基于逐个修正法的滑带土参数取值优化

滑带土强度参数是滑坡评价及治理工程设计的关键参数。较为常见的取值方法是剖面反演,单剖面反演的结果为参数的多种组合,然而两个以上剖面反演则存在数学上超定问题,不存在唯一的解。基于最优化理论与方法,重点讨论了多剖面反演参数方程组出现超定问题时,将逆问题转化为正问题,构造目标函数,利用逐个修正法间接反演参数,获得最优的参数取值。实现得到综合反映滑带土特点并适用于各个剖面的强度参数的目标。以黄角树滑坡为例,结合室内试验和反演分析结果,确定参数取值范围,用逐个修正法对参数取值进行优化,得到的优化参数为c=9.76kPa,φ=6.81°,验证各剖面均与变形状态相符合。对滑坡防治工程中的滑带土参数取值问题具有一定借鉴意义。但该方法并不适用所有情况,仅在必须要获得一组综合参数的情况下,具有一定的合理性。

Landslide soil parameters optimization based on one-by-one correction method

Landslide soil strength parameters are the key parameters in the landslide evaluation and management engineering design.Currently a common value-selection method is profile inversion.The result of single profile inversion is multiple combinations of parameters.The inversion of two or more profiles would present a mathematically overdetermined problem with no unique solution.Based on the optimization theory and method,when the equation set of multi-profile inversion parameters had an overdetermined problem,this paper transformed the inverse problem into a direct problem,constructed an objective function,indirectly inversed the parameters using the one-by-one correction method,and obtained the optimal values of the parameters.Thus,it obtained the strength parameters that reflected the characteristics of sliding soil and were suitable for each profile.In this paper,with Huangjiaoshu landslide as an example,we combined the results of indoor experiments and inversion analysis to determine the range of parameters values,and used one-by-one correction method to optimize parameters values.The optimized parameters were c=9.76 kPa,φ=6.81°,and they tallied with the deformation state when verified with each profile.This paper can provide reference for landslide soil parameters values selection in landslide prevention engineering.But the method does not apply to all cases;it is only feasible when a set of comprehensive parameters are needed.