采选技术与矿山管理

层理结构板岩动态断裂特性

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  • 1.中建六局水利水电建设集团有限公司,天津 300350
    2.中国建筑第六工程局有限公司工程技术研究院,天津 300171
    3.华侨大学土木工程学院,福建 厦门 361021
张玉(1987-),男,河南南阳人,工程师,从事水利水电工程技术设计和科技研发工作。zhangyu871030@163.com

网络出版日期: 2024-07-03

基金资助

中建六局科技研发计划资助课题“复杂环境条件下输水隧洞爆破施工关键技术研究”(CSCEC6B-2020-Z-12);国家自然科学基金项目“爆破震动诱发深部巷道围岩时效破坏机制与损伤模型”(51974136)

Fracture Performances of Bedding Structure Slate Under Dynamic Loading

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  • 1.China Construction Sixth Engineering Bureau Hydropower Construction Co. , Ltd. , Tianjin 300350, China
    2.Institute of Engineering Technology, China Construction Sixth Engineering Bureau Co. , Ltd. , Tianjin 300171, China
    3.College of Civil Engineering, Huaqiao University, Xiamen 361021, Fujian, China

Online published: 2024-07-03

摘要

基于动力冲击试验和插入黏聚力单元数值模拟方法,对层理结构板岩中心直切槽半圆盘(NSCB)试样在不同冲击速度和层理面倾角下的断裂性能展开研究。讨论了含层理结构岩样中的裂纹路径及其断裂参数。结果表明:冲击速度和层理面倾角对层理结构板岩裂纹扩展影响明显,在冲击速度较小的条件下,裂纹倾向于沿薄弱层理面扩展;随着冲击速度的增加,裂纹沿薄弱层理面扩展的长度逐渐减小,裂纹扩展路径更倾向于忽略薄弱层理面的影响,直接向加载点扩展。在冲击速度一定的情况下,裂纹沿薄弱层理面扩展的长度随层理面倾角的增加亦减小。随着冲击速度的增加,层理结构板岩的断裂韧度也逐渐增加;在给定冲击速度的条件下,层理结构板岩的断裂韧度随着层理面倾角的增加而增大。

本文引用格式

张玉, 王文己, 孙加奇, 肖永刚 . 层理结构板岩动态断裂特性[J]. 黄金科学技术, 2023 , 31(5) : 803 -810 . DOI: 10.11872/j.issn.1005-2518.2023.05.058

Abstract

Bedding structure slate can be always observed in civil and mining engineering in recent years,their physical and mechanical properties are significantly controlled by the existing bedding planes,which are generally considered as weak links that can cause various geological disasters.The fracture behavior of bedding structure slate under dynamic loading is therefore a critical issue for the selection of blasting parameters,stability analysis of rock mass,collapse and burst disaster prevention in tunnel,drift,and other underground structures.In order to investigate the effects of the inclination angle of bedding plane and impact velocity on the dynamic fracture behavior of bedding structure slate,the dynamic impact test and numerical simulation method inserted cohesive element were conducted on the notched semicircular bending(NSCB) specimens by a split-Hopkinson pressure bar(SHPB)system.Tests of NSCB specimens under static loading were conducted for comparison,and the inserted cohesive element method was also used to develop the numerical model of layered NSCB specimens under dynamic loading.The fracture initiation and propagation process of the layered specimen under varied loading conditions were modeled.The results show:(1)Impact velocity and the inclination angle of bedding plane has obvious influence on the crack propagation,and three typical cracking paths can be found for NSCB specimens under both static and dynamic loading.(2)The crack propagates along the bedding plane and then directly propagates to the loading point,the cracking path evidently exhibits dependence on the impact velocity and the inclination angle of bedding plane.For specimens under static loading,the dominated crack is more likely to propagate along the bedding planes while the cracks tend to ignore bedding planes as the impact velocity or the inclination angle of bedding plane increases.At the same time,the crack length along the bedding plane is considerably reduced under dynamic loading than under static loading.(3)It is obvious that the impact velocity and the inclination angle of bedding plane have important influence on fracture toughness,it becomes larger with the increasing impact velocity or the inclination angle of bedding plane.

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