Research And Application Of Electrical Prospecting On Tunnel Exploration

In spite of the rapid growth of transport engineering infrastructure, the complex geological environment of western region bring tunnel exploration and construction many difficulties. Like karst cave and chasm, common harmful geological body always leads to a series of geological disasters, like roof fall collapse, sudden gushing mud, lateral tunnels, mountain cracking etc. Recently, to avoid geological disasters, more attention is paid to tunnel exploration, resulting in more focus on research and application of precise and fast detection methods.Drilling, Penetration and Geophysical Exploration are tree main methods in tunnel exploration. Compared with the first two methods, Geophysical Exploration can macroscopically predict geological structure of subsurface more effectively, precisely and quickly. With the development of Geophysical Exploration, it is be widely used in tunnel exploration because of its progressive technique level and exploration accuracy. In the study, a geological survey was carried out on Baoding tunnel in expressway from Panzhihua to Dali. We used high-density resistivity and magnetotelluric sounding method to probe the surrounding area of the tunnel to find out the potential geological disasters. Good grasp of geological conditions of tunnel itself and its surroundings can provide basic information to tunnel design.In this paper, referring to related researches at home and abroad, we firstly expound basic theories of high-density resistivity and magnetotelluric sounding method. Then Based on finite element method, we did numerical simulation and built four typical geologic models. Compared with each other, advantages and disadvantages of both methods are found out. So we put forward the combination of both methods to better explain the geological condition of Baoding tunnel.In this paper, we made description of data collection technique of electrical prosp ecting in field work and key problems of data processing to ensure data quality and ac curacy of research output. By practical exploration of Baoding tunnel, we summarize t he geological condition of the tunnel. Associated with the engineering geological data,we use actual data collected by the combination high-density resistivity and magnetot elluric sounding method to explain the geologic tectonic features, rock broken zone and areas which may appear sudden water inflow of Baoding tunnel. This study not onl y achieved the intended purpose of the exploration, but also provide a reference to app lication of Electrical Prospecting on tunnel exploration.