一种基于GSI弱化的应变软化模型

彭俊; 荣冠; 周创兵; 蔡明; 彭坤

doi:10.11779/CJGE201403013

一种基于GSI弱化的应变软化模型 English Version

彭俊^{1, 2},
荣冠^1,2,,
周创兵^{1, 2},
蔡明³,
彭坤⁴

1. 武汉大学水资源与水电工程科学国家重点实验室,湖北武汉 430072; 2. 武汉大学水工岩石力学教育部重点实验室,湖北武汉 430072; 3. 劳伦森大学工程学院,加拿大萨德伯里 P3E 2C6; 4. 中船第九设计研究院工程有限公司,上海 200063

基金项目: 国家重点基础研究发展计划（973计划）项目（2011CB013501,2010CB732005）; 新世纪优秀人才计划（NCET-11-0406）; 中央高校基本科研业务费专项项目（2012206020215）

详细信息

作者简介:
彭俊(1986- )，男，博士研究生，主要从事岩体力学特性及水力耦合特性研究。E-mail：pengiun2010@gmail.com。

通讯作者:
荣冠

中图分类号: TU47
计量
- 文章访问数: 0541
- HTML全文浏览量: 0
- PDF下载量: 0520
出版历程
- 收稿日期: 2013-05-22
- 发布日期: 2014-03-19

A strain-softening model based on GSI softening

PENG Jun^{1, 2},
RONG Guan^1,2,,
ZHOU Chuang-bing^{1, 2},
CAI Ming³,
PENG Kun⁴

1. State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China; 2. Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering (Wuhan University), Ministry of Education, Wuhan 430072, China; 3. Bharti School of Engineering, Laurentian University, Sudbury, Ontario P3E2C6, Canada; 4. China Shipbuilding NDRI Engineering Co., Ltd., Shanghai 200063, China

摘要

摘要: Mohr-Coulomb和Hoek-Brown破坏模型是目前运用最广泛的两种岩体破坏模型。为了能够直观地描述围岩高应力条件下的脆性破坏,众多学者提出基于这两种破坏模型的岩体参数取值方法,主要包括基于Mohr-Coulomb模型的CWFS模型以及基于Hoek-Brown模型的DISL模型和BDP模型。上述模型在表征岩石的脆性破坏方面均有一定的适应性,但是由于存在高围压条件下的硬化现象以及参数取值物理意义不明确等问题,其在实际工程中的应用受到一定限制。在上述模型的基础之上进一步研究Hoek-Brown破坏模型的参数取值规律,在分析地质强度指标GSI值在岩石压缩变形过程中的变化规律的基础上,通过构建地质强度指标GSI值与围压以及塑性应变的函数关系式,建立一种新的基于GSI弱化的应变软化模型——GSI弱化应变软化模型；然后通过锦屏二级水电站白山组大理岩以及Tennessee大理岩三轴压缩试验数值模拟对该模型进行验证。分析表明：该应变软化模型能够较好地模拟大理岩的三轴力学特性。最后运用该模型评价锦屏二级水电站引水隧洞开挖松弛范围,可为岩体开挖支护提供一定参考。
- Hoek-Brown破坏模型 /
- 地质强度指标GSI /
- 岩体参数取值方法 /
- 锦屏二级水电站
Abstract: The Mohr-Coulomb and Hoek-Brown failure criteria are the two most widely used ones at present. To simulate brittle failure of rocks in deep tunnels, the models based on these two failure criteria have been proposed, including the CWFS (cohesion weakening and friction strengthening) model, the DISL (damage initiation and spalling limit) model, and the BDP (brittle ductile plastic) model. These models have been used to simulate brittle failure of hard rocks. However, because of the issues of strain hardening under high confinement and large ambiguity in model parameter determination, it is very challenging to apply these models in practical engineering application. Based on the variation of the GSI (geological strength index) value during compression of rocks and by defining the GSI value as a function of plastic strain and confinement, a strain-dependent GSI-softening model, which is based on the Hoek-Brown failure criterion, is proposed in this study. This model is implemented in FLAC^3D to simulate the triaxial compression tests on T_2b marble in Jinping-II Hydropower Station and the Tennessee marble. It is found that the proposed model is able to simulate the mechanical behaviors of the brittle-ductile transition observed in the triaxial compression tests on Jinping and Tennessee marbles. Finally, this model is used to evaluate the relaxation depth of a headrace tunnel in Jinping-II Hydropower Station, and the calculated depths are in good agreement with the field observations.
- Hoek-Brown constitutive model /
- geological strength index (GSI) /
- parameter valuing method of rock mass /
- Jinping-II hydropower station

HTML全文

参考文献(22)

