基于优化支持向量回归的磨古倾倒变形体参数反分析研究

Inverse Analysis of Mechanical Parameters of Mogu Toppling Deformed Slope Based on Improved SVR Model

岩土体力学参数的确定将直接影响对倾倒变形体稳定性的分析判断,野外原位监测数据作为反映倾倒变形体现场条件的重要信息,利用原位监测数据能有效地获得倾倒变形体岩土体参数.本文针对雅砻江两河口近坝库区磨古倾倒变形体,提出以海洋捕猎者优化算法对支持向量回归反分析模型参数进行寻优,构建MPA-SVR岩土体参数反分析模型.以倾倒变形体现场安全监测数据为输入信息,反分析得到适用于两河口磨古倾倒变形体折断带的力学参数,其反分析结果可为变形体稳定性分析提供重要数据基础.结果表明磨古倾倒变形体不同高程监测点具有相似的变形规律,变形速率发展趋势与水位变化趋势一致,变形累计值整体呈增长趋势,变形尚未完全收敛;随着分期蓄水进程的推进,倾倒变形体水动力作用特征明显,反分析得到的折断带力学参数逐渐降低,从第二阶段蓄水到第三阶段蓄水,折断带黏聚力下降3.68%,内摩擦角下降1.98%.

The determination of geotechnical parameters will directly affect the analysis and judgment of the stability of the toppling deformation body.The in-situ monitoring data can effectively get the geotechnical parameters of the toppling deformation body.In this paper,for the Mogu dumping deformation body of Yalong River Lianghekou reservoir area,the MPA-SVR model is constructed to back analyze the geotechnical parameters.The inverse analysis results can provide an important data basis for the stability analysis of the deformed body,and the mechanical parameters applicable to the fracture zone of the Mogu toppling deformed body in the Lianghekou reservoir area can be obtained by using the on-site safety monitoring data of the toppling deformed body as the input information.The results show that the different elevation monitoring points have similar deformation trend,the deformation rate is consistent with the water level change trend,and the deformation has not yet fully converged.With the advancement of the staged water storage process,the hydrodynamic effect of the dumping deformation body is obvious,and the mechanical parameter of the folded zone obtained by the inverse analysis decreases gradually.The cohesive force of the zone decreases by 3.68%from the second stage to the third stage of the storage,and the mechanical parameters of the zone decrease by 3.7%.From the second stage to the third stage of water storage,the cohesive force of the fracture zone decreased by 3.68%,and the angle of internal friction decreased by 1.98%.