PVDF薄膜传感器用于测试块状岩石表面爆炸应力的研究

采用PVDF（聚偏二氟乙烯）薄膜传感器对岩石表面爆炸应力进行测量，并分析炮孔内不同填塞介质对爆炸应力波在岩石介质中传播的影响。在直径为28 mm、孔深为25 cm的炮孔内填塞不同的介质（空气、水或沙子），采用不同的装药结构分别进行爆破试验，通过PVDF薄膜传感器得到了不同工况下岩石表面应力波时程曲线。分析炮孔内不同填塞介质对爆炸应力波透射的影响发现，水作为炮孔填塞介质时，爆炸应力波透射能力强，炸药爆炸产生的能量用于岩石破碎的比例高。水作为炮孔填塞介质时，为达到岩石开裂效果，装药结构设计为1发8^#雷管加2 g传爆药（聚黑-14）；当沙子作为炮孔填塞介质时，为达到岩石的开裂效果，装药结构设计为1发8^#雷管、2 g传爆药（聚黑-14）和20 g炸药（聚黑-2）；前者炸药用量仅为后者的15.3%。炸药使用量减少，也降低了爆破次生危害的影响程度。用PVDF薄膜传感器在岩石表面直接测量爆炸应力的方法是可行的。

Application of PVDF Thin Film Sensor in Explosive Stress Measurement on the Surface of Massive Rock

PVDF (polyvinylidene fluoride) thin film sensor was used to measure explosive stress on the surface of rocks, and the influences of different filling media in the blast hole on the propagation of explosive stress waves in rock media were analyzed. Different media, such as air, water, or sand, were filled into the borehole with a diameter of 28 mm and a depth of 25 cm. Blasting tests were conducted using different charging structures, and the time history curves of rock surface stress waves under different working conditions were obtained from PVDF. It was found that when water is used as the filling medium in the blast hole, the transmission ability of explosion stress waves is strong, and the proportion of energy generated by explosion used for rock fragmentation is high. When water is used as the filling medium in the blast hole, in order to achieve rock cracking, the charging structure is designed with one 8^# detonator and 2 g booster explosive (Juhei-14). When sand is used as the filling medium in the blast hole, in order to achieve rock cracking, the charging structure is designed with one 8^# detonator, 2 g booster explosive (Juhei-14), and 20 g of explosive (Juhei-2). The amount of explosives used in the former is only 15.3% of that in the latter. The reduction in the use of explosives also reduces the impact of secondary hazards caused by blasting. The method of directly measuring explosive stress on rock surface using PVDF thin film sensors is feasible.