The Arch Dam Foundation Rock Mass Unloading and Relaxation Deformation Characteristics and their Monitoring Result Analysis

Abstract:

After foundation excavation for a dam of a hydropower project, the rock mass would be unloaded and relaxed and its mechanical parameters would be lowered, thus influencing the dam stability. This paper makes an analysis of the deformation development law of the unloading rock mass of the dam foundation by analyzing the advance deformation of the dam foundation before excavation and the unloading rebound deformation of the dam foundation after excavation, and by analyzing the monitoring results of the compressive deformation after concreting of the dam and of the whole process deformation after impounding of the reservoir taking into account the results of both deformation test and acoustic test, which provides scientific basis for quality assessment of the arch dam foundation rock mass and for readjustment of the dam foundation rock mass mechanics design parameters, thus giving a reference to projects of the kind.

• Periodical: Advanced Materials Research (Volumes 255-260)
• Pages: 3514-3523
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.255-260.3514
• Online since: May 2011
• Authors: Shi Sheng Li, Ze Rong Dong, Qi Li, Hua Zhao, Hui Zhang
• Keywords: Dam Foundation Rock Mass, Deformation, Deformation Modulus, Monitoring, Unloading and Relaxation, Velocity Test of Rock

References

[1] Yang Genlan, Huang Runqiu, Lin Feng, et al. Numerical analysis for deformation damage in hydropower station dam foundation due to excavation in southwest China [J].Journal of Engineering Geology, Vol. 15 (2007), pp.356-361.

[2] Zhou Hua, Wang Guojin, Fu Shaojun, et al. Finite element analysis of foundation unloading and relaxation effects of Xiaowan Arch Dam [J]. Rock and Soil Mechanics, Vol. 30 (2009), pp.1175-1180.

[3] Wu Faquan, Liu Tong, Tang Xianliang, et al. Research on unloading and zonation of rock mass dam foundation excavation-a case study of Xiaowan hydropower station [J]. Chinese Journal of Rock Mechanics and Engineering, Vol. 28 (2009), pp.1091-1098.

[4] Feng Xuemin, Chen Shenghong, Li Wengang. Research on unloading relaxation criterion of high rocky slope excavation and its engineering application [J]. Rock and Soil Mechanics, Vol. 30 (2009), pp.452-456.

[5] Qi Shengwen, Wu Faquan, Zhuang Huaze, et al. Characteristics of unloading fissures in dam's base of Xiaowan hydropower station [J]. Chinese Journal of Rock Mechanics and Engineering , Vol. 27 (2008), pp.2907-2912.

[6] Bai Junguang, Chen Yongfu. Study on the Proper Excavation Method of Arch Dam Foundation in High Terrestrial Stress Area [J].Water Power, Vol. 33 (2007), pp.45-47,62.

[7] Li Chaozheng, Shen Rong, Li Wei, et al. Research on shear resistance of dam foundation unloading rockmass of Xiaowan Hydropower Station [J]. Rock and Soil Mechanics, Vol. 29 (2008), pp.485-490.

[8] Li Weishu, Zhou Huoming, Chen Hua, et al. Study of unloading rock mass deformation parameters for high arch dam foundation base of Goupitan hydropower station [J]. Chinese Journal of Rock Mechanics and Engineering , Vol. 29 (2010), pp.1333-1338.

[9] Dong Zerong, Zhao Hua, Huang Shijun, et al. Analysis of Result on Deformation Monitoring of Xiaowan Arch Dam Foundation Rock Mass [J]. Water Power, Vol. 35 (2009), pp.42-45.

[10] Dong Zerong, Zhao Hua, Huang Shijun, et al. Analysis on the Deformation in the Foundation Excavation of Xiaowan High Arch Dam [J]. Chinese Journal of Underground Space and Engineering, Vol. 2 (2006), pp.1014-1018,1024.

[11] Ma Hongqi. Key technical problems of Xiaowan hydropower project construction [J]. Hydro-science and Engineering, Vol. 37 (2009), pp.11-16.