Study On Anchoring Structure Behind Abutment Of Longitudinal Connected Slab Ballastless Track

Anchoring structure behind abutment is an important part of the longitudinal connected slab ballastless Track. No theoretical model at home and abroad to the mechanism and stress law of anchorage structure, the more the lack of test studies support. Down T main end thorn anchorage structure was used in the beijing-tianjin inter-city railway at domestic.Construction process and technology is very complex, at the same time,anchorage structure zone use cement grading-macadam and cost is higher, long-term performance need further observation and research. The anchorage structure was put forward which suitable for AB group packing roadbed, construction-convenient and satisfing the relevant requirements. In this paper, theoretical analysis and experimental research was put on by the research object of the beijing-shanghai high-speed railway.According to the composition of longitudinal connected slab ballastless Track structure and anchoring structure behind abutment, this paper analyzes the stress mechanism of the anchor structure,sets up the integration calculation model around interaction among the anchor structure, track structure and subgrade ontology, and tests the related parameter on the theory or experiment. In this paper, the application of Mohr-Coulom(M-C)criterion can describe the intensity of geotechnical material character, and establish the subgrade-model under horizontal load. Subgrade soil modulus of elasticity commonly under horizontal and the coefficient of friction model between friction plate and base plate adopted the field test results to make the model better reflect the actual situation.Using the established model, based analysis of CRCP anchorage structure on highway, and combining with setting-experience of anchoring structure behind abutment of CRTS II slab ballastless Track,the stress rule of the anchorage structure and the different types of main end thorn structure were calculated and analysed,As the result, the pepers put forward the anchorage ground beam structure form, as the same time, compared with single, double and three anchorage ground beam stress andt constraint effect and put forward the II type main end thorn anchorage structure design plan.The results obtained by analysing influenced law of designed parameters of the anchor structure show that effect of the friction coefficient to the longitudinal displacement of the structure is not big, but for the whole anchor structure force distribution have bigger influence;Different anchoring way between main end thorn and base plate affectes the whole structure of the thorn; The connections plate size between II type main end thorns is larger,structure stress and restrained deformation more favorable, at the same time,connecting plate size exists optimal datas; The impact of end-thorn’spacing to the structure stress and longitudinal displacement is not big; The influence of friction-plate size to the structure stress and longitudinal displacement is bigger,and friction-plate size exists optimal datas. At the last, according to analysed results of the designed parameters and influenced law, the papers analysed the primary end thorn structure combination and designed the optimal structure form.The field test scheme was designed. Through the Ⅱ type main end thorn structure field pushing test, changed rule of the end thorn structure of the displacement,stress and soil pressure under different loads was obtained:In the loads, the longitudinal displacement change of end thorn and friction plate is bigger and horizontal and vertical displacement change is smaller; End thorn longitudinal displacement is continuously increasing with the load increase, and the main end thorn longitudinal displacement change is more apparent and small end thorn a little small, and deformation is elastic; Longitudinal force is most bear by the end thorn;Test results also show that soil deformation around the end thorn is small, in it’s elastic range.The analyses of instability condition of the end thorn structure show that it is not satisfy the use requirement to the inverted T end thorn structure used at present, when the base plate stiffness reduces more than30%or subgrade using common A or B group of packing. The down T end thorn pushing test also shows:Longitudinal deformation of the down T main end thorn basic is made up its structure tilt and bending deformation; The lesser concretion-area of horizontal plate and vertical plate forming concentrated force and distribution force in the unit area is bigger, what can lead to concrete crack and affects the end thorn normal use. So the suggestion to strengthening design the concretion-point was drown; Cement graded gravel is vulnerable to cracking phenomenon and takes place the plastic damage, what leads to appear residual deformation, difficult to recover. And the design and construction’s controllable measures are further analysed and put forward to prevent cracking.