【摘要】 针对武汉市区内常见直埋球墨铸铁管道,设计实施邻近预埋管道的全尺寸爆破实验.结合有限元数值计算方法,考虑管道不同埋深,研究爆破地震作用下粉质黏土地层内直埋管道动力响应.研究结果表明,管道和地表峰值振速(PPVs)随爆源与管道距离的减小而增大,在管道正下方爆破为最危险工况.管道中心截面为危险截面,危险截面PPVs以管腰和管底较大,动态应变以轴向拉伸应变为主,环向应变次之,峰值有效应力以底部单元最大,管道肩部最小.管道不同埋置深度和PPVs具有比例关系,通过实测地表振速与管道有效应力关系可以预测管道截面爆破峰值有效应力,计算关系式可以为岩土爆破施工中邻近管道的安全性评价提供计算方法.更多还原

【Abstract】 A full-scale blasting experiment of adjacent pre-buried pipes was designed and implemented, aiming at the common direct-buried ductile iron pipes in the urban area of Wuhan. Combined with the finite element numerical calculation method and considering the different buried depth of the pipeline, the dynamic response of the directly buried pipeline in the silty clay layer under the action of the blasting vibration was studied. Results show that the pipeline and the surface peak particle velocities(PPVs) increase with the decrease of the blast distance, and the most dangerous working condition is blasting directly below the pipeline. The central section of the pipeline is dangerous.The PPVs at the waist and bottom of the tube are larger for the dangerous section. The dynamic strain is mainly the axial tensile strain and the hoop strain is smaller. The peak effective stress in the bottom element is the largest and that of the pipe shoulder is the smallest. There is a functional relationship between PPVS and different embedded depth of pipeline. By measuring the relationship between the surface PPVs and the peak effective stress, the peak effective stress of the pipeline section can be predicted, which provides a calculation method for the safety determination of related pipelines in engineering construction.更多还原