The Analysis Of Thermal Stress On Open Type Of Sluice In Frigid Area

The sluice is an important hydraulic structure of hydro-junction project. It is usually built in the plain river or mountain reservoir. However, a lot of projects expose many questions by operating many years, in which the cracks of concrete building are universal phenomenon. According to a large amount of engineering example, it is very universal, the constructed dam (including flood diversion sluice of dam) and the base plate of sluice, which frequently exposes in the atmosphere (e.g. flood-diversion sluice) come into being cracks. According to the reference, the primary reasons of cracks are not the exterior load function but the changed temperature and strong restraint of ground in the good superstructure of ground arrangement reasonable situation. Many investigation materials of domestic and foreign indicated that only 20%cracks of building structure root in loads, but 80% cracks are caused by temperature, contraction and non-uniform distortion. Therefore, in the structural design, even if under the computation load does not occur the tensile stress, the structure also can appear the tensile stress because of the temperature effect. The domestic and foreign have lucubrated bridge, gravity dam, arch dam and so on, but domestic and foreign have not studied the aspect of large-scale sluice. The temperature effect is more prominent to the structure especially in such cold area of XinJiang, in which temperature difference quite big. Therefore studied the structure temperature stress of sluice to have the vital scientific significance.The research technique of this dissertation:First,we use basic principle of finite Unit method and infer finite Unit formula of dam temperature field and temperature stress computation, which based on the elementary theory of heat conduction thermo-elasticity.Second, we find out limit condition of short and medium term temperature stress computation of dam structural design in the north of XinJiang according to the elementary theory of heat radiation and the heat convection and literature material.Third, take some hinge of quoted water as analysis object, and use analysis software ANSYS10.0 of large-scale finite unit analyses the structure stress field when we don't consider temperature load, the temperature rise of summer day and temperature drop of winter day and the structure stress field when we consider temperature load.According to the result of computation, we can get following understanding:First, short-term temperature change make the interior stress of structure happen great change. When temperature rise in summer, the outside of brake frusta crack, the neighborhood of interface between upriver brake frusta and base plate, and the structural stress nearby ox leg all exceed the terminal intensity of design under the conjunct action of the load of difference in temperature and other load.Second, the effects of temperature stress even more great when temperature lower in winter and temperature rise in summer. At the neighborhood of interface between back base plate of strobe and brake frusta, the neighborhood of interface between upriver brake frusta and base plate, the neighborhood of ox leg, upper surface of brake frusta all exceed the terminal intensity of design.Third, it is very essential to analyses and calculates temperature stress in the design of the sluice of cold district in the north of XinJiang.