300m级高拱坝大流量泄洪关键技术研究

Study on the key technologies of large discharge flood releasing of high arch dam at the level of 300 m

30 0m级高拱坝大流量泄洪关键技术研究专题主要结合小湾工程研究高拱坝增大坝身泄量 ,减少 1条泄洪洞的泄量分配和泄洪消能布置、拱坝流激振动、泄洪雾化及防护措施、水垫塘体形优化和衬护结构稳定、大型导流洞改建为泄洪洞或放空洞等关键技术问题 ,提出优化的泄水建筑物及其消能防冲布置和结构设计方案。其中多项研究成果和建议已在小湾工程中采用 。

The study subject of the key technologies of large discharge flood releasing of high arch dam at the level of 300 m high focuses on the following aspects, in combination with the Xiaowan project. These aspects are: the discharge distribution of increasing the releasing discharge through dam body and reducing one flood releasing tunnel, the arrangement of energy dissipaters for flood releasing, flow excitation vibration of arch dam, flood releasing atomization and its protection measures, shape optimization of water cushion and its lining structure stability, reconstruction of large diversion tunnel into flood releasing or emptying tunnel. This paper puts forward the optimized releasing structures, the layout of energy dissipation and anti scour structure, and their structural design alternatives. Many research results have been applied to the Xiaowan project and has solved some key technical problems in the layout of energy dissipaters and the structural design of such project. thyl N, N dialkyl] dithiocarbamates were prepared in laboratory. The extreme pressure, antiwear and friction reducing properties of rapeseed oil with thiophen and dithiocarbamates were prepared in laboratory. The extreme pressure, antiwear and friction reducing properties of rapeseed oil with thiophen and [S (2H thiophen 2 yl)methyl N,N dialkyl] dithiocarbamates as additives and the relationship between the additive structure and triobolgical properties were examined with a four ball machine. The worn surfaces of the steel ball were analyzed by means of X ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). It has been found that thiophen as additive in rapeseed oil worsens the antiwera and extreme pressure properties, while [S (2H thiophen 2 yl)methyl N,N dialkyl] dithiocarbamates at proper concentrations are effective in improving the antiwear, friction reducing behavior and load carrying capacity of rapeseed oil. The XPS analytical results of the worn steel surfaces indicate that tribochemical reactions were involved for steel steel frictional pair lubricated with rapeseed oil containing [S (2H thiophen 2 yl)methyl N,N dialkyl] dithiocarbamates as the additives, with the formation of a boundary lubricating and protecting film composed of triester of rapeseed oil and tribochemical reaction products of the lubricants. This contributes to improve the triblogical properties of the rapeseed oil base stock. Key words: thiophen; [S (2H thiophen 2 yl)methyl N, N dialkyl] dithiocarbamates; rapeseed oil; additive; tribological properties