|
|
|
| Centrifuge model test study on toppling deformation of anti-dip soft-hard interbedded rock slopes |
| HUANG Da1，XIE Zhouzhou1，SONG Yixiang1，MENG Qiujie1，LUO Shilin2 |
| (1. School of Civil and Transportation Engineering，Hebei University of Technology，Tianjin 300401，China；2. School of Civil Engineering，Chongqing University，Chongqing 400045，China) |
|
|
|
|
Abstract In view of the lack of understanding of the toppling deformation of anti-dip soft-hard interbedded rock slopes，based on similarity principle and geological data，three groups of slope physical models were established with cement and gypsum as similar materials，among which one group is an anti-dip layered rock slope with hard rock and the other two groups are soft-hard interbedded rock slopes with different layer thickness ratios. By carrying out centrifugal model tests and using image measurement technology，the differences of toppling deformation and failure modes between the anti-dip soft-hard interbedded rock slopes and the anti-dip layered rock slopes are studied，and the influence of the layer thickness ratios of soft rock to hard rock on the overall toppling deformation degree and the ultimate bearing capacity of the slope is analyzed. The following conclusions are obtained by the tests：(1) The pattern of toppling deformation of the anti-dip soft-hard interbedded rock slope is different from the anti-dip layered rock slope with hard rock. The former has two fracture surfaces including the primary fracture surface and the secondary fracture surface. The secondary fracture surface is first formed and the upper rock mass has an instability. Then，the deep discontinuous bending zones coalesce with each other，and finally the main fracture surface is formed and the slope fails as a whole collapsing downward. (2) Almost no toppling occurs in the rock mass below the primary fracture surface during toppling deformation，so the primary fracture surface can be defined as the boundary line between the toppling and non-toppling rock masses. The development depth of the secondary fracture surface is shallower than that of the primary fracture surface，but the shallow rock mass above the secondary fracture surface has a greater toppling deformation degree and is more prone to failure. The secondary fracture surface is the most dangerous fracture surface during the process of slope toppling deformation. (3) Due to the weak strength of the soft rock，the fracture surface of the anti-dip soft-hard interbedded rock slope is arc-shaped，which is different from that of single lithology layered anti-dip rock slope. (4) The existence of the soft rock also has influence on the ultimate bearing capacity and the toppling deformation degree of the slope，varying with the layer thickness ratio of the soft rock to the hard rock. Compared with the single hard rock layered anti-dip rock slope，the ultimate bearing capacity of the soft-hard interbedded rock slope with a thickness ratio of 1∶1 increases and the toppling deformation degree decreases，while for the soft-hard interbedded rock slope with a thickness ratio of 2∶1，the ultimate bearing capacity decreases and the toppling deformation degree increases.
|
|
|
|
|
|
[1] GOODMAN R E，BRAY J W. Toppling of rock slopes[C]// Proceedings of ASCE Specialty Conference，Rock Engineering for Foundations and Slopes. Colorado，Boulder：[s. n.]，1976：201–234.
[2] 谭儒蛟，杨旭朝，胡瑞林. 反倾岩体边坡变形机制与稳定性评价研究综述[J]. 岩土力学，2009，30(增2)：479–484.(TAN Rujiao，YANG Xuzhao，HU Ruilin. Review of deformation mechanism and stability analysis of anti-dipped rock slopes[J]. Rock and Soil Mechanics，2009，30(Supp.2)：479–484.(in Chinese))
[3] 徐佩华，陈剑平，黄润秋，等. 锦屏水电站解放沟反倾高边坡变形机制的探讨[J]. 工程地质学报，2004，12(3)：247–252.(XU Peihua，CHEN Jianping，HUANG Runqiu，et al. Deformation mechanism of Jiefanggou high steep dipslope in Jinping hydropower station[J]. Journal of Engineering Geology，2004，12(3)：247–252.(in Chinese))
[4] 王 飞，唐辉明. 雅砻江上游互层斜坡倾倒变形破坏机制与演化[J]. 工程地质学报，2017，25(6)：1 501–1 508.(WANG Fei，TANG Huiming. Mechanism and evolution of toppling in interbedded slopes at upstream of Yalong river[J]. Journal of Engineering Geology，2017，25(6)：1 501–1 508.(in Chinese))
[5] 吴关叶，郑全春，郑惠峰. 苗尾水电站边坡倾倒变形机制与加固效果分析[J]. 地下空间与工程学报，2017，13(2)：538–544.(WU Guanye，ZHENG Quanchun，ZHENG Huifeng. Slope toppling deformation mechanism and reinforce effectiveness analysis of Miaowei hydropower station[J]. Chinese Journal of Underground Space and Engineering，2017，13(2)：538–544.(in Chinese))
[6] 吴京涛，胡卸文. 汶马高速通化隧道进口边坡变形特征及机制[J]. 四川地质学报，2019，39(1)：105–108.(WU Jingtao，HU Xiewen. Slope deformation and it¢s mechanism at the Tonghua tunnel entrance of the WenchuanMarkam Motorway[J]. Acta Geologica Sichuan，2019，39(1)：105–108.(in Chinese))
[7] GU D M，HUANG D. A complex rock topple-rock slide failure of an anaclinal rock slope in the Wu Gorge，Yangtze River，China[J]. Engineering Geology，2016，208：165–180.
