梁家山隧道病害成因综合勘察分析与处治措施

针对运营隧道病害现状,采用地质踏勘、裂缝测绘、激光隧道断面仪观测方法对该隧道病害成因进行了系统调查。结果表明:截水沟径流水下渗软化土层,沟内水沿裂缝下渗加重基底土层软化,导致截水沟沉降拉裂破坏;坡积层错动或沉降引起隧道左侧边坡、路面裂缝;明洞回填土含水率急剧增加、强度丧失,导致衬砌向左、门墙向外变形;车辆荷载的作用下,坡积土路基沿土石交界面下错动,导致进口明洞衬砌、路面开裂。依据病害成因,提出采用截水沟改造、路面裂缝嵌补、封闭废弃的截水沟和接长明洞等处治措施。

Comprehensive survey analysis and treatment measures for engineering disease of Liangjiashan tunnel

In view of the present disease status of the operating tunnel,the methods such as geological ex-ploration,crack mapping,the observation with laser tunnel cross-section instrument were used to carry out the systematic investigation for the disease causes of the tunnel.The results indicated： the seepage water from cut-off ditch seeped into the soil layer,and the ditch water seeped along the cracks that resulted in the further softening of the base layers,which leaded to the failure of the cut-off ditch with the subsidence and tension fractures;the dislocation or subsidence of the diluvial layers caused the cracks in the left side slope and the pavement of the tunnel;a sharp increase of the water content of the backfill soil in the open cut tunnel and the lose of strength leaded to the leftward deformation of the lining and the outward deforma-tion of the gate wall;vehicles loads made the roadbed dislocation along the earth stone interface,causing the cracks of the pavement and the open cut tunnel lining.Based on the causes of disease,the treatment measures such as the transformation of the cut-off ditch,the embedded complement of pavement cracks,the closure of the abandoned cut-off ditch and the lengthening of the open cut tunnel are proposed.