Study On The Design Theory And Method Of Ballastless Continuous Welded Rail On Long-span Bridge In High-speed Railway

With the development of high-speed railway construction, long-span bridges are used for crossing valleys, rivers and roads frequently, so the laying of ballastless CWR on long-span bridge is inevitable. At present, in the Beijing-Tianjin inter-city railway, Wuhan-Guangzhou, Zhengzhou-Xi’an high-speed railway, Shanghai-Nanjing, Guangzhou-Zhuhai inter-city railway, Beijing-Shanghai, Guangzhou-Shenzhen-HongKong, Zhengzhou-Wuhan, Hefei-Fuzhou, Shanghai-Kunming high-speed railway and so on, ballastless CWR on long-span bridge is paved. But the problems existed in design, construction, maintenance and repair appear and should be solved timely.In connection with the deficiency of study on the design theory and method of ballastless CWR on long-span bridge in high-speed railway, on the basis of comprehensive analysis of present research situation of CWR on bridge home and abroad, the interaction mechanism among high-speed vehicle, CWR, ballastless track and long-span bridge is considered, spatial coupled static and dynamic theoretical analysis models are established, field static and dynamic experiments are made. The static and dynamic mechanical characteristics of ballastless track CWR on long-span bridge in high-speed railway are researched, analyzed, checked and evaluated from the point of theory and test. The suitable temperature span length are researched, and reasonable suggestion for designing are put forward. The main works and achievements are:1、The reasonable value of design parameters of ballastless track CWR on long-span bridge in high-speed railway are studied.The design parameters of general CWR on bridge or ballast track CWR are studied theoretically and experimentally home and abroad, but the studies on the design parameters of ballastless track CWR paved on long-span bridge in high-speed railway are relatively scarce. In connection with the deficiency of existing research, by the research and analysis of the differences of design parameter values among Germany, Japan, the other countries and organizations and China, the reasonable value of design parameters used in the research of this paper are determined.2、The spatial coupled refinement static analysis model of ballastless track CWR on long-span bridge in high-speed railway is established, and its static characteristics and influencing laws of design parameters are studied in detail. Based on the interaction mechanism among CWR, ballastless track and long-span bridge, the spatial coupled refinement static analysis model of ballastless track CWR on long-span bridge in high-speed railway is established firstly. The actual parameters and detailed composition of rail, fastener, track slab, mortar filling layer, bed plate, convex retaining block, resin filled layer, double-block sleeper, track bed slab, isolation layer, restricted groove, rubber pad, support layer, sliding layer, consolidation mechanism, high-strength plastic extrusion plate, L type lateral retaining block, long-span bridge, pier, friction plate, terminal restricted configuration, roadbed soil and so on, are considered exhaustively. Under the conditions of temperature variation, deflection and braking, the each detailed structure static characteristics and influencing laws of design parameters are analyzed in detail. The formation mechanism of existing disease is analyzed, and reasonable suggestions for designing are put forward.3、Analytical arithmetic used to calculate longitudinal force and deformation of anchorage system behind bridge abutment is derived.Based on the comprehensive consideration of interaction relationship among bed plate, friction plate, isolation layer, terminal restricted configuration structure and roadbed soil, the analytical arithmetic used to calculate longitudinal force and deformation of anchorage system behind bridge abutment is derived, and is verified mutually with finite element spatial coupled model. Based on that analytical arithmetic, the influencing laws of design size of main terminal restricted configuration and number of minor terminal restricted configuration on longitudinal displacement of anchorage system behind bridge abutment are analyzed.4、The spatial coupled refinement dynamic analysis model of ballastless track CWR on long-span bridge in high-speed railway is established, and its dynamic characteristics and influencing laws of design parameters are studied in detail.Based on the dynamic coupled interaction mechanism among high-speed vehicle, CWR, ballastless track and long-span bridge, the high-speed vehicle is regarded as multi-rigid-body system, considering adequately various nonlinear factors of car body, truck, wheel set, axle box suspension and central suspension, and the actual situation of rail, fastener, ballastless track, long-span bridge and terminal restricted configuration anchorage system, through the rigid-flexible coupling technology, the spatial coupled refinement dynamic analysis model of ballastless track CWR on long-span bridge in high-speed railway is established. The dynamic characteristics of detailed structure under the condition of high-speed are calculated and verified. The influencing laws of design parameters are researched in detail. The various dynamic response of ballastless track CWR on long-span bridge in high-speed railway of different ballastless track type are comparative analyzed.5、The field static and dynamic experiments of ballastless track CWR on long-span bridge in high-speed railway are made.The field static and dynamic experiments of unit style ballastless track CWR on long-span bridge in Zhengzhou-Xi’an high-speed railway and longitudinal connected style ballastless track CWR on Beijing-Hangzhou Canal long-span bridge in Beijing-Shanghai high-speed railway are made. The distribution of temperature gradient in the unit style ballastless track is tested, the variation law of rail temperature force of connected style ballastless track CWR on long-span bridge is researched, the coupling vibration law among high-speed vehicle, CWR, ballastless track and long-span bridge is mastered, and the security and stability of high-speed vehicle passing through ballastless track CWR on long-span bridge is evaluated.6、The static and dynamic check and evaluation on typical working sites of ballastless track CWR on long-span bridge in high-speed railway are made.With the application of design theory of ballastless CWR on long-span bridge in high-speed railway, on the basis of summary of static and dynamic check and evaluation indexes and relevant standards, using the spatial coupled refinement static and dynamic analysis model, the comprehensive static and dynamic check and evaluation on double-block ballastless track CWR on Chahe river long-span bridge in Changsha-kunming line of Shanghai-kunming high-speed railway and the CRTS Ⅱ slab ballastless track CWR on Beijing-Hangzhou Canal long-span bridge in Beijing-Shanghai high-speed railway are made.7、The reasonable temperature span length suitable for ballastless track CWR on long-span bridge are studied.When the bridge span length is large, for ensuring the safe application of track and bridge structure, certain amount rail expansion controller should be used. How to determine the reasonable temperature span length of ballastless track CWR on long-span bridge and reduce the setting of rail expansion controller are the key technology of the design of ballastless track CWR on long-span bridge in high-speed railway. With the application of design theory of ballastless CWR on long-span bridge in high-speed railway, reasonable temperature span length of ballastless track CWR on long-span bridge in high-speed railway suitable for different temperature range under the conditions of different section and rail wear are studied.