微风化花岗岩隧道围岩损伤破裂特征及爆破工艺研究  

Research on the Damage and Rupture Characteristics of Surrounding Rock in Slightly Weathered Granite Tunnel and Blasting Technology

作　　者：邱明亮 QIU Mingiang(China Railway 17th Bureau Group Co.Ltd.,Taiyuan Shanxi 030006,China)

机构地区：[1]中铁十七局集团有限公司,山西太原030006

出　　处：《铁道建筑技术》2024年第3期166-170,共5页Railway Construction Technology

基　　金：中铁十七局集团有限公司科技创新项目(2020-30)。

摘　　要：为解决微风化花岗岩的钻爆开挖问题,以漳武线新村隧道为研究对象,运用室内试验的方法,测试了爆破前后微风化花岗岩试样的超声波速度变化,分析了爆炸作用下围岩损伤破裂特征,并在此基础上进行了爆破工艺研究。结果表明:爆破产生的大量能量释放,使得岩体内部产生了损伤、裂纹和破碎,爆破后试样的超声波纵波初至时间明显增加,声波速度明显下降,初至后波幅振动频率明显增加;损伤因子曲线随着中心距离的增加呈“S”型单调递减函数变化,按照损伤因子的衰减速度,损伤区域可以划分为爆炸粉碎和破裂区、爆炸损伤扰动区、爆炸微扰动区;采用周边孔长短炮孔组合的爆破方式可以有效降低爆破冲击对围岩的损伤,其损伤范围约为超炮孔工况的0.5倍,有效保持了围岩完整性和整体性。In order to solve the problem of drlling and blasting tunnel in slightly weathered granite,the Xin Village Tunnel of the Zhangwu Expressway from Yongding to Shanghang was taken as the research object.Using indoor testing methods,the ultrasonic velocity changes of slightly weathered granite samples before and after blasting were tested,and the characteristics of surrounding rock damage and fracture under the action of blasting were analyzed.Based on this,the blasting process was studied.The results show that the release of a large amount of energy generated by blasting causes damage,cracks,and fragmentation inside the rock mass.After blasting,the initial arrival time of the ultrasonic longitudinal wave in the sample significantly increases,the sound wave velocity significantly decreases,and the amplitude vibration frequency of the wave increases significantly after the initial arrival;the damage factor curve shows an S-shaped monotonically decreasing function with the increase of center distance.According to the decay rate of the damage factor,the damage area can be divided into explosive crushing and rupture zone,explosive damage disturbance zone,and explosive micro disturbance zone;the blasting method of combining long and short peripheral holes can effectively reduce the damage to the surrounding rock caused by blasting impact,with a damage range of about 0.5 times that of the working condition beyond the blast hole,effectively maintaining the integrity of the surrounding rock.

关 键 词：微风化花岗岩 隧道工程 围岩损伤 破裂特征 爆破工艺 

分 类 号：U455.6[建筑科学—桥梁与隧道工程]