Macro-Micro Analysis of Soil Failure Mechanism in Unloading Condition

Abstract:

Article Preview

Numerical tests are carried out to research mechanism of hydraulic fracturing. As well as that: reservoir storage leads to bending of the embankment dam because of water pressure, especially upright core wall when reservoir storing rapidly, and then bending leads to vertical stress unload. The macro and micro mechanism of soil fracturing in unloading condition are analyzed by the Distinct Element Method (DEM). The results indicate that: (1) Initial stage of specimen will lead to volume response of dilatancy in the unloading condition. Actually, volume response is expressed as dilatancy consistently with the low level confining pressure and is expressed as dilatancy then compression latterly with the high level confining pressure. It suggests that the unloading condition may be a factor for granular material cracks. Particularly, not only the unloading condition with low level confining pressure leads to cracks, but also it helps the cracks development. So we argue that: unload condition, such as reservoir storage is a factor for hydraulic fracturing in the embankment dams, especially in low level stress areas. (2)The strength of soil in the unloading condition decreases than the loading condition, which contributes to hydraulic fracturing.

Info:

Periodical:

Edited by:

Mingjin Chu, Xiangran Li, Jingzhou Lu, Xingmin Hou and Xiaogang Wang

Pages:

1847-1855

DOI:

10.4028/www.scientific.net/AMM.170-173.1847

Citation:

X. Y. Liu et al., "Macro-Micro Analysis of Soil Failure Mechanism in Unloading Condition", Applied Mechanics and Materials, Vols. 170-173, pp. 1847-1855, 2012

Online since:

May 2012

Export:

Price:

$35.00

[1] Independent panel to review cause of Teton Dam failure. Report to U.S. Department of the Interior and the State of Idaho on Failure of Teton Dam, U.S. Bureau of Reclamation, Denver, Colo., (1976).

[2] Charles J A, Boden J B. The Failure of Embankment Dams in the United Kingdom. The Institution of Civil Engineers, London, 1985, pp.133-154.

[3] Ajaz A, Parry R H G. Stress-Strain Behavior of Two Compacted Clays in Tension and Compression [J]. Geotechnique, 1975, 25(3): 495-512.

DOI: 10.1680/geot.1975.25.3.495

[4] N. I. THUSYANTHAN, W. A. TAKE, S. P. G. MADABHUSHI et al, Crack initiation in clay observed in beam bending[J]. Geotechnique, 57, No. 7, 581–594.

DOI: 10.1680/geot.2007.57.7.581

[5] Harison Jack A, Hardin Bobby O, Mahboub Hamyar. Fracture toughness of compacted cohesive soils using ring test [J]. Journal of Geotechnical Engineering, 1994, 120(5): 872-891.

DOI: 10.1061/(asce)0733-9410(1994)120:5(872)

[6] Zhang Yan, Mechanism Study and Numerical Simulation of tensile crack propagation in high earth and rockfill dam [D]. Beijing: Tsinghua University, 2009. ( in Chinese).

[7] Belytschko T, Lu Y Y, Gu L. Element free Galerkin methods[J]. International Journal for Numerical Methods in Engineering, 1994, 37, 229-256.

DOI: 10.1002/nme.1620370205

[8] Belytschko T, Lu Y Y, Gu L. Crack propagation by element-free Galerkin method[J]. Engineering Fracture Mechanics, 1995, 51(2), 295-315.

DOI: 10.1016/0013-7944(94)00153-9

[9] Belytschko T, Tabbara M. Dynamic fracture using element-free Galerkin methods [J]. International Journal for Numerical Methods in Engineering, 1996, 39, 923-938.

DOI: 10.1002/(sici)1097-0207(19960330)39:6<923::aid-nme887>3.3.co;2-n

[10] Chung H J, Belytschko T. An error estimate in the EFG method [J]. Computational Mechanics, 1998, 21, 91-100.

DOI: 10.1007/s004660050286

[11] Zhu T, Zhang J, Atluri S N. A meshless local boundary integral equation (LBIE) method for solving nonlinear problems [J]. Computational Mechanics, 1998, 22, 174-186.

DOI: 10.1007/s004660050351

[12] Kou Xiaodong, Zhou Weiying. The application of element-free method to approximate calculation of arch dam crack propagation[J]. Journal of Hydraulic Engineering, 2000, 10, 28-35. ( in Chinese).

[13] Zhang Jianhui, Deng Anfu. The application of element free method to the computation of raft foundation[J]. Chinese Journal of Geotechnical Engineering, 1999, 21(6), 691-695. (in Chinese).

[14] Cundall PA, Strack ODL. The distinct numerical model for granular assemblies[J]. Geotechnique 1979; 29(1): 47–65.

[15] Mingjing Jiang, Serge Leroueil, M. ASCE et al. Yielding of Microstructured Geomaterial by Distinct Element Method Analysis [J]. JOURNAL OF ENGINEERING MECHANICS, 2005, 11, 1209-1213.

DOI: 10.1061/(asce)0733-9399(2005)131:11(1209)

[16] Mingjing Jiang, Haibin Yan. Micro-contact laws of bonded granular materials for DEM numerical analyses[J]. APCOM'07 in conjunction with EPMESC XI, Kyoto, Japan, 2007, 12: 3-6.

In order to see related information, you need to Login.