Study Of Technology And Application Of Roadbed Disease Exploration

With the rapid development of railway construction in China, the network size has been continuously expanded, the net framework strengthened and the network structure optimized. At the same time, the task of railway transportation has been more and more onerous, then the railways are constructed in different ages, complex geological conditions and effected by their designs and constructions as well, in addition, the railways are making advances to speed-up and load-over now, so many railway roadbed have the existence of all kinds of diseases in different degree. These diseases effect badly the normal railway operation, even they may bring about catastrophic accidents. Thus it has been deeply concerned that how these diseases are high efficiently found out but the railway operation cannot be effected at all. So, Rayleigh wave prospecting is presented in this thesis. Rayleigh wave method is a jumped-up and effective in-situ test. We can inverts the velocity structure of the strata through the quantitive interpretation of dispersion curve of Rayleigh wave with this method, then distinguish and determine the physico-mechanical properties of the strata by the wave velocity in order to solve the geotechnical problems. The successful application of Rayleigh wave prospecting in the exploration of railway roadbed disease of the existing lines demonstrates fully that this method is completely feasible. Therefore it has broad prospect for application and is worth much promotion. But the method has not been perfect so far. It's theory and application have been in development. Firstly the theory and prospecting principle of Rayleigh wave method are demonstrated, the characteristic of displacement, energy and it's attenuation of Rayleigh wave in free surface are analyzed and the engineering importance of Rayleigh wave velocity is discussed. Then the frequency divergent characteristic of Rayleigh wave in homogeneous and horizontal bedding medium is analyzed and the major factors effecting on the exploration precision of Rayleigh wave method are discussed. This thesis analyses and compares all kind of inversion methods then pointes out their own excellences and disadvantages respectively. Besides this thesis deals with the mechanism of the main railway roadbed diseases and introduces the field work method as well as some items worthy ofnote. With practical examples in a research mission, the thesis also analyses and studies the application of Rayleigh wave method in the railway roadbed disease exploration and acquired satisfied results. In the end, this thesis puts forward repair advice aiming at different diseases accordingly.