Slope engineering geology characteristics and stability evaluation of a grand bridge to Chengdu bank on the Sichuan-Tibet Railway
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摘要:
拟建的川藏铁路某特大桥是一座重要的控制性桥梁，其桥址区的地质安全风险评价具有重要的工程意义。该特大桥成都侧岸坡三面临空，海拔高差大，岩性复杂多变，岩体结构和完整性差，风化卸荷强烈，浅表部危岩体发育，调查表明成都岸八曲侧斜坡曾发生较大规模顺层岩质崩滑。采用遥感解译、剖面测量及稳定性计算等技术方法，调查成都侧岸坡地形地貌、地层岩性、结构面发育及变形破坏等特征，分析评价特大桥成都岸八曲侧顺层岩质斜坡稳定性。结果表明：天然和暴雨工况下，斜坡稳定系数大于1.1；强震（PGA>0.3 g）工况下，斜坡稳定系数小于1.0，可能出现局部或整体失稳破坏。建议在清除斜坡表部危岩体的基础上，进一步深入研究八曲侧顺层岩质斜坡未来可能出现的变形破坏范围和程度，提出针对性工程防治措施建议。
Abstract:The planned grand bridge is an important control bridge along the Sichuan-Tibet Railway. A large- scale bedding rock collapse occurred on the slope of the Baqu river side of Chengdu bank, with the protruding ridge, high elevation difference, complex and changeable lithology, poor rock mass structure and integrity, highly weathering and unloading and potential unstable rock mass on the surface of the slope. This paper investigates the topography and geomorphology, stratum lithology, discontinuities development and the characteristics of deformation and failure of the bank slope to Chengdu by remote sensing interpretation, profile measurement and stability calculation. The stability of bedding rock slope of the Baqu river side of Chengdu bank under natural and rainstorm conditions are analyzed and evaluated. The results show that the safety factor of slope stability is greater than 1.1; under the strong earthquake (PGA>0.3 g) conditions, the safety factor of slope stability is less than 1.0, and local or overall instability may occur. Based on removing the dangerous rock mass on the surface of the slope, it is suggested that the possible failure range and degree of the bedding rock slope on the Baqu river side should be further studied and the engineering prevention measures should be put forward.
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表 1 八曲侧斜坡稳定性计算参数表
Table 1. Calculation parameters of slope stability
名称 γ天然/
（g·cm−3）γ饱和/
（g.cm−3）c天然/
MPac饱和/
MPaφ天然/
（°）φ饱和/
（°）堆积体 2.0 2.20 0.08 0.05 40 36 强风化岩体 2.5 2.55 0.60 0.5 36 34 弱风化岩体 2.6 2.65 1.50 1.40 40 35 微风化岩体 2.6 2.65 2.00 1.90 47 45 强风化岩体中的
顺层片理面− − 0.12 0.095 33 26.3 弱风化岩体中的
顺层片理面− − 0.30 0.270 35 33.0 注：γ—密度；c—黏聚力；φ—内摩擦角。 
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表 2 八曲侧斜坡稳定系数计算结果
Table 2. FOS calculation results of stability of the Baqu slope
计算方法工况 一般条分法 Bishop法 Janbu法 Spencer法 Morgenstern法 滑面1 滑面2 滑面1 滑面2 滑面1 滑面2 滑面1 滑面2 滑面1 滑面2 天然 1.45 1.54 1.46 1.60 1.44 1.57 1.45 1.57 1.45 1.56 暴雨 1.15 1.25 1.15 1.29 1.13 1.22 1.15 1.28 1.14 1.27 地震（PGA=0.1 g） 1.26 1.31 1.28 1.36 1.24 1.32 1.25 1.33 1.25 1.33 地震（PGA=0.15 g） 1.18 1.21 1.21 1.26 1.15 1.22 − 1.23 1.17 1.23 地震（PGA=0.2 g） 1.11 1.12 1.13 1.17 1.07 1.13 − 1.15 − 1.14 地震（PGA=0.3 g） 0.98 0.97 1.00 1.01 0.93 0.97 − 0.99 − 0.99 暴雨+地震（PGA=0.1 g） 1.00 1.06 1.00 1.09 0.97 1.03 − 1.09 0.99 1.08 暴雨+地震（PGA=0.15 g） 0.94 0.98 0.95 1.01 0.90 0.98 − 1.01 0.93 1.00 暴雨+地震（PGA=0.2 g） 0.88 0.91 0.89 0.94 0.84 0.90 − 0.94 0.87 0.94 暴雨+地震（PGA=0.3 g） 0.78 0.78 0.79 0.81 0.73 0.77 − 0.82 − 0.81
