The Middle Route Of South-to-North Water Transfer Project A Research On Prestressed Structural Optimum Design For Large Aqueduct

The south-to-north water transfer project is the largest water diversion projects in the world,it invests south freshwater resources into the northern areas of water scarcity, it can satisfy the north people’s life and production water demand and effectively relieve regional shortage of water to our country after its building.The south-to-north water transfer project can also have a great significant for optimal allocation of water resources, promoting the regional economy, society, resources and environment sustainable development.Due to the the long route, complicated geological and geomorphic conditions,in the process of water diversion the south-to-north water transfer project needs to build many aqueduct structures across the valley and rivers.According to their characteristics such as the big volume,the long span and the gravity conveyance way,the design aqueduct structures are all very huge, it comes to a lot of unprecedented difficult problems in the design process.Based on the actual product requirements,this study takes the South-to-north water transfer project Shuangjihe aqueduct as the research object,the main content is as follows:(1) Analysis the hydrology,climate,geology,geomorphology and other natural conditions of the aqueduct structure site,preliminary to determine the the Aqueduct length,combined with flood control security and engineering layout analysis,finally determine that the upper length of the aqueduct structure is 630m.(2)Taking slot 2,slot 3,slot 4 as the Selection Schemes,consider the single-slot width and water purification height,combined with the nowadays construction technology level,and determine that whether it is rectangular or U-shaped cross-section structure all adopt slot 4 which is the common conveyance form.(3)Compared from the structural stress, structural safety, the construction, river flood control impact angle and economic point of view,initially identiy the rectangular and U-shaped program, finally determine that the super structure adopt 30m cross-rectangle aqueduct,water transfer form adopt two slots of a joint and double trough section.(4)Combined with the nature and construction conditions at the Aqueduct site, determine ten kinds of calculation condition ensuring that fully considering various stress state during the aqueduct building and running. Based on initially identified design programs,adopt structural mechanics method to calculate, the result identifies that reinforcement of the aqueduct upper structure is consistent with the resistancing crack requirements.(5)Based on the structural mechanics calculations result, use Ansys software for 3d entity aqueduct finite element recheck computation,determine that the design of the aqueduct structure is safe and reliable. Analysis the two results of two calculations mathods,draw that adopting a combination of two calculation methods for large aqueduct design is scientific and rational.(6) Using the finite element method calculation check aqueduct prestressing steel strand tensioning sequence, ensure the initial pre-tension order is scientific and rational.