下穿隧道爆破地震作用下埋地输气管道的动力响应规律研究  

Dynamic Response Law of Buried Gas Pipeline caused by Blasting Seismic Waves of Undercrossing Tunneling

作　　者：郑爽英[1] 杨立中[2] 

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]西南交通大学地球科学与环境工程学院,成都610031

出　　处：《爆破》2015年第4期69-76,109,共9页Blasting

基　　金：中央高校基本科研业务费科技创新项目(2682013CX050)

摘　　要：以下穿兰成渝输气管道的西安至成都客运专线仙女岩隧道爆破为背景,根据现场实测振动数据,采用LS-DYNA3D方法和掏槽孔爆破的等效药包原理,建立能反映输气管道与其周围土体相互作用的三维动力有限元模型,分析爆破地震波引起的埋地输气管道的动力响应规律,包括不同隧道埋深、管道直径与管道壁厚对管道振动特征及其响应动应力的影响规律。研究结果表明:爆破地震作用将引起埋地输气管道下部压缩、上部拉伸的动力响应;在隧道埋深20 m、掏槽孔总药量为14.4 kg同时起爆的条件下,直径512 mm、壁厚8 mm输气管道的最大轴向压应力和最大轴向拉应力分别是9.57 MPa和7.76 MPa,仅为管道屈服强度的1.99%和1.61%,相应的管道地表振速为15.28 cm/s;爆破地震作用引起的输气管道动应力随着隧道埋深的增加而显著降低,而管道直径的增加或壁厚减小都会引起管道动应力增大;管道上方地表土体的振动速度随着管径的增大而减小,管壁厚度对管道和土体的质点振动速度基本没有影响。Taking Xiannvyan tunnel blasting engineering passing through a buried gas pipeline of the high-speed railway from Xi^n to Chengdu as the background, according to the measured vibration data of tunneling blasting, the 3D non-linear dynamic finite element models of tunnel-pipeline were established to reflect the coupling action be- tween buried oil pipeline and soil mass by using LS-DYNA3D method and the theory of equivalent charge weight. The dynamic response law of buried gas pipeline caused by blasting seismic waves was studied thoroughly and compre- hensively, including the buried depth of tunnel, pipeline diameter and pipeline wall thickness influencing the vibra- tion characteristic of pipeline and the response dynamic stresses. The results show that the dynamic response of both pipeline compression and tension in lower and upper half respectively was produced by blasting seismic effect in tun- neling. When the total charge with 14.4 kg explosive was ignited simultaneously, the maximum dynamic longitudinal compressive and tensile stresses of buried gas pipeline with a 512 mm diameter and 8 mm wall thickness were 9.57 MPa and 7.76 MPa..which were only 1.99% and 1.61% of pipeline yield strength respectively, and the corre sponding vertical vibration velocity of ground surface over pipeline was 15.28 cm/s. With the increasing of the tunnel depth,the various kinds of dynamic stresses of a buried gas pipeline caused by blasting seismic effect significantly decreased, and the increase of pipeline diameter or decrease of pipeline wall thickness would increase the pipeline dynamic stresses. The vibration velocity of ground surface over pipeline decreased with the pipe diameter increasing, and the wall thickness of pipeline made little influence on the particle vibration velocity of both pipeline and soil.

关 键 词：隧道掘进 爆破地震波 埋地输气管道 动力响应 振动速度 动应力 

分 类 号：O382.2[理学—流体力学]