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| Loosening zone and earth pressure around tunnels in sandy soils based on ellipsoid theory of particle flows |
| WU Jun1, LIAO Shao-ming1, 2, ZHANG Di3 |
| 1. Department of Geotechnical Engineering, Tongji University, Shanghai 200092, China; 2. Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Tongji University, Shanghai 200092, China; 3. China Railway No.4 Survey and Design Group Co., Ltd., Wuhan 430063, China |
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Abstract The vertical loosening earth pressure on a tunnel in sandy soils is affected by the development of loosening zone and arching effect that is influenced by the sand particle flows. Based on the ellipsoid theory of particle flows, the method to determine the loosening zone of tunnels in sandy soils is presented, and the traditional Terzaghi loosening theory is improved. The research results show that, unlike the vertical sliding surface assumed by Terzaghi, the loosening zone of tunnels in sandy soils is an ellipse or part of it, which is related to the eccentricity and loosening factor associated with the shape of sand particles, granular composition, relative density and other characters of stratum. The lateral earth pressure coefficient of sliding surface in sandy soils is less than the value suggested by Terzaghi. Finally, the results of proposed method agree quite well with those reported in other literatures based on the Terzaghi theory. It can be used to analyze the vertical earth pressure in underground tunnel and pipe engineering.
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Received: 29 May 2012
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[1] TERZAGHI K. Theoretical soil mechanics[M]. NewYork: John Wiley & Sons, 1943:66-76.
[2] MARSTON A. The theory of external loads on closed conduits in the light of the latest experiments[R]// Iowa: Iowa State College, Ames, Iowa Engineering Experiment Station, 1930.The theory of external loads on closed conduits in the light of the latest experiments[R]// Iowa: Iowa State College, Ames, Iowa Engineering Experiment Station, 1930.
[3] BALLA A. Rock pressure determined from shearing resistance[M]. Budapest: Proc Int Conf Soil Mechanics, 1963:461.
[4] Tien Heisen-Jen. A literature study of the arching effect[D]. Taipei: Taiwan University, 1990:123-125.
[5] Finn. Boundary value problems of mechanics[J]. Journal of the Soil Mechanics and Foundation Division, ASCE,1963, 89SM5:39-72.
[6] . EVANS C H. An examination of arching in granular soils[D]. Cambridge: Massachusetts Institute of Technology, 1983.
[7] 周小文,濮家骝,包承钢. 砂土中隧道开挖稳定机理及松动土压力研究[J]. 长江科学院院报, 1999,164:9-13. ZHOU Xiao-wen, PU Jia-liu, BAO Cheng-gang.
Study on stability mechanism and relaxed soil pressure in sandy soil during excavation[J]. Journal of Yangtze River Scientific Research Institute, 1999, 164: 9-13. (in Chinese)
[8] LEE Chung-jung, CHIANG Kuo-Hui, KUO Chia-Ming. Ground movement and tunnel stability when tunneling in sand ground[J]. Journal of the Chinese Institute of Engineers, 2004,277:1021-1032.
[9] 李世平,吴振业. 岩石力学简明教程[M]. 北京: 煤炭工业出版社, 1996:105-108. LI Shi-ping, WU Zhen-ye.
Introduction to rock mechanics[M]. Beijing: China Coal Industry Publishing House, 1996: 105-108. (in Chinese)
[10] BRADY B H G, BROWN E T. Rock mechanics for underground mining[M]. 3rd ed. New York: Kluwer Academic Publishers, 2005:454-463.
[11] KVAPIL R. Sublevel caving. SME mining engineering handbook[M]. 2nd ed. HARTMAN H L, ed. New York: Soc Min Engrs,AIME, 1992:1789-1814.
[12] 陈若曦,朱 斌,陈云敏,等. 基于主应力轴旋转理论的修正Terzaghi松动土压力[J]. 岩土力学, 2010,315:1402-1406. CHEN Ruo-xi, ZHU Bin, CHEN Yun-min, et al. Modified Terzaghi loosening earth pressure based on theory of main stress axes rotation[J]. Rock and Soil Mechanics, 2010, 315
[13] RICHARD L H. The arch in soil arching[J]. Journal of Geotechnical Engineering, 1985,1113:302-318.
[14] MEGUID M A, SAADA O, NUNES M A,et al. Physical modeling of tunnels in soft ground：A review[J]. Tunneling and Underground Space Technology, 2008,23:185-198.
[15] CHAMBON P, CORTÉ J F. Shallow tunnel in cohesionless soil: Stability of tunnel face[J]. Journal of Geotechnical Engineering, 1994,1207:1148-1165.
[16] 蒋 波. 挡土结构土拱效应及土压力理论研究[D]. 杭州:浙江大学, 2005.JIANG Bo. Studies on soil arching effect and earth pressure for retaining structure[D]. Hangzhou
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