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Design Optimization for the Rapid Excavation of Inclined Shaft of the Long Tunnel and Construction Period Estimation
（1 State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300354；2 China Railway 19th Bureau Group Co., Ltd，Beijing 100176)
Abstract Based on the construction of the Aobaoliang Tunnel, this paper discussed the necessity of scheme opti? mization of inclined shaft before construction. In light of tight construction and low grade of surrounding rocks, the design schemes for the No. 1 and No. 3 inclined shaft were optimized from the following four aspects of designed alignment, section dimension, mucking equipment and support structure, e.g. 1) the single lane was changed to two lanes to solve the problem of vehicle passing in inclined shaft; 2) reinforcement mesh and cast-in place concrete lining were replaced by single-layer steel fiber reinforced concrete lining, and type I18 profile steel was optimized for type 150 lattice girder, so the cost of two-lane excavation and support structure was reduced. The results of toughness test show that the supporting performance of steel fiber reinforced shotcrete (40 kg/m3) is much better than that of reinforcement mesh, so the shotcrete and construction time is shortened. Due to the alignment adjustment, the lengths of main and auxiliary bore were balanced and the construction progress in auxiliary bore was speeded up. The mucking efficiency was improved and the gas emissions were decreased attributed to the design consisting of one electric hydraulic excavator and five dump trucks. Finally the construction period of main tunnel was shortened by 5.5 months and the labor cost of the Aobaoliang tunnel was reduced by RMB ￥15 million after optimization of the inclined shaft scheme.
Abstract：
Based on the construction of the Aobaoliang Tunnel, this paper discussed the necessity of scheme opti? mization of inclined shaft before construction. In light of tight construction and low grade of surrounding rocks, the design schemes for the No. 1 and No. 3 inclined shaft were optimized from the following four aspects of designed alignment, section dimension, mucking equipment and support structure, e.g. 1) the single lane was changed to two lanes to solve the problem of vehicle passing in inclined shaft; 2) reinforcement mesh and cast-in place concrete lining were replaced by single-layer steel fiber reinforced concrete lining, and type I18 profile steel was optimized for type 150 lattice girder, so the cost of two-lane excavation and support structure was reduced. The results of toughness test show that the supporting performance of steel fiber reinforced shotcrete (40 kg/m3) is much better than that of reinforcement mesh, so the shotcrete and construction time is shortened. Due to the alignment adjustment, the lengths of main and auxiliary bore were balanced and the construction progress in auxiliary bore was speeded up. The mucking efficiency was improved and the gas emissions were decreased attributed to the design consisting of one electric hydraulic excavator and five dump trucks. Finally the construction period of main tunnel was shortened by 5.5 months and the labor cost of the Aobaoliang tunnel was reduced by RMB ￥15 million after optimization of the inclined shaft scheme.
ZHAO Licai1,
2 YU Jianxing1
.Design Optimization for the Rapid Excavation of Inclined Shaft of the Long Tunnel and Construction Period Estimation[J] MODERN TUNNELLING TECHNOLOGY, 2019,V56(5): 50-57
2019, Vol. 56 