Design of Temperature Crack Treatment of Xiaowan Dam
(0) In the process of concrete placement of Xiaowan arch dam, a number of thermal cracks emerged in the middle of dam.Whereafter, a lot of drilling holes were implemented to investigate the extension range of crack.About 2 years later, the extension range of crack was revealed clearly.Based on the elaborate and deep analysis on the cause and mechanism of the crack, the old temperature control measures were adjusted in time, and a set of comprehensive measures were presented : the steel mesh was interlaced to prevent the further upward development of cracks ; chemical grouting measure was adopted to regain the entirety and stiffness of arch dam ; the drainage holes were drilled to release the water pressure in the cracks; the I steel were placed in the concrete around the diversion orifice to reinforce the dam locally.Through the laboratory test and site productive test, the chemical grouting materials were selected from many specimens, the proportion of grout was determined, and the grouting methodology and parameters that were suitable for the characters of cracks and the real site conditions were explored.Many useful experiences were also obtained from the tests.The results of numerical simulation by using the finite element method shows that most of cracks existed in the dam were closed tightly during the process of water-filling of reservoir, and there didn t seem much likelihood of further development for the cracks.Aftcr the chemical grouting, the safety of dam is not largely affected due to the cracks.The results obtained from the geomechanical model test also indicates that the cracked arch dam could maintain its elasticity at the water pressure of normal pool level, and the stress distribution in the dam was not largely affected due to the cracks.Through the geophysical prospecting and safety monitoring, it can be seen that when the reservoir was filled to the normal water level, there was no new crack grew in the dam, and no obvious change was found in existing cracks.The existing cracks were stable and did not developed.Comprehensive analyzing results indicates that the safety of dam can be recovered to some extent after the chemical grouting, and the working behavior of the dam is nearly the same as that of the intact dam.During the period of the rise and fall of reservoir water level, the crack in the dam remained stable.It is proved by theory and practice that the strategy of crack treatment is correct, and the measures adopted are effective.
arch dam temperature crack chemical grouting crack reinforcement
Li Yongming Zou Lichun Yu Jianqing Wang Guojin
Hydro China Kunming Engineering Corporation, Kunming 650051
国际会议
昆明
英文
809-817
2013-11-01（万方平台首次上网日期，不代表论文的发表时间）