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Experimental Study on Dust Reduction Technology for D&B Tunnelling
(1 Xi′an Highway Research Institute Co., Ltd., Xi′an 710065; 2 CCCC Second Highway Engineering Co., Ltd., Xi′an 710065;3 Central South Survey Design Institute Group Co., Ltd., Wuhan 430071)
Abstract In order to quickly deal with the dust and harmful gas after tunnel blasting, based on the Jiaoding tunnel project, this paper conducts a field test to get the distribution of the initial concentrations of dust and CO at seven characteristic points at different positions away from the tunnel face; and then it studies the variation pattern of dust and CO concentration in the tunnel under longitudinal ventilation conditions; furthermore it proposes the technical solutions of dust reduction and removal with water bag and mobile spray respectively and verifies the superiority of the two solutions through field tests. The study shows that: (1) the average concentration values of dust and CO at 50m away from the tunnel face after blasting are 8.2 times and 26.05 times of the allowable concentration, respectively;(2) under the condition of longitudinal ventilation, the first 10 mins is the stage where the dust and CO concentrations fall the most rapidly, with the rate of reduction reaching 50%; (3) the dust reduction effect of the water bag is significant, and the maximum reduction of dust and CO concentration can reach 52.62% and 43.91% respectively; (4)the dust removal effect of the mobile spray is better than that of the water bag, and the first 20 mins is the stage of the most rapid reduction of dust and CO concentration, and the reduction rate can reach 60%.
Abstract：
In order to quickly deal with the dust and harmful gas after tunnel blasting, based on the Jiaoding tunnel project, this paper conducts a field test to get the distribution of the initial concentrations of dust and CO at seven characteristic points at different positions away from the tunnel face; and then it studies the variation pattern of dust and CO concentration in the tunnel under longitudinal ventilation conditions; furthermore it proposes the technical solutions of dust reduction and removal with water bag and mobile spray respectively and verifies the superiority of the two solutions through field tests. The study shows that: (1) the average concentration values of dust and CO at 50m away from the tunnel face after blasting are 8.2 times and 26.05 times of the allowable concentration, respectively;(2) under the condition of longitudinal ventilation, the first 10 mins is the stage where the dust and CO concentrations fall the most rapidly, with the rate of reduction reaching 50%; (3) the dust reduction effect of the water bag is significant, and the maximum reduction of dust and CO concentration can reach 52.62% and 43.91% respectively; (4)the dust removal effect of the mobile spray is better than that of the water bag, and the first 20 mins is the stage of the most rapid reduction of dust and CO concentration, and the reduction rate can reach 60%.
WANG Fei1 WANG Qing2 JIAO Weining2 Qin Wei3
.Experimental Study on Dust Reduction Technology for D&B Tunnelling[J] MODERN TUNNELLING TECHNOLOGY, 2021,V58(5): 196-203
2021, Vol. 58 