大岗山双曲拱坝整体稳定三维地质力学模型试验研究  

EXPERIMENTAL STUDY OF 3D GEOMECHANICAL MODEL ON GLOBAL STABILITY OF DAGANGSHAN DOUBLE CURVATURE ARCH DAM

作　　者：董建华[1] 谢和平[1] 张林[1] 陈建叶[1] 胡成秋[1] 

机构地区：[1]四川大学水利水电学院,四川成都610065

出　　处：《岩石力学与工程学报》2007年第10期2027-2033,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展规划(973)项目(2002CB412705;2002CB412707);教育部高校博士点基金项目(20040610095);国家自然科学基金委雅砻江水电开发联合研究基金重点项目(50639100)

摘　　要：针对大岗山双曲拱坝的工程地质问题,采用三维地质力学模型试验技术,研究坝体和坝肩从加荷到破坏的整个过程和机制。试验过程模拟大坝基础的不连续岩体条件、岩体力学特性和整体双曲拱坝。试验考虑拱坝上游超载情况,同时还模拟两坝肩岩体中软弱结构面强度弱化的影响,为此研制适合该工程的变温相似材料及试验模拟新技术,并在一个模型上进行强度储备与超载相结合的综合法试验。试验结果给出拱坝在正常蓄水位和降强之后超载作用下的位移场,获得坝体和坝肩的变形及分布特征、内部断层典型测点的相对位移,揭示拱坝坝体和坝基失稳前后裂缝发展的全过程及其破坏机制。得到强度储备系数为1.25,超载系数为4.0～4.5,确定拱坝坝肩坝基整体稳定安全度为5.0～5.6。对试验数据的综合分析,可以评价边坡的稳定性,并针对坝肩的薄弱环节提出加固处理措施建议。Aiming at the engineering geological problems of the Dagangshan arch dam,by three-dimensional geomechanical model test,the whole failure process and mechanism of the arch dam and abutments from loading to failure are studied.The model simulates the discontinuous rock body of dam foundation,the mechanical properties of rock and the entire double curvature arch dam.The model considers the various factors influencing the stabilities of dam foundation and abutment during test,including overloading as well as strength-decreasing of weak structural planes in the rock mass of the dam foundation.A kind of model test material called temperature analogous material whose strength varies with temperature in the process of experiment is adopted to simulate the decrease of the weak structural planes.Then,the comprehensive method considering both overloading and strength-decreasing is successfully applied to the model.The displacement fields of arch dam under the pressure of normal pool level and overloading after strength-decreasing are obtained.The deformation characters of dam and abutment and relative displacements of internal fault for typical measurement points are obtained,and the overall developing process of displacement and crack before arch dam and foundation destabilization and its failure mechanism are revealed.The safety evaluation on the model experiment indicates that the strength reserve coefficient K1 and overloading coefficient K2 are 1.25 and 4.0–4.5 respectively,and the global safety factor for the dam foundation and abutment is 5.0–5.6.The slope stability can be evaluated by synthetically analyzing test data,and the reinforcing measures for the weak areas of dam abutment are advised.

关 键 词：水工结构工程 双曲拱坝 地质力学模型 变温相似材料 整体稳定安全度 综合法试验 

分 类 号：TV131[水利工程—水力学及河流动力学] P642[天文地球—工程地质学]