摘要
针对某大跨度地下互通式立交近接爆破施工振动控制问题,提出台阶法微差爆破施工技术,通过LS-DYNA显式数值计算仿真,探究上部WN匝道爆破施工后,下部SW匝道初支结构力学响应特征。结果表明:WN匝道微差爆破施工后,爆源正下方SW匝道拱顶部位呈现应力集中状态,峰值拉应力达0.20 MPa,峰值位移0.085 mm;随着掏槽→辅助→周边孔逐级微差爆破,各测点应力、振速、位移均呈上下振荡趋势,SW匝道初支X、Y、Z方向峰值振速均小于允许安全振速18.00 cm/s。微差爆破控制技术减弱爆破应力波的叠加效应明显,中空砂浆锚杆+锁脚锚杆多级支护措施进一步提升了主洞承载力,降低了施工风险。
To solve the vibration control issue of the adjacent blasting construction of a large-span underground interchange,a bench method-based millisecond blasting construction technology scheme was proposed.Through LSDYNA explicit numerical calculation simulation,this paper explored the mechanical response characteristics of the initial support structure of the lower SW ramp after the upper WN ramp blasting construction.The result shows that after the construction of WN ramp millisecond blasting,the stress concentration occurs at the vault of SW ramp directly below the blasting source,and the peak tensile stress reaches 0.20 MPa and the peak displacement is 0.085 mm.With the step-bystep millisecond blasting of cutting→auxiliary→peripheral holes,the stress,vibration velocity and displacement of each measuring point show an upward and downward oscillation trend.The peak vibration velocity of the initial support of SW ramp in X,Y and Z directions is less than the allowable safe vibration velocity of 18.00 cm/s.The millisecond blasting control technology weakens the superposition effect of blasting stress wave,and the multi-stage support measures of hollow mortar anchor+locking anchor pipe further improve the bearing capacity of the main hole and reduce the construction risk.
作者
侯象煜
李昊天
王星
黄帅
涂鹏
HOU Xiangyu;LI Haotian;WANG Xing;HUANG Shuai;TU Peng(CCCC Second Highway Engineering Bureau Co.,Ltd.,Xi'an 710065,China;CCCC Mountain Long Bridge and Tunnel Construction Technology Research and Development Center,Xi'an 710199,China)
出处
《路基工程》
2025年第4期147-152,共6页
Subgrade Engineering
基金
湖南省教育厅科学研究项目(20C0572)
中交第二公路工程局科技研发项目(2023S-4-28)。
关键词
台阶法
近接施工
微差爆破
叠加效应
支护加固
风险管控
bench method
proximity construction
millisecond blasting
superposition effect
support reinforcement
risk management and control
