高填方边坡设计因素敏感性分析及失稳破坏临界条件的确定

SENSITIVITY ANALYSIS OF HIGH FILL SLOPE DESIGN FACTORS AND DETERMINATION OF CRITICAL CONDITION OF BUCKLING FAILURE

基于强度折减法和正交试验设计,对高填方边坡平台稳定性的影响因素进行探究,采用极差分析法对各因素进行敏感性分析,结论如下:对高填方边坡平台稳定性有影响的4个因素影响程度依次为填筑坡角>填筑高度>平台填筑宽度>岩质边坡坡角。此外,通过定性分析和定量分析对高填方边坡的平台失稳破坏模式及发生失稳破坏的临界条件进行研究分析,结论如下:(1)发现沿土岩界面破坏的条件主要由平台填筑宽度和岩质边坡坡角确定,进一步比较发现,当平台宽度不大于20 m,且坡角在39°~45°时,坡体易沿土岩界面失稳破坏;(2)当平台宽度大于20 m时,潜在滑移面位置逐渐后移,填方边坡的失稳破坏模式由沿土岩界面失稳破坏变为从填方体内部剪出失稳破坏。此研究可为填方边坡平台设计提供参考。

Based on the strength reduction method and orthogonal test design,the factors affecting the stability of a high fill slope platform were studied,and the sensitivity analysis of various factors was conducted by means of range analysis,with the following conclusions.The descending order of the influence of four factors on the stability of the high fill slope platform is as follows:fill slope angle>fill height>fill platform width>rock slope angle.In addition,the buckling failure model of the high fill slope platform and the critical conditions for the buckling failure were studied through qualitative and quantitative analysis,and the conclusions are as follows.(1)It has been found that the soil-rock boundary failure mainly depends on the platform fill width and rock slope angle.Furthermore,when the platform width was 20m or less and the slope angle was 39°to 45°,the slope was prone to the buckling failure at the soil-rock boundary.(2)When the platform width was greater than 20m,the potential slip surface gradually moved backward,the buckling failure of the fill slope changed from the buckling failure at the soil-rock boundary to that inside the fill.This study provides a reference for the fill slope platform design.