临近基坑条形基础地基承载力简化上限解

Approximate Upper-Bound Solution for Bearing Capacity of Strip Footings near Excavations

利用极限分析的机动法估算了临近基坑条形基础地基承载力系数.作为一种简化手段,分别按土的粘聚力、基础埋深(超载)和土的自重三项估算临近基坑地基极限荷载.采用多滑块破坏机构及一种简单算法给出了基坑附近地基承载力系数,由此得到的承载力减损因数,可以很方便地借助地面水平时条形基础地基承载力去估算临近基坑地基承载力.根据极限分析上限理论,这种使影响地基承载力的每一项因素都单独达到最小的处理方法不是严格的上限解,但在工程实践中是可行的.

An estimate of bearing capacity coefficients for a strip footing near an excavation is made by using the kinematical approach of limit analysis in this paper. As accepted in other proposals, the estimate of the limit load near an excavation is made here respectively from the perspectives of the cohesion, the footing depth （overburden） and the soil weight. The results are given in terms of the bearing capacity coefficients by muti-block failure pattern, and reduction factors applicable as modifiers in the bearing capacity solution for strip footings near an excavation with the bearing capacity of strip footings on a horizontal soil mass. The method is no longer the same as that associated with a rigorous least upperbound. According to the upper-bound approach, such procedure is appropriate for practical purposes.