Model test apparatus for studying dynamic response and long-term settlement law of high-speed railway

Abstract

The invention relates to a novel experimental apparatus for a high-speed railway, in particular to a model test apparatus for studying the dynamic response and long-term settlement law of the high-speed railway, which can simulate and predict the driving conditions with the speed of more than 400km / h and can provide a basis for the settlement prediction under the long-term effect.

Description

Technical field [0001] The invention relates to a new type of high-speed railway experimental device, in particular to a model test device for studying the dynamic response and long-term settlement law of the high-speed railway. Background technique [0002] Before the present invention, indoor dynamic tests and field tests were commonly used methods in the research and test of the dynamic response and settlement laws of high-speed railways. Indoor dynamic tests include dynamic triaxial apparatus and hollow cylinder torsion apparatus. The research objects of these experiments are all soil samples, and the analysis of the dynamic characteristics of the soil sample micro-element bodies is very different from the force characteristics of the on-site roadbed. Moreover, the simulation of vibration load in the above-mentioned experimental research is mostly limited to symmetrical sinusoidal cyclic load, which is different from the pulse characteristics of vibration of traffic load. Th...

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Problems solved by technology

Moreover, the simulation of vibration loads in the above-mentioned experimental studies is mostly limited to symmetrical sinusoidal cyclic loads, which are different from the pulse characteristics of vibration of traffic loads, and the focus of research is basically limited to the influence of dynamic stress and cycle times on deformation.

In terms of field test research, due to the limitations of test conditions, test instruments and costs, at present, only the vibration displacement, velocity and acceleration tests can be carried out on the subgrade under the load of rail transit, but the dynamic stress caused by the train inside the foundation has not been tested. The research on the internal dynamic stress of the foundation is limited to the scope of theoretical analysis, and most of the existing research is limited to the impact of ground vibration caused by rail transit loads on the surrounding environment.

Moreover, the field test is based on the existing high-speed railway. For the high-speed railway with a speed of more than 300km / h that has not been built or opened to traffic, it is impossible to conduct experimental research, and it is impossible to predict its dynamic response and long-term settlement law.

In short, there are very few studies on reasonably simulating the dynamic characteristics of foundation soil under rail transit loads considering the pulse characteristics of cyclic loads, especially the lack of consideration of the complex stress state and stress path on the development process of dynamic stress and dynamic strain in the soil. However, this point is precisely the key to the combination of theoretical research and experimental research on the permanent deformation of foundation soil under traffic loads

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