摘要
针对某隧道联络风道超近接上跨主洞爆破损伤控制问题,通过有限元数值方法探究上部联络风道爆破施工后,下部主洞的结构力学响应特征。研究表明:联络风道上台阶爆破施工后,主洞初支结构位移、振速、应力均呈现自拱顶中心位置往四周不断减小的趋势,锚杆+拱架支护处于明显应力集中状态;初支结构X、Y、Z方向最大振速峰值分别为1.81、4.41、6.81 cm/s,均小于爆破安全规范值20.00 cm/s,拉应力处于1.10 MPa以内,局部位置由于锚杆弯撬作用形成应力集中状态,锚杆+钢拱架最大轴力小于400 kN。光面爆破微差控制技术可减弱爆破应力波的叠加,随着爆破时程的递增,衬砌结构应力、振速、位移曲线呈振荡衰减趋势,左线主洞结构风险整体可控。
For the damage control in blasting of a tunnel connecting air duct ultra-adjacent to overpassing main hole,finite element numerical method was used to explore the structural mechanical response characteristics of the main hole below after the blasting construction of connecting air duct above.The study shows that,after the upper bench blasting construction of connecting air duct,the displacement,vibration speed and stress of the primary supporting structure of the main hole show a trend of continuously diminishing in all directions from the center of vault,the support of anchor bolt plus arch frame stays in a state of significant stress concentration;the maximum peak vibration speed in X,Y,Z direction of the primary supporting structure is 1.81,4.41,6.81 cm/s respectively,all of them are less than the value of 20.00 cm/s in the blasting safety code,the tensile stress is within 1.10 MPa,and at local position,stress concentration occurs as a result of anchor bolt bending,the maximum axial force of anchor bolt+steel arch is less than 400 kN.The technology of millisecond controlled smooth blasting may diminish the superposition of blasting stress waves and,as the time history of blasting increases,the curves of stress,vibration speed,and displacement of the lining structure show a trend of oscillation attenuation,and the structural risk of the main hole on left line can be controlled generally.
作者
汪文兵
王星
黄帅
WANG Wenbing;WANG Xing;HUANG Shuai(CCCC Second Highway Consultants Co.,Ltd.,Wuhan 430052,China;CCCC Second Highway Engineering Co.,Ltd.,Xi'an 710065,China)
出处
《路基工程》
2025年第4期153-159,共7页
Subgrade Engineering
基金
中交第二公路工程局科技研发项目(GHTJ-07-QT-046)。
关键词
软岩隧道
台阶法
近接施工
微差爆破
支护加固
风险控制
soft rock tunnel
bench cut method
approaching construction
millisecond blasting
support reinforcement
risk control
