Application Research Of Geophysical Technology For Deep Tunnel Of Highway In Sichuan Province

In the process of investigation design and construction in deep tunnel of Highway, it often meets with bad geological phenomenon, such as fault,Karst and Landslide etc. These geological disaster shall cause huge hazard to highway construction, so it is an important forward topic that the geophysical macroscopic estimation of the deep, big, long tunnel, as well as it has much challage to be ugrently resolved.For a long time, in geophysical exploration of deep tunnel has not formed a comparatively perfect theory and method at home and abroad, this paper closely combined with a series of questions in the construction and development of highway in SiChuan province which through deep tunnel, and combined with concrete work area situation in Sichuan province, according to production practice of tunnel engineering geophysics, reading and collected a large quantity related data, After analysis which , the conclusions indicate that that application of engineering geophysics has strong pertinence and adaptability.In the paper it classify with familiar bad geological of deep long tunnel, then explain and analysis applicable geophysical method, then through some application examples to explain:(l) selecting of different geophysical methods in specific conditions;(2) selecting of engineering geophysics work in hole body and entrance position of deep tunnel;(3) selecting of engineering geophysics work in different geological conditions of tunnel.This paper summarizes engineering geophysics of tunnel which need to solve main problem:(l) Identification of formation (geologic stratification), find out depth and ickness of different strata in the tunnel which passed through profile.(2) Find out geological structure, axis segment of tunnel with or without fault, fracture zone, weak bedding surface etc.(3) Find out weathering degree of bedrock, and combine with velocity data to classify the surrounding rock.(4) Divide stratum Structure of hole body, and judge the stability of hole body.(5) Find out occurrence and activities condition of groundwater.(6) The existences of other bad geological phenomenon.Full text is systemic summary that applicable geophysical method in different investigation stages of tunnel, which provides guidance suggestion for method selection of tunnel exploration. Preliminary prospecting which is the most develop in geophysics work is described in detail, which provides applicable geophysical method for different geological condition in preliminary prospecting, it fill the gaps that geophysical method application research of deep tunnel in highway system of Sichuan province.The thesis includes 6 parts. Chapter One is an introduction that emphases on main research contents. Chapter Two isThe thesis includes 6 parts. Chapter One: expounding emphatically main research contents. Chapter Two :emphatically introducing principle and characteristic of geophysical method which is used in the main bad geological phenomenon of deep tunnel , mainly detailed analysis of high density resistivity imaging method and controlled source audio-frequency magnetotellurics ,and also introduce other common geophysical method. Chapter Three: using comprehensive geophysical method to investigate the Daxiangling tunnel which is the Longest and most deep tunnel in Sichuan at present ,and analyzing application effect which show the feasibility of geophysical method . Chapter Four: using comprehensive geophysical method to investigate the Xuyongguan tunnel in karst area,and using verification of borehole data to detect the validity of geophysical method. Chapter Five: Summarizing practical experience of tunnel in Sichuan and application of geophysical method at home and abroad, It is summarized the use of geophysical method in different Prospecting Stage.