Experiment of explosive consumption by blasting pretreated boulders with overlying stratum of rock-soil
-
摘要: 盾构机在风化花岗岩地层掘进会遇到高强度孤石,为降低施工风险、避免刀盘及刀具严重损坏,常采用地面钻孔爆破对前方孤石进行预处理,但其炸药单耗一般由经验公式确定,导致爆破效果不理想。结合实际工程对爆破块度小于30 cm的特殊要求,采用爆破模型实验对炸药单耗进行研究。实验结果表明:满足特殊块度要求的陆地钻孔爆破炸药单耗是常规钻孔爆破的5.4~6.5倍;上覆地层厚度与炸药单耗呈线性递增关系;实验得出的炸药单耗是瑞典经验公式计算值的3.4~4.9倍。由此提出满足工程需要的炸药单耗修正公式,应用于实际工程并通过验证取得良好效果,为类似工程孤石爆破预处理炸药单耗的计算提供依据和参考。Abstract: During the tunneling construction in hard granite strata utilizing shield machines, pretreatment of boulders by blasting was commonly used to prevent the abrading cutter from serious damages and reduce construction risks, but the explosive consumption was usually determined based on empirical formula, resulting in that the blasting effect was often far from satisfactory. In the present work, aiming to meet the special requirement that rock fragments from the blasting should be less than 30 cm in practice, we investigate the explosive consumption using a model test of blasting. The results show that the explosive consumption of land blasting is 5.4-6.5 times that of conventional blasting when the requirement of rock fragmentation is satisfied; the explosive consumption increases linearly with the depth of overlying stratum; and the explosive consumption of model test was 3.4-4.9 times that of the empirical formula. Thus, the revised empirical formula is derived and proved valid based on the on-the-site practice. The revised formula can serve as calculation basis and reference value for similar projects of tunneling construction.
-
Key words:
- mechanics of explosion /
- explosive consumption /
- blasting /
- boulder /
- shield /
- pre-treatment /
- model experiment
-
表 1 模型实验中选取的现场物理量、量纲及数值
Table 1. Dimensions and values of on-the-site physical quantities in model test
编号 符号 名称 单位 量纲 数值 1 Q 炸药量 kg M - 2 v 炸药爆速 m/s LT-1 4 000 3 ρ 炸药密度 kg/m3 ML-3 1 200 4 R 装药半径 m L 0.045 5 h 装药长度 m L 0.90 6 ρr 岩石密度 kg/m3 ML-3 2 800 7 vr 岩石纵波波速 m/s LT-1 4 000 8 σr 岩石强度 N/m2 ML-1T-2 1×106 9 L 岩石尺寸(正方体) m L 1.00 10 D 岩石破碎的平均块度 m L 0.30 11 H 岩石埋深 m L - 12 ρc 上覆层密度 kg/m3 ML-3 2 600 13 vc 上覆层纵波波速 m/s LT-1 2 400 表 2 相似律各参数含义及数值
Table 2. Parameters and values of similarity law
参数 数值 参数含义 π1 0.05 模型和实际的装药尺寸相似比 π2 0.045 模型与实际爆破的尺寸相似比 π3 0.15 模型与实际爆破的爆破块度相似比 π4 0.143 实验模型和几何原型的相似比 π5 0.005 2 炸药的爆轰压力与岩石强度的相似比 π6 0.43 炸药与岩石的波阻抗相似比 π7 1.8 岩石与覆盖层的波阻抗相似比 π8 62.8 装药量与装药半径的相似比 表 3 混凝土试块配合比(kg/m3)
Table 3. Proportions of components in concrete sample (kg/m3)
标号 水泥 砂 碎石(5~10 mm) 碎石(10~20 mm) 粉煤灰 聚羧酸高效减水剂 水 C50 376 659 468 703 94 4.7 145 表 4 试块爆破装药量及爆后块度统计
Table 4. Charge weight of samples and fragmentation statistics
