基于局部安全系数的边坡滑面搜索

Method for Searching Slope Critical Slip Surface Based on Local Safety Factors

边坡的破坏过程可以理解为潜在滑面上局部区域应力首先超出应力峰值并破坏,而后扩展成面逐步破坏,最终导致整个滑面贯穿的渐进破坏过程,该潜在滑面应与整体安全系数最小的滑面相对应。根据控制论中的最优性原理,当滑面上各处的安全系数均达到最小时,边坡的整体安全系数能达到最小值。基于上述认识,探究了一种基于局部安全系数由点及面确定边坡滑面的方法,并推导了基于局部安全系数的边坡整体安全系数表达式。通过算例分析,验证了所提方法的可靠性,并指出布点的合理间距应小于0. 04倍坡长。

The failure of slope is a progressive process that a special point’s strength is over its peak value to fail and then the failure evolves from points to lines and then lines to surfaces. And,the failure surface must correspond with the surface which has the minimum global safety factor. According to the knowledge of optimal principle,the global safety factor will reach its minimum value while all local safety factors on this failure surface being their minimum value. Based on above perceive,a new method to search the slope critical slip surface from points to line and then surface is proposed. And the formula of global safety factor expressed by a series of local safety factors is deduced as well. Also,the reliability of the recommend method to search the critical slip surface is verified with two critical slope cases. Moreover,it is points that the space between points should smaller than0. 04 times of slope length to acquire accurate results.