Techiniques Of High-Speed Railway Soft Soil Foundation Construction And Quality Test

With the improvement of the velocity of railway system and the development of technical criterion, the requirement of railway foundation work developed gradually. The main design idea of the ballast engineering had changed from the intensity control to the deformation control. High-speed railway presented more strict and high requirement for the deformation control of ballast. But there were lots of new problems in high-speed railway on soft ground under construction, especially the sedimentation of the dyke, because of the characters of soft ground, such as: the high moisture content, the high compressibility, the open grain, the middle sensitivity, the low density, intensity and permeability. Large human power and financial capability were inputted for all kinds of experimentation and the certification of the obtained achievements in scientific research or phased research findings before construction in every country. The aim was to provide the scientific and realistic design certification and job practice for engineering. Though some monographic study such as: the experimental investigation, the grasp of ground characteristics and deformation rules, the job practice, the quality control standards, the method of control, the realistic effects of many foundation stabilization methods were certificated; the stabilization program and corresponding design parameters and calculation methods were determined; the design philosophy, the design parameters, the job practice, the means of mass detect and so on were provided; the design and construction of similar railway foundation could draw lessons from them.During construction of Wenfu railway, three techniques were adopted: the plastic drain board combining overload pre-compression, the vacuum-heaped load combining pre-compression (vertical plastic drain board) and sand pile combining equal load per-compression. The rational construction techniques and arrangement of machines of the drainage consolidation method satisfying the design requirement of high-speed railway was concluded. The experiences could help make the construction regulations and research on the reliability, the applicability and controlling parameters of the test method on construction quality. As a result, the test method, the proper combination and frequency satisfying the requirement of high-speed railway were provided. As the engineering for the carrier, taking the test for the core, obtaining the test data from the project, the rationality of design proposal, construction technology and test method were verified. The test could help repair and improve the correlated codes and design parameters. According to the aim of the test, the construction technology, the arrangement of machines and tools, the construction design scheme and the correlated techniques of foundation treatment of the correlated engineering in domestic and overseas were investigated.This paper comprehensively evaluated the applicability and economy of above three technologies of the soft foundation treatment and made a conclusion about the merits and faults of all kinds of methods. The research production could provide scientific, realistic lessons for the design and construction of ballast under same conditions.