Mechanical characteristics of columnar jointed rock at dam base of Baihetan hydropower station

Abstract

Irregular columnar jointed structure is a primary irregular columnar morphological tensile fracture. In order to study the geometric features of irregular columnar joints and the new problems in geotechnical engineering, hydraulic and hydropower engineering caused by columnar jointed basaltic mass, Voronoi graph from geometry was introduced to simulate the irregular columnar jointed basaltic mass at Baihetan hydraulic station. Discrete element software UDEC was used to simulate the whole process of rigid bearing plate test. Anisotropic constitutive of columnar joints was adopted to analyze the stress diffusion of rock mass at dam base of Baihetan. The results show that, the compaction property and hysteresis effect are well simulated based on discrete element simulation of Voronoi joint structure by UDEC. Four stages of cyclic loading and unloading process are imaged clearly. The results from in situ rigid bearing plate tests are explicated and the stress diffusion rule of anisotropic body is affected by structure surface. The elements in the stress state of 4–5 MPa are the most, about more than 35% of the total. Appropriate constitutive must be proposed to columnar jointed rock mass with different styles. It has important significance to realize the nonlinear mechanical behavior of irregular columnar jointed basaltic mass.

Keywords

columnar joints / Voronoi graph / discrete element method / hysteresis effect / Baihetan hydropower station / stress diffusion

References

[1] MüellerG.. Experimental simulation of basalt columns [J]. Journal of Volcanology and Geothermal Research, 1998, 86(4): 93-96

[2] GOEHRING L, MAHADEVAN L, MORRIS S W. The dynamic similarity between columnar joints in basalt and starch [C]// American Geophysical Union Fall Meeting. San Francisco, 2007: 651–658.

[3] ColeD. M.. Crack nucleation in polycrystalline ice [J]. Cold Regions Science and Technology, 1988, 15(1): 71-79

[4] FrenchJ. W.. The fracture of homogeneous media [J]. Trans Geol Soc Glasgow, 1925, 17(1): 50-58

[5] HulD., CaddockB. D.. Simulation of prismatic cracking of cooling basalt lava flows by the drying of sol-gels [J]. Journal of Materials Science, 1999, 34(23): 57-67

[6] LiJ.-l., WangP.-j., ZhengC.-q., TangH.-f., WuY.-x., BianW.-hua.. Characteristics and genesis of rhyolite with columnar joints from the yingcheng formation in southeastern uplift of the songliao basin [J]. Journal of Jilin University: Earth Science Edition, 2007, 37(6): 56-62

[7] ShanZ.-qiang.. In search of pillars around China [J]. Chinese National Geography, 2009, 586(8): 32-64

[8] GrayeliR., HatamiK.. Implementation of the finite element method in the three-dimensional discontinuous deformation analysis (3D-DDA) [J]. International Journal for Numerical and Analytical Methods in Geomechanics, 2008, 32(15): 1883-1902

[9] YangM., FukawaT., OhnishiY., NishiyamaS., MikiS., HirakawaY., MoriS.. The application of 3-dimensional DDA with a spherical rigid block for rockfall simulation [J]. International Journal of Rock Mechanics and Mining Sciences, 2004, 41(Supp1): 251-256

[10] FengY. T.. On the central difference algorithm in discrete element modeling of impact [J]. International Journal for Numerical Methods in Engineering, 2005, 64(14): 1959-1980

[11] LiY., LiuS.-j., YuH.-yun.. Dynamic analysis of deep ocean mining system based on multi rigid body discrete element model [J]. Journal of Central South University of Technology, 2006, 37(4): 742-747

[12] MorenoN., WangF., MarceauD. J.. Implementation of a dynamic neighborhood in a land-use vector-based cellular automata model [J]. Computers, Environment and Urban Systems, 2009, 33(1): 44-54

[13] ChoH., SwartzlanderJ.. Adder and multiplier design in quantum-dot cellular automata [J]. IEEE Transactions on Computers, 2009, 58(6): 721-727

[14] Itasca Consulting Group.UDEC User’s guide [M], 2006, Minneapolis, Minnesota, Itasca Consulting Group Inc: 24-30

[15] AichholzerO., AignerW., AurenhammerF., HacklT., JuttlerB., PilgerstorferE., RablM.. Divide-and-conquer for Voronoi diagrams revisited [J]. Computational Geometry: Theory and Applications, 2010, 43(8): 688-699

[16] KleinR., LangetepeE., NilforoushanZ.. Abstract Voronoi diagrams revisited [J]. Computational Geometry: Theory and Applications, 2009, 42(9): 885-902

[17] MengG.-tao.Geomechanical analysis of anisotropic columnar jointed rock mass and its application in hydropower engineering [D], 2007, Nanjing, Hohai University: 68-79

[18] East China Investigation and Design Institute. Engineering geology’s research report of columnar jointed basalt at Baihetan hydropower station on Jinsha River [R]. 2006. (in Chinese)

[19] BoussinesqJ.Application research of elastic solid movement and balace potential [M], 1885, Paris, Gauthier-Villars

[20] ConwayH. D., IthacaN. Y.. Some problems of orthotropic plane stress [J]. Journal of Applied Mechanics, 1953, 20(1): 72-76

[21] ConwayH. D., IthacaN. Y.. Note on the orthotropic half space subjected to concentrated loads [J]. Journal of Applied Mechanics, 1955, 77(3): 130-135

[22] GoodmanR. E.Introduction to rock mechanics [M], 1989, New York, Wiley: 576-583

[23] ChenS. H., FengX. M., IsamS.. Numerical estimation of REV and permeability tensor for fractured rock masses by composite element method [J]. International Journal for Numerical and Analytical Methods in Geomechanics, 2008, 32(12): 1459-1477

[24] EsmaieliK., HadjigeorgiouJ., GrenonM.. Estimating geometrical and mechanical REV based on synthetic rock mass models at Brunswick Mine [J]. International Journal of Rock Mechanics and Mining Sciences, 2010, 47(6): 915-926