Research And Application Of The Geophysical Method For The Detection Of Municipal Pipelines

With the rapid development of city, the construction of the underground limited space also began rapidly.The subway, tunnel, andpipe gallery have become the basic configuration of a city. Because of the historical development and other reasons, the underground pipelines included in the city infrastructure remains a lot of problems. Underground pipelines are an important part of city infrastructure. In order to meet the needs of urban construction, we need urgently to carry out urban underground pipeline information census.Geophysical prospecting method is one of the main methods of underground pipeline detection because this kind of method is rapid andnondestructive detection, so it has been more and more widely used.The survey indicates that underground pipelines in the city can be divided into two categories: metal pipeline with electrical conductivity and nonmetal pipeline with weak conductivity.It is very important to choose the most suitable method depending on the physical sensitivity parameter.For metal pipe, Electromagnetic method is the most direct and the convenient detection geophysical technology, which has the advantages of simple, convenient, low cost, high efficiency, accuracy.This thesis summarized the methods and techniques of underground pipeline pipeline detection based on electromagnetic theory and field practice, then tested the methods in the study area and verified the effectiveness of the methods.For nonmetal pipe, electromagnetic wave method is the most simple, efficient and non-destructive method. But due to the energy attenuation of fast and the underground complex environment, electromagnetic wave method is limited to the application. There exist many problems to be solved in the practical work. In this thesis, through the theory analysis of GPR detecting the pipeline and the forward modeling of the different pieline scenarios to provide the basis and support for the actual inversion of pipeline detection. At the same time, studying on the response characteristics of the geological radar can help pipeline detection and recognition though the information of the kown pipeline. And using the similar seismic data processing method, the high resolution processing of radar data was carried out and improved the accuracy of the interpretation of pipeline detection.The technology and methods summarized by this thesis are applied to the pipelines investigation project in a district of Chongqing City, and it achieved a good result, and led to the excellent completion of the census work.