临近基坑矩形浅基础地基承载力上限估算
Approximate upper-bound solution for bearing capacity of rectangular footings near excavations
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摘要: 临近基坑或边坡的既有建筑物地基承载力减损情况是一个值得关注的问题。文中利用极限分析中的机动法,构建了一个临近基坑矩形浅基础的三维机动许可破坏模式,按照地基承载力的传统表达方式,分别给出了单独考虑土的粘聚力、基础埋深(超载)和土的自重影响的承载力系数。根据极限分析上限理论,这种使影响地基承载力的每一个因素都达到最小的简化处理方法,已不是严格意义上的极限分析上限解答,但用于工程设计是可行的。最后将计算结果与已有文献资料进行了分析比较,并以地面水平时矩形基础地基承载力系数为基准,得到临近基坑矩形浅基础地基承载力减损因数上界估算值。Abstract: It is a notable case when the vicinal slopes or excavations are likely to reduce significantly the bearing capacity of foundation.To estimate of ultimate bearing capacity from the cohesion and unit weight of soil and embedded depth(overburden),the kinematical approach of limit analysis based on the three-dimensional mechanism was used.In view of the upper-bound approach,the simplified procedure was appropriate for design despite of inconsistency from a theoretical standpoint.The comparison of results with existing solutions to minimize the influential factors of bearing capacity as well as the reduction factors of the bearing capacity of rectangular footings near excavations were given finally.