节理影响下的滚石碰撞破碎规律研究  

Collision and fragmentation patterns of rockfalls under the influence of joints

作　　者：郑路 陈元睿 吴怡涵 张学略 毕钰璋 ZHENG Lu;CHEN Yuan-rui;WU Yi-han;ZHANG Xue-lue;BI Yu-zhang(College of Civil Engineering,Fuzhou University,Fuzhou,Fujian 350108,China;Fujian Architectural Design and Research Institute Co.,Ltd.,Fuzhou,Fujian 350108,China;College of Resources and Environment,Fujian Agriculture and Forestry University,Fuzhou,Fujian 35002,China)

机构地区：[1]福州大学土木工程学院,福建福州350108 [2]福建省建筑设计研究院有限公司,福建福州350108 [3]福建农林大学资源与环境学院,福建福州350002

出　　处：《岩土力学》2025年第3期729-749,共21页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.41977233)。

摘　　要：通过物理试验研究了节理影响下的滚石碰撞破碎规律,并在室内碰撞试验的基础上,采用非连续变形分析(discontinuous deformation analysis,简称DDA)并行计算方法对滚石冲击―碰撞―破碎过程进行数值模拟。主要探讨节理和坡面的夹角β、节理的连通率k和滚石的冲击速度V对滚石破碎特征的影响。采用滚石表面积与初始滚石表面积之比η,作为定量描述滚石破碎程度的量值,η值越大,破碎程度越高。通过研究发现:(1)η随k的增大而增大;在较大速度冲击条件下时,k=0.75时的η值是k=0.25时的1.2倍;(2)k=0.25时,η随β的变化不大,当k=0.50和0.75时,η随β的增加而减小;(3)高速冲击下(6.8~7.4 m/s)的η相对于低速条件(3.5~4.5 m/s)的η提升了1.5倍;(4)随着滚石单节理连通率k从0增大到0.75,能量恢复系数呈现逐渐减小的趋势,其数值降低了1.6~1.9倍;(5)随着撞击速度的增加,滚石的能量恢复系数随节理夹角β的增加而逐渐增大,最大可达1.6倍。(6)数值模拟与室内碰撞试验得到的破裂特征和破碎程度基本相同,单节理连通率和节理与坡面夹角的扩大影响了应力的传播,改变了试件破裂特征。(7)多节理滚石撞击破碎时,裂缝不沿节理设置轮廓延伸,不与远离岩石中心的节理相交。撞击后的碎片速度略低于撞击前的速度。本研究对揭示滚石原生节理影响下的碰撞破碎具有一定的参考意义。The collision and fragmentation patterns of rockfalls under the influence of joints were studied through physical experiments.Based on indoor collision tests,the discontinuous deformation analysis(DDA)parallel computing method was used to simulate the impact-collision-fragmentation process of rockfalls.The main focus is on discussing the influence of the anglebbetween the joint and the slope,the connectivity rate k of the joint,and the impact velocity V of the rockfall on its crushing characteristics.The ratiohof the surface area of the rockfall to its initial surface area is used as a quantitative measure of the degree of fragmentation,with a largerhindicating a higher degree of fragmentation.The research findings are as follows:1)hincreases with k;under high-velocity impact conditions,thehvalue at k=0.75 is 1.2 times that at k=0.25.2)When k=0.25,hdoes not vary significantly withb;however,when k=0.50 and 0.75,hdecreases asbincreases.3)Thehvalue under high-speed impact(6.8-7.4 m/s)is 1.5 times higher than that under low-speed conditions(3.5-4.5 m/s).4)As the single-joint connectivity rate k of the rockfall increases from 0 to 0.75,the energy recovery coefficient exhibits a decreasing trend,with its value reduced by 1.6 to 1.9 times.5)With the increase in impact velocity,the energy recovery coefficient of the rockfall gradually increases with the increase in joint angleb,up to 1.6 times.6)The fracture characteristics and degree of fragmentation obtained through numerical simulation and indoor collision tests are basically the same.An increase in the single-joint connectivity rate and the angle between the joint and the slope surface affects stress propagation and alters the fracture characteristics of the specimens.7)When a multi-jointed rockfall is impacted and broken,the cracks do not extend along the outline of the joint setting and do not intersect with joints far from the center of the rock.The velocity of the debris after impact is slightly lower than that before impact.This study has certain reference signi

关 键 词：碰撞破碎 原生节理 滚石灾害 物理试验 能量恢复系数 

分 类 号：P642[天文地球—工程地质学]