Time-dependent stability analysis of open-pit slope considering life-cycle
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摘要: 基于开挖岩体蠕变劣化效应对露天矿高边坡稳定性的影响，提出了全生命周期内边坡的稳定性模型。引入岩石强度劣化理论，推导了时间效应下安全系数的计算公式。考虑锚索的预应力损失和边坡蠕变现象，建立了预应力损失条件下边坡安全系数的表达式，分析了时间因素和锚索预应力损失对边坡稳定性的影响规律。以大孤山西井边坡为例，借助FLAC3D内置的FISH语言把劣化理论嵌入到强度折减法中，利用改进的强度折减法计算了边坡的时效安全系数。结果表明：岩石强度随时间延长呈“L”型劣化，使得蠕变型边坡的安全系数低于只考虑开挖的情况，与实际工程更加吻合，受锚索预应力损失的影响已加固边坡仍有失稳的风险。比选了4种锚索的加固调控方案，在满足全生命周期内安全生产的前提下，获得了经济效益最优的方案。Abstract: Based on the influence of excavation and creep degradation on the stability of high slopes in open-pit, a stability model of slopes in life-cycle is proposed. By introducing the deterioration theory of rock strength, the calculation formula of safety factor under time effect is derived. Considering the prestress loss of anchor cable and the creep phenomenon of slope, the expression of safety factor of creep slope under prestress loss condition is established. Forthemore, the influence law of time factor of slope and prestress loss of anchor cable on slope is discussed. Taking Dagushan Xijing slope as an example, the decay theory is embedded into the strength reduction method with the help of the flash language built in the FLAC3D, and the improved strength reduction method is used to calculate the time-dependent safety factor of the slope. The results show that the "L" shaped deterioration of rock strength over time makes the factor of safety for creeping slopes lower than for excavation only, which is more consistent with the actual engineering. The reinforced slope still has the risk of instability due to the prestress loss of anchor cable. Four kinds of reinforcement control schemes of anchor cable are compared and selected, on the premise of meeting the safety production in the whole life cycle, the scheme with the best economic benefit is obtained.
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Key words:
- creep /
- life cycle /
- decay theory /
- prestress loss /
- time effective safety factor
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表 1 边坡岩体力学参数
Table 1. Rock mechanics parameters of slope
岩性 容重/(kN·m-3) 内摩擦角/(°) 黏聚力/kPa 弹性模量/GPa 黏弹性模量/GPa Maxwell系数/(GPa·d) Kelvin系数/(GPa·d) 泊松比 千枚岩 25.3 22.0 101 1.72 15.9 1 927.6 114 0.30 绿泥片岩 26.0 28.0 75 2.61 23.2 1 584.3 82 0.28 石英绿泥片岩 26.5 34.5 90 3.47 25.4 1 207.5 100 0.30 太古代花岗岩 27.2 38.0 8 100 27.00 77.1 0 60 0.21 
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表 2 锚索力学参数
Table 2. Rock mechanics parameters of slope
锚索布置区域/m 锚索间距/m 锚索长度/m 锚固角度/(°) 预应力/kN 锚索直径/mm -105~-125 5 30~40 15 750 5束7ϕ15.2 -125~-145 5 30~40 20 750 -145~-175 4 30~60 15 850 -175~-210 3 45~70 15 1 000
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表 3 锚索加固方案
Table 3. Anchor cable reinforcement scheme
方案 坡面6锚索/根 坡面7锚索/根 坡面8锚索/根 初始方案 4+5 2 7 方案1 3+4 2 7 方案2 3+5 0 7 方案3 3+4 2 6
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表 4 加固方案预算
Table 4. Reinforcement plan and budget
方案 单排锚索总数/根 工程概量/m 经济指标/元 概算/万元 初始方案 18 13 920 650 904.80 方案1 16 11 652 650 757.38 方案2 15 10 924 650 710.06 方案3 15 10 783 650 700.90
