Tunnel block collapse instability characteristics and optimized design of targeted support based on multi-scale modeling method
HE Peng1，AN Jie1，SHI Shaoshuai2，HU Jie3，WU Weitao4，YAN Zhiqiang2
(1. School of Civil Engineering and Architecture，Shandong University of Science and Technology，Qingdao，Shandong 266590，China；2. Geotechnical and Underground Engineering Research Institute，Shandong University，Jinan，Shandong 250061，China；3. School of Safety Science and Engineering，Nanjing University of Science and Technology，Nanjing，
Jiangsu 210094，China；4. School of Mechanical Engineering，Nanjing University of Science and
Technology，Nanjing，Jiangsu 210094，China)
Abstract：The uncertainty in the development patterns and combinations of structural surfaces makes it difficult for the effective prevention and control of disasters such as landslides and block falls during the excavation of jointed rock tunnels. It is crucial to consider the impact of weak-scale joints on the mechanical properties of the surrounding rock，as well as the controlling effect of large-scale structural planes on local stability，in order to provide reasonable support. To this end，based on the morphological distribution law of two-dimensional trace lines in sequential tunnel face images，the rapid extension and prediction of dominant structural planes in three-dimensional space have been achieved. Using the embedding coefficient method in Sadovsky?s theory，the theoretical values for different structural plane scale divisions were determined. By employing the secondary development function of 3DEC，a multi-scale DFN-DEM equivalent modeling method for jointed rock masses was proposed，constructing an equivalent rock mass model that retains only the dominant structural planes and large-scale joint sets. This method was validated and analyzed through a series of tests conducted in the Erlangshan Tunnel project of Linzi-Linyi Expressway in Shandong Province. The results indicate that the multi-scale equivalent modeling method for jointed rock masses，which incorporates the dominant structural plane extension method，more effectively reveals the collapse evolution laws of the local surrounding rock in tunnels，especially the morphological distribution characteristics of key block groups. The rose diagram of hazardous rock groups provide a theoretical basis for understanding the spatial distribution of overbreak caused by dangerous rockfall in tunnels from a probability and statistics perspective. By integrating these methods，targeted support schemes can be provided for structure-controlled surrounding rock，offering both a theoretical basis and field guidance for the prevention and control of local collapse instability in jointed rock mass tunnel engineering.
1] ZOU X，WANG C，ZHANG H，et al. A practical method for the automatic recognition of rock structures in panoramic borehole image during deep-hole drilling engineering[J]. Applied Sciences，2021，11(21)：10 490.
[2] 朱梦琦，朱合华，王 昕，等. 基于集成CART算法的TBM掘进参数与围岩等级预测[J]. 岩石力学与工程学报，2020，39(9)： 1 860–1 871.(ZHU Mengqi，ZHU Hehua，WANG Xin，et al. Study on CART-based ensemble learning algorithms for predicting TBM tunneling parameters and classing surrounding rockmasses[J]. Chinese Journal of Rock Mechanics and Engineering，2020，39(9)：1 860– 1 871.(in Chinese))
[3] 方恩权，王耀东，李星言，等. 地铁盾构隧道渗漏水病害图像识别算法[J]. 隧道与地下工程灾害防治，2022，4(4)：28–33.(FANG Enquan，WANG Yaodong，LI Xingyan. et al. Algorithms of leakage disease images recognition in subway tunnel[J]. Tunnel and Underground Engineering Disaster Prevention，2022，4(4)：28–33.(in Chinese))
[4] 李 胜，熊自明，刘一鸣，等. 基于改进DBSCAN算法的岩体结构面智能识别方法[J]. 隧道与地下工程灾害防治，2022，4(2)：49–58.(LI Sheng，XIONG Ziming，LIU Yiming，et al. Intelligent identification of rock discontinuities based on an improved DBSCAN algorithm[J]. Tunnel and Underground Engineering Disaster Prevention，2022，4(2)：49–58.(in Chinese))
[5] 霍磊晨，杜 岩，谢谟文，等. 基于多层次动力学指标的危岩体识别方法[J]. 岩石力学与工程学报，2022，41(增2)：3 124–3 131. (HUO Leichen，DU Yan，XIE Mowen，et al. Unstable rock mass identification method based on multi-level dynamic parameters[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(Supp.2)：3 124–3 131.(in Chinese))
[6] CHEN J，ZHOU M，HUANG H，et al. Automated extraction and evaluation of fracture trace maps from rock tunnel face images via deep learning[J]. International Journal of Rock Mechanics and Mining Sciences，2021，142：104 745.
