Settlement Analysis And Assessment Practice In High Speed Railway

The high requirements of track ride comfort and strict limits to settlement after construction of underline engineering in high-speed railway brought large numbers of new technical problems to unballasted track laying and design as well as construction of underline foundation. In order to control the settlement after construction of subgrade strictly and satisfy the related requirements of fastener adjustment and smoothness of railway vertical curve, each high-speed railway built or building took measures to consolidate foundation in soft soil sections and carried settlement observation to monitor and control the settlement of subgrade at the beginning of design.Firstly, the paper discussed the settlement deformation mechanism of high-speed railway embankment settlement from the theory, including foundation settlement, road base settlement and a large area of subsidence on surface area and the related internal settlement mechanism, and found root causes of the settlement deformation during high-speed railway construction and operation. Then this paper put forward the technical measures to control the settlement in the process of building high-speed rail as to meet the safety and comfort of the opening and operation of high-speed driving after operation.Basis for the settlement of the current assessment of the domestic high-rail carry out late, and not yet fully formed a scientific, efficient, settlement system of observation on non-ballasted track system and analytical assessment of the status of implementation, following the "Technical Guidelines for Assessing" and "high-speed rail specification ",Under the premise of combining the analysis of long-term field settlement assessment of practical experience, this paper offers to" assume (calculated)-actual-forecast-Inversion comparative analysis "as the main program of the relevant calculation, and sets the opening of the new The Shanghai-Nanjing Intercity Railway Subgrade assessment as an example, tests and evaluations the scientific and practical of the methods to further explore the influence of different construction techniques on subgrade line engineering Settlement.At last, drawing lesson from the subgrade settlement observation evaluation of Shanghai-Nanjing Intercity Rail, combined the actual observation conditions in field, proposes that settlement evaluation should be conducted before preloading soil of subgrade unloaded and unballast track laid respectively, with process monitoring and management during the period. Based on the strict standards according to The Evaluation Technique Guide to the Unballast Track Laying Conditions in Passenger Dedicated Line during the re-evaluation, it conducts adjustment and control towards the first evaluation index and remedies the defects of it by the measurements such as re-evaluation and process monitoring to solve the contradiction between the construction schedule and high-tech requirements.