Model Test Study Of The Dynamic Performance Of Soil Subgrade Bed For Unballasted Track

Followed our country ordinary train speed is raising in the recent years, as well as the forward development and the construction tendency of high-speed railroad. The road conditions and the driving conditions were changing more and more important to enhance the driving security and the comfort. Unballasted track structure has obtained the widespread application on the overseas high-speed railroad construction because of its flatness and the few services as well as the high comprehensive economic efficiency.Because the high-speed railroad construction just started in our country, the reference material and the design experience are very few, moreover the designing of the soil subgrade bed on the unballasted track construction is at the blank condition. Based on the above reason, the essential engineering research on the designing of the soil subgrade bed seemed to be extremely urgent and important. The indoor great proportion subgrade bed model test was done in this article based on the construction practice of unballasted track on soil subgrade of Sui-Yu Railway Line. The filler of the surface layer of subgrade bed is graded broken stone and the bottom layer of subgrade bed is A,B group filling. This model test altogether is divided three groups: The thickness of surface layer is 0.4 meter and the thickness of bottom layer is 1.8 meter in the first group; The thickness of surface layer is 0.3 meter and the thickness of bottom layer is 1.8 meter in the second group; the third group is rain test. The filler of the surface layer of subgrade bed is graded broken stone and the bottom layer of subgrade bed is A,B group filling, all the padding have been taken from the Sui-Yu Railway Line experiment section work site. The modelling process and test condition and data processing were introduced in detail. Analyzed the changing rule of the dynamic stress, deformation, acceleration and progressive settlement in the subgrade bed under the train dynamic load function. Obtained the data of the dynamic performance of soil subgrades bed for Unballasted Track,which will provide the basis for further improving subgrades bed design.