[7] 冷 彪，张 毅，杨 辉，等. 隧道掌子面岩体裂隙快速识别方法[J]. 西南交通大学学报，2021，56(2)：246–252.(LENG Biao，ZHANG Yi，YANG Hui，et al. Rapid recognition of rock mass fractures in tunnel faces[J]. Journal of Southwest Jiaotong University，2021，56(2)：246–252.(in Chinese))
[8] XUE Y，CAO Y，ZHOU M，et al. Rock mass fracture maps prediction based on spatiotemporal image sequence modeling[J]. Computer-Aided Civil and Infrastructure Engineering，2023，38(4)：470–488.
[9] FARAHMAND K，VAZAIOS L，DIEDERICHS M S，et al. Investigating the scale-dependency of thegeometrical and mechanical properties of a moderately jointed rock using a synthetic rock mass(SRM) approach[J]. Computers and Geotechnics，2017，95：162–179.
[10] 周 喻，王 莉，丁剑锋，等. 多尺度节理岩体力学特性的颗粒流分析[J]. 岩土力学，2016，37(7)：2 085–2 095.(ZHOU Yu，WANG Li，DING Jianfeng，et al. Particle flow code analysis of multi-scale jointed rock mass based upon equivalent rock mass technique[J]. Rock and Soil Mechanics，2016，37(7)：2 085–2 095.(in Chinese))
[11] 吴顺川，周 喻，高利立，等. 等效岩体技术在岩体工程中的应用[J]. 岩石力学与工程学报，2010，29(7)：1 435–1 441.(WU Shunchuan，ZHOU Yu，GAO Lili，et al. Application of equivalent rock mass technology to rock engineering[J]. Chinese Journal of Rock Mechanics and Geotechnical Engineering，2010，29(7)：1 435– 1 441.(in Chinese))
[12] LIU Z J，WANG H B，ZHANG C Q，et al. Size dependences of the mechanical behaviors of basalt rock blocks with hidden joints analyzed using a hybrid DFN-FDEM model[J]. Engineering Fracture Mechanics，2021，258：1–22.
[13] MA，G W，LI M Y，WANG H D，et al. Equivalent discrete fracture network method for numerical estimation of deformability in complexly fractured rock masses[J]. Engineering Geology，2020，277：105 784.
[14] WANG X，CAI M A. A DFN-DEM multi-scale modeling approach for simulating tunnel excavation response in jointed rock masses[J]. Rock Mechanics Rock Engineering，2019，53(3)：1 053–1 077.
[15] WEI Y R，FENG Y C，TAN Z L. Borehole stability in naturally fractured rocks with drilling mud intrusion and associated fracture strength weakening：A coupled DFN-DEM approach[J]. Journal of Rock Mechanics and Geotechnical Engineering，2024，16(5)：1 565–1 581.
[16] MAHBOUBI N，MEISAM. A DFN-DEM Approach to study the influence of confinement on the REV Size of fractured rock masses[J]. Iranian Journal of Science and Technology，Transactions of Civil Engineering，2020，44：587–601.
[17] 陈庆发，郑文师，牛文静，等. 裂隙岩体几何与力学尺寸效应的关联性研究[J]. 岩石力学与工程学报，2019，38(增1)：2 857–2 870. (CHEN Qingfa，ZHENG Wenshi，NIU Wenjing，et al. Correlation of the geometrical and mechanical size effects of fractured rock masses[J]. Chinese Journal of Rock Mechanics and Engineering，2019，38(Supp.1)：2 857–2 870.(in Chinese))
[18] 罗战友，黄 斌，杜时贵，等. 基于形貌全覆盖的岩石结构面抗剪强度尺寸效应试验研究[J]. 岩石力学与工程学报，2024，43(2)：287–297.(LUO Zhaoyou，HUANG Bin，DU Shigui，et al. Experimental study on size effect of shear strength of rock joints[J]. Chinese Journal of Rock Mechanics and Engineering，2024，43(2)：287–297.(in Chinese))
[19] LIU Z，WANG H，ZHANG C，et al. Size dependences of the mechanical behaviors of basalt rock blocks with hidden joints analyzed using a hybrid DFN-FDEM model[J]. Engineering Fracture Mechanics，2021，258：108 078.
