狭窄基坑条件下基于普朗德尔地基极限承载力公式的隆起稳定性研究

Uplift stability of narrow foundation pits based on Prandtl formula

在市政行业的基坑支护工程中,支护桩+内支撑支护是广泛使用的支护形式。传统的基坑隆起稳定性分析方法是采用普朗德尔地基极限承载力计算公式分析,但是该地基极限承载力计算公式不适用于狭窄基坑。本文从提出狭窄基坑的定义出发,根据普朗德尔地基极限承载力计算公式的基本原理,重新假定了狭窄基坑条件下的破坏模式及相关参数,并推导了相应的地基极限承载力计算公式。算例显示,该公式能较好的反映狭窄基坑的实际条件,安全系数有适当提高。

Drilled piles and internal supporting structures are widely used at present especially in the foundation pit supporting works of municipal industry.The traditional uplift stability analysis method based on the the Prandtl formula for calculating the ultimate bearing capacity which,however,is not suitable for narrow foundation pits.Starting from the definition of the narrow foundation pit and according to the basic principle of the Prandtl formula for calculating the ultimate bearing capacity,the failure modes and relevant parameters suitable for the narrow foundation pit are reassumed,and the corresponding formula for calculating the ultimate bearing capacity of foundation is derived.Example shows that the proposed formula can better reflect the actual conditions of narrow foundation pits,and the safety factor is appropriately raised.