水下钻孔爆破应力分析与孔网参数优化

水下钻孔爆破中,影响爆破效果的主要因素是被爆岩石的峰值应力,而孔网参数的选取则直接影响岩石的应力变化。为探究水下钻孔爆破应力响应规律与最佳孔网参数,运用LS-DYNA软件,选用算法,建立有限元分析模型。通过数值模拟,研究了不同起爆方式、不同水深以及不同孔网参数条件下,被爆岩石的应力变化,发现了各条件下岩石的应力变化情况以及不同外部条件对水下爆破的影响。选出了符合爆破要求,而又节约爆破成本的最佳孔网参数模型。通过模拟得出各监测单元的应力变化,得出结论：(1)三种不同起爆方式其应力变化情况各有其特点。(2)在不同水深条件下,岩石的峰值应力变化较小,水深对于岩石峰值应力的影响可忽略不计。(3)在不同孔网参数条件下,由于孔距、排距、填塞长度变化,不同部位的峰值拉应力会出现一定的变化规律。根据数值模拟情况,最终通过分析讨论得出最优孔网参数。

Underwater Drilling and Blasting Stress Analysis and Optimization of Hole Network Parameters

In underwater drilling and blasting, the main factor affecting the blasting effect is the peak stress of the blasted rock, and the selection of the hole mesh parameters directly affects the stress change of the rock. In order to explore the stress response law and optimal hole mesh parameters of underwater borehole blasting, LS-DYNA software is used to select an algorithm to establish a finite element analysis model. Through numerical simulation, the stress changes of the blasted rocks under different detonation methods, different water depths and different pore mesh parameters were studied, and the stress changes of rocks under various conditions and the influence of different external conditions on underwater blasting were found. The optimal orifice mesh parameter model that meets the blasting requirements while saving blasting costs is selected. The stress changes of each monitoring unit are simulated and concluded: (1) The stress changes of the three different detonation modes have their own characteristics. (2) Under different water depth conditions, the peak stress change of rock is small, and the impact of water depth on rock peak stress is negligible. (3) Under the condition of different pore mesh parameters, due to the change of pore spacing, row spacing and packing length, the peak tensile stress of different parts will change to a certain law. According to the numerical simulation, the optimal pore mesh parameters are finally obtained through analysis and discussion.