INTERNAL DRIVING FORCE OF DEFORMATION AND FAILURE OF ROCK MASS STRUCTURE-UNBALANCED FORCE
-
摘要: 岩体结构的变形破坏是一个渐近过程,常规的强度设计与极限分析均无法描述这一过程。在回顾总结岩体结构破坏控制、变形控制的基础上,提出岩体结构变形破坏控制最终要落实到开裂控制上来。总结了岩体结构开裂计算的特点和难点,阐明了用不平衡力描述岩体结构变形破坏过程的理论依据。分别从单轴压缩试验、边坡开挖卸荷、拱坝坝踵坝趾开裂等3个具体的数值案例论证不平衡力与开裂破坏的内在相关性。提出了蓄水导致不可逆的谷幅变形也是不平衡力作用结果:裂隙水压力使屈服面收缩、原先处于屈服或临界屈服状态的岩体应力状态超出屈服面,产生不平衡力和不可逆的塑性变形。指出了不平衡力本质是岩体结构非平衡态到平衡态的距离,岩体结构非平衡演化的总体趋势服从最小塑性余能原理,进一步指出了无法消除的不平衡力是岩体结构变形破坏的内在驱动力。不平衡力不仅可以作为岩体结构变形破坏的判据,还能给出相应的加固措施,具有重要的工程意义。Abstract: The deformation and failure of rock mass structure is an asymptotic process, which cannot be described by conventional strength design and limit analysis. After reviewing the methods of failure control and deformation control of rock mass structure, we proposed a cracking control method, which should be the final control of the deformation and failure of rock mass structure. We analysed the difficulties of cracking simulation of rock mass structure, and expounded the theoretical basses for describing it by unbalanced force. We analysed the correlations between cracking and unbalanced force by three numerical cases: uniaxial compression test, excavation and unloading of slope and arch dam cracking test. It is proposed that the irreversible valley width reduction caused by impounding is also the result of unbalanced force: the pore water pressure shrinks the yield surface, making that the original stress state of rock mass exceeds the yield surface, resulting in unbalanced force and irreversible plastic deformation. Unbalanced force describes the distance from the unbalanced state to the balanced state of the rock mass structure, and the general trend of the evolution of the unbalanced rock mass structure obeys the principle of minimum plastic complementary energy. Unbalanced force can not only be used as the criterion of deformation and failure of rock mass structure, but also provide corresponding reinforcement measurements, which is of great engineering significance.
-
Key words:
- Unbalanced force /
- Deformation and failure /
- Rock mass structure /
- Driving force
-
图 2 含预置裂纹石膏试件破坏过程裂缝分布图(陈新等,2014)
a.加载过程1;b.加载过程2;c.加载过程3;d.加载过程4
Figure 2. Cracking maps of gypsum specimens with preset cracks (Chen et al., 2014)
图 4 白鹤滩拱坝左岸建基面继续开挖至538 m高程过程中某典型剖面的不平衡力矢量图(程立等,2017)
a.开挖至590 m高程;b.开挖至560 m高程;c.开挖至550 m高程;d.开挖至538 m高程
Figure 4. Unbalanced force vector map of a typical section during the excavation to 538 m elevation of left slope of Baihetan arch dam(Cheng et al., 2017)
图 10 考虑裂隙水压力的屈服准则(杨强等,2015)
a. Mohr-Coulomb准则;b. Drucker-Prager准则
Figure 10. Yield criterion considering pore water pressure (Yang et al., 2015)
-
Belytschko T, Black T. 1999. Elastic crack growth in finite elements with minimal remeshing[J]. International Journal for Numerical Methods in Engineering, 45(5): 601-620. http://cn.bing.com/academic/profile?id=67aeb002e836ff89f2edd104c261e536&encoded=0&v=paper_preview&mkt=zh-cn Chen L, Liu Y R, Tao Z F, et al. 2017. Variation of unbalanced force during excavation of arch dam base surface and treatment effects[J]. Chinese Journal of Geotechnical Engineering, 29(9): 1670-1679. http://d.old.wanfangdata.com.cn/Periodical/ytgcxb201709015 Chen X, Li D W, Wang L X, et al. 2014. Experimental study on effect of spacing and inclination angle of joints on strength and deformation properties of