Feedback Simulation Study Of Puding RCC Arch Dam

Puding Hydropower Station is located in Guizhou province of China on the upper reaches of Wujiang river. The dam is the first roller compacted concrete arch dam in China and was also the highest RCC arch dam in the world at that tune. It was designed as an arch dam with constant thickness but variable radius and central angles.During the construction period, various observation devices have been arranged and embed in dam body and rock foundation. The prototype observation items of the Puding RCC arch dam include stress and strain observation, temperature monitoring, observation of joints, crack and seepage pressure. According to the construction record given by Guiyang Hydroelectric Investigation, Design and Research Institute of China, there are 190 observation instruments and 116 of those are still working very well.The temperature variations at some locations of Puding arch dam were obtained and the observation data show that the result of temperature filed simulation computation is generally consistent with the real condition. However after 6 years of operating, this arch dam was observed to have 49 cracks in January 1999. Above all, two of them penetrated from upstream face to downstream face and caused minor leakage.According to all the researches during the Seventh Five Year Plan period of China, crack would not occur in this arch dam during the construction and operation period. And even if cracking took place, it should be expected in induced joints instead of the other parts of the dam body. Obviously, this research conclusion is not consistent with the fact. Therefore, it is worth to do further research to find out the cause of crack in the dam body and the correct way of the induced joint deployment.The main research results are listed as follows:1) The functional parts of the software ANSYS has been re-organized, in this way the software can be used to simulate the transient temperature field and stress field of RCC arch dam during the construction and operation period.2 ) The sensitive analysis for the influence factors of dam temperature has been made. 3) According to the construction and operation record of the Puding RCC arch dam, the temperature simulation has been conducted. The calculation results have been comparedwith the monitored data.4) According to the construction and operation record of the Puding RCC arch dam, the stress simulation has been conducted. The calculation results have been compared with the monitored data, and the cause of crack has been analyzed.5) The temperature control requests and crack cause have been summarized. Based on these knowledge the feasible crack prevention measures have been proposed .