Damage Study Of Semi-rigid Base Materials Under Hydrodynamic Pressure

Under the condition of dynamic water, the damage of semi-rigid material is caused by the traffic load. By using rational experimental methods and scientific theories, this paper aims to study the damage mechanism of semi-rigid material under the effect of dynamic water and get the deterioration equation of materials.In this paper, we use dynamic water generator and three-triaxial apparatus to conduct erosion test under cycled dynamic water. Besides, we use universal testing machine to conduct uniaxial compression test. Based on seepage mechanics, concrete damage theory and damage soil mechanics, we discuss the coupling effect of pore water pressure and materials and establish the damage evolution model that meets the mechanic properties of materials. Finally, we use the experiment results to validate the model and draw some conclusion as follows:(1)By doing strength test under normal state and water-saturated state using three-triaxial apparatus, we find that the failure strength of materials is related to pore water pressure.(2)During the erosion test under cycled dynamic water, we conduct contrast experiment using different confining pressure and axial pressure. We discuss the relationship between pore water pressure and confining pressure, also we discuss the impact of pore water pressure and stress state of specimen to deterioration mechanisms of materials. Besides, we use test specimen of different maintenance to discuss the impact of material properties to test purpose.(3)During the erosion test under cycled dynamic water, the coupling effect of pore water pressure and materials promotes development of pore and micro-fissure, thus providing a path for pore water pressure. On the other hand, the growing path of pore water pressure provides a platform for interaction between pore water pressure and the specimen, which further changes the physical properties of specimen and aggravates the deterioration of material performance. From a macro perspective, the ultimate load decreases and the initial compression strain increases during the uniaxial loading test.(4)By uniaxial compression test we can get stress strain curve of materials, in which we take the slope of the line segment as elastic modulus of materials. Also, we analysis the attenuation law of elastic modulus under influence of dynamic water with different number. (5)We use concrete damage theory and damage soil mechanics to analysis the deterioration of materials under influence of dynamic water, from which we get the deterioration equation and establish damage model of materials.