A Fragmentation Modelling Framework for Underground Ring Blasting Applications

Empirical approaches for predicting fragmentation from blasting continue to play a significant role in the mining industry in spite of a number of inherent limitations associated with such methods. These methods can be successfully applied provided the users understand or recognize their limitations. Arguably, the most successful empirical based fragmentation models have been those applicable to surface blasting (e.g., Kuz-Ram/Kuznetsov based models). With widespread adoption of fragmentation assessment technologies in underground operations, an opportunity has arisen to extend and further develop these type approaches to underground production blasting.

This paper discusses the development of a new fragmentation modelling framework for underground ring blasting applications. The approach is based on the back-analysis of geotechnical, blasting and fragmentation data gathered at the Ridgeway sub level caving (SLC) operation in conjunction with experiences from a number of surface blasting operations.

The basis of the model are, relating a peak particle velocity (PPV) breakage threshold to a breakage uniformity index; modelling of the coarse end of the size distribution with the Rosin-Rammler distribution; and modelling the generation of fines with a newly developed approach that allows the prediction of the volume of crushing around blastholes.

Preliminary validations of the proposed model have shown encouraging results. Further testing and validation of the proposed model framework continues and the approach is currently being incorporated into an underground blast design and analysis software to facilitate its application.     

Ground Vibration due to Blasting in Limestone Quarries

A database of ground vibration due to blasting at 27 limestone quarries, located in various parts of India, has been created. The database contains peak particle velocity (PPV), frequency, other vibration related and blast design parameters. Regression analysis of the data is carried out to derive site constants of the USBM predictor equation for individual quarries. It is found that these site constants are correlated with each other. By combining all the data, a generalised predictor equation is developed to assess and control ground vibration. In addition, mean zone of attenuation has been delineated using the predictor equations of the individual quarries. The dominant frequency of ground vibration with respect to distance and the possibility of modifying it by changing delay intervals in production blasts are also examined.     

四川彭山钙芒硝矿开采引起的生态环境影响与控制研究--多段微差挤压爆破技术的应用

多段微差挤压爆破起爆系统的研究应用，有效控制了同段起爆最大药量，使钙芒硝矿地下开采大爆破引起地面生态环境的影响得到控制。应用时，安全可靠，爆破质量好，操作简便，社会效益和经济效益明显。     

静态控制破碎技术的研究

通过实验分析了静态破碎剂膨胀压的产生过程及膨胀过随温度变化的规律,把静态破碎剂的应用温度范围分为速效高效阶段,普通高效阶段和“滞死”阶段,为解决“滞死”阶段的药剂失效问题,研制了可回收利用的温控计,在此基础上,进行了控制同步破碎的理论分析及计算方法的研究。     

射水法建造混凝土防渗墙施工技术及应用

结合长江干堤的应用,从施工条件,机械设备,应用效果等方面介绍了射水法建造混凝土防渗墙施工技术,并对该技术的推广应用及进一步改进提出了建议。     

桩基动测仪在爆破振动测量中的抗干扰处理

论述了网络分析法在滤波器设计中的基本理论。分析了某电站扩建工程中土石方爆破振动信号的干扰源。设计了一个抗干扰测振信号低通传输滤波器,从而提高了桩基动测仪在爆破振动测量中的抗干扰性能。     

爆破振动对铁厂沟村房屋选择性破坏的调查与分析

乌鲁木齐矿务局露天矿的剥离爆破对距爆点１ｋｍ外的铁厂沟材房屋产生了选择性破坏,振动对个体房屋的破坏呈现出鲜明的选择性,不同房屋遭受的破坏程度差异极大。     

有限元模拟在路堑边坡稳定性分析中的应用

以沪蓉国道主干线湖北省高坪-吉心段某开挖深路堑为例，探讨有限元分析在边坡稳定性计算中应用的基本方法和基本步骤，并用剩余推力法的计算结果与之进行对比。比较结果表明，两种方法的计算结果都认为本路堑自然稳定性较好，按此次计算方案开挖后不存在失稳问题，但剩余推力法计算稳定系数略大于有限元分析计算结果。换而言之，用有限元分析计算结果更偏向于安全。     

爆破地震波作用下框架结构与地基共同工作的非线性动力分析

对岩石爆破地震波作用下房屋结构进行了动力分析，建立了岩土爆破地震波作用下地基与房屋结构共同工作的非线性时程分析方法。并利用福建周宁水电站地下厂房开挖爆破的地震波，对其周边的一栋七层钢筋混凝土框架结构进行了实例分析，通过与构造地震波作用下结构的动力反应进行了对比，对其安全性进行了评估。