摘要
防渗帷幕是保障水库蓄水和水工建筑物运行安全的重要组成部分,也是典型的地下隐蔽工程。地质条件对帷幕施工材料、施工工艺及设计优化起着决定作用。为防止施工期间产生大的不确定性风险,需在大规模帷幕工程实施前通过灌浆试验获得包括浆液材料、浆液配比、灌浆孔布置、浆液有效扩散半径、灌浆压力等施工信息,同时通过试验孔检验获得灌浆质量等成幕指标。通过分析JN水电站微风化至新鲜节理岩体灌浆试验,从岩体结构出发,分析影响岩体可灌性的主要因素,即地层岩性、地质构造、水文地质条件、地应力、岩体质量、浆液材料配比以及施工工艺,结合压水试验及灌浆试验成果分析,对试验段成幕可行性和帷幕质量进行评价。结果表明节理岩体可灌性受多项因素共同影响,决定性因素有节理张开和联通状态、节理密度、灌浆压力。不同间距试验段灌浆和压水结果表明,单排帷幕浆液有效扩散半径1.0~1.5 m,成幕可行灌浆孔间距为1.0 m。为增加帷幕可靠性,建议帷幕设计方案中增加倾斜孔和增加灌浆孔排数。
Curtain is an important part to ensure reservoir water storage and dam safety.It is a typical underground project.Geological conditions play a decisive role in material selection,construction process and design optimization of the curtain.In order to prevent large uncertainty risks during construction,it is necessary to obtain construction information through tests before the implementation of large-scale curtain project,including slurry material,ratio,holes layout,effective diffusion radius,injecting pressure,and grouting quality.This paper analyzes the grouting test of the slightly weathered to fresh jointed rock mass of JN Hydropower Station.Starting from the rock mass structure,this paper analyzes the main factors affecting the groutability of the rock mass,that is,lithology,geological structure,hydrogeological conditions,in-situ stress,rock mass quality,slurry material ratio and construction process.Combined with the results of water pressure test and grouting test,this paper evaluates the feasibility and curtain quality of the test area.The results show that the groutability of the jointed rock mass is affected by many factors,and the decisive factors are the joint opening and connecting state,the joint density,and the grouting pressure.The results of grouting and water pressure tests with different distance show that for a single-row curtain,the effective slurry diffusion radius is 1.0 m to 1.5 m,and the spacing of reliable grouting holes is 1.0 m.In order to increase the reliability of the curtain,it is recommended to increase the number of inclined holes and the rows of grouting holes.
作者
刘超杨
张毅
赵代尧
左周昌
LIU Chaoyang;ZHANG Yi;ZHAO Daiyao;ZUO Zhouchang(Guiyang Engineering Corporation Geotechnical Engineering Co.Ltd.,Hydro China,Guiyang 550081,China;Guiyang Engineering Co.Ltd.,Power China,Guiyang 550081,China)
出处
《贵州科学》
2023年第6期90-96,共7页
Guizhou Science
关键词
节理岩体
岩体可灌性
帷幕可靠性
浆液扩散半径
微风化至新鲜岩体
jointed rock mass
groutability of rock mass
curtain reliability
slurry diffusion radius
slightly weathered to fresh rock mass