摘要
强震区高拱坝抗震问题的研究十分重要,高拱坝静力稳定研究和极限抗震能力复核,是确保地震后不发生库水失控下泄的关键课题之一。采用物理模型试验与数值计算的方法,根据汶川震后新核定参数,并考虑降强因素的影响,对沙牌碾压混凝土拱坝进行静动力分析和复核。通过三维地质力学模型综合法静力破坏试验,研究拱坝坝肩在正常荷载作用下的稳定安全性,得到沙牌拱坝坝肩综合稳定安全系数为3.76,建议对两坝肩开裂较严重区域进行加固处理。在此基础上,基于反应谱理论进行三维有限元动力分析,将应力成果导入开发程序由Drucker-Prager(D-P)和Mohr-Coulomb(M-C)准则对加固后的沙牌拱坝进行动力复核计算,并研究大坝的开裂情况和极限抗震能力,计算结果表明,沙牌拱坝的整体抗震稳定性能良好,仅在万年一遇地震工况下发生坝肩浅表层失稳。研究成果表明,沙牌拱坝坝肩稳定性较高、坝肩加固效果良好,从而在"5.12"汶川地震中表现出超强的整体稳定性和抗震能力,其全面开展的研究工作和采取的工程措施可供国内强震区同类型拱坝工程建设及运行借鉴和参考。
The seismic response of high-arch dam in meizoseismal area is of great importance. Analysis of static stability and ultimate seismic resistance is one of the crucial issues to ensure the reservoir safety during earthquakes. By using the verified parameters after the Wenchuan Earthquake and considering the influence of strength reduction, the static and dynamic analysis for Shapai roller-compacted concrete arch dam are performed based on physical model tests and numerical calculation. Through the 3D static geomechanical model destruction test by comprehensive method, the stability of arch dam abutment under the normal load is studied. The comprehensive stability safety coefficient is determined as 3.76, and the areas destroyed seriously are suggested to be reinforced. Based on this, the 3D dynamic finite element analysis is conducted based on the method of superposition response spectrum. The calculated stresses are used to analyze the dynamic response of Shapai arch dam after reinforcement, based on the Drucker-Prager criterion and Mohr-Coulomb criterion. The fracture situation of dam and ultimate seismic resistance are discussed. The calculation results show that the seismic resistance of Shapai arch dam is good, only the instability of shallow surface will occur under the condition of earthquake in ten thousand years. The results also show that the abutment stability and reinforcement effect of Shapai arch dam is favorable. Thus Shapai arch dam performed very well with regard to overall stability and seismic resistance in ＂5.12＂ Wenchuan Earthquake. The comprehensive researches and these engineering treatment measures can provide valuable reference for other similar projects in meizoseismal area.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2015年第12期3541-3547,3575,共8页
Rock and Soil Mechanics
基金
国家自然科学基金资助项目(No.51379139
No.51409179)~~
关键词
碾压混凝土拱坝
地质力学模型试验
三维动力有限元分析
坝肩稳定
坝体开裂
roller-compacted concrete arch dam
geomechanical model test
three-dimensional dynamic finite element analysis
abutment stability
dam cracking
