在棚洞结构顶部覆盖一层砂土缓冲垫层能有效减小滚石对棚洞顶板的冲击力，以往多采用有限元方法开展研究，无法考虑砂土垫层离散特征，研究手段有待改进。以棚洞垫层物理模型试验为原型，考虑砂土颗粒离散性和棚洞混凝土结构的连续性，采用离散元-有限差分耦合算法，其中离散元模拟砂土垫层，有限差分法模拟棚洞混凝土结构，在充分发挥两种模拟方法优势下，开展滚石以不同角度、不同速度冲击棚洞垫层的动力响应数值模拟研究，通过对受冲击棚洞支座反力、棚洞顶板位移、滚石冲击力分析，揭示棚洞结构的动力响应特征。研究结果表明：冲击角度和冲击速度对支座反力影响显著，冲击角度增大，支座反力随之增大。相对而言，在较小冲击角度下，支座反力受冲击角度的影响较大，而较大冲击角度下，冲击速度的影响则更明显；冲击力方面，伴随冲击角度和冲击速度增大，滚石冲击力随之增大，较大冲击角度下，角度的增大对冲击力的提升更加明显；棚洞顶板中心处竖向位移值随冲击角度和冲击速度的增大而显著增大，且在较小冲击角度下，冲击角度对顶板位移的影响更大，而较大冲击角度下，冲击速度的影响更为显著。
Abstract
The impact of rolling stone on roof of shed tunnel can be effectively reduced by covering a layer of sand cushion on shed structure roof. In the past, the finite element method was used to do this study, but discrete characteristics of sand cushion could not be considered, so the study method needed to be improved. Here, taking shed tunnel cushion’s physical model test as the prototype, considering the dispersion of sand particles and the continuity of shed tunnel concrete structure, the discrete element-finite difference coupled algorithm was adopted. The discrete element model was used to simulate sand cushion, and the finite difference method was used to simulate shed tunnel concrete structure. With advantages of the two simulation methods, the dynamic response of shed tunnel cushion under impact of rolling stones with different angles and velocities was numerically simulated. Through analyzing bearing reaction force of the impacted shed tunnel, its roof displacement and rolling stone impact force, dynamic response characteristics of the shed tunnel structure were revealed. The results showed that rolling stone’s impact angle and impact velocity affect significantly bearing reaction, with increase in impact angle, bearing reaction increases; under the condition of smaller impact angle, bearing reaction is more affected by impact angle, while under the condition of larger impact angle, impact velocity affects bearing reaction more obviously; with increase in impact angle and impact velocity, impact force of rolling stone increases, under the condition of larger impact angle, increase in impact angle has more obvious action to lift impact force; vertical displacement value at roof center of shed tunnel increases significantly with increase in impact angle and impact velocity; under smaller impact angle, impact angle has larger influence on roof displacement, while under larger impact angle, effects of impact velocity on roof displacement are more significant.
关键词
滚石 /
棚洞 /
冲击角度 /
离散元-有限差分耦合
{{custom_keyword}} /
Key words
rolling stone /
shed tunnel /
impact angle /
discrete element-finite difference coupling
{{custom_keyword}} /
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
［1］章广成, 唐辉明, 向欣. 冲击地面过程中落石特征参量的理论分析［J］. 岩石力学与工程学报，2012，31(增刊1)：2839-2846.
ZHANG Guangcheng, TANG Huiming, XIANG Xin. Characteristic parameters theoretical analysis of rockfall impact on ground［J］. Chinese Journal of Rock Mechanics and Engineering, 2012, 31(Suppl.1): 2839-2846.
［2］吕庆, 周春锋, 于洋,等. 滚石坡面碰撞破裂效应的试验研究［J］. 岩石力学与工程学报, 2017, 36(增刊1): 3359-3366.
L Qing, ZHOU Chunfeng, YU Yang, et al. Experimental study on fragmentation effects of rockfall impact upon slope［J］. Chinese Journal of Rock Mechanics and Engineering, 2017, 36(Suppl.1): 3359-3366.
［3］叶四桥, 陈洪凯, 唐红梅. 落石冲击力计算方法［J］. 中国铁道科学, 2010, 31(6): 56-62.
YE Siqiao, CHEN Hongkai, TANG Hongmei. Rockfall impact force calculation method［J］. Chian Railway Science, 2010, 31(6): 56-62.
［4］何思明，沈均，吴永. 滚石冲击荷载下棚洞结构动力响应［J］. 岩土力学，2011，32(3)：781-788.
