台阶法隧道岩体爆破特性研究及岩石碎片块度预测  

Study on Blasting Characteristics of Rock Mass and Prediction of Rock Fragment Size by Bench Blasting in Tunnel Excavation

作　　者：董武俊 DONG Wu-jun(China Railway 11th Bureau Group Co.,Ltd.,Wuhan 430064,China)

机构地区：[1]中铁十一局集团有限公司,武汉430064

出　　处：《爆破》2023年第2期81-88,153,共9页Blasting

基　　金：高速铁路山岭隧道智能化建造技术研究(K2018G014)。

摘　　要：爆破炸药单耗及岩体爆破碎片块度预测方法均起源于露天矿爆破,台阶法隧道上下台阶岩体应力状态与露天矿大不相同,以上预测方法是否适用于台阶法隧道爆破尚未可知。根据天江里隧道台阶法爆破统计数据,采用几种露天矿常用计算方法预测了上下台阶炸药单耗及碎片分布,并与实测结果进行了对比,得出如下结论:Kuznetsov模型和Kansake模型仍然适用于台阶法隧道工程炸药单耗的预测,且Kuznetsov模型考虑了岩体特性的影响,比Kansake模型更加实用;此外,Kuznetsov模型可以预测爆破碎片平均值,作为爆破碎片分布模型的基础。上台阶爆破单耗高,岩体爆破后细颗粒含量高、整体块体小;下台阶爆破单耗低,岩体爆破后细颗粒含量低、整体块度大。对于块度在平均值以下的小块体爆破碎片,采用Kuz-Ram模型预测效果较好;对于块度在平均值以上的大块体爆破碎片,采用KCO模型预测效果较好,且KCO模型对最大爆破块体的预测较准确。分析了预测模型的适用条件及范围,为隧道爆破炸药单耗和块度分布提供了依据。The conclusions including:the Kuznetsov and kansake models are still applicable to the prediction of unit explosive consumption in bench blasting tunnel engineering,and the Kuznetsov model considers the influence of rock mass characteristics,which is more practical than the kansake model.In addition,the Kuznetsov model can predict the average blasting fragment as the basis of the distribution model of blasting fragment.Compared with the lower bench,the upper bench has higher single blasting consumption,higher content of fine particles and smaller fragments.The Kuz-Ram model has a good prediction effect for the small blasting fragments that below the average value.For the large blasting fragments that above the average value,the KCO model has a better prediction effect,and it has more accurate for the prediction of the largest blasting fragment.This paper analyzes the applicable conditions and scope of the prediction model for rock fragment,which provides a basis for the unit explosive consumption and fragment distribution of tunnel blasting.The methods for predicting the specific consumption of explosives and the fragmentation of rock mass during blasting originated from open-pit blasting.However,the stress state of the rock mass in stepped tunnels is different from that in open-pit mines,so it is unknown whether the above prediction methods are applicable to stepped tunnel blasting.Based on statistical data from the bench blasting in the Tianjiangli tunnel,several commonly used calculation methods in open-pit mines were used to predict the specific consumption of explosives and the distribution of fragments,and the predicted results were compared with the actual measurements.The results show that the Kuznetsov model and the Kansake model are still applicable to predicting the specific consumption of explosives in stepped tunnel blasting,and the Kuznetsov model takes into account the influence of rock mass characteristics,making it more practical than the Kansake model.In addition,the Kuznetsov model can predict

关 键 词：爆破 炸药单耗 碎片分布 模型 块度 

分 类 号：TU745.3[建筑科学—建筑技术科学]