试块 Q/g D/cm q/(kg·m-3) H/cm 实验场地 qb/(kg·m-3) 实验现象 1-1 20 2.00 5.93 0 实验用水池 3.26 在砂层表面形成明显爆坑 1-2 11 4.50 3.26 1-3 8 5.54 2.37 2-1 12 4.63 3.56 30 实验用水池 3.85 覆盖层表面出现了直径约30 cm左右的塌腔 2-2 13 4.54 3.85 2-3 14 4.40 4.15 3-1 14 4.67 4.15 50 实验用水池 4.44 表面出现直径约45 cm的环状裂纹且试块上部出现空腔 3-2 13 5.33 3.85 3-3 15 4.48 4.44 4-1 16 4.46 4.74 70 工地料场 4.74 表面无裂纹,试块周边出现空区 4-2 17 4.28 5.04 4-3 18 3.98 5.33 5-1 15 4.85 4.44 100 工地料场 5.04 表面无裂纹,试块周边出现空区 5-2 18 4.09 5.33 5-3 17 4.45 5.04 6-1 22 3.78 6.52 150 工地料场 5.93 表面无裂纹,试块周边出现空区 6-2 20 4.65 5.93 6-3 19 4.31 5.63 表 5 模型实验和现场爆破的炸药单耗
Table 5. Explosive consumption in model experiment and on-the-tsite blasting
Hm/m Hf/m qb/(kg·m-3) 0 0 3.26 0.3 2.1 3.85 0.5 3.5 4.44 0.7 4.9 4.74 1.0 7.0 5.04 1.5 10.5 5.93 表 6 水下爆破炸药单耗经验公式对比
Table 6. Comparison of explosive consumption empirical formula in underwater explosion
公式来源 表达式 考虑的主要因素 中国水利系统 q水=q陆+0.01H水+0.02H介质+0.03H梯 水深、炸药埋深、梯段高度 日本炸药协会 $ \left\{ \begin{array}{l} {L_\alpha } = H{C_\alpha }\;\;\left( {水压修正} \right)\\ {L_\beta } = {H_0}{C_\beta }\;\;\;(上覆土岩修正) \end{array} \right. $ 水深、上覆层厚度 瑞典经验公式 q=q1+q2+q3+q4 水深、梯段高度、覆盖层高度 《工程爆破实用手册》 Q=KWaH[1.45+0.45Exp(-0.33H0/W)] 水深、抵抗线、孔距、梯段高度 表 7 瑞典经验公式和本文拟合公式的炸药单耗对比
Table 7. Comparison of explosive consumption between results of Sweden empirical formula and fitting formula
H/m q/(kg·m-3) η 式(5) 瑞典经验公式 0 1.10 3.39 3.39 5 1.37 4.63 3.38 10 1.52 5.87 3.86 15 1.67 7.11 4.26 20 1.82 8.25 4.53 25 1.97 9.59 4.87 表 8 孤石段与正常段盾构掘进参数对比表
Table 8. Comparison of boulder's driving parameters with those of normal section
掘进段 v/(mm·min-1) t/min F/kN 孤石段 15.5 121 18 739 正常段 13.8 108 18 035 -
[1] 刘建国.深圳地铁盾构隧道技术研究与实践[M].北京:人民交通出版社, 2011. [2] 杜力编译.无自由面爆破破碎岩盘[J].爆破, 1990(4): 66-69. http://www.cqvip.com/qk/91438X/199301/1286481.htmlDu Li Translated. Blasting rock without free surface[J]. Blasting, 1990(4): 66-69. http://www.cqvip.com/qk/91438X/199301/1286481.html [3] 徐朝辉.台山核电站取水隧洞基岩及孤石处理技术[J].陕西水利, 2010(6):81-82. http://d.old.wanfangdata.com.cn/Periodical/shanxsl201006045Xu Zhaohui. Treatment technology of bedrock and boulders in Taishan nuclear intake tunnel[J]. Shaanxi Water Resources, 2010(6):81-82. http://d.old.wanfangdata.com.cn/Periodical/shanxsl201006045 [4] 洪开荣.水下盾构隧道硬岩处理与对接技术[J].隧道建设, 2012, 32(3):361-365. http://d.old.wanfangdata.com.cn/Periodical/sdjs201203021Hong Kairong. Case study on hard rock treatment technology and shield docking technology in boring of underwater tunnels[J]. Tunnel Construction, 2012, 32(3):361-365. http://d.old.wanfangdata.com.cn/Periodical/sdjs201203021 [5] 路耀邦, 刘洪震, 游永锋.海底盾构隧道孤石爆破预处理关键技术[J].现代隧道, 2012, 49(5):117-122. doi: 10.3969/j.issn.1009-6582.2012.05.020Lu Yaobang, Liu Hongzhen, You Yongfeng. Key techniques for the pretreatment of boulder blasting in an under-sea shield-driven tunnel[J]. Modern Tunnelling Technology, 2012.49(5):117-122. doi: 10.3969/j.issn.1009-6582.2012.05.020 [6] 海瑞克股份公司.台山核电引水隧道盾构机说明书[M].海瑞克股份公司, 2010. [7] 刘美山, 吴新霞, 张恒伟.混凝土水下爆破炸药单耗试验分析[J].