Ice And The Interaction Of Bridge Piers

In China, lakes, reservoirs, rivers and other waters in the north of North latitude35°will be frozen in winter and make melting ice flood near spring, much more serious especially Rivers on the Qinghai-Tibet plateau, Nenjiang upstream, downstream of the Yellow River, upstream of Heilongjiang, the Yilan downstream of Songhua river, the Yellow River in Inner Mongolia. Ice often congests the watercourse and badly impact the flood control, transportation, water supply and drainage, water conservancy and hydropower engineering construction. Therefore, it is much more significant to study ice and the interaction of piers, anti-icing bump measures, the prevention and cure of ice disasters to ensure the security of the people’s life and property.For the ice melting ice flood rivers in China, in this paper, the writer investigates the bridge safety and disaster impact, analyzes the river ice formation and evolution, aiming at the Heilongjiang, northeastern Inner Mongolia region and the middle and upstream of Huanghe River. Four typical test sections are selected to build flow glacial river ice temperature test field for a long-term observation. Five typical test rivers are selected to make river ice mechanics performance test. According to experimental results, establish the relationship between the temperature, strain rate and the river ice strength, elastic modulus and conclude the calculation method of river ice strength standard values considering factors such as temperature and strain rate. Simultaneously, with the help of LS-DYNA, based on the theory of nonlinear finite element analysis and contact-collision theory, simulation analysis the simulation analysis process of bridge pier were studied, builds the analysis and calculation model, and discusses the impact from ice floe characteristics and the piers ice shape. The main works are as follows:(1) Convection glacial river ice temperature field research, it is concluded that the test points glacial river flow along the ice thickness distribution. To general global optimization method and quasi Newton method as the basis, using1stopt packages, set up three regions in Heilongjiang province points, water temperature, the temperature of the relationship between the three numerical models.(2) In combination with the river ice mechanics performance test, put forward the points, the strain rate effect on compressive strength and compression modulus of elasticity and the bending strength and bending modulus of elasticity, the influence of temperature and strain rate in a range is roughly similar change rule.(3)Under the condition of same temperature and loading rate, get ice of Heilongjiang province each region is larger than the bending strength, compressive strength under the same loading rate effect, compression modulus of elasticity is about half of the bending modulus of elasticity, uniaxial compression strength was about1.7times that of bending strength of the conclusions.(4) Through the study of factors affecting the modeling of simulation calculation of impact force, analysis the influence of contact type and contact algorithm. Calculated ice impact force as the ice floe strength, elastic modulus, ice floe and showed a trend of increase with the increase of the thickness.(5) Ice pressure standard calculation method is proposed, the ice strength standard values according to the weighted average of the calendar year when ice minimum points and the largest ice velocity calculated and determined, it can also according to the historical lowest temperature, water temperature and the maximum flow ice velocity calculated and determined. This determination method accord with the actual situation of the river bridge site, greatly improving the calculation accuracy.(6) The ice body shape, the mechanism of impact damage Angle the influence of the impact force convection ice. Put forward different pier model set up by the different Angle and the vertical front edge Angle scope, improve collision effect.(7) Summed up the four damage form of piers, to propose principles of designing anti-icing bump piers, developed economic and practical anticollision measures.The study of interaction between ice and pier anti-icing bump further technical measures of research foundation, and provide effective reference designs for the anti-icing bump piers.