黄土中联合板索基础的抗拔承载力变化规律及其影响因素

 假设黄土为符合Mohr-Coulomb 屈服准则的理想弹塑性材料且锚板为刚性体, 采用有限差分模拟软件FLAC^3D建立三维数值模型, 利用接触面单元分析联合板索基础锚板上拔过程中黄土变形破坏机理, 研究了锚板抗拔承载力的变化规律及其影响因素。结果表明, 锚板的抗拔承载力随着锚板埋置深度的增加呈现近似线性增大, 但当埋深超过临界深度时锚板抗拔承载力趋于定值;增大锚板面积能够提高总承载力, 但单位面积承载力会下降;相同面积条件下, 圆形锚板抗拔承载力最大, 方形锚板次之, 矩形锚板抗拔承载力随着长宽比的增大而逐渐减小;锚板抗拔承载力随土体抗剪强度的增大而增大, 提升地基土体的抗剪强度指标(特别是黏聚力), 能够有效提高联合板索基础的抗拔承载力。

Vertical Uplift Capacity of Combined Cable-slab Foundation in Loess and Influencing Factors

Based on the assumption that loess is an elastic-perfectly plastic material which obeys Mohr-Coulomb yield condition and the anchor plate is a rigid body, a three-dimensional numerical analysis model is established by use of the finite-difference software FLAC^3D and the anchor-soil interaction is then simulated. The deformation mechanism of loess around plate anchors during uplifting is analyzed by the contact plane element. The influencing factors including depth ratio, loess shear strength parameter, shape and size of anchor plate are considered in the ultimate pull-out capacity analysis. It is found that the ultimate pull-out capacity of anchor plate is jointly influenced by these factors. It increases with the increased depth ratio and loess shear strength, however the influencing extent is different. Expanding the plate size can increase the total capacity, but the capacity per unit area will decrease. For plates of same area, the circular one has the biggest ultimate pull-out capacity while the square takes the second. The coefficient of a rectangle plate decreases when the length-width ratio increases. The rules revealed by this study have a reference value for the study and promotion of combined cable-slab foundation in loess areas.