基于隧洞衬砌和等效锚杆模拟的江坪河密集地下洞室群稳定性分析  

Stability Analysis of Close-located Underground Caverns Based on Lining and Equivalent Bolt Simulation

作　　者：刘杰 唐亮 李建林 胡静 范留军 夏骏 

出　　处：《灾害与防治工程》2014年第1期8-17,共10页Disaster and Control Engineering

基　　金：国家重点基础研究发展计划（973）前期研究专项课题“大型水电工程库岸边坡致灾机理及稳定评价理论研究”资助（2012CB426502）;国家自然科学基金资助（51009083,51079077,51109120）;湖北省自然科学基金计划项目资助（2011CDBl82）;中国水利水电科学研究院流域水循环模拟与调控国家重点实验室开放研究基金（IWHR-SKL-2012221）;宜昌市科学技术研究与开发项目资助（A2012-302-03）.

摘　　要：江坪河水电站右岸地下洞群依次布置为导流洞、泄洪放空洞、溢洪道①、溢洪道②4条隧洞，洞室密集，地质条件复杂。三维模型以洞室模拟为主，同时精确模拟了3个洞室出口边坡，4条较大断层，多个岩层分层及坡表的实际形态。洞室开挖后，采用预应力锚索、系统锚杆、初期衬砌和二期衬砌等多种支护措施。支护计算时，对预应力锚索进行了精细模拟。对系统锚杆采用二维“子模型”的进行等效计算，确保了必要的计算精度，提高了建模可行性和计算效率。两期衬砌模拟采用三维壳体结构单元中的Shell单元，通过2次位移等效分别得到考虑锚杆衬砌效应的修正后初期衬砌和二期衬砌变形参数。根据关键点的变形趋势及洞室的最大弯矩值的变化情况对衬砌厚度进行了优化。针对设计规范中衬砌结构配筋所需基础参数，指出利用衬砌单元可有效地读取衬砌弯矩值和剪力值，同时标定其具体位置。分析认为，泄洪洞开挖坡锚索和2条溢洪道之间的上层的对穿锚索可能由于水泥浆强度较低而出现滑移，同时指出加固措施使临空面的最大位移大幅降低，也能一定程度抑制塑性区发育。Underground caverns of Jiangping River Hydropower Station include the diver- sion tunnel, flood discharge tunnel, spillway①, and spillway② in turn. There are inten-sive caverns, and the geological conditions are complex and the constructions are difficult. Simulating caverns are mainly in three-dimensional model, simulating three chambers slope of the outlet, four large faults, and the actual shapes of a number of rock stratification and slope table accurately. Pre-stressed anehor, bolt and lining systems and other support measures are used in the project after excavation, the pre-stressed anchor are simulated ac- curately in supporting calculations. System bolt are simulated by using two-dimensional mini-model for equivalent calculations. These measures ensure the necessary accuracy, but also improve the modeling and calculation efficiency. Secondary, the lining simulation uses the shell unit of three-dimensional shell structure, gets revised deformation parameters of the initial lining and secondary lining considering the effect of bolt lining though two dis- placement equivalent. Lining thickness has been optimized according to the deformation trends of the key points and the maximum change of cavern. Cavern bending moment and shear force value can be read though lining unit effectively. Bending and shear force values of lining structural of the most dangerous condition provide a reference for the reinforce- ment. The diagram of displacement values and the plastic zone map before and after the re- inforcement are given in the calculation results. And the reinforcement of measures signifi- cantly reduced the maximum displacement, the plastic zone is improved.

关 键 词：地下洞室群 FLAC3D 锚索 衬砌 锚杆 稳定性 

分 类 号：TV554[水利工程—水利水电工程]