[1]	张春生, 陈祥荣, 侯靖, 等. 锦屏二级水电站深埋大理岩力学特性研究[J]. 岩石力学与工程学报, 2010, 29(10): 1999-2009. (ZHANG Chun-sheng, CHEN Xiang-rong, HOU Jing, et al. Study of mechanical behavior of deep-buried marble at Jinping II hydropower station[J]. Chinese Journal of Rock Mechanics and Engineering,2010,29(10): 1999-2009. (in Chinese))
[2]	MARTIN C D. The strength of massive Lac du Bonnet granite around underground openings[D]. Winnipeg: Department of Civil and Geological Engineering, University of Manitoba, 1993.
[3]	MARTIN C D. Seventeenth Canadian geotechnical colloquium: The effect of cohesion loss and stress path on brittle rock strength[J]. Canadian Geotechnical Journal, 1997, 34(5): 698-725.
[4]	HAJIABDOLMAJID V, KAISER P K, MARTIN C D. Modelling brittle failure of rock[J]. International Journal of Rock Mechanics & Mining Sciences, 2002, 39(6): 731-741.
[5]	HAJIABDOLMAJID V. Mobilization of strength in brittle failure of rock[D]. Kingston, Ontario: Department of Mining Engineering, Queen's University, 2001.
[6]	GOLCHINFAR N, CAI M. Modeling depth of failure using brittle Mohr-Coulomb failure model[C]// Proc 21st Canadian Rock Mech. Symp, Edmonton, 2012: 127-135.
[7]	CUNDALL P, CARRANZA-TORRES C, HART R. A new constitutive model based on the Hoek-Brown criterion[C]// Proceedings of the 3rd International FLAC Symposium. Sudbury: A.A. Balkema Press, 2003: 17-25.
[8]	DIEDERICHS M S. The 2003 Canadian geotechnical colloquium: Mechanistic interpretation and practical application of damage and spalling prediction criteria for deep tunneling[J]. Canadian Geotechnical Journal, 2007, 44(9): 1082-1116.
[9]	HOEK E, BROWN E T. Underground excavations in rock[M]. London: Institution of Mining and Metallurgy, 1980.
[10]	HOEK E, BROWN E T. Empirical strength criterion for rock masses[J]. Journal of the Geotechnical Engineering Division, ASCE, 1980, 106(GT9): 1013-1035.
[11]	HOEK E, WOOD D, SHAH S. A modified Hoek-Brown criterion for jointed rock masses[C]// Proceedings of the ISRM-Eurock Symposium on Rock Characterization. Chester, 1992: 209-213.
[12]	HOEK E. Strength of rock and rock masses[J]. ISRM News Journal, 1994, 2(2): 4-16.
[13]	HOEK E, CARRANZA-TORRES C, CORKUM B. Hoek- Brown criterion-2002 edition[C]// Proc NARMS-TAC Conference. Toronto, 2002: 267-273.
[14]	HOEK E, KAISER P K, BAWDEN W F. Support of Underground Excavations in Hard Rock[M]. Rotterdam, Netherlands: A.A. Balkema Press, 1997.
[15]	MARTIN C D, CHANDLER N A. The progressive fracture of Lac du Bonnet granite[J]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts,1994,31(6)：643-659.
[16]	EBERHARDT E, STEAD D, STIMPSON B. Quantifying progressive prepeak brittle fracture damage in rock during uniaxial compression[J]. International Journal of Rock Mechanics & Mining Sciences, 1999, 36(3): 361-380.
[17]	DIEDERICHS M S, KAISER P K, EBERHARDT E. Damage initiation and propagation in hard rock tunnelling and the influence of near-face stress rotation[J]. International Journal of Rock Mechanics and Mining Sciences, 2004, 41: 785-812.
[18]	CAI M, KAISER P K, TASAKA Y, et al. Generalized crack initiation and crack damage stress thresholds of brittle rock masses near underground excavations[J]. International Journal of Rock Mechanics and Mining Sciences, 2004, 41(5): 833-847.
[19]	CAI M, KAISER P K, UNO H, et al. Estimation of rock mass strength and deformation modulus of jointed hard rock masses using the GSI system[J]. International Journal of Rock Mechanics and Mining Sciences, 2004, 41(1): 3-19.
[20]	CAI M, KAISER P K, TASAKA Y, et al. Determination of residual strength parameters of jointed rock masses using the GSI system[J]. International Journal of Rock Mechanics and Mining Sciences, 2007, 44(2): 247-265.
[21]	WAWERSIK W R, FAIRHURST C. A study of brittle rock fracture in laboratory compression experiments[J]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts, 1970, 7(5): 561-575.
[22]	严鹏, 卢文波, 陈明, 等. 深部岩体开挖方式对损伤区影响的试验研究[J]. 岩石力学与工程学报, 2011, 30(6): 1097-1106. (YAN Peng, LU Wen-bo, CHEN Ming, et al. In-situ test research on influence of excavation method on induced damage zone in deep tunnel[J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 30(6): 1097-1106. (in Chinese))