Economic Appraisal Research On Ballastless Track Of High-speed Railway Based On Life Cycle Cost

Ballastless track is used in high-speed railway all over the world.As the construction cost of ballastless track is higher than ballast track,its maintainance cost is the major part of railway maintenance and there are several kinds of ballastless track with different characteristics adopted in our country,it is essential to carry on economic appraisal research on ballastless track of high-speed railway and gives decision support to choose proper type of ballastless track in design phase,optimal design of ballastless track structure and optimal maintainance strategy in operation phase.Based on LCC,RAMS and LCA, theory and method research on ballastless track of high-speed railway is conducted in this thesis and economic appraisal indices are proposed. Major research work is as follows:1.The thesis applies Life Cycle Cost Analysis(LCCA) to study economic appraisal for ballastless track of high-speed railway,divides the life cycle cost into research cost,design cost,construction cost,maintainance cost and disposal cost according to the process,takes research cost as sunk cost and focuses on construction cost and maintainance cost.And the thesis compares the economic value of different ballastless bed in bridge,tunnel and subgrade section and double block ballastless track of CRTS I type under different design speed,and takes a railway project as an example to compare the economic value of four kinds of ballastless track under same design speed and analyses the reason and studies the influence of the proportion of bridge,tunnel length on the construction cost of ballastless track.2. Computational formula of track maintainance cost is proposed,and LCC of double block ballastless track of CRTS I type and ballast track is obtained based on two high-speed railways and uncertainty analysis is carried out.The research shows that LCC of double block ballastless track of CRTS I is less than ballast track,and if the annual maintainance cost of double block ballastless track of CRTS I increases by 29.5 percent or the rate of return exceeds 6.47 percent its LCC will be higher than ballast track,and both LCC are influenced by the life cycle and the correspondence between them exists.3. Integration of LCC and RAMS method is applied to study economic appraisal for ballastless track of high-speed railway.To combine the qualitative research of RAMS to quantitative research of LCC,reliability index and availability cost and safety cost are added to economic appraisal indices.Transverse reliability index of the slab of slab ballastless track of CRTS II is calculated,and availability cost is defined which consists of loss of passenger revenue and penalty and the computational formula is proposed and safety cost is defined and analysed.4. Integration of LCC,RAMS and LCA method is applied to study economic appraisal for ballastless track of high-speed railway. And vibration impact cost and noise impact cost are defined and added to economic appraisal indices and the computational formula of them are put forward and analysed.5.The vibration impact characteristic of slab ballastless track of CRTSIII in subgrade section of the railway from Chengdu to Dujiangyan is tested.Based on the testing results of the railway from Chengdu to Dujiangyan and from Wuhan to Guangzhou, the vibration and noise impact of several kinds of ballastless track are analysed. And a method is achieved which uses speed-distance curve to get the running speed of the train when passing by optional position of the railway line and an example is illustrated.