Experiment Research On Freezing Damage Of Canal Lining At Ningxia Irrigation Area

Canal lining project have been suffered from freeze for a long time at Ningxia irrigation area and cause some serious results. A great deal of capital has been spent in convinence and rebulid of old canal lining every year, it affects badly positive benefit of hydraulic project and delays the development speed of irrigation area. So, it is very urgent to resolve the problem of freeze of canal lining project.Ningxia Yellow river irrigation area is a big famous irrigation area in China and has over 2,000 years history, there are 17 main canals(1540 km length) and 6,450,000 mu area, it plays a very important role in development of ecnomic and social of Ningxia autonomous region. During 1970s-1980s, irrigation management department launched canal lining for main canal. Irrigation management department initiated large scale canal lining project because of great government finacial investment on water saving project resconstruction since 1995. But some difficult problems occurred, in construction due to shortage of system experiment on anti freeze of main canal lining project, it is very essential to carry out related experiment research for providing instruction of engineering practice and theory surppot of anti freeze of main canal lining project.The experiment follows out leading thought on cutting and siutting freeze of fundation and enforcing inflexibility of concrete slate, choose Han canal as typical experiment segment, collect freeze index of various canal lining framework, refer the advaced method at home and abroad,adapt new material to make experiment design. The test obsvervation include air temperature, ground temperature, foundation moisture, freeze depth, freeze capicity, freeze residual capicity, groundwater table and shape transform of canal lining, etc.Throught systemic observation, analysis of impact about each factor on fundation freeze capicity, evaluate effect on anti freeze of various canal lining, comparison on technology and ecnomic of different method, a kind of main canal lining format is been recommended toengineering practice with siutable to Ningxia local feature, fufilling the need of main canal safeyi application, economic and practical, that is using polystyrene plate laying under concrete slateand grit taking replace of filling layer and optimizing design. At the same time, this paper point out it is a development direction making use of macromolecule material to develop flexible and inflexible mixed canal lining frame or flexible frame with credible technology, simple configuration and rational price.