隧道爆破荷载作用下埋地管道动力响应试验

埋地管道爆破动力响应特性是城市管道抗震优化设计的依据。设计并开展城市地铁隧道爆破荷载作用下埋地管道动力响应的相似模型试验,监测埋地管道应变、加速度及地表振动速度值,解析地铁隧道爆破地震波的传播衰减机制及其对邻近埋地管道动力响应影响规律。结果表明,基于量纲分析理论的振动速度预测模型用于隧道爆破时地表PPV预测切实可行;相同爆破荷载作用下,埋地钢管加速度峰值是PVC管的1.5～1.8倍;隧道"空洞效应"导致埋地管道在成洞区一侧的加速度响应更为剧烈;埋地PVC管在各测点处环向应变大于轴向应变,且大于钢管应变值,试验得到可有效监测埋地钢管和PVC管应变响应的最大临界比例距离分别为117 m/kg和263 m/kg。

Experimental study on dynamic response of buried pipeline subjected to blasting load of tunnel

The blasting dynamic response characteristics of buried pipelines are the basis of seismic optimization design of urban pipelines.Similar model tests of dynamic response of buried pipelines under blasting loads of urban metro tunnels are designed and carried out to monitor the strain and acceleration of buried pipelines and the ground vibration velocity.The propagation and attenuation mechanism of blasting seismic wave of metro tunnel and its influence on the dynamic response of adjacent buried pipelines are analyzed. The results show that, the prediction model of vibration velocity based on dimensional analysis theory is feasible for peak particle velocity(PPV) prediction of ground surface during tunnel blasting.The peak acceleration of buried steel pipe is 1.5-1.8 times that of PVC pipe under the same blasting load.The tunnel "void effect" results in the acceleration response of buried pipelines on the side of the cave-forming area more intense; the circumferential strain of buried PVC pipes at each measuring point is larger than the axial strain, and larger than the strain value of steel pipes. The test results show that the maximum critical proportionate distances that can effectively monitor the strain response of buried steel pipe and PVC pipe are 117 m/kg and 263 m/kg respectively.