摘要
研究目的:扩堑石方的爆破安全一直是铁路增建二线急需解决的施工难题,目前,扩堑石方的开挖通常采用预留岩墙的爆破施工方法,该方法将整个工程的施工难点转移到预留岩墙的爆破拆除上面。为保证爆破拆除预留岩墙的安全,本文通过理论分析,并在渝怀铁路扩堑工程中开展逐排爆破岩墙来验证试验。研究结论:(1)提出了岩墙爆破极限失稳厚度的概念,并根据多边界石方爆破理论,分析了极限失稳厚度的计算方法;(2)通过分析岩墙表观、声波速度和振动速度的变化结果,并结合岩墙爆破拆除实际情况,确定了极限失稳厚度应为最小抵抗线的2倍;(3)极限失稳厚度是保证预留岩墙爆破安全的关键因素,该参数的确定可为复线铁路扩堑石方爆破开挖提供技术支持。
Research purposes:The safety of rock blasting for cutting expansion has always been a major concern in the second railway line construction.In the process of cutting expansion,the reserved rock wall is widely set when carrying out rock blasting,which results in difficulties in blasting demolition of the reserved rock wall.In order to ensure the safety of blasting demolition of the reserved rock wall,theoretical analysis about the critical safe thickness of rock wall under blasting demolition was conducted,and row-by-row blasting experiments for validating the theory were carried out during blasting demolition of the reserved rock wall in Chongqing-Huaihua railway.Research conclusions:(1)The critical safe thickness of rock wall under blasting demolition was proposed,and the corresponding calculation approach of the critical safe thickness was developed based on the theory of rock blasting with multiple free surfaces.(2)The critical safe thickness of the reserved rock wall should be twice the minimum burden,which was acquired by analyzing the variation of the surface feature,the acoustic velocity,and the vibration velocity during blasting demolition of the reserved rock wall.(3)The critical safe thickness is a key factor ensuring the safety of blasting demolition of the reserved rock wall,whose determination can provide technical support for rock blasting in cutting expansion of double track railway.
作者
孟海利
康永全
薛里
郭云龙
孙崔源
MENG Haili;KANG Yongquan;XUE Li;GUO Yunlong;SUN Cuiyuan(China Academy of Railway Sciences Corporation Limited,Beijing 100081,China)
出处
《铁道工程学报》
EI
CSCD
北大核心
2024年第3期106-111,共6页
Journal of Railway Engineering Society
基金
中国国家铁路集团有限公司科技研究开发计划重大项目(K2019G056)。
关键词
既有线
预留岩墙爆破
极限失稳厚度
损伤
爆破振动速度
existing railway line
reserved rock wall blasting
critical safe thickness
rock damage
blasting vibration velocity