[8] ADHIKARY D P，DYSKIN A V. Modelling of progressive and instantaneous failures of foliated rock slopes[J]. Rock Mechanics and Rock Engineering，2007，40(4)：349–362.
[9] ADHIKARY D P，DYSKIN A V，JEWELL R J. Numerical modelling of the flexural deformation of foliated rock slopes[J]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts，1996，33(6)：595–606.
[10] 赵 华，李文龙，卫俊杰，等. 反倾边坡倾倒变形演化过程的模型试验研究[J]. 工程地质学报，2018，26(3)：749–757.(ZHAO Hua，LI Wenlong，WEI Junjie，et al. Model test study on toppling deformation evolution process of counter-tilt slope[J]. Journal of Engineering Geology，2018，26(3)：749–757.(in Chinese))
[11] 杨国香，叶海林，伍法权，等. 反倾层状结构岩质边坡动力响应特性及破坏机制振动台模型试验研究[J]. 岩石力学与工程学报，2012，31(11)：2 214–2 221.(YANG Guoxiang，YE Hailin，WU Faquan，et al. Shaking table model test on dynamic response characteristics and failure mechanism of antidip layered rock slope[J]. China Journal of Rock Mechanics and Engineering，2012，31(11)： 2 214–2 221.(in Chinese))
[12] 郑 达，黄润秋，黄 刚. 地下开采作用下“反倾上硬下软”型斜坡崩塌形成机制研究——以贵州开阳磷矿崩塌为例[J]. 工程地质学报，2014，22(3)：464–473.(ZHENG Da，HUANG Runqiu，HUANG Gang. Mechanism of rockfall with anti-dip and top hard-bottom soft rock by underground mining：A case study of rockfall in Kaiyang phosphorite，Guizhou[J]. Journal of Engineering Geology，2014，22(3)：464–473.(in Chinese))
[13] 郑 达，王沁沅，毛 峰，等. 反倾层状岩质边坡深层倾倒变形关键致灾因子及成灾模式的离心试验研究[J]. 岩石力学与工程学报，2019，38(10)：1 954–1 963.(ZHENG Da，WANG Qingyuan，MAO Feng，et al. Centrifuge model test study on key hazard-inducing factors of deep toppling deformation and disaster patterns of counter-tilt layered rock slopes[J]. Chinese Journal of Rock Mechanics and Engineering，2019，38(10)：1 954–1 963.(in Chinese))
[14] 陆文博，晏鄂川，邹 浩，等. 我国倾倒变形体发育规律研究[J]. 长江科学院院报，2017，34(8)：111–119.(LU Wenbo，YAN Echuan，ZOU Hao，et al. Development rules of toppling deformation slopes in China[J]. Journal of Yangtze River Scientific Research Institute，2017，34(8)：111–119.(in Chinese))
[15] 黄 达，马 昊，孟秋杰，等. 软硬互层岩质反倾边坡弯曲倾倒离心模型试验与数值模拟研究[J]. 岩土工程学报，2020，42(7)： 1 286–1 295.(HUANG Da，MA Hao，MENG Qiujie，et al. Centrifugal model test and numerical simulation for anaclinal rock slopes with soft-hard interbedded structures[J]. Chinese Journal of Geotechnical Engineering，2020，42(7)：1 286–1 295.(in Chinese))
[16] 水利水电科学研究院，水利水电规划设计总院，水利电力情报研究所. 岩石力学参数手册[M]. 北京：水利水电出版社，1991：145–148.(Institute of Water Resources and Hydropower Research，China Renewable Energy Engineering Institute，Institute of Water Resources and Electric Power Information. Handbook of rock mechanics parameters[M]. Beijing：China Water Power Press，1991：145–148.(in Chinese)
[17] 工程地质编委会. 工程地质手册[M]. 北京：中国建筑工业出版社，2018：217–220.(Engineering Geology Editorial Board. Geological engineering handbook[M]. Beijing：China Architecture and Building Press，2018：217–220.(in Chinese))
[18] 李祥龙，唐辉明. 逆层岩质边坡地震动力破坏离心机试验研究[J]. 岩土工程学报，2014，36(4)：687–694.(LI Xianglong，TANG Huiming. Dynamic centrifugal modelling tests on toppling rock slopes[J]. Chinese Journal of Geotechnical Engineering，2014，36(4)：687–694.(in Chinese))
[19] AYDAN O，AMINIM M. An experimental study on rock slopes against flexural toppling failure under dynamic loading and some theoretical considerations for its stability assessment[J]. Journal of the College of Marine Science and Technology Tokai University，2009，7(2)：25–40.
[20] 吴 昊，赵 维，年廷凯，等. 反倾层状岩质边坡倾倒破坏的离心模型试验研究[J]. 水利学报，2018，49(2)：223–231.(WU Hao，ZHAO Wei，NIAN Tingkai，et al. Study on the anti-dip layered rock slope toppling failure based on centrifuge model test[J]. Journal of Hydraulic Engineering，2018，49(2)：223–231.(in Chinese))
|
|
|
|
2021, Vol. 40 
