Analyze of the Affection of Excavation Unloading of the Rock Mass of the Spillway Tunnel of a Hydropower Station on the Slope’s Stability

Abstract:

After the excavation of the rock , the rock mass stress state changes and the quality of rock mass damage deterioration. Rock excavation of spillway tunnel of the hydropower station may have some influence on the stability of the tunnel-face side slope. In this paper, combined with the engineering practice, based on the unloading rock mass theory and through two dimensional finite-difference method. Selected seven feature points near the excavation surface as monitoring points for calculation ,then calculated the effect on the stress and strain of the slope caused by the excavation of the spillway tunnel and analysed the changes in the distribution of the slope rock mass plastic zone and the point factor of safety. The results show that spillway tunnel excavation in excavated slope have some impact on the excavated slope stability, and it is more obvious for the effect on stability of excavated slope in considering rock mass unloading effect than do not consider the rock mass unloading effect.

• Periodical: Advanced Materials Research (Volumes 594-597)
• Pages: 621-626
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.594-597.621
• Online since: November 2012
• Authors: Le Hua Wang, Jun Lei Bai
• Keywords: Excavated Slope, Mohr-Coulomb, Spillway Tunnel, Stability, Unloading

References

[1] Er Lei,Xu yan,Dai Shulin, et al. Slope engineering[M].Beijing: Science Press,2010.

[2] Li Jianlin,Wang Lehua,Liu Jie,et.al.Rock slope engineering[M].Beijing:China Water Power Press, (2006)

[3] Li Jianlin,Wang Lehua.Study on unloading nonlinear mechanical characteristics of jointed rock mass [C]// Special report Of the Ninth National Rock and Soil Mechanics numerical analysis and analytical methods Seminar.Wuhan,2007: 1968-1975.

[4] Xu Ping ,Zhou Huoming.Rheological Analysis on Rock Mass of High Slope Considering Effects of Excavation Unloading[J]. CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING,2000(4)

[5] Jia Shanpo,Chen Weizhong,Yang Jianping,Chen Peishuai. Based on modified Mohr-Coulomb criteria elasto plastic constitutive model and its numerical implementation of [J].Rock and Soil Mechanics,2010,31 (7).

[6] SU Jihong,WANG Zheng-xing,REN Wen-min1,et al. Study and Application of Yield Criteria to Rock and Soil[J]. Engineering Mechanics,2003(03)

[7] Bi Jihong,Wang Hui.Engineering Elastic Plastic Mechanics[M]. Tianjin:Tianjin University press, (2008)

[8] Liu Bo,Han Yanhui.FLAC Examples Principle and Application Guide[M].Beijing:China Communications Press, (2005)

[9] Wang Ruihong, Li Jianlin,Chen Xing.Three-dimensional Finite Element Analysis of Slope Engineering Based on the Unloading Rock Mass Theory[J]. Water Power,2010,36(4).

[10] Ministry of Water Resources People's Republic of China.SL386-2007. Design code for engineered slopes in water resources and hydropower projects[S].Beijing :China Water Power Press , 2007.