| Shandong Province as China’s agricultural province,irrigation channels throughout.At the same time,Shandong is in the frozen area,the winter climate is cold,the channel is easy to freeze,and damage is often from the lining,such as the occurrence of lining slip,broken,resulting in cracks,uplift,surface peeling,etc.Channel impermeability decreased rapidly,resulting in channel leakage and waste of water resources.In this context,this paper combines the characteristics of channel lining failure in practical engineering,and uses the direct shear method to simulate the shear failure process of the channel contact between the channel foundation and the concrete lining: the soil samples taken from the irrigation area and the concrete lining After treatment were placed on the upper and lower shear box,after full preload,frozen after the shear test.By adjusting the moisture content of the soil,the temperature at the time of freezing,the freezing time and the normal stress at the time of cutting,the shear strength of the frozen contact surface between the foundation and the concrete lining is studied with different water content,freezing temperature and normal stress And the freezing time and other influencing factors.The main results of this paper are:1.In the initial stage of shear,there is a local shear stress release in the contact surface.The amount of release is affected by soil moisture content,normal stress and freezing time factor,but it is not affected by freezing temperature.In the range of the test parameters: the higher the soil moisture content,the greater the release;the greater the normal stress,the greater the release;the longer the freezing time,the smaller the release.2.The shear strength of frozen contact surface is closely related to soil moisture content,freezing temperature,normal stress and freezing time.In the range of the experimental parameters,the peak shear strength of the contact surface increases with the increase of the soil moisture content,the normal stress and the freezing time,and decreases with the decrease of the freezing temperature.The peak shear strength The stress and freezing time are linear in the range of this test parameter.3.The shear strength of the frozen contact surface is essentially the cementing force between the ice crystals in the frozen soil and the contact surface of the concrete lining,and the cohesion and friction between the soil and the concrete lining contact surface.Soil water in the formation of low temperature ice and concrete lining the surface through the formation of cementing.The peak shear strength is mainly affected by the cementing force.The cohesion and friction are mainly affected by the normal stress and the freezing time. |
