近距离爆破引起的隧道周边振动场

首先分析了近距离爆破造成的隧道周边振动场分布规律 ,指出最大振动速度出现在爆破振动波正入射部位的墙壁和拱部 ,墙脚点振动速度较小 ,背爆侧振速只有迎爆侧的 1 / 2 5。其次 ,根据大量测试数据分析 ,论述了爆破性质、地质条件对振动衰减的影响 ,并作了进一步的理论解释。最后根据振动分析 ,提出了有关降低爆破振动的措施

RESEARCH ON REDUCTION OF INFLUENCES ACTED BY BORDER EFFECT IN EXPLOSIVE WELDING

Border effect is a common problem existing in explosive welding,how to eliminate the effect becomes one of the key technologies of improving the welding quality.In this paper,two methods are put forward to reduce non-welding border area.One is to adopt the way of increasing charge width and mass ratio R properly in the window of explosive welding in the case of same area,so the influence of sparse wave is drawn outside the composite area,and hence reducing the its influence on the flying speed of flyer plate from the border charge sparse wave.The other is to adopt the method of digging a slice or cutting a stress groove at the flyer plate in the case of varied area to reduce the injures and cracks at the border.A lot of experiments are conducted with the two methods,showing that the welding condition around the composite plate is very satisfied.This research not only saves 10% of charge,but also decreases the conflicting velocity between the base border and the flyer plate,so it is very useful to reduce the integer distortion of composite plate and to solve the fracture problem in explosive welding.This research optimizes the welding technology to a great extent.