Research On Safety Assessment Technology For Operating High-speed Rail Corridors In Soft Soil Areas

Along with the large-scale construction of high-speed railways, the number of high-speed rail that have been built and under construction are increasing. At present, the city scale extending rapidly, and high-speed rail segmentation effect is significant increasingly. Since the municipal planning can not promptly follow up, many municipal roads or pipe have to cross the existing high-speed railway bridges. In soft soil area, the ballastless track of high-speed railway bridges has strict requirement for settlement and bearing capacity. In order to ensure the safety of the high-speed railway bridge and reduce the possibility of engineering accidents, generally it needs special protective design of construction and systematic safety evaluation for engineering near or under high-speed rail. But there is no standard to follow for the protection measure and safety assessment technology of such engineering, so it is necessary to study the protective design and safety assessment technology for engineering near the high-speed rail in soft soil area to provide technical support for such work.In this paper, based on the Wuqing Cuiheng road engineering through the Beijing-Tianjin Express Railway project which is the first interchange project in china down-traversing running high-speed railway,and it's high in security risk, complex in construction technology and difficult to build. This paper focus on subsidence evaluation technology of channel engineering ajdcent to running high-speed railway in soft soil area, using empirical formula method and three-dimensional finite element method, construction precipitation and foundation excavation influence to nearby high-speed railway structure has been analyzed individually. Furtherly, in order to verify the assessment effection, the analysis result has been compared with measured data.The results show that: the engineering near the high-speed rail should focus on controlling the water table changes, excavation unloading and loading problems of casting structure. Using high pressure jet grouting pile closed seal design can effectively reduce the settlement of existing high-speed rail affected by the pumping of pit or precipitation near the railway and ensure that high-speed rail deformation measured meet regulatory requirements. Comparison between modeling analysis and the measured data proved that this safety assessment method is adopted, feasible and it can provide reference for the safety assessment of similar engineering in the future.