颗粒形状对人工模拟堆石料强度和变形特性影响的试验研究

Experimental study of influence of particle shape on strength and deformation for artificial rockfill materials

颗粒形状对堆石料的强度和变形特性有着明显的影响。采用水泥净浆浇筑方法,制备了相同体积不同形状的粗颗粒近似模拟堆石料颗粒。通过三轴剪切试验,研究了不同围压条件下颗粒形状对人工模拟堆石料的强度和变形特性的影响。结果表明:颗粒形状对人工模拟堆石料的强度和剪胀特性有影响,随着颗粒球度的增大,人工模拟堆石料峰值强度增大,低围压下剪胀特性越明显;极限应力比随着颗粒球度的增大而减小;初始切线模量和切线体积模量随着颗粒球度的增大而增大;初始内摩擦角受颗粒球度影响较小,内摩擦角增量受颗粒球度的影响相对较大,随着颗粒球度的增大而减小。

Particle shapes have great influence on strength and deformation of rockfill material. Particles with same volume and different shapes are made by cement paste pouring to simulate the rockfill material. The effect of particle shape on strength and deformation of artificial rockfill materials are investigated under different confining pressures in a series of triaxial shear tests. Test results show that the particle shape influences strength and dilatation of artificial rockfill material. As the particle roundness increases, the peak strength of artificial rockfill material increases. The rockfill material presents high dilatancy under a low confining pressure. As the particle roundness increases, ultimate stress ratio decreases, and initial tangent modulus and tangent bulk modulus increase. Initial internal friction angle is trivially affected by the particle roundness, and increment of internal friction angle is influenced by the particle sphericity. Larger particle sphericity leads to a less increment in internal friction angle.