摘要
新建隧道下穿既有铁路爆破施工时,爆破振动可能影响铁路结构正常运行和安全稳定.其施工关键在于确定合理的振动控制标准,使铁路结构变形在控制范围内.通过Peck沉降槽理论分析路基沉降与地面沉降的关系,计算得出下穿铁路路基沉降允许值为5 mm.以厦门轨道交通3号线新建隧道下穿既有铁路线为工程背景,用ls-dyna分析爆破掘进距离变化对铁路路基沉降影响规律,结果表明靠近铁路结构下方爆破时路基沉降变形值逐渐增大,且在铁路中心线正下方沉降值达到最大,远离铁路段沉降值减小然后趋于平缓.在铁路中心线正下方达到沉降变形控制值所需爆破峰值荷载值最小,但振动响应最剧烈.通过调整爆破掘进距离和爆破峰值荷载,控制铁路路基的沉降变形值在5 mm左右时,取铁路结构振速2.6 cm/s为本工程的铁路振动控制标准,研究结果对下穿铁路工程爆破具有借鉴和指导意义.
During the blasting construction of a new tunnel underneath an existing railway,the blasting vibration may affect the normal operation,safety and stability of the railway structure.The key to the construction is to determine the reasonable vibration control standard so that the deformation of the railway structure is within the control range.This paper explores the relationship between subgrade settlement and ground settlement based on the Peck settlement formula,and calculates the theoretical allowable value of subgrade settlement under the railway is 5mm.Taking the newly-built tunnel of Xiamen Rail Transit Line 3 under the existing railway line as the engineering background,ls-dyna was used to analyze the change of the blasting distance influence the settlement of the railway subgrade.The result shows that the settlement deformation value of the subgrade gradually increases when blasting close to the bottom of the railway structure,and the settlement value reaches the maximum directly below the railway centerline,and the blasting peak load value is the smallest but the vibration response is the strongest when blasting is directly below the railway centerline.By adjusting the blasting distance and blasting peak load,when the settlement deformation value of the railway subgrade is controlled to be about 5mm,the railway structure vibration speed 2.6cm/s was selected as the railway vibration control standard of the project.The research results have a certain guiding significance for the blasting of the underpass railway project.
作者
石伟民
何方
陈士海
揭海荣
李海波
SHI Weimin;HE Fang;CHEN Shihai;JIE Hairong;LI Haibo(College of Civil Engineering,Huaqiao Univ.,Xiamen 361021,China;China Railway 24th Bureau Group Fujian Railway Construction Co.,Ltd,Fuzhou 350013,China;Wuhan Institute of geotechnical mechanics,Chinese Academy of Sciences,Wuhan 430071,China)
出处
《三峡大学学报（自然科学版）》
CAS
2021年第6期50-55,共6页
Journal of China Three Gorges University：Natural Sciences
基金
国家自然科学基金资助项目(51974136)
2020年度厦门市高校产学研项目(3502Z20203045)
华侨大学研究生科研创新基金资助项目(18013086026)。