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[1] 张培震, 郑德文, 尹功明, 等. 有关青藏高原东北缘晚新生代扩展与隆升的讨论[J]. 第四纪研究,2006,26(1):5 − 13. [ZHANG Peizhen, ZHENG Dewen, YIN Gongming, et al. Discussion on late Cenozoic growth and rise of northeastern margin of the Tibetan Plateau[J]. Quaternary Sciences,2006,26(1):5 − 13. (in Chinese with English abstract) doi: 10.3321/j.issn:1001-7410.2006.01.002
[2] 彭建兵, 崔鹏, 庄建琦. 川藏铁路对工程地质提出的挑战[J]. 岩石力学与工程学报,2020,39(12):2377 − 2389. [PENG Jianbing, CUI Peng, ZHUANG Jianqi. Challenges to engineering geology of Sichuan-Tibet Railway[J]. Chinese Journal of Rock Mechanics and Engineering,2020,39(12):2377 − 2389. (in Chinese with English abstract)
[3] 邱鹏, 苏培东, 郭长宝, 等. 川藏铁路规划区K208滑坡数值模拟分析[J]. 水力发电,2016,42(11):42 − 46. [QIU Peng, SU Peidong, GUO Changbao, et al. Numerical analysis of K208 landslide in planning area of Sichuan-Tibet Railway[J]. Water Power,2016,42(11):42 − 46. (in Chinese with English abstract) doi: 10.3969/j.issn.0559-9342.2016.11.011
[4] 吴瑞安, 郭长宝, 杜宇本, 等. 川藏铁路加查-朗县段地质灾害发育特征研究[J]. 现代地质,2017,31(5):956 − 964. [WU Rui'an, GUO Changbao, DU Yuben, et al. Research on geohazard developing characteristics in Jiacha to Langxian section of Sichuan-Tibet Railway[J]. Geoscience,2017,31(5):956 − 964. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-8527.2017.05.007
[5] 王家柱, 高延超, 冉涛, 等. 川藏铁路交通廊道某大型古滑坡成因及失稳模式分析[J]. 现代地质,2021,35(1):18 − 25. [WANG Jiazhu, GAO Yanchao, RAN Tao, et al. Analysis of genetic mechanism and failure mode of a large paleo-landslide in Sichuan-Tibet Railway transportation corridor[J]. Geoscience,2021,35(1):18 − 25. (in Chinese with English abstract)
[6] 宋章, 张广泽, 蒋良文, 等. 川藏铁路高陡边坡深厚卸荷带特征分析[C]//川藏铁路建设的挑战与对策——2016 学术交流会论文集. 北京: 人民交通出版社股份有限公司, 2017: 177−184.
SONG Zhang, ZHANG Guangze, JIANG Liangwen, et al. Analyzed the characteristic of deep unloading fracture zone of high and steep slope of the Sichuan-Tibet Railway[C]//Proceedings of the 2016 Academic Exchange Conference on Challenges and Countermeasures of Sichuan-Tibet Railway Construction. Beijing: China Communication Press Co Ltd, 2017: 177−184. (in Chinese with English abstract)
[7] 蓝康文. 川藏铁路高山峡谷边坡卸荷带变形破坏模式及稳定性研究[D]. 成都: 西南交通大学, 2015.
LAN Kangwen. Study on failure modes and stability of unloading zone of slopes in alpine-gorge region along Sichuan-Tibet Railway[D]. Chengdu: Southwest Jiaotong University, 2015. (in Chinese with English abstract)
[8] 王俊, 赵建军, 瞿生军, 等. 卸荷条件下高边坡大规模开挖的“地质-力学”响应研究—以西藏如美水电站右坝肩为例[J]. 水文地质工程地质,2018,45(4):37 − 44. [WANG Jun, ZHAO Jianjun, QU Shengjun, et al. A study of the geological-mechanical response during large-scale excavation of high slope under unloading condition: Exemplified by the right abutment of the Tibet Rumei Hydropower Station[J]. Hydrogeology & Engineering Geology,2018,45(4):37 − 44. (in Chinese with English abstract)
[9] 周洪福, 冉涛, 陈波, 等. 川西顺层斜坡破坏模式及层间弱面连通率对斜坡稳定性的影响[J]. 现代地质,2021,35(1):137 − 144. [ZHOU Hongfu, RAN Tao, CHEN Bo, et al. Failure modes and influence of interlaminar fracture zone connectivity on slope stability of bedding rock slope in Ya'an, west Sichuan[J]. Geoscience,2021,35(1):137 − 144. (in Chinese with English abstract)
[10] 马文著, 徐衍, 李晓雷, 等. 基于黏聚力裂缝模型的反倾层状岩质边坡倾倒破坏模拟[J]. 水文地质工程地质,2020,47(5):150 − 160. [MA Wenzhu, XU Yan, LI Xiaolei, et al. A numerical study of the toppling failure of an anti-dip layered rock slope based on a cohesive crack model[J]. Hydrogeology & Engineering Geology,2020,47(5):150 − 160. (in Chinese with English abstract)
