Time-Depended Back-Analysis Of Subgrade Settlement For Guangzhou-Zhuhai Intercity Railway In Service

The soft soil subgrade settlement problems related to the quality of railway construction, normal operation and maintenance work, especially for the dedicated passenger line, which have high requirements for the post-construction settlement. For the subgrade settlement rule of DPL in operating period, regardless of the basic theory of analysis or the analysis of the measured data, the result usually have has complexity and uncertainty, and the railway subgrade settlement in operating period seriously affected the track regularity, thereby increasing the workload and job difficulty maintaining railway works. In this paper, according to the Guangzhou-Zhuhai intercity rail relevant sections of the subgrade settlement measured data, studied the subgrade settlement calculation method for its operating period, mainly in the following three points:(1) Using Merchant model describes the foundation of soft soil’s creep properties in railway operating period, using ABAQUS finite element software to achieve the numerical model of the process of Merchant. On this basis, paper established finite element calculation model of the typical subgrade section to Guangzhou-zhuhai intercity railway K73+967-K74 +226 section.(1) Starting from the idea of parameter identification based on the model inversion analysis, using artificial neural network model to replace the traditional finite element calculation model for inversion analysis of deformation of soil parameters, at the same time introducing PSO algorithm to optimize parameters, high efficiency and global convergence of the neural network is established. On this basis, conducted the training of network and the inversion model parameters, and by comparison with the measured data, got more consistent inversion soil deformation parameters with the actual situation. It can better reflect the law about subgrade settlement by the changes of time in the FEM calculation; the results can be used to investigate the settlement characteristics of Guangzhou-Zhuhai intercity railway, and its long-term settlement deformation prediction.(2) Based on the inversion analysis of the established numerical model and analysis results, research Guangzhou-Zhuhai intercity rail subgrate structure model deformation of the settlement under the loads, analyzed the influence of the structural parameters of composite foundation, external loads and soil parameters on soft ground settlement, and drew the appropriate conclusions, and analyzed of the internal relation of these factors and settlement, the conclusion is reference significance to explore time-varying regularity of settlement deformation, at the same time also to have certain reference for optimization design of actual engineering.(3) Based on the Guangzhou-Zhuhai intercity railway K73+967-K74+967 section of subgrade settlement measured data, used different methods compared calculation settlement law of prediction research section. Combined with the inversion results, reproducted process of various sections settlement development, predicted of the final settlement. The result provides a reference for PDL subgrade settlement evaluation in operating period.