不耦合装药爆破孔壁压力峰值的实验研究

不耦合装药爆破孔壁压力峰值是控制岩体轮廓成形质量及进行非流固耦合爆破振动响应数值模拟分析的重要参数，本文采用实验方法研究了不耦合装药爆破的孔壁压力峰值:利用材质为20钢的无缝薄壁钢管模拟不耦合装药爆破炮孔，以高灵敏度、高精度的应变片为传感器，选用超动态应变仪采集钢管内置柱状炸药卷爆炸过程中钢管外壁产生的环向应变，应用动荷载作用下薄壁圆筒的动力响应计算方法，反演分析采集的钢管外壁环向应变数据，得到了爆破过程中空气冲击波作用于钢管内壁的冲击荷载压力峰值，间接测量了不耦合装药爆炸后的孔壁压力峰值。实验获得了6种不耦合装药工况下的爆破孔壁压力峰值测试数据，并计算了相应工况下实验值较准静态爆生气体压力的增大倍数，拟合结果表明压力增大倍数随不耦合系数的增大近似呈线性增长。同时也分析了部分试验工况下爆炸测试结果不理想的原因，研究成果可为轮廓爆破孔壁压力峰值的测试与计算提供参考。

Experimental study on the peak pressure of borehole wall in decoupling charge blasting

The peak pressure of borehole wall in decoupling charge blasting is an important parameter to control the quality of rock mass profile forming and to carry out numerical simulation analysis of blasting vibration response of non-fluid-solid coupling. In this paper, the peak pressure of borehole wall in decoupling charge blasting was studied from an experimental perspective. Based on the characteristics that the difference between the two higher wave impedance media, steel pipe and rock, has little effect on the peak pressure of borehole wall, the seamless thin-walled steel pipe made of 20# steel was used to simulate the borehole in decoupling blasting with high-sensitivity-high-precision strain gauge as sensor, four strain gauges arranged along the circumferential direction of a certain section of each steel pipe. Ultrahigh dynamic strainometer was used to collect the circumferential strain of steel pipe during the explosion process of built-in columnar explosive cartridge; the method of calculating the dynamic response of thin-walled cylinder under dynamic load is used to calculate the collected circumferential strain; the elastic dynamic formula of the thin-walled cylinder was used to deduce the collected circumferential strain; and the peak pressure on the borehole wall by the air shock wave has been measured indirectly. The peak pressure on the borehole wall under six working conditions was obtained, and calculated the ratio of the experimental values to the quasi-static gas-pressure under the corresponding working conditions to obtain increase multiples. The decoupling coefficient was taken as the abscissa and the pressure increase multiple as the ordinate for the fitting, the fitting results indicate that the pressure increase multiples increase approximately linearly with the increase of the decoupling coefficients, and the fitting correlation coefficient is as high as 0.99 or more.At the same time, the reasons why the experimental results under some working conditions are unsatisfactory have been analyzed, which can be referred to the measurement and calculation of the peak pressure of borehole wall in contour blasting.