Construction Technology Analysis And Application Of Underground Comprehensive Pipe Gallery Project In A City

This paper mainly takes the underground comprehensive pipe corridor project of a city as the research object.It is found out that the construction difficulties in the construction process of the project,through systematically analyzes and studies its engineering overview,geological hydrology and surrounding environment,and puts forward the construction solutions and measures based on the actual situation.The main research work carried out during the project research and the research results are as follows:(1)It was investigated and collected on site that the construction conditions,construction environment and other contents of the project.(2)The construction difficulties of the comprehensive pipe gallery project are mainly divided into two parts according to the construction position: old city construction and cross-river construction.Among them,the construction difficulties in the construction of the old city are mainly concentrated in the following aspects: traffic diversion along the line,operation and construction of the high-voltage line area,dewatering and water interception in the construction area,pipeline relocation and cross construction.The difficulties in the construction of cross river basin are concentrated in the following aspects: river course diversion,water stop curtain construction,foundation reinforcement and treatment in the area of river mechanical operation,and the construction of split cofferdam.(3)For old tube along the corridor of the construction of the traffic guidance,follow the construction principle of "first channel after excavation",according to the width of the intersection and the number of inward and outward take different framing construction plan.The half-width construction period of the project is more than 30% at the intersection,compared with the estimated construction period of the fully enclosed construction,and three-part construction period of the project is more than 60% at the intersection,compared with the estimated construction period of the fully enclosed construction.(4)For the construction of high voltage line area pipe gallery,to ensure the safety of high voltage line is given priority to,adopt the construction concept of "first reinforcement,then enclosure,then construction",give priority to the force bar,pylon enclosure and foundation reinforcement treatment,and then choose construction measures according to the affected area of high voltage line.Affected by the high-voltage line,the overall construction machinery efficiency of the section is reduced by about 35%-40%,and the overall construction cost expenditure is increased by 35%-40%.(5)Compared with the general urban underground integrated pipe gallery project,the construction of the project in the old city area needs to increase the construction period by more than 30%.Among them,due to the impact of high-voltage lines and pipeline migration,the overall construction machinery efficiency and artificial work efficiency are reduced by about 35%-40%.The construction cost should be increased by more than 30%,and the cost of custom machinery and manual secondary handling which is affected by the high-voltage line needs to increase by about 40%.The preliminary construction preparation phase accounts for more than 50% of the construction period and construction cost of the entire river basin in the cross-river construction.