| The train-induced vibration will spread outward through the medium of around strata, and induce the secondary vibration of construction in further, which brings great influence to construction and people's daily life. How to analysis the environment effect cased by vibration has become a very important problem.The track system is composed of rail-, sleeper ballast and substrate. When the train moves, the wheel and'the track system will interact each other. Because of the action of the wheel, the track may bright bent transformation, and the transformation change into load, which act on the foundation. Then the ground will be vibration caused by the transformation spreads in the ground.In order to get the neural network' training samples, the paper will use the data computed by some analytic method as training samples besides using existing data which measured by in locale. The paper based on the mechanism of the vibration's production and transmission, uses the analytic method of finite elastic layer to calculate the transmission of the ground vibration caused by track traffics. Then gets the result of wave numbers-frequency field through solving the wave equation of the three-dimension elastic layer. Then gets the dynamic response characteristic of the ground through dispersing the wave numbers. Finally gets the result of the space-time field through using reverse fast Fourier transform.The paper gives the expressions of the moving load in the time-space field. The paper gives stiffness matrix and mass matrix in finite element analysis of the ground vibration problem caused by track traffic by using three-dimension finite element method. Because three-dimension finite element analysis is very difficult, it is transmitted into a quadratic programming, which can be calculated by neural network.The paper analyzes the ground vibration caused by track traffic in two ways by neural network and genetic algorithm fusion. One side is forward analysis, on the other side is inversion. And the paper implements the three-dimensional dynamic simulation of the ground vibration. It mainly includes five parts.(1) The paper has studied the contractive mapping genetic algorithm, which can be converged to a global optimal solution proved by fixed-point theorem of Banach space. It remedies the shortage of standard genetic algorithm. Furthermore, the paper discusses the genetic operation in the algorithm such as the coding, select, cross over and mutation etc. It will be help to the next work about fusion with the neural network.(2) The paper has studied the structure and training algorithm of BP neural network. And it is applied to the modeling of constitutive model. Considering the shortage of BP neural network such as too long training time and easily converging the local optimal value, the paper applies the contractive mapping genetic algorithm to BP neural network1 training, which make it consequently converges to the globe optimal value more quickly.(3) The paper has studied the structure and stability of Hopfield feedback neural network. And it uses the Lyapunov method to analysis the stability of the TH neural network, which id mended from Hopfield neural network. The paper applies the TH neural network to a quadratic programming, which is transmitted from finite element computing. Finally the paper applies the contractive mapping genetic algorithm to search the equilibrium point of TH neural network in a quadratic programming computing for the first time.(4) The paper has studied the structure and training algorithm of self-recursion neural network. It also studies the convergence and stability of self-recursion neural network' training algorithm by using Lyapunov method. Then the paper use inversion method to simulate the vibration field of ground vibration caused by track traffic by self-recursion neural network for the first time. Considering self-recursion' structure can work on its inversion effect, so the paper uses contractive mapping genetic algorithm to search its optimal struct...
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