乐滩水库引水灌区窑瓦-六浪隧洞TBM施工段工程地质勘察与研究

通过对乐滩水库引水灌区工程区域地质发育史、地层岩性、地形地貌、地质构造、水文地质条件、岩溶水动力条件、勘探试验资料、隧洞开挖涌水量预测、TBM施工隧洞围岩分类等进行了全面系统的分析评价,得出了陈村-北四段属浅埋隧洞,绝大部分洞段岩溶不发育,北四-六浪段隧洞埋深一般150-300 m,绝大部分洞段位于地下分水岭之下,地下水位季节变化带埋深约70 m左右,隧洞围岩岩溶一般为弱发育-不发育,仅局部洞段岩溶较发育的结论。因此,只要对局部岩溶发育段做好超前地质预报,发现溶洞及时处理,采用TBM施工是可行的。

Engineering geological investigation and study for Yaowa-Liulang TBM construction tunnel section of Letan Reservoir Irrigation Zone

Overall and systematic analysis and study was made on the Letan Reservoir Inrrigation Zone project area in respects of geological development history,lithologic characters of strata,topography and geomorphy,geologic structure,hydro-geological conditions,karst hydraulic conditions,exploration testing data,tunnel excavation outflow rate prediction,surrounding rock classification for tunnel sections incorporating TBM construction,based on which it is concluded that the Chencun-Beisi section is a shallow tunnel with most surrounding rock undeveloped;the Beisi-Liulang tunnel section is about 150~300m deep with most parts below underground watershed divide;the embedment depth of underground water level seasonal variation belt is 70m approximately;karst surrounding the tunnel behave as weakly developed ~ undeveloped generally and relatively developed at local tunnel subsections.Therefore,TBM construction is feasible with correct geologic prediction of local karst developed subsections and timely treatment.