单边超载作用下的地基临界荷载

Critical load of ground under the one side surcharge

传统的地基临界荷载计算公式只适用于地基超载为对称的情况,无法直接应用于非对称超载情况。沿用传统地基临界荷载推导方法,推导并计算了只有一边有超载条件下的地基附加应力和临界荷载。计算分析结果表明:相对于无超载情况,单边超载使地基附加应力的影响深度和宽度均增大,且向有超载一侧偏移的趋势;在单边超载和地基临界荷载的作用下,地基的塑性区不再是对称的,而是只出现在和超载相对的一侧。单边超载对地基临界荷载的影响有限,基本可以忽略不计,这也定量地验证了规范(GB50007)关于非对称超载条件下地基临界荷载规定的合理性。

The traditional calculation formula of subsoil critical load is applicable only to the case of symmetrical surcharge, which cannot be applied to the case of unsymmetrical surcharge. This paper follows the derivation method of traditional critical load, and derives and calculates the subsoil additional stress and critical load in condition of one side surcharge. The calculated results indicate that the one side surcharge enlarges the influence range of additional stress, and offsets to one side with surcharge. Under the one side surcharge and critical load, the subsoil plastic zone is no longer symmetrical, and only appears in the opposite side subsoil of the surcharge. Analyses show that the influence of one side surcharge on the critical load of the foundation is limited and it can be neglected. This conclusion also validates quantitatively the specification of 'code for design of building foundation'(GB50007-2011) on subsoil critical load under the case of unsymmetrical surcharge.