摘要
三峡库区在高程145~175 m之间的周期性水位调控,促使库区巫峡段灰岩岸坡劣化损伤加剧,稳定性衰减。通过引入劣化深度L 0以及岩层滑移厚度H建立了滑移-拉裂计算模型,研究巫峡段顺层灰岩岸坡受侵蚀劣化脱空时的滑移-拉裂破坏。研究结果表明:当L 0不变时,随着H增加,岸坡易于失稳且失稳距离x明显增大;随着L 0变大,同一H岩层面滑移失稳距离x明显变大,可增加约3倍有余,岩层面参数的劣化衰减使顺层岸坡更易发生深厚层、大规模的失稳破坏;当L 0较小时,易沿坡肩后部“滑移-拉裂”破坏,随着L 0逐渐变大,破坏模式变为坡肩前后部同时发生滑移-拉裂失稳。针对岩层面易受库水损伤的顺层岸坡,治理方案建议为:坡肩及后缘滑移块锚索(杆)加固+坡肩前缘岩层出露面“挂网+喷浆+随机锚杆”组合方案,以达到“固头”以及隔绝“劣化损伤”通道的目的。研究成果可为库区内顺层灰岩岸坡岩体劣化稳定性分析以及工程治理提供一定技术参考。
The periodic water level regulation in the Three Gorges reservoir area between 145~175 m promotes the deterioration damage and stability attenuation of the limestone bank slope in Wuxia section of Three Gorges Reservoir.In this paper,a slip-tensile calculation model was established by introducing deterioration depth L 0 and slip-thickness H to study the slip-tensile risk caused by erosion and deterioration of bedding limestone bank slope in the Wuxia section.The results showed that when L 0 was unchanged,the bank slope was more prone to instability and the instability distance x significantly increases with the increase of H.As L 0 increased,the slip instability distance x of the same H rock layer obviously increased,which can be increased by more than three times.The deterioration attenuation of the parameters of the rock strata made the bedding bank slope more prone to deep layer and large-scale instability failure.When L 0 was small,it was easy to slide and crack along the back of the slope shoulder.As L 0 gradually increased,the failure mode was transformed to sliding tensile instability that occurred simultaneously at the front and rear of slope shoulder.It was suggested to adopt the combined scheme of sliding block anchor cable(rod)reinforcement for the slope shoulder and the back edge+"net hanging+shotcrete+random bolt"support for the rock formation at the front edge of the slope shoulder to achieve the purpose of"fixing head"and plugging"deterioration damage"channel.The research results provide a certain technical reference for the stability analysis of rock mass deterioration and engineering treatment of bedding limestone bank slopes in reservoir areas.
作者
郑洪春
闫国强
孙位
冯冰洋
唐瑶
ZHENG Hongchun;YAN Guoqiang;SUN Wei;FENG Bingyang;TANG Yao(China Three Gorges Corporation,Chengdu 610041,China)
出处
《人民长江》
北大核心
2024年第6期159-166,共8页
Yangtze River
基金
国家自然科学基金项目(42077234)。
关键词
顺层灰岩岸坡
稳定性分析
岩体劣化
劣化深度
三峡库区
consequent bedding limestone slope
stability analysis
rock mass deterioration
deterioration depth
Three Gorges Reservoir area
