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Establishment of a Ventilation Network and the Shaft Ventilation Effect in a Large Underground Cavern Group
(1 Key Laboratory of Transportation Tunnel Engineering, Ministry of Education, Southwest Jiaotong University, Chengdu 610031;2 China Railway Second Bureau Engineering Co. Ltd., Chengdu 610091)
Abstract Large underground cavern groups are usually built in stages, and forced ventilation is often adopted during construction of the upper part. The air duct and air supply must be improved in order to maintain forced ventilation during construction at the middle and lower parts due to a more serious pollution source compared to the upper part.However, it′ s not feasible to increase the air supply volume that is restricted by the size of the construction adit,which results in deterioration of ventilation conditions. Based on the construction ventilation case of the Jinzhou underground oil storage cavern, the shaft ventilation effect is studied and a further study of the effects of the shaft diameter, location, and depth on construction ventilation is conducted by Fluent calculation software and field measurements. The results show that the shaft diameter has a certain influence on the cavern′s ventilation, but the effects of ventilation enhancement are limited by changing the shaft diameter; the ventilation effect is closely related to shaft depth, and the optimal shaft depth is 70 m; with the forcing of fresh air by the axial flow fan installed at the shaft mouth and entrance of the construction adit (transportation passage leading to the cavern from the surface) used as an exit for polluted air, an orderly virtuous axial ventilation network could be formed.
Abstract：
Large underground cavern groups are usually built in stages, and forced ventilation is often adopted during construction of the upper part. The air duct and air supply must be improved in order to maintain forced ventilation during construction at the middle and lower parts due to a more serious pollution source compared to the upper part.However, it′ s not feasible to increase the air supply volume that is restricted by the size of the construction adit,which results in deterioration of ventilation conditions. Based on the construction ventilation case of the Jinzhou underground oil storage cavern, the shaft ventilation effect is studied and a further study of the effects of the shaft diameter, location, and depth on construction ventilation is conducted by Fluent calculation software and field measurements. The results show that the shaft diameter has a certain influence on the cavern′s ventilation, but the effects of ventilation enhancement are limited by changing the shaft diameter; the ventilation effect is closely related to shaft depth, and the optimal shaft depth is 70 m; with the forcing of fresh air by the axial flow fan installed at the shaft mouth and entrance of the construction adit (transportation passage leading to the cavern from the surface) used as an exit for polluted air, an orderly virtuous axial ventilation network could be formed.
.Establishment of a Ventilation Network and the Shaft Ventilation Effect in a Large Underground Cavern Group[J] MODERN TUNNELLING TECHNOLOGY, 2018,V55(1): 203-209
2018, Vol. 55 