摘要
双江口水电站深埋大型地下厂房洞室群布置在左岸山体内,地层岩性为脆性硬岩花岗岩,实测地应力达37.82 MPa,为高~极高地应力区。研究发现地下厂房松弛深度介于2.2~4.4 m,围岩损伤总体随分层爆破开挖呈增强趋势,但松弛深度变幅小,松弛层平均破碎变幅均小于10%,围岩破裂滞后效用缩短。提出高应力脆性硬岩洞室开挖损伤区(GEDZ)分布可以采取声波检测为主、辅以创新性提出的半定量指标“破裂形态”(新生裂缝、残余爆破孔半孔率、岩爆破坏深度)、定量指标渗透性等判别标准合理地评价,较好地指导了现场设计与施工,研究成果可为今后类似水电地下厂房提供参考。
The deep buried large underground powerhouse cavern group of Shuangjiangkou Hydropower Station is arranged in the left bank mountain,and the geological lithology is brittle hard rock granite.The measured ground stress reaches 37.82 MPa,which is a high to extremely high stress zone.Research has found that the relaxation depth of underground power plants ranges from 2.2 m to 4.4 m,and the overall damage to surrounding rock shows an increasing trend with layered blasting excavation.However,the relaxation depth variation is small,and the average fragmentation variation of the relaxation layer is less than 10%.The lag effect of surrounding rock fracture is shortened.The GEDZ distribution in high stress brittle hard rock caverns can be evaluated using acoustic detection as the main method,supplemented by innovative semi quantitative indicators such as"rupture morphology"(new cracks,residual blasting hole half hole rate,rock burst failure depth),and quantitative indicators such as permeability to reasonably evaluate the distribution of excavation damage areas in surrounding rock.This can better guide on-site design and construction,and provide reference for similar hydropower underground power plants and Sichuan Xizang Railway projects in the future.
作者
马行东
张世殊
黎昌有
袁国庆
贾翔
Ma Xingdong;Zhang Shishu;Li Changyou;Yuan Guoqing;Jia Xiang(PowerChina Chengdu Engineering Corporation Limited,Chengdu 610072,P.R.China)
出处
《地下空间与工程学报》
北大核心
2025年第6期2159-2166,共8页
Chinese Journal of Underground Space and Engineering
关键词
高应力
脆性硬岩
岩爆
损伤区
破裂形态
high stress
brittle hard rock
rockburst
damage zone
rupture morphology
