Physical model test on landslide thrust distribution on double-row stabilizing piles
-
摘要:
双排抗滑桩后侧滑坡推力分布是其设计中要考虑的关键要素之一。针对一大型基岩-覆盖层式滑坡，进行四组不同后排桩布设方式的双排桩加固滑坡的室内物理模型试验，通过采用坡体外注水，经过特定通道渗入滑带的方法来模拟强降雨条件对滑带的软化效应，测得不同工况下两排桩后侧滑坡推力分布特征，并通过FLAC3D数值模拟方法对试验结果进一步验证。试验结果表明，后、前排桩上坡体压力均呈两端小、中间大的抛物线型分布模式且峰值点相对靠近滑面位置；桩位不变时，后桩后侧坡体压力峰值随沉埋深度增大而减小且峰值点位置上移，前桩后侧坡体压力峰值随后桩沉埋深度增大而增大，但峰值点位置无明显变化；滑带软化效应并不改变双排桩上推力分布模式，但会增大前、后排桩后侧坡体压力，且相比桩顶和底部，桩身中间部分坡体压力增加幅度较大；注水软化前后，后、前排桩上坡体压力分别增大约14.3%～21.4%与17.9%～24.8%。
Abstract:Distribution pattern of thrust force on double-row stabilizing piles is one of the essential factors for the design of stabilizing piles. For a bedrock-overburden landslide strengthened with double-row stabilizing piles, four sets of laboratory physical model test are conducted considering various rear-row pile configurations. In particular, slip surface softening effect due to heavy rainfall is physically simulated using external water injection and infiltration into the shear band through a special channel. Distribution characteristics of the landslide thrust on the two piles are measured, which is further verified by a numerical simulation method FLAC3D. The test results show that the thrusts on the rear and fore piles present a parabolic distribution pattern, and the location with peak value is relatively close to the slip surface. If the pile location remains unchanged, the peak value of the thrust force behind the rear pile decreases with the increase of its embedded depth and the position with peak value moves upward; while the peak value of the thrust behind the fore pile increases with the embedded depth of the rear pile top, and the position with peak value changes unobviously. The slip surface softening effect does not change the distribution pattern of the thrust forces on piles, but it can increase the thrusts behind the piles; compared with the top and bottom of the piles, the increase of the thrust in the middle part of the piles is relatively larger. The thrust forces on the rear and fore piles under external water injection are about 14.3%~21.4% and 17.9%~24.8% higher than those before the softening action, respectively.
-
-
表 1 实例坡体主要物理力学参数
Table 1. Main physical and mechanical parameters of the practical landslide
地层 重度
/（kN·m−3）黏聚力
/kPa内摩擦角
/（°）弹性模量
/MPa泊松比 块石土 21 15 24 40 0.30 含砾黏土 19 5 20 30 0.33 中风化砂岩 22 800 28 1000 0.22 
下载: 导出CSV
表 2 各组试验滑带、滑体及滑床的物理力学参数
Table 2. Main physical and mechanical parameters of testing models
组号 φ/(°) c/kPa γ/(kN·m-3) ω/% 滑
带一 20.6(19.7) 0(0) 19.3 6.21 二 20.3(19.6) 0(0) 20.1 7.21 三 20.8(20.0) 0(0) 19.4 7.68 四 20.6(19.9) 0(0) 19.3 6.21 滑
体一 24.5 1.6 20.5 6.09 二 24.5 1.6 20.5 6.09 三 23 1 21.2 8.16 四 24 1 20.8 7.80 滑
床一 27.7 19.5 21.6 5.12 二 28.2 20.3 21.8 5.23 三 28 18.6 21.5 5.02 四 27.8 19.7 21.8 5.17
下载: 导出CSV
表 3 各组试验注水前、后所得后排桩上推力比较
Table 3. Comparison of thrust on the rear piles before and after grouting water in four tests
/(kN·m−1) 试验组别 后排桩 前排桩 注水前 注水后 注水前 注水后 试验一 2.76 3.17 0.78 0.92 试验二 2.23 2.55 0.84 0.99 试验三 2.04 2.37 1.25 1.56 试验四 1.12 1.36 1.08 1.34
下载: 导出CSV
