摘要
基于凸多面体顶点和面之间的拓扑关系,利用python语言编制三维随机块石生成程序,对生成的块石填充土体进而形成冰碛体数值模型。采用块体离散元程序对不同冰碛体试样进行了大型三轴试验模拟,研究了空间分布、围压大小和块石含量对冰碛体力学特性及变形破坏的影响。数值模拟结果表明,在三轴加载下,冰碛体试样发生剪胀现象,破坏后的剪切带表现出一定的绕石现象,形态上呈非对称的X形分布且受块石含量、空间分布、围压大小共同影响。冰碛体强度随着围压的增大而增大,侧面鼓胀随围压增大而减小,当围压大于800 kPa时,冰碛体在破坏后表现出应变硬化;随着含石量由5%增至35%,冰碛体黏聚力提高了68.21 kPa,内摩擦角提高了8.63°,内部块石分布造成的强度差异由0.03%增长到7%。其中含石量15%~30%阶段,抗剪强度参数急剧增大,块石对土颗粒约束增强,冰碛体由“块石悬浮”转变为“土石密实”,其余阶段黏聚力和内摩擦角缓慢增大。
Based on the topological relationship between the vertices and faces of convex polyhedron,a three-dimensional random rock generation program was compiled with Python language,and the generated rock was filled with soil to form a moraine numerical model.The large-scale triaxial test simulation of different moraine samples is carried out by using the block discrete element program.The effects of spatial distribution,confining pressure and rock content on the mechanical properties,deformation and failure of moraine were studied.The numerical simulation results show that under triaxial loading,the moraine sample has shear dilatancy,and the damaged shear band shows a certain phenomenon of surrounding rocks.The shape is asymmetric X-shaped distribution,which is jointly affected by the content of rock,spatial distribution and confining pressure.The strength of moraine body increases with the increase of confining pressure,and the lateral bulge decreases with the increase of confining pressure.When the confining pressure is greater than 800 kPa,the moraine body shows strain hardening after failure;With the increase of stone content from 5%to 35%,the cohesion of moraine body increases by 68.21 kPa,the internal friction angle increases by 8.63°,and the strength difference caused by internal rock distribution increases from 0.03%to 7%.In the stage of 15%~30%rock content,the shear strength parameters increase sharply,the restriction of rock on soil particles is strengthened,the moraine body changes from“rock suspension”to“soil and rock compaction”,and the cohesion and internal friction angle increase slowly in other stages.
作者
宋玉香
钱均益
刘勇
Song Yuxiang;Qian Junyi;Liu Yong(School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China;Key Laboratory of Roads and Railway Engineering Safety Control of Ministry of Education,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)
出处
《石家庄铁道大学学报（自然科学版）》
2022年第2期39-45,共7页
Journal of Shijiazhuang Tiedao University(Natural Science Edition)
基金
国家重点研发计划(2018YFC0808704)
石家庄铁道大学研究生创新资助项目(YC2021021)。
关键词
冰碛体
力学特性
变形破坏
大型三轴试验
离散元
moraine
mechanical properties
deformation and failure
large scale triaxial test
discrete element method