rock masses under uniaxial compression[J]. Chinese Journal of Geotechnical Engineering, 36(12): 2236-2245. http://d.old.wanfangdata.com.cn/Periodical/ytgcxb201412015 Cheng L. 2017. Study on the mechanism and control of the deformation and failure of super high arch dams[D]. Beijing: Tsinghua University. Fakhimi A A, Fairhurst C. 1994. A model for the time-dependent behavior of rock[C]//International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts. Pergamon, 31 (2): 117-126. He M C. 2016. Research on the double-block mechanics based on Newton force measurement[J]. Chinese Journal of Rock Mechanics and Engineering, 35(11): 2161-2173. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=yslxygcxb201611001 Hu Q J, Xie Q, Zheng L N. 2011. Research on evolvement of the progressive slide and failure mechanism of the long bedding slope[J]. Hydrogeology & Engineering Geology, 38(3): 31-37. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=swdzgcdz201103006 Li L X, Wang T J. 2005. The extended finite element method and its applications-A review[J]. Advances in Mechanics, 35(1): 5-20. Li S G, Huang D, Shi L, et al. 2018. Numerical modeling of the evolution of slope failure using the limit strain criterion and dynamic strength reduction method[J]. Journal of Engineering Geology, 26(5): 1227-1236. http://d.old.wanfangdata.com.cn/Periodical/gcdzxb201805015 Pan J. 1980. Anti-sliding stability and landslide analysis of buildings[M]. Beijing: China Hydraulic Press. Serafim J L. 1987. Malpasset dam discussion—remembrances of failures of dams[J]. Engineering Geology, 24(1-4): 355-366. Silling S A. 2000. Reformulation of elasticity theory for discontinuities and long-range forces[J]. Journal of the Mechanics and Physics of Solids, 48(1): 175-209. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=4+tvPgbzbcR+SI5JSYwnPGh64NhgNTVJ0TX3bqCNcXc= Sun Q H, Ma F S, Zhao H J, et al. 2019. Deformation and failure of surrounding rock considering weakening of mechanical parameters under seepage damage-stress coupling[J]. Journal of Engineering Geology, 27(5): 955-965. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=gcdzxb201905003 Wang L J, Xu J F, Wang J X. 2019. An overview and advances of nonlocal elasticity theories in the background of contemporary materials[J]. Chinese Quarterly of Mechanics, 40(1): 1-12. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=lxjk201901001 Wang S J. 2002. Coupling of earth's endogenic and exogenic geological processes and origins on serious geological disasters[J]. Journal of Engineering Geology, 10(2): 115-117. http://cn.bing.com/academic/profile?id=eaa68cf280c0c6a03e46eac90b5274f0&encoded=0&v=paper_preview&mkt=zh-cn Yang Q, Chen X, Zhou W Y, et al. 2002. A practical 3D elasto-plastic incremental method in FEM based on D-P yield criteria[J]. Chinese Journal of Geotechnical Engineering, 24(1): 16-20. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=ytgcxb200201003 Yang Q, Chen X, Zhou W Y, et al. 2004. On unbalanced forces in 3D elasto-plastic FEM analysis[J]. Chinese Journal of Geotechnical Engineering, 26(3): 323-326. Yang Q, Chen X, Zhou W Y. 2005. On microscopic thermodynamic mechanisms of damage evolution laws[J]. International Journal of Damage Mechanics, 14(3): 261-293. