A CALCULATION MODEL OF SAFETY FACTOR OF SHEAR FRACTURED FALLING DANGEROUS ROCK MASS BASED ON NATURAL FREQUENCY
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摘要:
错断式坠落危岩体的安全稳定程度受后缘裂缝深度控制,基于静力学的稳定系数计算可得到后缘裂隙深度临界值,但静力学计算方法无法得到裂隙深度的实时变化。基于修正Timoshenko梁建立岩梁动力学方程,结合动力基础半空间理论对岩梁的约束刚度及边界条件做深入分析,得到不同裂缝深度条件下危岩体固有频率理论解析。基于数值计算验证固有频率算法的正确性,并得出结论:随裂隙深度增大,固有频率不断降低,固有频率对危岩体后缘裂隙深度变化较为敏感,根据危岩体的固有频率值可反算危岩体后缘裂隙深度。基于固有频率与危岩体后缘裂隙深度之间的关系建立错断式坠落危岩体稳定系数计算模型,并采用室内试验进行验证,得出结论:危岩体固有频率与其后缘裂隙深度近似为负线性相关。基于固有频率的错断式坠落危岩体稳定系数计算模型可为危岩体自动化监测提供有益借鉴。
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关键词:
- 错断式坠落危岩体 /
- 稳定系数 /
- 修正Timoshenko梁理论 /
- 动力基础半空间理论 /
- 固有频率
Abstract:The safety and stability of shear fractured falling dangerous rock mass is controlled by the depth of trailing edge fracture. The critical value of the depth of trailing edge fracture can be obtained by calculating the stability factor based on statics, but the statics calculation method cannot obtain the real-time change of the fracture depth. Based on the modified Timoshenko Beam theory, the dynamic equation of rock beam was established. Combined with the half-space theory of dynamic foundation, the constraint stiffness and boundary conditions of rock beam were analyzed in depth, and theoretical analysis of natural frequency of dangerous rock mass under different fracture depths was conducted. The correctness of the natural frequency algorithm was verified through numerical calculation. It was concluded that the natural frequency decreases with the increase of crack depth, and the natural frequency is sensitive to the change of fracture depth at trailing edge of dangerous rock mass. According to the natural frequency value of dangerous rock mass, the fracture depth at trailing edge of dangerous rock mass can be inversely calculated. Based on the relationship between the natural frequency and the fracture depth of the trailing edge of dangerous rock mass, the calculation model of the stability coefficient of the dangerous rock mass was established, and the indoor test was used to verify it. It was concluded that the natural frequency of the dangerous rock mass is approximately negative-linearly correlated with the crack depth of the trailing edge. The calculation model of stability factor of shear fractured falling dangerous rock mass based on natural frequency can provide useful reference for automatic monitoring of dangerous rock mass.
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表 1 F1(α1)计算式
Table 1 Formulas of F1(α1)
ν′ 0 0.25 0.5 F2(α1) 4−0.5a21 5.3−a21 8−2a21 注:ν′为半无限空间材料泊松比。 表 2 材料属性表
Table 2 Material property table
材料属性 材料参数 弹性模量E/GPa 0.28 泊松比ν 0.33 密度ρ/(kg·m−3) 2300 表 3 模型材料配比
Table 3 Model material ratio
成分 质量比例/kg 石英砂 50 重晶石粉 30 石膏 8 甘油 1.5 纯净水 10 缓凝剂 0.02 表 4 模型材料力学参数
Table 4 Mechanical parameters of model materials
参数名称 参数值 密度ρ/(kg⋅m−3) 2250 弹性模量E/GPa 0.28 泊松比ν 0.33 内聚力c/MPa 3.1 抗拉强度Rt/MPa 0.18 表 5 固有频率与稳定系数值
Table 5 Natural frequency and stability coefficient
裂隙深度h/cm 稳定系数 固有频率ω/Hz 理论值 试验值 2 72.7 225.1 222.4 4 62.7 221.5 215.3 6 53.4 197.8 194.7 8 44.9 165.0 163.9 10 37.1 133.8 133.1 12 30.0 108.1 106.8 14 23.7 87.4 84.6 16 18.2 70.7 68.6 18 13.3 56.9 55.7 20 9.3 45.0 42.3 22 5.9 34.4 32.4 24 3.3 24.5 21.2 26 1.5 15.4 13.4 -
[1] 高买燕. 突发性崩塌灾害风险评估方法研究 [D]. 重庆: 重庆交通大学, 2012. GAO Maiyan. Method of Rockfall disaster risk assessment [D]. Chongqing: Chongqing Jiaotong University, 2012. (in Chinese)
[2] BERTRAN P. The rock-avalanche of February 1995 at Claix (French Alps) [J]. Geomorphology, 2003, 54(3/4): 339 − 346. doi: 10.1016/S0169-555X(03)00041-2
[3] BRAATHEN A, BLIKRA L H, BERG S S, et al. Rock-slope failures in Norway: Type, geometry, deformation mechanisms and stability [J]. Norsk Geologisk Tidsskrift, 2004, 84(1): 67 − 88.