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[1] 倪卫达. 基于岩土体动态劣化的边坡时变稳定性研究[D]. 武汉: 中国地质大学, 2014. [2] 周创兵. 水电工程高陡边坡全生命周期安全控制研究综述[J]. 岩石力学与工程学报, 2013, 32(6): 1081-1093. doi: 10.3969/j.issn.1000-6915.2013.06.001Zhou Chuangbing. A prospect of researches on life-cycle safety control on high-steep rock slopes in hydropower engineering[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(6): 1081-1093. doi: 10.3969/j.issn.1000-6915.2013.06.001 [3] 才庆祥, 周伟, 舒继森, 等. 大型近水平露天煤矿端帮边坡时效性分析及应用[J]中国矿业大学学报, 2008, 37(6): 740-744. doi: 10.3321/j.issn:1000-1964.2008.06.003Cai Qingxiang, Zhou Wei, Shu Jisen, et al. Analysis and opplicaiton on end-slope timeliness of internal dumping under flat dipping ore body in large surface coal mine[J]. Journal of China University of Mining & Technology, 2008, 37(6): 740-744. doi: 10.3321/j.issn:1000-1964.2008.06.003 [4] 芮勇勤, 徐小荷, 杨天鸿, 等. 露天矿顺层蠕动边坡稳定性动态分析探讨[J]. 中国矿业, 1999, 8(6): 57-60. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGKA199906020.htmRui Yongqin, Xu Xiaohe, Yang Tianhong, et al. Dynamic analysis of stability of bedding creeping type slope at an open pit coal mine[J]. China Mining Magazine, 1999, 8(6): 57-60. https://www.cnki.com.cn/Article/CJFDTOTAL-ZGKA199906020.htm [5] 陈宇龙, 曹鹏. 混凝土时间相关断裂模型研究综述[J]. 矿业科学学报, 2021, 6(3): 290-295. doi: 10.19606/j.cnki.jmst.2021.03.005Chen Yulong, Cao Peng. Review of time-dependent fracture model of concrete[J]. Journal of Mining Science and Technology, 2021, 6(3): 290-295. doi: 10.19606/j.cnki.jmst.2021.03.005 [6] Kemeny J. The time-dependent reduction of sliding cohesion due to rock bridges along discontinuities: a fracture mechanics approach[J]. Rock Mechanics and Rock Engineering, 2003, 36(1): 27-38. doi: 10.1007/s00603-002-0032-2 [7] Shao J F, Zhu Q Z, Su K. Modeling of creep in rock materials in terms of material degradation[J]. Computers and Geotechnics, 2003, 30(7): 549-555. doi: 10.1016/S0266-352X(03)00063-6 [8] 刘波, 杨伟红. 考虑时间效应的隧道开挖三维沉降预测模型及应用[J]. 矿业科学学报, 2019, 4(5): 384-393. http://kykxxb.cumtb.edu.cn/article/id/237Liu Bo, Yang Weihong. Prediction model and application of three-dimensional ground surface settlement induced by tunnel excavation considering time effect[J]. Journal of Mining Science and Technology, 2019, 4(5): 384-393. http://kykxxb.cumtb.edu.cn/article/id/237 [9] 陈国庆, 黄润秋, 石豫川, 等. 基于动态和整体强度折减法的边坡稳定性分析[J]. 岩石力学与工程学报, 2014, 33(2): 243-256. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201402006.htmChen Guoqing, Huang Runqiu, Shi Yuchuan, et al. Stability analysis of slope based on dynamic and whole strength reduction methods[J]. Chinese Journal of Rock Mechanics and Engineering, 2014, 33(2): 243-256. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201402006.htm [10] 李连崇, 李少华, 李宏, 等. 基于岩石长期强度特征的岩质边坡时效变形过程分析[J]. 岩土工程学报, 2014, 36(1): 47-56. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201401004.htmLi Lianchong, Li Shaohua, Li Hong. Time-dependent deformation of rock slopes based on long-term strength characteristics of rocks[J]. Chinese Journal of Geotechnical Engineering, 2014, 36(1): 47-56. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC201401004.htm [11] 程辉, 赵洪宝, 徐建峰, 等. 基于滑移线场理论的巷道底鼓机理与防治技术研究[J]. 