor reinforcing the loose soil has the same effect as the rock mass. Compared with the numerical and the analytical method results, it indicates that the tendency of the beam's analytic solution is right. The solution of finite element method is safer than that of analytical method. A coefficient of safety 1.3 is recommended for the design based on the analytical solutions. The same design is recommended for all beams in the different direction and the design for the internal beam is also the same as that for the external beam.