[4] ISHIKAWA M, KURASHIGE Y, HIRAKAWA K. Analysis of crack movements observed in an alpine bedrock cliff [J]. Earth Surface Processes and Landforms, 2004, 29(7): 883 − 891. doi: 10.1002/esp.1076
[5] AREF M O A N. Causes of rockfalls in AI-Huwayshah area, Yemen [J]. Global Geology. 2009, 12(1): 5 − 12.
[6] 陈洪凯, 鲜学福, 唐红梅. 危岩稳定性断裂力学计算方法[J]. 重庆大学学报, 2009, 32(4): 434 − 437. CHEN Hongkai, XIAN Xuefu, TANG Hongmei. Stability analysis method for perilous rock by fracture mechanics [J]. Journal of Chongqing University, 2009, 32(4): 434 − 437. (in Chinese)
[7] 陈维, 徐则民, 刘文连. 差异风化型危岩力学模型及破坏机制研究[J]. 岩土力学, 2015, 36(1): 195 − 204. doi: 10.16285/j.rsm.2015.01.027 CHEN Wei, XU Zemin, LIU Wenlian. Mechanical model and failure mechanism of unstable cantilevered rock blocks due to differential weathering [J]. Rock and Soil Mechanics, 2015, 36(1): 195 − 204. (in Chinese) doi: 10.16285/j.rsm.2015.01.027
[8] 王根龙, 伍法权, 祁生文. 悬臂-拉裂式崩塌破坏机制研究[J]. 岩土力学, 2012, 33(增刊 2): 269 − 274. Wang Genlong,Wu Faquan,Qi Shengwen. Research on failure mechanisms for cantilever and tension crack-type collapse [J]. Rock and Soil Mechanics, 2012, 33(Suppl 2): 269 − 274. (in Chinese)
[9] 王存根, 王述红, 张紫杉, 等. 含结构面岩体的岩桥贯通系数修正及其应用[J]. 工程力学, 2017, 34(5): 95 − 104. doi: 10.6052/j.issn.1000-4750.2015.11.0905 WANG Cungen, WANG Shuhong, ZHANG Zishan, et al. Rockbridge coalescence coefficient correction of rock mass with structural surface and its application [J]. Engineering Mechanics, 2017, 34(5): 95 − 104. (in Chinese) doi: 10.6052/j.issn.1000-4750.2015.11.0905
[10] 刘传正. 崩塌滑坡灾害风险识别方法初步研究[J]. 工程地质学报, 2019, 27(1): 88 − 97. LIU Chuanzheng. Analysis methods on the risk identification of landslide disasters [J]. Journal of Engineering Geology, 2019, 27(1): 88 − 97. (in Chinese)
[11] STEAD D, EBERHARDT E, COGGAN J S. Developments in the characterization of complex rock slope deformation and failure using numerical modelling techniques [J]. Engineering Geology, 2006, 83(1-3): 217 − 235. doi: 10.1016/j.enggeo.2005.06.033
[12] 郝宪杰, 袁亮, 卢志国, 等. 考虑煤体非线性弹性力学行为的弹塑性本构模型[J]. 煤炭学报, 2017, 42(4): 896 − 901. HAO Xianjie, YUAN Liang, LU Zhiguo, et al. An elastic-plastic-soften constitutive model of coal considering its nonlinear elastic mechanical behavior [J]. Journal of China Coal Society, 2017, 42(4): 896 − 901. (in Chinese)
[13] 杨晓杰, 侯定贵, 王嘉敏, 等. 南芬露天铁矿下盘高陡边坡稳定性分析与监测预警技术研究[J]. 采矿与安全工程学报, 2017, 34(5): 1000 − 1007. YANG Xiaojie, HOU Dinggui, WANG Jiamin, et al. Study on the stability and remote real-time monitoring for high steep slope in Nanfen open pit iron mine [J]. Journal of Mining & Safety Engineering, 2017, 34(5): 1000 − 1007. (in Chinese)