HE Siming, SHEN Jun, WU Yong. Rock shed dynamic response to impact of rock-fall［J］. Rock and Soil Mechanics，2011，32 (3)：781-788.
［5］杨璐，李士民，吴智敏，等. 滚石对棚洞结构的冲击动力分析［J］. 交通运输工程学报, 2012, 12(1)：25-30.
YANG Lu, LI Shimin, WU Zhimin, et al. Dynamic analysis of rock-fall impact on shed tunel structure［J］. Journal of Traffic and Transportation Engineering, 2012, 12(1): 25-30.
［6］王东坡，何思明，欧阳朝军，等. 滚石冲击荷载下棚洞钢筋混凝土板动力响应研究［J］. 岩土力学，2013，34(3)：881-886.
WANG Dongpo, HE Siming, OUYANG Chaojun, et al. Study of dynamic response of shed reinforced concrete slab to impact load of rock-fall［J］. Rock and Soil Mechanics, 2013, 34(3): 881-886.
［7］王东坡，何思明，吴永，等.滚石防护棚洞EPS垫层结构缓冲作用研究［J］. 振动与冲击，2014，33(4)：199-203.
WANG Dongpo, HE Siming, WU Yong, et al. Cushioning effect of rock sheds with EPS cushion on rock-falls action［J］. Journal of Vibration and Shock, 2014, 33(4): 199-203.
［8］程鹏，李伟，翟敏刚，等. 双层泡沫铝夹芯板抗滚石冲击结构性能优化研究［J］. 振动与冲击，2018，37(5)：85-91.
CHENG Peng, LI Wei, ZHAI Mingang, et al. Structure performance optimization of double-layer Aluminum foam sandwich panels under rockfalls impact［J］. Journal of Vibration and Shock, 2018, 37(5): 85-91.
［9］裴向军，刘洋，王东坡. 滚石冲击棚洞砂土垫层耗能缓冲机理研究［J］. 工程科学与技术，2016，48(1)：15-22.
PEI Xiangjun, LIU Yang, WANG Dongpo. Study on the energy dissipation of sandy soil cushions on the rockshed under rockfall impact load［J］. Advanced Engineering Sciences, 2016, 48(1): 15-22.
［10］王玉锁，徐铭，王涛，等. 落石冲击下无回填土拱形明洞结构可靠度设计［J］. 西南交通大学学报，2017，52(6)：65-71.
WANG Yusuo, XU Ming, WANG Tao, et al. Structural reliability design of non-backfilling arch open tunnel structure under rock-fall impaction［J］. Journal of Southwest Jiaotong University, 2017, 52(6): 65-71.
［11］张群利，王全才，吴清，等. 不同结构类型棚洞的抗冲击性能研究［J］. 振动与冲击，2015，34(3)：72-76.
ZHANG Qunli, WANG Quancai, WU Qing, et al. Anti-impact performances of different kinds of shed-tunnel structures［J］. Journal of Vibration and Shock, 2015, 34(3): 72-76.
［12］CAI M, KAISER P K, MORIOKA H, et al. FlAC/PFC coupled numerical simulation of AE in large-scale underground excavations［J］. International Journal of Rock Mechanics Mining Sciences, 2007, 44(4): 550-564.
［13］SONG W, HONG R. PFC/FLAC coupled numerical simulation of excavation damage zone in deep schist tunnel［J］. Applied Mechanics Materials, 2012, 236/237: 622-626.
［14］JIA M C, YANG Y, LIU B, et al. PFC/FLAC coupled simulation of dynamic compaction in granular soils［J］. Granular Matter, 2018, 20(4): 76.
［15］沈均，何思明，吴永. 滚石灾害研究现状及发展趋势［J］. 灾害学，2008，23(4)：122-125.
SHEN Jun, HE Siming, WU Yong. Present research status and development trend of rockfall hazards［J］. Journal of Catastrophology, 2008, 23(4): 122-125.
［16］Itasca Consulting Group. Particle flow code in 3 dimensions version 5.0 0.30 user’s guide［M］. Minneapolis: Itasca Consulting Group, 2017.
［17］SU Y C, CUI Y F, NG C W W, et al. Effects of particle size and cushioning thickness on the performance of rock-filled gabions used in protection against boulder impact［J］. Canadian Geotechnical Journal, 2018, 56(2):198-207.
［18］石崇，张强，王盛年. 颗粒流（PFC5.0)数值模拟技术及应用［M］. 北京：中国建筑工业出版社，2018.
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}
PDF(2630 KB)
