复杂岩溶地区火成岩对建坝成库的影响——以张家寨水库为例  

Influence of igneous rocks on dam and reservoir construction in complex karst areas:case of Zhangjiazhai Reservoir

作　　者：余加松 伍登浩 顾兴华 YU Jiasong;WU Denghao;GU Xinghua(PowerChina Guiyang Engineering Corporation Limited,Guiyang 550081,China;GuiZhou Water&Power Survey-Design Institute Co.,Ltd.,Guiyang 550002,China)

机构地区：[1]中国电建集团贵阳勘测设计研究院有限公司,贵州贵阳550081 [2]贵州省水利水电勘测设计研究院有限公司,贵州贵阳550002

出　　处：《人民长江》2024年第7期123-129,共7页Yangtze River

基　　金：中国电建集团贵阳院科技项目“水电工程地质评价标准化及平台开发研究”(YJZD2023-03)。

摘　　要：张家寨水库地处岩溶发育区,火成岩的存在形成了新的构造界面并切割了原有的地层分布,进而改变了地下水文地质条件。因此,查明该水库的地质构造特征、不同岩性的差异风化及火成岩分布对岩溶发育的影响,成为工程建设成功的关键。以张家寨水库工程区为研究对象,综合分析了该区域岩溶与火成岩复合物质条件下的建库难题,并提出了针对性措施。研究发现:该地区玄武岩分布区风化深度普遍较深,这直接影响了坝址的选择;辉绿岩侵入体与薄层灰岩的接触带差异风化明显,部分接触带闭合完整,可作为坝基持力层和地下水位低槽区帷幕灌浆下限;而局部接触带形成风化深槽,降低了岩体工程地质参数,不能满足建坝地基要求,需采取专门工程措施进行处理;此外,辉绿岩侵入灰岩料场中部,导致料场储量大为减少,对水库建设材料供应造成不利影响。研究成果可供类似工程借鉴。The Zhangjiazhai Reservoir is located in a karst developed area,where the igneous rocks have formed new structural interfaces and cut across the distribution of original rock layers,thereby altering the hydrogeological conditions.Therefore,a thorough investigation of the geological structural features of the reservoir,the differential weathering processes of diverse lithologies,and the repercussions of igneous rock distribution on karst development are imperative for the successful execution of engineering projects.Research findings have unveiled that:regions dominated by basalt have notable levels of weathering depth,playing a critical role in site selection for dam construction.Moreover,the interface between diabase intrusions and thin limestone layers exhibits differential weathering,with certain sections demonstrating cohesive closures,which is suitable for foundational support layers and the lower boundary of grouting curtains within the low-flow zone of the subsurface aquifer.Conversely,localized regions at these interfaces have spawned deep weathering troughs,leading to a reduction in the engineering geological parameters of the rock mass,which can not meet the requirements of dam foundation construction,and it is necessary to adopt specialized engineering measures.Furthermore,the intrusion of diabase into the central region of the limestone quarry has resulted in a substantial reduction in material reserves,posing challenges to the procurement of construction materials for the reservoir project.The research findings can provide valuable references for similar engineering projects.

关 键 词：岩溶地区 火成岩 建坝成库 茅口组灰岩 侵入体 张家寨水库 

分 类 号：TV221.2[水利工程—水工结构工程]