边坡稳定性分析的斜条分法

Oblique slice method of slope stability analysis

在考虑坡面荷载、地震作用、渗流、坡顶张裂缝及加固措施等一般情况下,对斜条分进行受力分析,得到严格的安全系数统一计算公式,并在分析斜条分与竖直条分条间力关系的基础上,建立基于传统M-P法下的斜条条间力假设。当采用特定参数的滑动面时,研究本文斜条条间力假设的合理性和不同斜条倾角下安全系数的计算变化与收敛情况,并分析传统M-P法和Sarma法条间力假设在斜条分中的适用性。然后,在均质边坡、地震作用边坡、具有张裂缝临河边坡、倾斜分层边坡和锚索加固边坡算例中对本文斜条条间力假设进行验证。研究结果表明:传统M-P法和Sarma法条间力假设在斜条分中存在一定的局限性,而本文斜条条间力假设在斜条分中是可行性的,计算得的安全系数稳定且收敛快;随斜条倾角的增大,从滑动面滑出点开始向上条间剪切力方向出现反向,这是影响传统M-P法和Sarma法条间力假设出现偏差的主要因素;各算例表明在本文斜条条间力假设下计算得的结果与以往研究成果接近,验证了本文斜条条间力假设的合理性,因而可为边坡稳定性斜条分法提供参考。

When considering general situation such as load on slope surface, earthquake, seepage, tension cracks on top of slope and reinforcement measures, the strict and unified formula for calculating factor of safety is obtained after analyzing stress of oblique slices. And inter-forces assumption of oblique slice is established based on traditional M-P method after analyzing the relationship of interaction forces between oblique slice and vertical slice. When adopting sliding surface with specific parameters, reasonableness of inter-forces assumption of oblique slice, change and convergence of calculated factor of safety under different inclination angle of oblique slice are studied, and applicability of inter-force assumption of traditional M-P method and Sarma method is analyzed. Thereafter, in examples of homogeneous slope, slope under earthquake, slope with tension crack near river, declining layered slope and slope reinforced with anchor cable, inter-force assumption of oblique slice is verified. The results show that there is some limitation in oblique slice method when usin^inter-force assumption of traditional M-P method and Sarma method, while it is feasible to use this article＇s inter-force assumption of oblique slice in oblique slice method and calculated factor of safety that could be got quickly through iteration is stable. With the increase of inclination angle of oblique slice, inter shear force appear to change its direction on the location of slide-out point and upper it of sliding surface, which is main factor to affect appearance of deviation of inter-force assumption in traditional M-P method and Sarma method. These examples show that calculated results under this article＇s inter-force assumption of oblique slice are close to previous research results, so reasonableness of this article＇s inter-force assumption of oblique slice has been verified, and it could provide reference for oblique slice method to analyze stability of slope.