摘要
岩体开挖卸荷松弛效应对边坡的稳定性影响巨大,如何控制岩体卸荷松弛程度非常重要。以锦屏一级水电站左岸高边坡为研究对象,区域3维地应力场反分析结果表明:工程区域内地应力水平较高,水平构造应力较大,河床处的最大主应力达到40～50 MPa。施工期声波波速及钻孔变模的测试数据表明:边坡高地应力区的岩体卸荷松弛现象非常明显,岩体卸荷松弛深度随着地应力的增大而增大。边坡高地应力区开展的先挖后锚和先锚后挖的两种岩体卸荷松弛控制试验表明:先锚后挖能够有效地改善岩体的应力释放,同时能够较好地控制岩体的变形。
Slope stability is influenced by the excavation unloading relaxation effects of rock masses obviously,and how to control the degree of excavation unloading relaxation is very important.The left bank slope at Jinping ⅠHydropower Station was selected for the case study,and the unloading relaxation effects of rock mass and excavation measures for high in-situ stress slope were researched.Back-analysis results of three-dimensional in-situ stress of study region showed that,the in-situ stress at the study region is very high,the horizontal tectonic stress is higher than vertical direction,and the maximum first principle stress is about 40~50 MPa at the riverbed.The acoustic wave velocity and borehole deformation modulus test results showed that,the unloading relaxation effect of rock masses in the high in-situ stress region is obviously and the unloading relaxation degree is increased with the in-situ stress.Two field experiments of anchoring after excavation and anchoring before excavation methods for control the excavation unloading relaxation showed that the anchoring before excavation method can improve the stress relaxation and control the deformation of rock masses well.
出处
《四川大学学报（工程科学版）》
EI
CAS
CSCD
北大核心
2012年第3期55-62,共8页
Journal of Sichuan University (Engineering Science Edition)
基金
国家自然科学基金资助项目(41102194)
关键词
高边坡
高地应力
岩体
卸荷松弛
控制措施
high slope
high in-situ stress
rock masses
unloading relaxation
control measures
