The Research Of The Key Technology Of The PCCP Pipe Construction Used In Supply Water Piping Line

PCCP that is the combination of steel pipe and pre-tension concrete pipe is the non-metal high quality pipe. It is well known that it was regarded as the most effective and environmental pipe material. With regard to the superiority performance and high quality, as yet, no others materials can substitute for PCCP. China has imported the equipments and technical from overseas since 1980's and 1990's. China has issued the standard JC625-1996 on Pre-tension Concrete Pipe in the field of construction in 1996. The national standard on pre-tension Concrete Pipe will be issued .There is no industry or national standard and criterion on PCCP of designing, engineering, checking and acceptance until now.This article describes the qualities of the PCCP pipe, a non-metal compound pipe material chosen for supply water piping line through comparing with and selecting among normal pipe materials applied in the same area. It also sums up the installation points of PCCP piping from the lately year PCCP piping construction experience and offers some relevant suggestion which will be the accordance of the establishment of the erodes of the construction and the standards of the quality acceptance of the PCCP pipe. An experienced formula of how to calculate the push force of the rubber ring joint is concluded and a method of pulling with chain pulley with horizon rod used in pipe installation are proposed, which is the substitution of the traditional one of pulling arch chain pulley and which is applied in actual engineering.It is also pending item that full-pipe water pressure test will be replaced by water-pressure test for double-seal coupling on PCCP. Amount of measuring data from full-pipe water pressure tests for a portion of PCCP during engineering via sample check separately will regarded as the strong technical data for substitute.The deficiency of leakage from the PCCP piping line when the water supply piping line was put into use exists in actual engineering .The main reasons of the leakage of large diameter PCCP piping are the fall of the underground water mark and the expansion of theclay when forcer .Measures of how to improve the ability of the load of the piping foundation are proposed to avoid the leakage of the piping line. Such as by fastening the piping foundation and by substituting the clay of the piping foundation, which will be the accumulations of the construction experiences for the similar engineering.