摘要
为保证埋地混凝土管道在爆破施工过程的安全性,采用现场监测和动力有限元数值模拟相结合的研究方法,对超浅埋地铁站通道爆破开挖邻近埋地混凝土管道的动力响应进行研究.通过建立管道拉应力峰值和振动速度峰值的函数关系,由最大拉应力强度理论得到管道的爆破控制振速.由管道不同断面最大振速与对应位置管道正上方地表振速之间关系,提出保证管道安全的地表爆破控制振速.结果表明:空管状态下,掌子面后方,管道断面底部和中部振速较为接近,顶部振速最小;掌子面前方,管道断面质点振速呈现出底部最大、中部次之、顶部最小的振动特征;沿着管道轴线方向,质点振速最大的位置出现在掌子面前方3 m管道断面底部位置.管道在空管和满水两种状态下质点振动特征基本一致,管道中水的存在能降低管道质点振速,最大降低幅度为7.3%.管道的爆破控制振速为10.84 cm/s,保证管道安全的地表爆破控制振速为4.53 cm/s.确定的爆破控制振速可以指导现场爆破施工.
To ensure the safety of buried concrete pipeline during the process of blasting construction,field monitoring and numerical simulation were adopted to study the dynamic response of the adjacent buried concrete pipeline induced by the blasting excavation of an ultra-shallow buried underpass. The relationship model between the peak partical velocities( PPVs) and tensile stresses of the pipeline is established. Based on the ultimate tensile strength criterion,the blasting vibration safety criterion of the pipeline is calculated by the relationship model. The relationship between the maximum PPVs at different pipe sections along the pipeline and the PPVs at the ground points right above the pipe sections is also established. Combined the blasting vibration safety criterion of the pipeline,the blasting vibration safety criterion of ground is determined to ensure the safety of the pipeline. Results show that when the pipeline is empty,behind the working face,the PPVs at the middle and bottom of pipe section are approximately equal,and the smallest is at the top of pipe section. At the front of the working face,the greatest PPV is at the bottom of pipe section,followed by the middle and the top of pipe section. Along the axis of pipeline,the PPV reaches its maximum at the bottom of pipe section 3 m ahead of the working face. In the case that the pipeline is empty and full of water,the vibration characteristics are basically similar. The water in the pipeline lowers PPVs and the largest percentage of decrease is 7. 3%. The blasting vibration safety criterion of pipeline is10.84 cm/s and the blasting vibration safety criterion of ground is set to be 4.53 cm/s to ensure the safety of the pipeline. The determined safety criteria of blasting vibration can provide guidance for the field blasting construction.
出处
《哈尔滨工业大学学报》
EI
CAS
CSCD
北大核心
2017年第9期79-84,共6页
Journal of Harbin Institute of Technology
基金
国家自然科学基金(41372312
51379194)
黄鹤英才(科技)计划项目(2015055003)
中国博士后科学基金特别资助(2015T80854)
关键词
爆破开挖
地下通道
埋地混凝土管道
动力响应
安全控制
blasting excavation
underpass
buried concrete pipeline
dynamic response
safety control
