锚杆+微型桩复合土钉支护基坑稳定的可靠性

考虑预应力锚杆、微型桩与土钉的共同作用,应用边坡极限平衡理论与圆弧滑动条分法建立了预应力锚杆+微型桩复合土钉支护基坑内部整体稳定性分析的功能函数与最危险滑动面的计算模型。将土体的力学参数作为随机变量,推导了功能函数对各随机变量的偏导数。利用改进的一次二阶矩法计算了预应力锚杆+微型桩复合土钉支护基坑内部整体稳定的可靠性指标,并分析了土体力学参数的变异系数对可靠性指标的影响。

Reliability of stability of foundation pit supported by pre-stressed soil anchor+micro-pile composite soil nailing

Given the co-action of pre-stressed soil anchor,micro-pile,and soil nailing,this paper begins with the application of the slope limit equilibrium theory and the circular sliding slice method to the development of the performance function and the calculation model of sliding surface for the inner global stability of foundation pit supported by the pre-stressed soil anchor+micro-pile composite soil nailing.The paper proceeds with the deduction of the partial derivatives of the performance function to all random variables with the shear strength indexes of soil as random variables,and the use of the improved first order second moment method to the calculation of the reliability index of inner global stability of foundation pit supported by the pre-stressed soil anchor+micro-pile composite soil nailing,and ends with an analysis of the effects of coefficients of variability of the random variables on reliability index.