下穿既有管线矿山法微断面隧道控爆设计及振动影响研究

Study on Explosion Control Design and Vibration Influence of Micro-section of Under-crossing and Close to the Existing Pipeline

中俄原油管道二线项目呼玛河隧道设计采用尺寸为3.0 m×3.0 m的微断面形式,矿山法施工。该隧道与既有漠大一线输油管道在K0+207 m处有交叉,交叉角38°,上下垂直距离仅为16 m,隧道爆破开挖及振动影响给既有管道的运营带来极大的安全隐患。在满足振动条件、工期要求及经济性情况下,通过对交叉点前后70 m范围爆破振动的跟踪监测,并根据经验公式对监测数据进行拟合计算,据此对爆破参数及掏槽方式进行合理优化,将原设计的斜眼掏槽方式优化为直眼掏槽,有效控制并减小爆破开挖对邻近管线的影响,最终实现了近接施工的安全顺利完成。

The huma river tunnel,a second-line project of Sino-Russian crude oil pipeline,is designed in the form of 3.0*3.0 m micro-section and constructed by mine tunneling method.The tunnel intersected with the existing desert first-line oil pipeline at K0+207 with an intersection Angle of 38 and a vertical distance of only 16 m between them.There are great safety risks caused by the impact of blasting excavation and vibration on the operation of the existing pipeline.Two cut models of inclined cut and parallel cut Taken as research objects in this paper.Based on requirements of vibration conditions,construction period and economic situation,by tracking detection the blasting vibration of the area that covered 70m range before and after the intersection point,the empirical formula parameters of particle velocity,explosive charge per period and distances from center of explosion are obtained by fitting calculation of the monitoring data,through the calculation of monitoring data.According to the empirical formula parameters,the blasting parameters and cutting mode are rationally optimized and the original oblique cut is optimized to parallel cut.The blasting vibration,which doesn’t exceed the blasting vibration safety value of 10 cm/s,effectively controls and reduces the influence on the adjacent pipeline.The approaching excavation is safe and successful.This construction experience can provide reference for similar projects.