楼房爆破拆除塌落冲击作用下邻近地铁隧道动力响应及安全评估研究  

Study on Dynamic Response and Safety Assessment of Adjacent Underpass Tunnels Influenced by Collapse Impact of Building Demolised by Blasting

作　　者：姚颖康 杨成 贾永胜 黄小武[3] 孙金山 YAO Ying-kang;YANG Cheng;JIA Yong-sheng;HUANG Xiao-wu;SUN Jin-shan(State Key Laboratory of Precision Blasting,Jianghan University,Wuhan 430056,China;Hubei Key Laboratory of Blasting Engineering,Jianghan University,Wuhan 430056,China;Wuhan Explosions and Blasting Corporation Limited,Wuhan 430056,China)

机构地区：[1]江汉大学省部共建精细爆破国家重点实验室,武汉430056 [2]江汉大学爆破工程湖北省重点实验室,武汉430056 [3]武汉爆破有限公司,武汉430056

出　　处：《爆破》2023年第3期1-11,共11页Blasting

基　　金：湖北省自然科学基金面上项目(2021CFB541);湖北省重点研发计划项目(2020BCA084);湖北(武汉)爆炸与爆破技术研究院博士科研启动基金项目(PBSKL-2022-QD-02)。

摘　　要：高大建(构)筑物爆破拆除产生的冲击振动可能会影响邻近地铁隧道的安全服役。论文依托距离地铁隧道仅6.5 m的24层框架结构楼房爆破拆除工程,首先开展了楼房对应区域地铁隧道的振动与动应变现场测试与分析,其次应用ANSYS/LS-DYNA有限元软件建立了适于描述楼房爆破拆除塌落体触地冲击的地铁隧道结构动力响应三维有限元计算模型,模拟了塌落冲击作用下隧道结构的振动响应特征与动应力变化情况,并与现场实测结果对比分析。研究结果表明:承重立柱钻孔爆破引起的地铁隧道内质点振动速度峰值(8.61 mm/s)大于楼房切口闭合触地冲击引起的质点振动速度峰值(4.95 mm/s),爆破振动主频为100 Hz左右,塌落冲击振动主频为2 Hz左右,塌落冲击荷载作用下的地铁隧道振动速度与Ⅲ级地震烈度引起的结构振动相当(3.82~8.19 mm/s);楼房切口闭合时的低频塌落冲击振动会使地铁隧道管片产生较为明显的附加动应力,管片环向产生4 MPa左右的动态压应力,轴向和切向产生0.4 MPa左右的动态拉应力;受动态拉压循环冲击作用,管片结构若存在内部损伤或施工缺陷,可能会出现既有裂缝扩大或层裂剥落现象;现行《爆破安全规程》(GB6722—2014)确定的f<10 Hz时的10~12 cm/s安全允许质点振动速度值偏于危险,应结合频率特性与动态应变特征进行调整。论文可为塌落冲击作用下地铁隧道的安全评价与安全防护提供参考。The impact vibration caused by blasting demolition of tall buildings(structures)may affect the service status of adjacent subway tunnels.In order to demolish a 24 story frame structure building only 6.5 meters away from the subway tunnel,on-site tests and analysis of blasting vibrations and dynamic strains were first conducted.And then,a three-dimensional finite element calculation model was established for analyzing the dynamic response of the subway tunnel structure by ANSYS/LS-DYNA,which can reasonably describe the impact of the collapsed part on the ground during the blasting demolition of the building.Finally,the vibration response characteristics and dynamic stress changes of the tunnel structure under the impact of building collapse were simulated and compared with the field measured data.The research results show that the peak particle vibration velocity(8.61 mm/s)in the subway tunnel caused by the drilling and blasting of the load-bearing columns is greater than the peak particle vibration velocity(4.95 mm/s)caused by the impact of the building on the ground.The main frequency of the blasting vibration and the collapse impact vibration are about 100 Hz and 2 Hz,respectively.The vibration velocity of the subway tunnel under the action of the collapse impact load is equivalent to the structural vibration caused by an earthquake with an intensity of LevelⅢ(3.82~8.19 mm/s).The low-frequency collapse impact vibration can cause relatively obvious additional dynamic stress to the subway tunnel.The dynamic compressive stress generated in the circumferential direction of the tunnel is about 4 MPa,and the dynamic tensile stress generated in the axial and tangential directions is about 0.4 MPa.The existing cracks may expand,or delamination may occur when the internal damages or construction defects are generated in the tunnel structure under the impact of dynamic tension and compression cycles.The safety allowable particle vibration velocity value of 10~12 cm/s when f<10 Hz required in the current blasting safety

关 键 词：高层楼房 爆破拆除 塌落冲击 地铁隧道 振动特性 动力响应 

分 类 号：TU9[建筑科学]