糯扎渡水电站调压井围岩力学参数反演与反馈分析  

Inversion and feedback analysis of mechanical parameters of surrounding rock of relief well of Nuozhadu Hydropower Station

作　　者：聂卫平[1,2] 杨云浩[1,2] 石崇[1,2] 刘兴宁[3] 

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河海大学岩土工程科学研究所,江苏南京210098 [3]中国水电顾问集团昆明勘测设计研究院,云南昆明650051

出　　处：《河海大学学报（自然科学版）》2011年第1期54-60,共7页Journal of Hohai University(Natural Sciences)

基　　金：“十一五”国家科技支撑计划(2008BAB29B01);国家自然科学基金(50911130366)

摘　　要：针对糯扎渡水电站调压井工程区的特点,建立三维仿真模型,根据实测位移分析、BP神经网络和最小残差原理,反演出工程区各岩层弹性模量,并将反演参数导入模型进行三维弹塑性反馈计算.实测位移分析表明,调压井拱顶位移随着开挖方量的增大而增大,最大位移发生在1号调压井与连通上室连接处,最大值1.68 mm;反演得到的各岩层弹性模量分别为:微新层24.11 GPa,弱风化上层10.13GPa,弱风化下层3.16GPa,强风化层0.20GPa,断层0.62GPa,最小位移残差为16.82 mm2;监测和计算的位移、位移增量变化趋势基本一致,说明反演参数可靠;因实际开挖瞬间卸荷,计算位移比监测位移一般要大,最大计算位移为3.22mm;洞室开挖后围岩变形主要朝临空面方向,围岩变形较小,围岩较稳定.Based on the characteristics of project area of relief well of Nuozhadu Hydropower Station,a 3D mathematical model was established.The elastic moduli of various rock strata in the project area were inversed according to the analysis of measured displacements,the method of BP neural network and the principle of the minimum residual error.Furthermore,the inversed parameters were introduced into the model for 3D elastic-plastic feedback calculation.The inverse analysis of the measured displacements show that the crown displacement of the relief well increases with the increase of excavated quantity,the maximum displacement of 1.68 mm occurs at the connecting point of the 1st relief well and the upper chamber.The inversed elastic moduli of various rock strata are as follows： 24.11 GPa for fresh rock mass,10.13 GPa for the superstratum of slightly weathered rock mass,3.16 GPa for the substratum of slightly weathered rock mass,0.20 GPa for strongly weathered rock mass and 0.62 GPa for fault.The minimum residual is 16.82 mm2.The observed and calculated displacements and displacement increments basically have the same varation tendency,indicating that the inversed parameters are reliable.The calculated displacement is generally larger than observed one because of instantaneous unloading during actual excavation,and the largest calculated displacement is 3.22 mm.The deformation direction of surrounding rock is mainly towards the free face,the deformation is small,and the surrounding rock is relatively stable.

关 键 词：三维弹塑性 反演 反馈 位移增量 BP神经网络 围岩 调压井 糯扎渡水电站 

分 类 号：TV653[水利工程—水利水电工程] TU457[建筑科学—岩土工程]