[14] 王永亮, 王建辉, 张磊. 含多裂纹损伤圆弧曲梁自由振动扰动的有限元网格自适应分析[J]. 工程力学, 2021, 38(10): 24 − 33. doi: 10.6052/j.issn.1000-4750.2020.10.0708 WANG Yongliang, WANG Jianhui, ZHANG Lei. Adaptive mesh refinement analysis of finite element method for free vibration disturbance of circularly curved beams with multiple cracks [J]. Engineering Mechanics, 2021, 38(10): 24 − 33. (in Chinese) doi: 10.6052/j.issn.1000-4750.2020.10.0708
[15] 王慧, 王乐, 田润泽. 基于时域响应相关性分析及数据融合的结构损伤检测研究[J]. 工程力学, 2020, 37(9): 30 − 37. doi: 10.6052/j.issn.1000-4750.2019.10.0588 WANG Hui, WANG Le, TIAN Runze. Structual damage detection using correlation functions of time domain vibration responses and data fusion [J]. Engineering Mechanics, 2020, 37(9): 30 − 37. (in Chinese) doi: 10.6052/j.issn.1000-4750.2019.10.0588
[16] 王春生, 王世超, 王茜, 等. 危旧预应力混凝土箱梁承载性能足尺试验[J]. 工程力学, 2019, 36(8): 171 − 181. doi: 10.6052/j.issn.1000-4750.2018.07.0420 WANG Chunsheng, WANG Shichao, WANG Qian, et al. Experimental study on bearing capacity of dangerous and/or old pre-stressed concrete box girders [J]. Engineering Mechanics, 2019, 36(8): 171 − 181. (in Chinese) doi: 10.6052/j.issn.1000-4750.2018.07.0420
[17] 陈敬一, 杜修力, 韩强, 等. 摇摆双层桥梁地震反应及抗倒塌能力分析[J]. 工程力学, 2020, 37(10): 56 − 69. doi: 10.6052/j.issn.1000-4750.2019.10.0647 CHEN Jingyi, DU Xiuli, HAN Qiang, et al. Analysis of seismic response and overturning resistance of rocking double-deck bridge system [J]. Engineering Mechanics, 2020, 37(10): 56 − 69. (in Chinese) doi: 10.6052/j.issn.1000-4750.2019.10.0647
[18] 霍磊晨, 杜岩, 谢谟文, 等. 基于时频域动力学参量的危岩体识别方法[J]. 岩石力学与工程学报, 2021, 40(增刊 2): 3156 − 3162. HUO Leichen, DU Yan, XIE Mowen, et al. Unstable rock mass identification method based on time and frequency domain dynamic parameters [J]. Chinese Journal of Rock Mechanics and Engineering, 2021, 40(Suppl 2): 3156 − 3162. (in Chinese)
[19] DU Y, LU Y, XIE M, et al. A new attempt for early warning of unstable rocks based on vibration parameters [J]. Bulletin of Engineering Geology and the Environment, 2020, 79(8): 4363 − 4368. doi: 10.1007/s10064-020-01839-2
[20] BURJÁNEK J, GISCHIG V, MOORE J R, et al. Ambient vibration characterization and monitoring of a rock slope close to collapse [J]. Geophysical Journal International, 2018, 212(1): 297 − 310. doi: 10.1093/gji/ggx424
[21] AMITRANO D. Seismic precursory patterns before a cliff collapse and critical point phenomena [J]. Geophysical Research Letters, 2005, 32(8): 1 − 5.
