River Course Piers Hydraulic Characteristic And Its’ Influence On River Ice Processes Research

The river located at the high latitude will be frozen in winter, thawed carelessly in spring. During the process of frozen and thawed, ice jam and ice dam may be happened, which will be caused ice flood disaster. Different channel forms have the different impacts on the process of the formation of the river ice. This article through measured the surface velocity of the Yellow River(Inner Mongolia) downstream county Hai sheng Bu Lang of the Yellow River bridge, and using the software to simulate software for surface velocity at the same time. Then concluded that the natural river bridge pier in the hydraulic characteristics, and use this to analyze the process of frozen and thawed, compare with the field observation experiment. The result show that, the existence of the pier have two main way to influence the process of the frozen. For the case that the pier which located in the middle of the river, because of the length of the pier is shorter than the river channel and Near the bridge pier velocity is large, so it has not impact the ice transporting ability of the river channel, and it will not impact the ice transporting in the early and middle of the ice flow. In the later period of the ice flow, because of the density of the ice flow have increased, it may be blocked in this place. For the case that the pier which located near the river bank, it will decrease the velocity near the bridge, In addition, because of the blocking effect of piers, the ice flow is easier to accumulated in this place, so the alluvial land ice will be formed. With the increasing number of the land ice, the ice transporting ability of the river channel will be descended. When the density of the ice flow continues to increase, the ice will be blocked in this place, the ice flow will be accumulated in this place than ice sheet will be formed and extends to the upstream be frozen. The period of thaw divided into tranquil break and violent break. Tranquil break dominated by thermodynamic factors, the existence of the piers will not affect the tranquil break carelessly. Violent break is usually accompanied by a large number of huge chunks of ice to transport to the downstream. When the number of the ice is very huge, because of the ice transporting ability of river channel is declined, ice flow may be blocked in this place, than ice dam may be formed.