Study On The Dynamic Water Characteristic In The Seam Of Layer Of CRTSâ… Double-Block Ballastless Track

According to the survey, a large number of seams are found in the layer of CRTS I double-block ballastless track on the road. In rainy areas in the southern China, water is easy to enter the seam, and when the train go through with the high-speed, the water in the seam will be squeezed out, which is oozing slurry phenomenon. With the train load and water, the damage of the layer will be accelerated, which directly affects the durability of CRTS I double-block ballastless track. Therefore, the study on dynamic water characteristic in the seam of the layer of CRTS I double-block ballastless track,with the train load and water, is essential.(1) Through the field survey and collecting the research data of domestic and foreign concrete water damage, the reason and the expansion process of the seam of layer are summarized. And the fluid theory and the solid theory and fluid-solid coupling theory and ANSYS-CFX are introduced.(2) The model test which tests the dynamic water pressure in the seam of the layer, with the train load and water, is designed. Which research the pressure from the seam at a different location, and the influence of the amplitude and frequency of load to pressure. And for all test conditions, the pressure with the software is calculated, and comparatively analysis, in order to verify the validity of the simulation with software. The results show:the dynamic water pressure variation is consistent and the value is little difference, with the test and software. Therefore, the software calculation has a certain validity.(3) Taking the CRTS I double block ballastless track on the road for example, according to the basic principles of fluid-solid coupling, the calculation model of dynamic water characteristic in the seam of the layer with the train load and water is established. While calculating, assuming the fluid is uniform, incompressible ideal liquid. With the numerical analysis method and the use of calculation model, the dynamic characteristic is studied. The results are as follows:when the train load acts on the double-block ballastless track, the dynamic water pressure and flow rate in the seam appear positive and negative alternating phenomena. The dynamic water pressure at the tip of the seam is max, and at the opening is min, and the farther from the tip, the smaller dynamic water pressure is. The dynamic water flow rate at the tip of the seam is min, and at the opening is max, and the farther from the tip, the greater dynamic water flow rate is. The thickness and depth of the seam, speed of the train are important factors affecting the dynamic water characteristic in the seam of the layer. The dynamic water pressure and flow rate decrease with the thickness of the seam increasing; and increase with the depth of the seam increasing, and increase greatly when the depth is more than 1000mm; and increase with the train speed increasing.