[22] 路光, 谢谟文, 刘卫南, 等. 基于振幅比的危岩体稳定性分析方法[J]. 矿业研究与开发, 2022, 42(1): 82 − 86. LU Guang, XIE Mowen, LIU Weinan, et al. Stability analysis method of dangerous rock mass based on amplitude ratio [J]. Mining Research and Development, 2022, 42(1): 82 − 86. (in Chinese)
[23] HAN L, CHEN S, SHU J, et al. Experimental study on vibration instability model of rock slope based on parallel chaotic algorithms [J]. Chaos, Solitons & Fractals, 2019, 128: 252 − 260.
[24] 叶阳升, 蔡德钩, 闫宏业, 等. 激振作用下坠落式危岩振动特性试验研究[J]. 中国铁道科学, 2015, 36(6): 16 − 21. doi: 10.3969/j.issn.1001-4632.2015.06.03 YE Yangsheng, CAI Degou, YAN Hongye, et al. Experimental study on vibration characteristics of falling unstable rock under excitation [J]. China Railway Science, 2015, 36(6): 16 − 21. (in Chinese) doi: 10.3969/j.issn.1001-4632.2015.06.03
[25] 杜岩, 谢谟文, 蒋宇静, 等. 基于自振频率的监测预警指标确定方法[J]. 岩土力学, 2015, 36(8): 2284 − 2290. DU Yan, XIE Mowen, JIANG Yujing, et al. Methods for determining early warning indices based on natural frequency monitoring [J]. Rock and Soil Mechanics, 2015, 36(8): 2284 − 2290. (in Chinese)
[26] VALENTIN J, CAPRON A, JONGMANS D, et al. The dynamic response of prone-to-fall columns to ambient vibrations: Comparison between measurements and numerical modelling [J]. Geophysical Journal International, 2016, 208(2): 1058 − 1076.
[27] DU Y, XIE M, JIANG Y, et al. Experimental rock stability assessment using the frozen–thawing test [J]. Rock Mechanics and Rock Engineering, 2017, 50(4): 1049 − 1053. doi: 10.1007/s00603-016-1138-2
[28] 刘卫南. 坠落式边坡危岩体稳定性动力学评价模型研究 [D]. 北京: 北京科技大学, 2022. LIU Weinan. Study on the stability dynamics evaluation model of falling dangerous rock masses on slope [D]. Beijing: University of Science and Technology Beijing, 2021. (in Chinese)
[29] 王延平. 崩塌灾害变形破坏机理与监测预警研究 [D]. 成都: 成都理工大学, 2016. WANG Yanping. Study on deformation and failure mechanism of rockfall hazards and monitoring and early warning [D]. Chengdu: Chengdu University of Technology, 2016. (in Chinese)
[30] 李建林. 三峡工程岩石拉剪断裂特性的试验研究[J]. 地下空间, 2002, 22(2): 149 − 152. doi: 10.3969/j.issn.1673-0836.2002.02.013 LI Jianlin. A study on tension-shear crack property of rock related to the three gorges project [J]. Chinese Journal of Underground Space and Engineering, 2002, 22(2): 149 − 152. (in Chinese) doi: 10.3969/j.issn.1673-0836.2002.02.013
[31] 夏呈. 修正铁摩辛柯梁受迫振动响应分析及其应用[D]. 南京: 东南大学, 2017. XIA Cheng. The analysis of forced vibration response of modified Timoshenko beam theory and its application [D]. Nanjing: School of Civil Engineering Southeast University, 2017. (in Chinese)
[32] 严人觉, 王贻荪, 韩清宇. 动力基础半空间理论概论[M]. 北京: 建筑工业出版社, 1981. YAN Renjue, WANG Yisun, HAN Qingyu. Introduction to half-space theory of dynamic foundation [M]. Beijing: Building Industry Press, 1981. (in Chinese)
[33] 吴邦达, 吴丽波. 地基半空间等效集总体系的比拟法与实测分析[J]. 地震工程学报, 2015, 37(4): 1029 − 1036. doi: 10.3969/j.issn.1000-0844.2015.04.1029 WU Bangda, WU Libo. Analog method for the equivalent lumped system of foundation half-space theories and associated field measurements [J]. China Earthquake Engineering Journal, 2015, 37(4): 1029 − 1036. (in Chinese) doi: 10.3969/j.issn.1000-0844.2015.04.1029
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