藏式毛石砌体受压力学性能试验与数值模拟研究

Experimental and numerical simulation study on compressive mechanical properties of Tibetan rubble masonry

通过试验和PFC2D二维数值计算对2组共计8个典型藏式毛石棱柱体试件进行单轴压缩性能分析,获得了棱柱体压缩破坏全过程、应力-应变全曲线和弹性模量等基本力学参数。发现藏式毛石砌体受压过程呈现出阶段性和明显的非线性行为,得到了PFC2D二维数值模拟能较好地再现毛石砌体的压缩破坏形态和裂缝开展情况,黏土中增添碎石能提高约23%的承载力,且能有效改善试件失稳破坏形态,石材抗拉强度和黏土弹性模量是影响试件初裂强度和峰值强度的关键。为工程中评估藏式毛石砌体抗压承载力提供了一种新方法。

The uniaxial compression performance of two groups of 8 typical Tibetan rubble prism specimens was anayzed by experiments and PFC2D two-dimensional numerical calculation.The basic mechanical parameters such as the whole process of compression failure,the full stress-strain curve and elastic modulus of the prism were obtained.It is found that the compression process of Tibetan rubble masonry presents stage change and obvious nonlinear behavior.The results show that PFC2D two-dimensional numerical simulation can reproduce the compression failure pattern and crack development of rubble masonry well.Adding gravel into clay can increase the bearing capacity by 23%and effectively change the instability failure mode of the specimen.The tensile strength of stone and elastic modulus of clay are the key factors affecting the initial crack strength and peak strength of specimens.A new method for evaluating the compressive capacity of Tibetan rubble masonry in engineering was provided.