【作者】 蒋德群；

【导师】 靳晓光；

【作者基本信息】 重庆大学 ， 桥梁与隧道工程， 2010， 硕士

【摘要】 隧道工程中的地下水问题是富水地层中存在的重要问题,地下水的流动对隧道围岩和仰坡稳定性有重要影响。隧道在开挖时,地下水位会发生变化,从而影响应力场的变化,而应力场的变化又会影响渗流场的变化,往往会造成结构的受力变化,进而引起变形,因此在计算中需要考虑地下水位的影响。在隧道裂隙岩体中所存在的渗流场和应力场之间是会相互影响的,称为耦合作用。本文结合走马岭隧道进口段堆积体地层展开了以下几方面的研究工作:①阐述了有限单元法分析地下工程渗流应力耦合的基本原理,运用MIDAS/GTS软件进行渗流—应力耦合模拟,分析了渗流对围岩位移、应力、锚杆轴力、喷射混凝土应力隧道围岩塑性区的影响。结果表明:在渗流–应力耦合作用下,围岩、锚杆、喷射混泥土的应力均有所增大,应力扰动范围也相应的增大,不利于洞室的稳定。②研究了注浆层厚度对施工涌水以及对围岩和衬砌结构的影响。通过有限元模拟发现注浆层厚度对涌水量影响小,注浆圈渗透系数对涌水影响很大,控制注浆圈渗透系数在1.0E-9m/s以下可以有效的满足隧道施工和运营。同时,注浆很好的改善了围岩和结构的受力条件。③渗流对堆积体地层隧道仰坡稳定性有很大的影响,雨水入渗使土体饱和度增加,基质吸力减小,从而引起土体的抗剪强度减小。所以当持续降雨的历时和强度超过某种限度时,雨水入渗达到一定的深度,再加上施工因素,则可导致仰坡失稳。更多还原

【Abstract】 The groundwater problem in tunnel engineering is issue which affects stability of tunnel and slope. Tunnel excavation,the groundwater level will change, affecting the stress field change, and changes in stress field changes will affect the flow field, often leads to changes in the structure of the force, thereby causing distortion, so the calculation needs consider the impact of groundwater level. In the fractured rock in the tunnel exists between seepage and stress fields will influence each other, known as coupling. This statement and a sloping soil slope tunnel started in the following aspects of work:①Finite element analysis described underground engineering and the basic principle of coupled seepage and stress, the use of MIDAS/GTS software indirect flow - stress coupling simulation and analysis of seepage on the surrounding rock displacement, stress, bolt axial force and shotcrete tunnel plastic stress Zone. The results showed that: in the flow - stress coupling, the surrounding rock, bolt, spray for mixed stress had increased, the stress range corresponding increase disturbance is not conducive to the stability of caverns.②Thickness of the grouting of the lining of the construction of water gushing and structure. Grouting through the finite element simulation found that the thickness effect on the discharge of small, slip ring great influence on permeability coefficient, permeability coefficient control grouting circle m/s can effectively meet the following construction and operation of the tunnel. At the same time, improve the well grouting surrounding rock and the structure of the force.③Seepage slope stability on the accumulation of body formation, infiltration of rain water to soil saturation increases, causing suction reduced the shear strength of soil decreases, so when the duration and intensity of ongoing rainfall over a certain time limit , infiltration of rain water to reach a certain depth, together with the construction factors, can lead to slope failure.更多还原