运用滑移线理论确定挤扩多盘桩盘下土体应力计算模式

Defining the Calculate Model about the Soil Stress Under the Under-Reamed of the Push-Extend Multi-Under-Reamed Pile by Using the Theory of Sliding Line

通过对挤扩多盘桩桩周土体极限破坏机理的理论分析及试验研究,证明盘下土体的破坏形式为滑移破坏。据此,应用Coulumb-Mohr定律建立了应力函数表达式,并运用滑移线理论,通过简单破坏区域,选择适合盘下土体的破坏形式Prandtl区域应力场,建立极坐标应力方程,从而推导出挤扩多盘桩盘下土体应力的计算模式,以便进一步确定土体极限承载力。

Through test and analysis about the principle of the soil around the push-extent multi-under-reamed pile, it is provided that the failure of soil under the multi-under-reamed of bearing loads is based on the theory of sliding line. Thereby, in the paper, according to the failure strain of the soil under the under-reamed of the pushed-extend multi-under-reamed pile, the calculate model about the soil stress is defined, through building the stress function applying Coulumb-Mohr law, and the Prandtl region field is selected by using the theory of sliding line so as to suit to the form of failure, and the stress equation is put forward so that the calculating model is defined and on the basis of it, the limit bearing capacity of soil is defined.