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=10.1177/1056789505050356 Yang Q, Leng K D, Chang Q, at al. 2012. Failure mechanism and control of geotechnical structures[C]//Proceedings of the 2nd International Symposium on Constitutive Modeling of Geomaterials-Advances and New Applications. Berlin: Springer: 63-87. Yang Q, Liu Y R, Chen Y R, et al. 2008. Deformation reinforcement theory and its application to high arch dams[J]. Science in China Series E:Technological Sciences, 51(2): 32-47. http://cn.bing.com/academic/profile?id=af1a1a1b3e2a6dc60424f9d3c77b697c&encoded=0&v=paper_preview&mkt=zh-cn Yang Q, Liu Y R, Chen Y R, et al. 2008. Deformation reinforcement theory and global stability and reinforcement of high arch dams[J]. Chinese Journal of Rock Mechanics and Engineering, 27(6): 1121-1136. http://cn.bing.com/academic/profile?id=393ea7bf8a3c76359a49c5d279e5e071&encoded=0&v=paper_preview&mkt=zh-cn Yang Q, Pan Y W, Chen L, et al. 2015. Mechanism of valley deformation of high arch dam and effective stress principle for unsaturated fractured rock mass[J]. Chinese Journal of Rock Mechanics and Engineering, 34(11): 2258-2269. http://cn.bing.com/academic/profile?id=cb0f23cae9a7fc25c938e0c9ad44c5cf&encoded=0&v=paper_preview&mkt=zh-cn Zhou Z F, Zhuang C, Li M W, et al. 2019. Analysis on the characteristics and geological causes of reservoir plate deformation[J]. Journal of Engineering Geology, 27(1): 38-47. http://d.old.wanfangdata.com.cn/Periodical/gcdzxb201901005 陈新, 李东威, 王莉贤, 等. 2014.单轴压缩下节理间距和倾角对岩体模拟试件强度和变形的影响研究[J].岩土工程学报, 36(12): 2236-2245. http://d.old.wanfangdata.com.cn/Periodical/ytgcxb201412015 程立, 刘耀儒, 陶灼夫, 等. 2017.拱坝建基面开挖过程中不平衡力变化及处理效果研究[J].岩土工程学报, 39(9): 1670-1679. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=ytgcxb201709015 程立. 2017.特高拱坝变形破坏的机制与控制研究[D].北京: 清华大学. http://cdmd.cnki.com.cn/Article/CDMD-10003-1018875878.htm 何满潮. 2016.基于界面牛顿力测量的双体灾变力学模型研究[J].岩石力学与工程学报, 35(11): 2161-2173. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=yslxygcxb201611001 胡启军, 谢强, 郑立宁. 2011.长大顺层边坡渐进滑移失稳演化机理研究[J].水文地质工程地质, 38(3): 31-37. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=swdzgcdz201103006 李录贤, 王铁军. 2005.扩展有限元法(XFEM)及其应用[J].力学进展, 1 : 5-20. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=lxjz200501002 李世贵, 黄达, 石林, 等. 2018.基于极限应变判据-动态局部强度折减的边坡破坏演化数值模拟[J].工程地质学报, 26(5): 1227-1236. doi: 10.13544/j.cnki.jeg.2018-088 潘家铮. 1980.建筑物的抗滑稳定和滑坡分析[M].北京:水利出版社. 孙琪皓, 马凤山, 赵海军, 等. 2019.基于渗流-损伤-应力耦合作用下考虑力学参数弱化的巷道围岩变形破坏分析[J].工程地质学报, 27(5): 955-965. doi: 10.13544/j.cnki.jeg.2019171 王林娟, 徐吉峰, 王建祥. 2019.非局部弹性理论概述及在当代材料背景下的一些进展[J].力学季刊, 40(1): 1-12. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=lxjk201901001 王思敬. 2002.地球内外动力耦合作用与重大地质灾害的成因初探[J].工程地质学报, 10(2): 115-117. http://www.gcdz.org/article/id/9362 杨强, 陈新, 周维垣, 等. 2004.三维弹塑性有限元计算中的不平衡力研究[J].岩土工程学报, 26(3): 323-326. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=ytgcxb200403004 杨强, 陈新, 周维垣. 2002.基于D-P准则的三维弹塑性有限元增量计算的有效算法[J].岩土工程学报, 24(1): 16-20. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=ytgcxb200201003 杨强, 刘耀儒, 陈英儒, 等. 2008.变形加固理论及高拱坝整体稳定与加固分析[J].岩石力学与工程学报, 27(6): 1121-1136. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=yslxygcxb200806005 杨强, 潘元炜, 程立, 等. 2015.高拱坝谷幅变形机制及非饱和裂隙岩体有效应力原理研究[J].岩石力学与工程学报, 34(11): 2258-2269. http://www.cnki.com.cn/Article/CJFDTotal-YSLX201511009.htm 周志芳, 庄超, 李鸣威, 等. 2019.水库库盘变形的特征及其地质成因分析[J].工程地质学报, 27(1): 38-47. doi: 10.13544/j.cnki.jeg.2018-280 -