框架预应力锚杆边坡支护结构的稳定性分析方法及其 应用

以边坡极限平衡理论及框架预应力锚杆边坡支护结构的圆弧滑动破坏模式为基础,在考虑框架、锚杆对土体边坡稳定性影响的情况下,基于圆弧滑动条分法的思想利用积分法建立了内部稳定性安全系数计算模型和最危险滑移面搜索模型。确定滑移面圆心坐标为几何控制参数,推导了安全系数计算模型中各变量与滑移面圆心坐标之间的函数关系式,从而获得了滑移面几何控制参数与内部稳定性安全系数之间的函数关系。利用网格法对框架预应力锚杆支护结构最危险滑移面的圆心坐标进行动态搜索和求解。最后采用Matlab语言编制了框架预应力锚杆边坡支护结构的稳定性分析程序,并结合工程实例进行了验算,讨论了此种方法的适用条件,结果表明该方法简明适用,较传统的经验分析方法更加合理。

STABILITY ANALYSIS METHOD FOR PRESTRESSED ANCHOR AND GRILLAGE SUPPORTING STRUCTURES AND ITS APPLICATION

This paper is based on the slope limit equilibrium theory and the circular sliding failure model of prestressed anchor and grillage supporting structures. It considers the effects of grillage and anchor on the stability of soil slope, and uses the idea of circular slice method. The calculation model for internal global safety factor and the search model for the most dangerous sliding surface are established respectively by applying integration method. The centre coordinates of sliding surface are regarded as geometrical controlling parameters. The function relation for variables in the calculation expression of safety factor and the centre coordinates of sliding surface is derived. Then the function relations among the geometrical controlling parameters of sliding surface and the internal stability safety factor are deduced. The centre coordinates of the most dangerous sliding surface of grillage supporting structure with prestressed anchor have been dynamically searched and solved using mesh method. Finally, the calculation program for stability analysis of the grillage supporting structure with prestressed anchor is compiled with the language Matlab. An engineering example is used to check the stability of the calculation program. The applicable conditions of the proposed method are discussed. The results show that this method is concise and applicable, which is more reasonable than the conventional empirical analysis methods.