[20] 李立辰，吴文兵，杨 松，等. 基于表征分形维数的结构面产状分组效果评价方法及应用[J]. 岩石力学与工程学报，2018，37(7)： 1 641–1 648.(LI Lichen，WU Wenbing，YANG Song，et al. An evaluation method of clustering results of discontinuity orientation based on the representative fractal dimension and its application[J]. Chinese Journal of Rock Mechanics and Engineering，2018，37(7)：1 641–1 648.(in Chinese))
[21] 张奇华，张 煜，李利平，等. 块体理论在地下洞室围岩稳定分析中的应用进展[J]. 隧道与地下工程灾害防治，2020，2(4)：9–18.(ZHANG Qihua，ZHANG Yu，LI Liping，et al. Advances in application of block theory to stability analysis of rock mass surrounding caverns[J]. Tunnel and Underground Engineering Disaster Prevention，2020，2(4)：9–18.(in Chinese))
[22] 禹海涛，何 爽，李 攀，等. 基于地层参数随机场模型的长隧道纵向地震响应分析[J]. 隧道与地下工程灾害防治，2020，2(3)：58–66.(YU Haitao，HE Shuang，LI Pan，et al. Longitudinal seismic response analysis of long tunnels based on random field model of strata parameters[J]. Tunnel and Underground Engineering Disaster Prevention，2020，2(3)：58–66.(in Chinese))
[23] 张雨霆，肖 明，丁秀丽等. 复杂岩石块体识别的单元重构–聚合方法[J]. 岩石力学与工程学报，2012，31(3)：507–523.(ZHANG Yuting，XIAO Ming，DING Xiuli，et al. identification method of complex rock blocks usingelement reconstruction and aggregation technioue[J]. Chinese Journal of Rock Mechanics and Engineering，2012，31(3)：507–523.(in Chinese))
[24] SHI G H，GOODMAN R E. The key blocks of unrolled joint traces in developed maps of tunnel walls[J]. International Journal of Numerical Analytical Methods in Geomechanics，1989，13(2)：131–158.
[25] 邬爱清，周火明，任 放. 岩体三维网络模拟技术及其在三峡工程中的应用[J]. 长江科学院院报，1998，15(6)：15–18.(WU Aiqing ZHOU Huoming，REN Fang. Research on 3D rock joint net work simulation techniques and its application to TGP[J]. Journal of Yangtze River Scientific Research Institute，1998，15(6)：15–18.(in Chinese))
[26] 卢 波，陈剑平，王良奎. 基于三维网络模拟基础的复杂有限块体的自动搜索及其空间几何形态的判定[J]. 岩石力学与工程学报. 2002，21(8)：1 232–1 238.(LU Bo，CHEN Jianping，WANG Liangkui. Automatic seeking for complex finite rock block and judgment of its spatial geometrical shape based on 3D network modeling[J]. Chinese Journal of Rock Mechanics and Engineering，2002，21(8)：1 232– 1 238.(in Chinese))
[27] 王述红，穆檄江，张 航，等. 岩体结构面精细化空间模型及块体失稳分析[J]. 东北大学学报：自然科学版，2012，33(8)：1 186– 1 189.(WANG Shuhong，MU Xijiang，ZHANG Hang，et al. Spatial modeling of refined structural plane of rockmass and block stability analysis[J]. Journal of Northeastern University：Natural Science，2012，33(8)：1 186–1 189.(in Chinese))
[28] 郑程程，贺 鹏，王 刚，等. 隧道裂隙岩体结构信息解译与危石垮塌空间展布规律研究[J]. 岩石力学与工程学报，2022，41(3)：515–532.(ZHENG Chengcheng，HE Peng，WANG Gang，et al. Structure information interpretation of fractured rock mass and spatial distribution law of dangerous rock collapse in tunnels[J]. Chinese Journal of Rock Mechanics and Engineering，2022，41(3)：515–532.(in Chinese))
[29] 刘才华，李育宗. 考虑横向抗剪效应的节理岩体全长黏结型锚杆锚固机制研究及进展[J]. 岩石力学与工程学报，2018，37(8)：1 856–1 872.(LIU Caihua，LI Yuzong. Research progress in bolting mechanism and theories of fully grouted bolts in jointed rock masses[J]. Chinese Journal of Rock Mechanics and Engineering，2018，37(8)：1 856–1 872.(in Chinese))
[30] 冷 彪，仇文革，王 刚，等. 数字图像处理在隧道工程地质分析中的应用研究[J]. 铁道标准设计，2013，(11)：77–81.(LENG Biao，QIU Wenge，WANG Gang，et al. Research on digital image processing technology used in geologica analysis of tunnel Engineering[J]. Railway standard design，2013，(11)：77–81.(in Chinese))
[31] HE P，WANG G，XU F，et al. GPR-MCS model of reliability analysis of key blocks and its engineering application[J]. International Journal for Numerical and Analytical Methods in Geomechanic，2021，45(5)：1–17.
[32] ZHENG C C，HE P，WANG G，et al. Analysis of progressive collapse disaster and its anchoring effectiveness in jointed rock tunnel[J]. International Journal for Numerical and Analytical Methods in Geomechanics，2024，48(16)：3 876–3 908.
[33] SADOVSKY M A. Natural lumpiness of rocks[J]. Reports of Academy of Sciences，1979，247(4)：829–832.
2025, Vol. 44 
