摘要
以目前国内设计地震烈度最大的水电站工程——大岗山坝肩边坡工程为实例,根据规范,选用拟静力法对坝肩边坡地震工况下的稳定性进行分析,并对该方法进行相应改进。基于合理的边坡岩体参数、锚固参数和地震参数,对坡体在不同地震加速度下的应力、应变、塑性区及锚索应力进行研究。指出不同剖面地质条件下,不同烈度下边坡关键点位移随边坡高度的变化规律,同时得到不同剖面地震作用的主要影响区域(敏感区域)和地震中塑性区随地震加速度的演化规律,提出相应滑移模式,为支护提供依据。分析认为,考虑50a超越概率5%的地震加速度时,边坡的V类岩体和表面坡积物及岩脉γL5,γL6,XL316–1,XL9–15,β6处有较大塑性区,并呈贯通趋势。分析指出V类岩体分层线及岩脉XL316–1,XL9–15对岩坡稳定性有着重要的影响,建议调整V类岩体参数并进一步查明岩脉XL316–1,XL9–15的分布情况及连通率。
The general engineering situation of an abutment slope located in the complex area of Dagangshan Hydropower Station with the maximum design and check seismic intensity at present in China is introduced. According to relative regulations, the pseudo-static method is selected to analyze the stability of Dagangshan dam abutment slope under earthquake; and the method has been improved correspondingly. Based on reasonable rock mass parameters, anchoring parameters and seismic parameters of slope, the stress, strain, plastic zone of the slope under different earthquake accelerations and the cable＇s stress are studied. Then the variation laws of displacement of critical points changing with slope height under different geological conditions and seismic intensities are pointed out; and the main affected area（sensitive area） of different sections under earthquake, the evolutionary laws of plastic zone in the process of earthquake and the corresponding slip modes are obtained, which could offer references for supports. It is considered that, under the earthquake acceleration with 5% exceeding probability in the next 50 years, large plastic area appears in the rock grade V, accumulation body and the areas with rock dikes γL5, γL6, XL316 - 1, XL9 - 15 and 136. The plastic areas become larger and show a tendency of transfixion. It is shown that layers in the rock grade V and rock dikes XL316 - 1, XL9 - 15 are important for stability of rock slope. It is also suggested that parameters of rock grade V needs to be adjusted so as to further ascertain the distribution and connectivity rate of rock dikes XL316 - 1, XL9 - 15.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2009年第8期1562-1570,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(90610029)
湖北省自然科学基金计划项目(2008CDB366)
三峡大学校基金资助项目(00956)
关键词
岩石力学:坝肩边坡
拟静力法
塑性区
演化规律
rock mechanics
abutment slope
pseudo-static method
plastic zone
evolutionary law
