兰州轨道交通建设中的工程地质问题与对策探讨

Countermeasures for Engineering Geological Problems Faced in Construction of Lanzhou Rail Transit

研究目的:兰州轨道交通场区工程地质、水文地质条件比较复杂,岩土体类型变化较大,由此而产生的工程地质问题将比较多,为了更好地解决这些工程地质问题,本文对兰州轨道交通工程概况及地质环境进行分析,提出其主要工程地质问题处理对策及勘察工作的建议,为本工程设计提供依据。研究结论:(1)兰州轨道交通的主要工程地质问题有围岩稳定性,工程水害和渗透变形,轨道交通隧道建成后的工程积水、地基沉降等;(2)对兰州轨道交通建设中遇到的各种工程地质问题,选用新奥法、盾构法、明挖顺作法、盖挖逆作法、地下防渗墙、隔离桩等合理设计方案、施工对策,可使问题得到圆满解决或控制;(3)对轨道交通岩土勘察,应充分利用各种技术手段,除查明常规岩土力学参数,还应考虑电阻率、基床系数等参数,而且对不同的施工方法需进行差异性、针对性的勘察;(4)该研究成果可应用于轨道交通建设中工程地质问题的处理。

Research purposes： The engineering geological and hydrogeological conditions are rather complex along the Lanzhou rail transit, with lots of the engineering geological problems due to the big variety of rock and soil types. In order to solve the engineering geological problems better in this paper, the introduction is given to the general situation and geological environment of the Lanzhou rail transit and the main geological problems, the countermeasures for them and the ideas on the survey are presented. Research conclusions： （1） The main geological problems of the Lanzhou rail transit included the stability of the surrounding rock, the engineering water disaster, the seepage deformation, the engineering ponding after completion of the tunnel construction and the foundation settlement. （2） The various engineering problems faced in construction of the Lanzhou rail transit could be overcome or controlled by making the reasonable design scheme and taking the corresponding construction measures, such as using the New Austrian Tunneling Method, the shield tunneling method, the open cut method, the top - down method, the underground diaphragm wall and the isolation piles etc. （ 3 ） The various technical means should be used for the geoteehnieal survey for the rail transit. Besides, the routine geotechnical mechanics parameters should be well known, the parameters like the resistivity and foundation bed coefficient should also be considered. In addition, the differential and corresponding surveys should be conducted for the different construction methods. （4） This study results can be applied in treatment of the engineering geological problems in construction of rail transit.