东莞至惠州城际轨道交通东江隧道主要工程地质问题研究

Study of Major Engineering Geological Problems in Dongjiang Tunnel of Dongguan-Huizhou Intercity Rail Transit

东莞至惠州城际轨道交通东江隧道下穿东江,为极高风险隧道。采用地质调绘、钻探、一孔多用(数字式全景钻孔摄像、声波测井)、水文地质试验、土工试验等综合勘察方法,运用岩体完整性系数定量分析岩体的完整性,采用水文地质试验测试含水层的渗透系数,利用裘布依理论公式定量计算隧道涌水量,采用室内试验测试软土力学指标,利用岩石抗压试验定量计算泥岩和泥质粉砂岩的软化系数。依据上述测试成果,研究了东江隧道突涌水、软土大变形、软岩变形、流砂、基坑开挖引发周边地面及建筑物变形、惠州断裂等主要工程地质问题,提出了相应的防治措施建议。研究结论为:东江隧道主要工程地质问题突出,但是可以采取相应的工程措施进行处理。

Dongjiang tunnel of Dongguan-Huizhou Intercity Rail Transit is an extremely high-risk tunnel which passes through the Dongjiang River.To ascertain the major engineering geological problems,the comprehensive prospecting methods were used including geological survey,geological drilling,multipurpose drill(digital panoramic borehole camera,acoustic logging),hydrogeological test,laboratory soil test etc.,moreover,the rock integrity was quantitated by the intactness index of rock mass,the permeability coefficient of aquifer was obtained by the hydrogeological test,the inflow of water in the tunnel was quantitatively computed through Dupuit formula,mechanics index of soft soils was tested by the laboratory,and the softening coefficient of mudstone and argillaceous sandstone was calculated through the rock compression tests.In accordance with the previous results,the major engineering geological problems which influence the Dongjiang tunnel were studied,such as sudden water inflow in tunnel,larger deformation of soft soils,deformation of soft rock,quicksand,deformation of the nearby ground and buildings derived from deep excavation,Huizhou fault and so on,furthermore,several appropriate preventive measures were suggested.According to the study,a conclusion could be drawn:although the engineering geological problems of Dongjiang tunnel are prominent,appropriate engineering measures could be taken to solve.