Study On The Construction Key Technology Of PCCP Pipe Engineering In South Water To North Supplying Project

The south water to north project is the main way to deal with shortage ofwater in Tianjin. The middle route project of this project is that, providing watersupply engineering in Tianjin with part of Yangtze River water from the mainline. PCCP pipelines are employed for water supply engineering. Since Tianjinarea, especially the Binhai new area is recently deposited stratum, of which ismainly very soft clay, the installation technology requirements of the pipeline isrelatively high, and it’s hard to choose a suitable backfilling method. Therefore,the backfilling method is the key problem for water supply engineering inTianjin.Further more, the south water to north project pass through severalfishponds, of which the bearing capacity is low, the void ratio is large, soilproperties differ much, which will cause non-uniform settlement. And safetyoperation of PCCP pipeline will be influenced for large radius. Therefore,combining the practical project, it’s necessary to make correlation research onkey technology for PCCP pipeline. Indoor test, field tests and numerical analysismethods are used to make the following analysis:(1)Tianjin soft foundation is mainly very soft clay, of which theengineering properties are very complex, and non-uniform. Therefore, thedeformation characteristics of soil are analyzed combining operatingcharacteristics of PCCP pipelines.(2)Reasonable degree of compaction of backfill, construction technologyand control measures suitable for Tianjin soft soil foundation are put forwardaccording to field tests. A safe and convenient detection method suitable forPCCP pipeline and degree of compaction is obtained.(3)By analysis on relative angle of PCCP pipeline induced by non-uniformsettlement, an application range of the relative angle in practice is determined.