单向非贯通节理岩体滚刀破岩特性离散元模拟  

Discrete Element Simulation of the Rock-breaking Characteristics of a One-way Non-through Jointed Rock Mass Using Hob

作　　者：陈晓坚 CHEN Xiaojian(Xiamen Rail Transit Construction&Development Group Corporation Limited,Xiamen,Fujian 365004)

机构地区：[1]厦门轨道建设发展集团有限公司,福建厦门365004

出　　处：《都市快轨交通》2023年第6期99-107,共9页Urban Rapid Rail Transit

基　　金：福建省科技计划引导性项目(2020H0014)。

摘　　要：相较于贯通节理,岩桥的存在使非贯通节理岩体受力破坏过程更加复杂。为探明其对破岩影响,通过采用PFC2D建立单向非贯通节理岩体滚刀破岩离散元模型,研究岩桥长度和倾角对岩体破碎模式、法向力、裂纹数量及比能耗等参数的影响,揭示非贯通节理岩体滚刀破岩特性。研究发现:岩体以张拉破坏为主,节理对裂纹扩展的“导向作用”明显,裂纹扩展方向总是趋向于和其距离最近的节理;竖向应力水平随节理倾角增加呈现先增大后减小的趋势,在45°倾角下达到最大值,应力区形状受到节理位置影响,两者具有一致性;完整岩体法向力均值和峰值均大于节理岩体,节理对于破岩过程具有明显的促进作用;0°、60°、90°节理倾角下的比能耗值明显低于其他节理组合,60°倾角下呈减小趋势,在岩桥长度为25 mm时取得最小值;0°、90°倾角下呈先减小后增大趋势,在岩桥长度为15 mm时取得最小值。Compared with penetrating joints,the existence of rock bridges in non-penetrating jointed rock masses complicates their failure process.To explore their influence on rock breaking,a discrete element model of rock breaking using a disc cutter in a unidirectional non-penetrating jointed rock mass is established using PFC2D.The influence of rock bridge length and dip angle on the rock-breaking mode,normal force,crack number,and specific energy consumption is examined,and the rock-breaking characteristics of the disc cutter in the non-penetrating jointed rock mass are revealed.The results indicate that the rock mass is dominated by tensile failure,and the joint exerts an evident"guiding effect"on crack growth.Furthermore,the crack growth direction always tends to the nearest joint.The vertical stress level initially increases and then decreases with an increase in the joint dip angle and reaches a maximum value at a dip angle of 45°.The shape of the stress zone is affected by the joint position,but both are consistent.The mean and peak values of the normal force of the intact rock mass are greater than those of the jointed rock mass,and the jointed rock exerts a clear promoting effect on the rock-breaking process.The specific energy consumption at joint dip angles of 0°,60°,and 90°is significantly lower than that observed under other joint combinations.The energy consumption decreases at a joint dip angle of 60°,and the minimum value is obtained when the length of the rock bridge is 25 mm.At 0°and 90°,the energy consumption decreases initially and then increases,and the minimum value is obtained when the length of the rock bridge is 15 mm.

关 键 词：隧道 滚刀 数值计算 非贯通节理 岩桥 破岩 比能耗 

分 类 号：U25[交通运输工程—道路与铁道工程]