矿业科学学报, 2021, 6(3): 314-322. doi: 10.19606/j.cnki.jmst.2021.03.008Cheng Hui, Zhao Hongbao, Xu Jianfeng, et al. Study on floor heave mechanism and control technology of roadway based on slip line field theory[J]. Journal of Mining Science and Technology, 2021, 6(3): 314-322. doi: 10.19606/j.cnki.jmst.2021.03.008 [12] 朱晗迓, 尚岳全, 陆锡铭, 等. 锚索预应力长期损失与坡体蠕变耦合分析[J]. 岩土工程学报, 2005, 27(4): 464-467. doi: 10.3321/j.issn:1000-4548.2005.04.020Zhu Hanya, Shang Yuequan, Lu Ximing, et al. Coupling analysis of long-term prestress loss and slope creep[J]. Chinese Journal of Geotechnical Engineering, 2005, 27(4): 464-467. doi: 10.3321/j.issn:1000-4548.2005.04.020 [13] 左建平, 文金浩, 刘德军, 等. 深部巷道等强支护控制理论[J]. 矿业科学学报, 2021, 6(2): 148-159. doi: 10.19606/j.cnki.jmst.2021.02.002Zuo Jianping, Wen Jinhao, Liu Dejun, et al. Control theory of uniform strength support in deep roadway[J]. Journal of Mining Science and Technology, 2021, 6(2): 148-159. doi: 10.19606/j.cnki.jmst.2021.02.002 [14] 孙玉科, 牟会宠, 姚宝魁. 边坡岩体稳定性分析[M]. 北京: 科学出版社, 1998. [15] Li Y S, Xia C C. Time-dependent tests on intact rocks in uniaxial compression[M]. International Journal of Rock Mechanics and Mining Sciences, 2000, 37(3): 467-475. [16] 吴顺川, 张化进, 肖术, 等. 考虑服务年限的露天矿边坡时变目标可靠度研究[J]. 采矿与安全工程学报, 2019, 36(3): 542-548. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201903015.htmWu Shunchuan, Zhang Huajin, Xiao Shu, et al. Study on time-varying target reliability of open-pit slope considering service life[J]. Journal of Mining & Safety Engineering, 2019, 36(3): 542-548. https://www.cnki.com.cn/Article/CJFDTOTAL-KSYL201903015.htm [17] 张强勇, 杨文东, 张建国, 等. 变参数蠕变损伤本构模型及其工程应用[J]. 岩石力学与工程学报, 2009, 28(5): 732-739. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX200904014.htmZhang Qiangyong, Yang Wendong, Zhang Jianguo, et al. Variable parameters-based creep damage constitutive model and its engineering application[J]. Chinese Journal of Rock Mechanics and Engineering, 2009, 28(5): 732-739. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX200904014.htm [18] 闫莫明. 岩土锚固技术手册[M]. 北京: 人民交通出版社, 2004. [19] 刘德军, 左建平, 刘海雁, 等. 我国煤矿巷道支护理论及技术的现状与发展趋势[J]. 矿业科学学报, 2020, 5(1): 22-33. http://kykxxb.cumtb.edu.cn/article/id/262Liu Dejun, Zuo Jianping, Liu Haiyan, et al. Development and present situation of support theory and technology in coal mine roadway in China[J]. Journal of Mining Science and Technology, 2020, 5(1): 22-33. http://kykxxb.cumtb.edu.cn/article/id/262 [20] 陈沅江, 尹进, 胡毅夫. 软岩边坡锚索预应力定量损失规律研究[J]. 岩石力学与工程学报, 2013, 32(5): 1685-1691. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201308023.htmChen Yuanjiang, Yin Jin, Hu Yifu. Research on prestress quantitative loss law of soft rock slope anchor cable[J]. Chinese Journal of Rock Mechanics and Engineering, 2013, 32(5): 1685-1691. https://www.cnki.com.cn/Article/CJFDTOTAL-YSLX201308023.htm [21] 蒋树, 文宝萍, 蒋秀姿, 等. 基于非线性损伤理论的改进CVISC模型及其在FLAC3D中实现[J]. 水文地质工程地质, 2019, 46(01): 56-63. https://www.cnki.com.cn/Article/CJFDTOTAL-SWDG201901008.htmJiang Shu, Wen Baoping, Jiang Xiuzi, et al. A non-linear damage rheological constitutive model and its application to a giant slow-moving landslide[J]. Hydrogeology and Engineering Geology, 2019, 46(01): 56-63. https://www.cnki.com.cn/Article/CJFDTOTAL-SWDG201901008.htm -
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