[11] 周洪福, 符文熹, 叶飞, 等. 陡倾坡外弱面控制的斜坡滑移-剪损变形破坏模式[J]. 地球科学,2021,46(4):1437 − 1446. [ZHOU Hongfu, FU Wenxi, YE Fei, et al. Study on sliding- shearing deformation and failure mode of rock slope with steep weak structural plane[J]. Earth Science,2021,46(4):1437 − 1446. (in Chinese with English abstract)
[12] 冉涛, 周洪福, 徐伟, 等. 川西交通廊道雅安-泸定段典型岩质边坡失稳模式、破坏机理及防治措施[J]. 自然灾害学报,2020,29(4):200 − 212. [RAN Tao, ZHOU Hongfu, XU Wei, et al. Research on the instability modes, failure mechanisms, and preventive measures of representative rock slopes within Ya’an- Luding section of the western Sichuan transportation corridor[J]. Journal of Natural Disasters,2020,29(4):200 − 212. (in Chinese with English abstract)
[13] 成永刚, 赵晓彦. 川藏高速公路雅(安) 康(定) 段玄武岩边坡工程地质分析与防治[J]. 水利与建筑工程学报,2020,18(5):165 − 169. [CHENG Yonggang, ZHAO Xiaoyan. Engineering geological analysis and prevention of basalt slope in Sichuan Tibet expressway[J]. Journal of Water Resources and Architectural Engineering,2020,18(5):165 − 169. (in Chinese with English abstract) doi: 10.3969/j.issn.1672-1144.2020.05.029
[14] 杨志法, 张路青, 祝介旺. 四项边坡加固新技术[J]. 岩石力学与工程学报,2005,24(21):3828 − 3834. [YANG Zhifa, ZHANG Luqing, ZHU Jiewang. Four new techniques in slope reinforcement[J]. Chinese Journal of Rock Mechanics and Engineering,2005,24(21):3828 − 3834. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2005.21.004
[15] 龚建辉. 高陡不稳定路堑边坡加固技术探讨[J]. 高速铁路技术,2020,11(3):71 − 74. [GONG Jianhui. Discussion on reinforcement technology of high and steep unstable cutting slope[J]. High Speed Railway Technology,2020,11(3):71 − 74. (in Chinese with English abstract)
[16] 王栋, 张广泽, 李新坡, 等. 川藏铁路折多山隧道进口岩崩运动特征及防治措施[J]. 科学技术与工程,2017,17(34):118 − 123. [WANG Dong, ZHANG Guangze, LI Xinpo, et al. Movement characteristics and prevention of talus slope in Zheduoshan tunnel of Sichuan-Tibet Railway[J]. Science Technology and Engineering,2017,17(34):118 − 123. (in Chinese with English abstract) doi: 10.3969/j.issn.1671-1815.2017.34.019
[17] 钟卫, 李秀珍, 崔云, 等. 崩塌滑坡灾害对川藏铁路康定-昌都段选线的影响[J]. 铁道标准设计,2018,62(1):34 − 38. [ZHONG Wei, LI Xiuzhen, CUI Yun, et al. The influence of landslide and collapse hazards on railway alignment in Kangding-Changdu section of Sichuan-Tibet Railway[J]. Railway Standard Design,2018,62(1):34 − 38. (in Chinese with English abstract)
[18] 赵晓彦, 肖典, 罗改, 等. 强降雨条件下碎裂岩质边坡锚墩式主动网加固机理模型试验[J]. 工程地质学报,2021,29(2):365 − 374. [ZHAO Xiaoyan, XIAO Dian, LUO Gai, et al. Model testing of anchored active net for cataclastic rock slope stabilizing under heavy rainfall[J]. Journal of Engineering Geology,2021,29(2):365 − 374. (in Chinese with English abstract)
[19] 王鹏. 川藏铁路金沙江特大桥岸坡稳定性研究[D]. 成都: 西南交通大学, 2016.
WANG Peng. Study on the slope stability of bridge over Jinsha river in Sichuan-Tibet Railway[D]. Chengdu: Southwest Jiaotong University, 2016. (in Chinese with English abstract)
[20] 杜杰贵, 严松, 李继兴, 等. 考虑卸荷带和岩体软化特性的某桥址边坡稳定性研究[J]. 水利与建筑工程学报,2021,19(2):12 − 18. [DU Jiegui, YAN Song, LI Jixing, et al. Slope stability analysis of a bridge site considering unloading zone and rock softening characteristics[J]. Journal of Water Resources and Architectural Engineering,2021,19(2):12 − 18. (in Chinese with English abstract)
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