Experimental Study On Uniaxial Compressive Strength Of Wuliangsuhai Ice

Since the 20 s century,human beings have paid more attention to the mechanical behavior of ice,we wish to estimate the ultimate load of the structure more accurately to ensure the safety of cold zone structure and reduce the disaster caused by ice.The uniaxial compressive strength of ice is an important parameter in the calculation of ice load.Therefore,it is of practical significance to study the uniaxial compressive strength of ice for the design and protection of the structure.In this paper,we chose the Wuliangsuhai ice to test in order to provide support for accumulating the uniaxial compressive strength of columnar ice.In January 2016,we collected ice billets in Inner Mongolia's Wuliangsuhai,and roughed the ice billets.We grinded the ice into thin slices in the field.It is observed that the ice crystal structure is a typical columnar ice structure and the average equivalent diameter of the crystal increases with the increase of ice thickness.In the low temperature environment laboratory of Dalian University of Technology,The samples were processed into standard cuboid samples of 7cm×7cm×17.5cm for uniaxial compression strength test.From November 2016 to June 2017,by using an electronic universal testing machine with strict temperature control and displacement speed control,we obtained a series of stress-strain curves for two types of samples with the loading direction vertical to the ice surface and the loading direction parallel to the ice surface at-2°C?-5°C?-7°C?-10°C?-15°C and took photos of the samples destroyed.The effects of strain rate,loading direction and temperature on uniaxial compressive strength are studied in the test.The test results show that under the same temperature,with the increase of the strain rate,the uniaxial compressive strength of the samples increases first to the peak value,then decreases,and finally tends to be stable;in the temperature range of the test,the uniaxial compressive strength of the samples improves obviously with the temperature decreasing;the uniaxial compressive strength of samples is affected by temperature and strain rate at the same time,and it can be expressed by a two element statistical relation surface.For the columnar ice in Wuliangsuhai,the peak uniaxial compressive strength of samples loading direction vertical to the ice surface is 2.1 times samples loading direction parallel to the ice surface;the strain rate of peak uniaxial compressive strength increases with the increase of temperature,and it can be expressed with exponential function;the logarithmic function can be used to express the peak uniaxial compressive strength with the change of temperature.There are three kinds of failure forms of the ice samples in Wuliangsuhai,namely,bulge failure,shear failure and splitting failure.