| With the increasing of water conservancy basis, strategic supporting role in the economic and social development, the construction of major water conservancy is already booming in recent years. In the use of nearly 20 years of research and experience in the process of selection,PCCP profits from economic and practical, reliable and durable, excellent comprehensive performance has been generally recognized.Thus PCCP has become the inter basin water resources deployment project selection of pipe in national key project including the south to North Water Diversion Project. This project.has large flow,high pressure with the result that pipe size and weight is huge, there are particularities and difficulties in transportation, hoisting for those super large diameter PCCP greater than DN3.0m,the choice of the construction way is directly related to the whole project quality,time and cost. Because of the significant breakthrough and difficult in the nominal pressure, wall thickness of pipe weight lifting and transportation etc,Taking 2-DN4.0m PCCP in the South to North Water Diversion Project in Beijing section as the object of study. Therefore,it has a realistic significance to carry out experimental study on key construction technology including transportation,installation of super large diameter PCCP.In the modes of supply for super large diameter PCCP,the site construction and factory direct shipment has taken in implementation of the project. After comparing two methods by means of the scheme comparison method and score optimization method,the site construction is preferred and we choose the optimal construction scheme with minimum transport cost method. Pipe factory site layout should be near the mid point in the supply pipe section,the first choice of site selection of program implementation phase is the way combining with the local enterprises,which make full use of the existing plant,reduce the requisition and accelerate the construction of pipe factory.PCCP transport mainly depends on the size of pipe section,concave trailer and special pipe carrying vehicle are two ways in super large diameter PCCP transport. The concave trailer check its ability to climb by using car balance equation,yet special pipe carrying vehicle show focuses tubing process. we testing transport properties of both vehicle performance in field. By proposing safety measures,matching requirements,resource allocation and control requirements of the vehicle and calculating the pipeline transportation efficiency,concave trailer and special pipe carrying vehicle both can realize the safe transport. Special pipe carrying vehicle dominants in turning radius,transportation stability,transport efficiency and the efficiency of loading and unloading trucks,but the scope is limited,costly.PCCP lifting should be as a whole to considered with supply and transport. On the basis of screening the commonly used equipment and lifting equipment applicating in the actual project,two mutually exclusive program namely crawler cranes and gantry cranes uses scoring to preferred. Considering all the factors,gantry crane on the bottom of the groove is better than the scheme of crawler crane. Based on this to analysis gantry crane lifting construction method and process engineering methods typical characteristics, comprehensively summarized and classified the quality control standards, control content of the installation process. Through calculating PCCP installation process time and analyzing the efficiency of pipeline installation combined with the two lifting docking method installation test.The south to North Water Diversion Project in Beijing section of PCCP was completed in 2008,the project operates in recent 7 years safely. water transport to Beijing accumulated up to 16.1 ×108m~3 as of 2014 April,the quality of construction projects has been proved in the operation period of a long time. |
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