爆破, 2007, 24(1):10-15. doi: 10.3963/j.issn.1001-487X.2007.01.003Liu Meishan, Wu Xinxia, Zhang Hengwei. Experimental analysis on specific charge of underwater explosion of concrete[J]. Blasting, 2007, 24(1):10-15. doi: 10.3963/j.issn.1001-487X.2007.01.003 [8] 刘慧, 冯叔瑜.炸药单耗对爆破块度分布影响的理论探讨[J].爆炸与冲击, 1997, 17(4):359-362. http://www.bzycj.cn/article/id/10486Liu Hui, Feng Shuyu. Theoretical research of the effect on the blasting fragentation distribution from the explosive specific charge[J]. Explosion and Shock Waves, 1997, 17(4):359-362. http://www.bzycj.cn/article/id/10486 [9] 陈运轩.爆破块度效应对炸药单耗的影响[J].爆破, 1996, 13(3):19-22. http://www.cnki.com.cn/Article/CJFDTOTAL-BOPO603.004.htmChen Yunxuan. Effect on the explosive specific charge considering blasting fragmentation[J]. Blasting, 1996, 13(3):19-22. http://www.cnki.com.cn/Article/CJFDTOTAL-BOPO603.004.htm [10] 马建军, 熊祖钊, 段卫东, 等.工程爆破模拟试验的相似律[J].武汉科技大学学报:自然科学版, 2001, 24(2):170-173. http://d.old.wanfangdata.com.cn/Periodical/whkjdxxb200102020Ma Jianjun, Xiong Zuzhao, Duan Weidong, et al. Similarity law in simulation test of engineering blasting[J]. Jounal of Wuhan University of Science &Technology: Natural Science Edition, 2001, 24(2):170-173. http://d.old.wanfangdata.com.cn/Periodical/whkjdxxb200102020 [11] 杨振声.工程爆破的模型试验与模型律[J].工程爆破, 1995, 1(2):1-15. http://www.cnki.com.cn/Article/CJFDTOTAL-GCBP502.000.htmYang Zhensheng. Modeling experiment of exgineering blasting and model theory[J]. Engineering Blasting, 1995, 1(2):1-15. http://www.cnki.com.cn/Article/CJFDTOTAL-GCBP502.000.htm [12] 秦绍兵, 秦绍红.井下中深孔爆破模型试验的相似性研究[J].工程爆破, 2001, 7(2):9-12. doi: 10.3969/j.issn.1006-7051.2001.02.003Qin Shaobing, Qin Shaohong. Study on the similarity of model experiment of underground medium-length-hole blasting[J]. Engineering Blasting, 2001, 7(2):9-12. doi: 10.3969/j.issn.1006-7051.2001.02.003 [13] 王伟, 李小春.无临空面深层岩体爆破增渗模型试验相似律研究及相似条件的实现[J].岩土力学, 2009, 30(7):1892-1898. doi: 10.3969/j.issn.1000-7598.2009.07.003Wang Wei, Li Xiaochun. Study of similar law of model test of blasting echanced permeability in deep rock mass without free surface and its implementation[J]. Rock and Soil Mechanics, 2009, 30(7):1892-1898. doi: 10.3969/j.issn.1000-7598.2009.07.003 [14] 左启东.模型试验的理论和方法[M].北京.水利水电出版社, 1984. [15] Ma Qinyong, Cai Meifeng. Determination of similarity of explosives for a model experiment[J]. Combustion, Explosion and Shock Waves, 2003, 39(5):606-609. doi: 10.1023/A:1026178222336 [16] 李泉.几种水下钻孔爆破炸药单耗计算公式的分析与比较[J].爆破, 2012, 29(1):94-97. http://d.old.wanfangdata.com.cn/Periodical/bp201201025Li Quan. Analysis and comparision of several calculation formulas of specific charge underwater drilling blasting[J]. Blasting, 2012, 29(1):94-97. http://d.old.wanfangdata.com.cn/Periodical/bp201201025 [17] Arpaz E, Uysal O, Tola Y, et al. Comparison of blasting-induced ground vibration predictors in Seyitomer coal mine[M]. Harmonising Rock Engineering and the Enviroment, 2011, 25(2): 153-175.