Research On Analysis Of The Steel Liner To The Deep Outlet's Orifice Stress In Concrete Dam

With the market economy developing in china, many hydropower projects are developing rapidly. Some huge hydropower stations with the characteristics of higher dam and larger reservoir will be built in recent. For the large amount of flood dam project in the dam body to set up large holes in the flood discharge has significant advantages, therefore, an increasing number of dam body with dam spillway sluice hole. In general, due to high water head and concrete dam of the deep (bottom) outlet velocity quickly, it is need to layout steel liner on the scupper flow channel. In view of the deep (bottom) outlet lined the design conditions, the main role of the steel liner is to prevent high-speed flow from erosion and attrit on the scupper flow and to prevent seepage of the dam structure produces hydraulic fracturing. Therefore, the study of scupper flow channel whether steel liner as well as different steel liner thickness on the impact of orifice stress is necessary.At first, the finite element submodel method in this paper carried out the verification analysis. The results show that analysis of opening stress with submodel method not only meets calculation accuracy, but also greatly reduces calculation work, saves time and computer memory. So this is the effective method to analyze opening stress. This paper taking into account the effect of contact between the concrete and steel plate, use this method to calculate the deep outlet in high-head thin arch dam. This paper main analyse the stress state whether the steel-lined hole flow passage and the different steel liner thickness on the pore wall, roof, and backplane, as well as upstream and downstream impact of cantilever structure. The results showed that compared with scuppers not lined steel liner, the tensile stress of the flow channel upstream and downstream side of the wall significantly reduced, the tensile stress of the flow channel floor and roof have also been reduced; as the thickness of the steel plate increases, the tensile stress of the flow channel upstream and downstream side of the wall gradually reduced, the tensile stress of the flow channel floor and roof have also been reduced; scuppers with steel liner do not affect the stress state of the basic structure of upstream and downstream cantilever. Scuppers whether changing the thickness of steel liner or lining the steel liner or not does not affect the basic structure of upper and lower cantilever stress state. The study also shows that the tensile stress in depth of wall along the section of the decay rate broadly consistent with the direction; Scuppers whether changing the thickness of steel liner and lining the steel liner or not, have a great effect on the tensile stress of the flow channel around the concrete, especially the tensile extreme stress of wall surface.