摘要
结合武汉轨道交通光谷广场综合体深基坑开挖爆破工程,建立LS-DYNA有限元模型,分析了爆破作用下邻近污水管道的动力响应规律和振动速度安全阈值;并根据弹性波场论分析P波斜入射和垂直入射产生的拉应力,由极限拉应力准则建立管道爆破振动速度安全阈值计算模型。结果表明:管道迎爆侧的爆破质点位移和振速均大于背爆侧,管道上入射角为0~40°的部分为易破坏区域,管道正上方的地表振速约为埋地管道最大振速的0.75倍;并最终确定管道正上方的地表振速安全阈值为10 cm/s;基于数值模拟得出的振动速度安全阈值大于理论分析得出的结果,因此在进行相似工程的设计研究时,不建议采用单一方法分析出结果,以便为实际工程安全施工提供更切实的指导。
Based on the sampling project of the deep foundation pit in the Optics Valley Square of Wuhan Rail Transit,the present paper is aimed at making a simulated study of the great impact of the blasting excavation of foundation pit on the surrounding building structures,so as to ensure the safety of the sewage pipeline regular operation by controlling the blasting process through numerical simulation and theoretical analysis. For the aforementioned purpose,we have analyzed the dynamic response and the safety vibration velocity threshold of the adjacent pipeline under the blasting conditions by setting up a LS-DYNA finite-element model while taking into account the difference between the alternative situations of no water or/and full water in the pipelines. According to the elastic wave field theory,we have worked out the tensile stresses that are likely to be induced by the oblique and vertical incidence of P wave and in turn established a calculation model for testing the said pipeline safety threshold. The research results we have gained prove that the particle displacement and the particle vibration velocity of the front-face blasting side caused by the blasting seismic waves turn out to be greater than those of the back-blasting side,which tends to destroy the pipeline stability and safety on the condition when the blasting seismic wave strength rises between 0-40°. At that point,the vibration velocity of the ground-above pipeline is supposed to be about 0. 75 times of the maximum vibration speed in comparison with the buried one. And,finally,the safety vibration velocity threshold of ground-above pipeline can be set up to 10 cm/s. Thus,the safety vibration velocity threshold gained through our simulation has been turning to be greater than that we have gained from the theoretical analysis. Hence,the single method shouldn＇t be recommended when similar projects are to look for a practical as well as scientific safe construction of the project.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2017年第6期2191-2195,共5页
Journal of Safety and Environment
基金
国家自然科学基金项目(41372313)
武汉市"黄鹤英才(科技)计划"项目
关键词
安全工程
爆破振动
管道
理论分析
数值模拟
safety engineering
blasting vibration
pipeline
theoretical analysis
numerical simulation
