水下钻孔爆破孔网参数优化研究

发布时间：2018-01-22 13:08

本文关键词： 水下钻孔爆破孔网参数优化模型数值模拟　出处：《武汉科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来，我国对海洋资源的开发力度逐渐加大，水下钻孔爆破技术在海底炸礁工程中的应用日益广泛，但是水下环境的复杂性使得水下钻孔爆破比陆地钻孔爆破更加复杂。水下钻孔爆破孔网参数的优化研究，对爆破施工设计及节约经济成本具有十分重要的意义。本文以厦门港口二期炸礁工程为背景，从研究水下钻孔爆破岩石破碎机理出发，探讨了水下钻孔爆破的主要影响因素，结合爆破优化模型、数值仿真技术以及现场实验，对水下钻孔爆破孔网参数进行了优化研究，取得了以下研究成果：（1）结合岩石破碎机理和水下钻孔爆破的特点，讨论了水下钻孔爆破岩石破碎机理，对水深、岩体结构及岩性等主要影响因素进行了系统的分析。（2）基于经典的钟汉荣爆破优化模型提出了水下钻孔爆破孔网参数的优化模型，根据现场统计资料，综合运用数理统计方法和破碎块度方程，得到了厦门港口二期炸礁工程优化模型的表达式以及满足约束条件的最优孔网参数。（3）运用ANSYS/LS-DYNA动力有限元分析软件，建立了不同炮孔间距、排距及堵塞长度的8种水下钻孔爆破模型，分析不同模型在孔底起爆和中间起爆时的应力云图和单元应力时程曲线，发现爆破载荷作用下岩石的破碎主要取决于切向拉应力，且中间起爆时被爆岩石内产生较为均匀的应力场，有利于降低大块率。（4）以最小孔网参数的数值计算模型为基础，分析对比8种模型岩石单元的应力状态，发现第6种模型所采用的孔网参数能够在经济成本最低的情况下实现破碎目标。结果表明，厦门港口二期炸礁工程的最优孔网参数为孔距2.5m，排距2.2m，堵塞长度1.5m，炸药单耗1.75kg/m3。采用该优化参数进行施工时，平均大块率降低了30%，，浅点率降到了2%以内，大大缩短了施工工期，降低了施工成本，可以为类似水下钻孔爆破工程提供参考。
[Abstract]:In recent years, the development of marine resources in China has gradually increased, underwater drilling blasting technology in submarine reef blasting engineering is increasingly widely used. But the complexity of underwater environment makes underwater borehole blasting more complex than terrestrial borehole blasting. It is of great significance for blasting construction design and saving economic cost. Based on the second stage reef blasting project of Xiamen port, this paper discusses the main influencing factors of underwater drilling blasting based on the study of rock fragmentation mechanism of underwater drilling blasting, combined with the blasting optimization model. Numerical simulation technology and field experiments are used to optimize the parameters of hole network of underwater borehole blasting. The results are as follows: 1) combined with the characteristics of rock fragmentation mechanism and underwater drilling blasting, the rock fragmentation mechanism of underwater drilling blasting is discussed, and the main influencing factors, such as water depth, rock mass structure and lithology, are systematically analyzed. 2) based on the classical Zhong Hanrong blasting optimization model, the optimization model of hole network parameters of underwater borehole blasting is proposed. According to the field statistical data, the mathematical statistical method and fragmentation equation are used synthetically. The expression of the optimization model for the second stage reef blasting project of Xiamen Port and the optimal hole network parameters satisfying the constraint conditions are obtained. 3) by using ANSYS/LS-DYNA dynamic finite element analysis software, eight kinds of underwater borehole blasting models with different hole spacing, spacing and plugging length are established. This paper analyzes the stress cloud diagram and element stress history curve of different models during the initiation of hole bottom and intermediate detonation. It is found that rock fragmentation under blasting load mainly depends on the tangential tensile stress. And the uniform stress field is produced in the detonated rock during the intermediate initiation, which is helpful to reduce the boulder ratio. (4) based on the numerical calculation model of minimum pore network parameters, the stress states of eight model rock elements are analyzed and compared. It is found that the hole network parameters used in the sixth model can achieve the breakage target with the lowest economic cost. The results show that the optimum hole network parameters of the second stage reef blasting project of Xiamen Port are as follows: hole spacing 2.5 m, row distance 2.2 m, blocking length 1.5 m. The unit consumption of explosive is 1.75 kg / m ~ (3). When the optimized parameters are used, the average bulk rate is reduced by 30%, the shallow point rate is reduced to less than 2%, and the construction period is greatly shortened and the construction cost is reduced. It can provide reference for similar underwater drilling blasting engineering.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P756.5

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