粗粒料水平循环单剪动力特性试验研究

Experimental Study on Dynamic Property of Coarse-grained Materials by Horizontal Cyclic Simple Shearing Test

针对利用动三轴试验设备进行粗粒料动力特性试验时存在试验成本高和工序复杂等问题,采用自主研发的水平向单剪试验仪,通过大型水平循环单剪试验,研究了粗粒料的动剪切模量和动阻尼比等动力特性。试验结果表明,粗粒料的动剪切模量、动阻尼比与水平剪应变、初始竖向应力、剪切速率和循环数等因素有关。水平剪应变越小,初始竖向应力越大,循环数越多,动剪切模量越大,动阻尼比越小,且动阻尼比随循环数的增多,其减小和增长速率均变小,最终达到收敛。试验结果与动三轴剪切试验结果规律类似,可见采用大型水平循环单剪仪进行粗粒料动力特性试验研究可行、合理。

For the problems of high cost and complex process by using the dynamic triaxial test apparatus for the dy-namic characteristics of coarse-grained materials, the independent research and development of horizontal simple sheartest apparatus has been adopted. Through the horizontal cyclic simple shearing tests, dynamic properties of coarse-grained materials, such as dynamic shearing modulus and dynamic damping ratio, are studied. Tests show that the dy-namic shearing modulus and dynamic damping ratio are affected by shearing strain, vertical stress, shearing speed andnumber of cycles. The higher the vertical stress is, the bigger the dynamic shearing modulus is; the bigger the number ofcycles is, the bigger the dynamic shearing modulus is; the smaller the shearing strain is, the bigger the dynamic shearingmodulus is. As the increment of the number of cycles, the rate of the dynamic damping ratio decreases; finally, it reaches a stable value. The laws of the results are similar to those of dynamic triaxial shear tests. Therefore, it is feasible and reasonable to dothe research on the dynamic properties of coarse-grained materials by using the horizontal cyclic simple shearing tests.