EXPERIMENTAL STUDY ON EFECT OF INTERFACIAL ROUGHNESS ON DESICCATION CRACKING BEHAVIOR OF SOIL

In the process of evaporation and drying, soil will cracks, which greatly change the nature of its engineering, triggering a variety of engineering geological disasters. In order to study the effect of interfacial roughness on soil cracking, two kinds of cracking tests are carried out, by applying Vaseline at the bottom of the container(S1) and posting sandpaper(S2) to change the interface roughness. During the experiment, the fissure development of the soil is recorded on a regular basis. The geometric characteristics of the fractures are quantitatively analyzed by digital image technology. The dynamic development process and related parameters of soil crack under different interface roughness are obtained. The results show the following aspects. (1) Soil evaporation process can be divided into three typical stages:constant rate stage, deceleration rate stage and residual stage. (2) Cracks are generally divided into three typical stages:the main fissure generation stage, the secondary fissure generation stage and the fracture growth stabilization phase. (3) The interface roughness has an important effect on the development of the fissure. For the relatively smooth interface of the base, the soil sample tends to shrink to the center as a whole, and the surface hardly produces cracks. For the rough interface, by the role of the base friction, soil surface developed criss-crossing the fissure network. The influence of interface roughness on the growth rate of fissure is different in different fissure development stages. The higher the interface roughness, the lower the surface fissure in the final stability.