岩溶区运营公路隧道衬砌受力特性模型试验研究

发布时间：2018-06-16 11:03

本文选题：岩溶区 + 运营公路隧道　；参考：《湘潭大学》2017年硕士论文

【摘要】：岩溶区地质条件复杂多变且存在诸多不确定性。岩溶区内可溶性岩的溶蚀对工程实践产生不利影响。隧道的修建改变了原有地下水平衡,同时由于溶洞的存在,水压力作用在隧道衬砌上会产生集中应力,导致隧道结构损伤、开裂,甚至出现涌水、涌泥、衬砌脱落等现象,严重的威胁到隧道的正常运营与安全。论文以广东省岩溶地区运营公路隧道为工程依托,基于室内隧道模型试验,研究岩溶区运营公路隧道在不同溶洞空间分布形态大小特征、不同节理倾角、不同降雨强度以及加载条件下衬砌的受力特性,通过对隧道衬砌表面应变、孔压、土压力和衬砌周边围岩位移的试验测试数据为分析依据。主要获得以下结论:1、本试验研究中,所设定的两种溶洞分布状态(沿经过隧道衬砌中心位置的水平面和竖直面对称布置与沿经过隧道衬砌中心位置走向为45°和135°平面的对称布置)对隧道衬砌的安全性影响存在极大的差异,且前者对隧道的不良作用较小;2、溶洞的直径对于隧道衬砌受力特性影响最小,其作用主要是通过与围岩节理面倾角和溶隧间距(溶洞与隧道的距离)的组合来体现;3、溶隧间距对隧道衬砌的安全性具有显著的直接影响,伴随该距离从一倍隧道直径逐渐增大,隧道衬砌的安全性表现为先减弱后增强,约在该距离为1.5倍隧道直径时,隧道衬砌的安全性最差;4、围岩的节理面倾角对隧道衬砌安全性的影响较为复杂,主要表现为以围岩沿节理面方向运动发生的附加应力作用和地下水沿节理面渗流所发生的孔压调节作用。当围岩节理面倾角小于45°时,前者居于主导地位,而伴随节理面倾角的增大,后者的作用逐渐增强。
[Abstract]:The geological conditions in karst area are complex and changeable, and there are many uncertainties. The dissolution of soluble rock in karst area has an adverse effect on engineering practice. The construction of the tunnel has changed the original groundwater balance. At the same time, due to the existence of the cave, the water pressure will produce concentrated stress on the tunnel lining, which will lead to tunnel structure damage, cracking, even water gushing, mud gushing, lining falling off and so on. A serious threat to the normal operation and safety of the tunnel. Based on the model test of indoor tunnel in karst area of Guangdong Province, this paper studies the spatial distribution characteristics of tunnel in different karst area and different joint inclination angle, which is based on the project of running highway tunnel in karst area of Guangdong province. Based on the experimental data of tunnel lining surface strain, pore pressure, earth pressure and surrounding rock displacement under different rainfall intensity and loading conditions. The main conclusions are as follows: 1. In this experiment, The safety of tunnel lining under two kinds of cave distribution states (symmetrical arrangement along horizontal plane and vertical face through the center of tunnel lining and symmetrical arrangement along 45 掳and 135 掳plane along the center of tunnel lining) There are great differences in sexual effects, The former has less adverse effect on the tunnel, and the diameter of the cavern has the least influence on the mechanical characteristics of the tunnel lining. Its function is mainly reflected by the combination of the inclination angle of the surrounding rock joint and the distance between the dissolved tunnel and the tunnel, and the distance between the dissolved tunnel and the tunnel has a significant direct effect on the safety of the tunnel lining. With the increase of the distance from twice the diameter of the tunnel, the safety of the tunnel lining is first weakened and then enhanced, about 1.5 times the diameter of the tunnel. The safety of tunnel lining is the worst, and the influence of joint inclination angle on tunnel lining safety is complex. The main performance is the additional stress of surrounding rock moving along the joint surface and the pore pressure regulating action of groundwater seepage along the joint surface. When the inclination of the joint surface of surrounding rock is less than 45 掳, the former occupies the dominant position, and the latter gradually increases with the increase of the dip angle of the joint surface.
【学位授予单位】：湘潭大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U451

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