The Simulation Of Metro Stray Current Based On CDEGS

Metro is an effective tool to ease the urban traffic pressure and can promote the urbanization. It brings people convenient transportation and also has many problems. The DC stray current corrosion on the structural basis and surrounding metal structure is one of the larger harmful problems.It is necessary to further clarify the relevant characteristics of the metro stray current in order to reduce the stray current corrosion. In this paper, the professional software CDEGS was used to simulate the metro stray current. With the module MALZ in the CDEGS, a realistic Three-dimensional tunnel model was established. By comparison with the results of the resistor network analysis method, the model was validated to be correct. On the basis of this model, the static characteristics of stray current was simulated in the continuous and discrete parameters and also the dynamic characteristics was simulated in different load. The efficiency of the drainage net was defined and analyzed the factors affecting the efficiency of the drainage net. On the basis of this model, the rail to earth transition resistance was tested and found the factors affecting the transition resistance.The following conclusions were reached through the systematic simulation:The current flowing in the different rebar of the structural steel mesh and the drainage net was different in value, the metal near the rail was more susceptible to corrosion. That the part of rail longitudinal resistance increase has a "segment" effect on the stray current and the part of rail insulation damage has a "point" effect on the stray current. The rail is in corroded state no matter draining or not and corrosion in the middle of it is most serious. That drainage or not has little influence on the efficiency of the drainage net and the amount of stray current in draining state was nearly four time than not drain. That use the centralized distribution method and let the drainage net near the rails can improve the drainage net efficiency. The transition resistance mainly in the rail insulating layer and keeping the rail with good insulation was the only way to improve transition resistance...