The Research Of Thermal Stress Of Large Outlet On Rock Base

The sluice is an important part of hydroproject engineering; According to large numbers of sluice engineering example in our country, including reservoir flood diversion sluice, the appearance of crack is very universal in the sluice pier and base plate often exposed in the air (such as flood diversion gate), which are constructed on the rock base of foundation; the location, type and size of crack have some regularity; some of cracks have formed permeability crack, length of some crack has exceeded ninety percent height of pier; both of them destroy construction integrity and affect ordinary operation of sluice. The main cause of crack generation is the effect of temperature varying and foundation constrain; especially, the influence of long time and short term temperature differential is more prominence to sluice pier and base plate which are often exposed in the air.Firstly in this dissertation, the research object matter of thermal stress of large outlet sluice is illustrated; the definition, type and research status of thermal stress are expounded. Secondly, the sort of crack of concrete construction, cause of crack generation, characteristic of temperature crack, crack harm to the structure and some ways of prevention, control and repair crack are depicted. Then, the ultimate principles of heat transmission theory and thermal stress theory have specification; the thermal stress of sluice when temperature is variance during operating period is analyzed. With that, the initial condition of short term thermal stresses of sluice and water boundary and air boundary condition are analyzed; thermal radiation theory and heat transmission theory are depicted; the external surface area temperature of pier is computed on the two worst conditions of summer temperature upraising and winter night temperature building down; sluice temperature field and FEM form of thermal stress are deduced. Finally, a large outlet sluice is been as example, analyzes structural stress without temperature load, temperature filed and thermal stress of summer temperature upraising and winter night temperature building down and make preliminary research of influence of the base elastic modulus variation to thermal stress. Inthe last charter, all of works in the paper are summarized, and some advice to the paper defect and future work are made.