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堆积体是一种典型的二元介质,由软弱的基质土与坚硬的碎、块石构成。利用元胞自动机模型对随机离散单元进行演化,模拟堆积体的分布结构、“聚团”特征;利用弹性应力波传播原理计算波的等效速度,研究了堆积体内介质分布、软硬程度对动力学参数的影响规律。研究发现,堆积体内的波速由基质与充填物共同决定,基质材料越弱,地震波传播速度越慢,二者呈对数变化;堆积体内碎石含量越高,则波速越快,波速与充填碎石块含量呈对数关系增长,而振幅系数与碎石含量关系不大,主要取决于碎块石的分布结构;由于堆积体介质密度不均,导致堆积体内波传播速度与入射波频率密切相关,高频波速度快、低频波速度慢,横波速度与入射波频率成指数递增关系。研究表明,采用基于元胞自动机模型研究动变形参数,可以更好地反映出堆积体的波动力学性能,是一种获得复杂介质动参数的重要方法,可以弥补室内及现场试验的不足。
Accumulation is a typical binary medium, composed of weak matrix soil and hard crushed stone. The cellular automaton model was used to evolve the random discrete elements to simulate the distribution structure of the pile body and cluster characteristics. The equivalent wave velocity was calculated by using the principle of elastic stress wave propagation. The distribution of medium in the pile body, Influence of degree on kinetic parameters. The results show that the wave velocity in the sediment is determined by both the matrix and the filler. The weaker the matrix material, the slower the propagation velocity of the seismic wave is. The higher the content of the gravel, the faster the wave velocity, The stone content increases logarithmically, but the amplitude coefficient is not related to the gravel content, which mainly depends on the distribution structure of the crushed rock. Due to the uneven density of the media, the wave propagation velocity in the deposit body is closely related to the incident wave frequency , The high-frequency wave velocity is fast, the low-frequency wave velocity is slow, and the shear wave velocity and incident wave frequency are exponentially increasing. The research shows that the dynamic deformation parameters based on Cellular Automata model can reflect the fluctuating mechanical properties of the deposit better. It is an important method to obtain dynamic parameters of complex media and can make up for the shortcomings of indoor and field tests.