华南地区某在建隧道复杂地质情况超前地质预报

Advanced Prediction of Complex Geological Conditions of a Tunnel Under Construction in Southern China Area

华南某在建隧道位于广西壮族自治区河池市,隧道横穿一大型的环形断裂,该断裂为压扭型断裂,断层下盘岩性为灰岩,岩溶较发育,上盘为钙质砂岩,岩体中结构面发育,岩体破碎。由于压扭性断裂部位往往应力集中,隧道开挖应力释放,往往导致整体或者局部失稳,而下盘岩性为灰岩,岩溶强发育,加之该地区地下水位线较高,易产生突泥突水事故,给隧道的安全施工与运营带来隐患;为了查明掌子面前方围岩完整程度及岩溶发育情况,文章拟采用地表调查结合地震波超前预报法查明掌子面前方围岩情况,指导隧道安全施工,取得了较好的效果,可作为今后类似条件下隧道施工的参考依据。

A tunnel under construction is located in hechi city, guangxi zhuang autonomous region, south China,it across a large ring fracture which is pressure torsional type. The lithology of the footwall of the fault is limestone,which the karst is more developed, and the upper wall is calcareous sandstone.Structural planes grow in the rock and the rock is fragmentation.Because of stress concentration and the tunnel excavation stress release, tunnel was instability. There are many karst in the footwall of the fault, and the water table is high in the area, which is easy to produce the water inrush accident,it will bring hidden dangers to the safety of tunnel construction and operation.In order to investigate the rock integrity and karst development in front of the tunnel face, this paper uses geological survey combined with seismic prediction to find out the condition in front of tunnel face. The forecast results use for guiding the safety of tunnel construction which have achieved the desired results, and it can be used as reference for tunnel construction under similar conditions in the future.