表 4 试验一双排桩后侧推力试验值与数值解对比
Table 4. Comparison of thrust on the fore and rear piles in test model 1 between the measured and numerical values
/(kN·m−1) 方法 后排桩 前排桩 注水前 注水后 注水前 注水后 试验值 2.76 3.17 0.78 0.92 数值解 3.44 3.82 1.17 1.28
下载: 导出CSV
-
[1] 徐邦栋. 滑坡分析与防治[M]. 北京: 中国铁道出版社, 2001
XU Bangdong. Landslide analysis and prevention [M]. Beijing: China Railway Publishing House, 2001. (in Chinese)
[2] 闫玉平, 肖世国. 考虑滑带强度参数分区取值的堆积层滑坡稳定性分析方法[J]. 中国地质灾害与防治学报,2020,31(2):44 − 49. [YAN Yuping, XIAO Shiguo. Stability analysis method for bedrock-talus landslides considering strength parameter partition of slip shear band[J]. The Chinese Journal of Geological Hazard and Control,2020,31(2):44 − 49. (in Chinese with English abstract)
[3] 邹宗兴, 唐辉明, 熊承仁, 等. 大型顺层岩质滑坡渐进破坏地质力学模型与稳定性分析[J]. 岩石力学与工程学报,2012,31(11):2222 − 2231. [ZOU Zongxing, TANG Huiming, XIONG Chengren, et al. Geomechanical model of progressive failure for large consequent bedding rockslide and its stability analysis[J]. Chinese Journal of Rock Mechanics and Engineering,2012,31(11):2222 − 2231. (in Chinese with English abstract) doi: 10.3969/j.issn.1000-6915.2012.11.010
[4] WANG J J, LIANG Y, ZHANG H P, et al. A loess landslide induced by excavation and rainfall[J]. Landslides,2014,11:141 − 152. doi: 10.1007/s10346-013-0418-0
[5] XIAO S G, ZENG J X, YAN Y P. A rational layout of double-row stabilizing piles for large-scale landslide control[J]. Bulletin of Engineering Geology and the Environment,2017,76(1):309 − 321. doi: 10.1007/s10064-016-0852-z
[6] XIAO S G. A simplified approach for stability analysis of slopes reinforced with one row of embedded stabilizing piles[J]. Bulletin of Engineering Geology and the Environment,2017,76(4):1371 − 1382.
[7] 申永江, 杨明, 项正良, 等. 双排桩桩排间土拱效应的发育规律研究[J]. 水文地质工程地质,2015,42(1):70 − 74. [SHEN Yongjiang, YANG Ming, XIANG Zhengliang, et al. Development of soil arching between the double-row anti-sliding piles[J]. Hydrogeology & Engineering Geology,2015,42(1):70 − 74. (in Chinese with English abstract)
[8] ITO T, MATSUI T, HONG W P. Extended design method for multi-row stabilizing piles against landslide[J]. Soils and Foundations,1982,22(1):1 − 13. doi: 10.3208/sandf1972.22.1
[9] 戴自航. 抗滑桩滑坡推力和桩前滑体抗力分布规律的研究[J]. 岩石力学与工程学报,2002,21(4):517 − 521. [DAI Zihang. Study on distribution laws of landslide-thrust and resistance of sliding mass acting on antislide piles[J]. Chinese Journal of Rock Mechanics and Engineering,2002,21(4):517 − 521. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2002.04.013
[10] 肖世国. 似土质边(滑)坡抗滑桩后滑坡推力分布模式的近似理论解析[J]. 岩土工程学报,2010,32(1):120 − 123. [XIAO Shiguo. Approximate theoretical solution of distribution modes of landslide thrust on anti-sliding piles in soil-like slopes or landslides[J]. Chinese Journal of Geotechnical Engineering,2010,32(1):120 − 123. (in Chinese with English abstract)
[11] ITO T, MATSUI T. Methods to estimate lateral force acting on stabilizing piles[J]. Soils and Foundations,1975,15(4):43 − 59. doi: 10.3208/sandf1972.15.4_43
[12] RANDOLPH M F. The response of flexible piles to lateral loading[J]. Géotechnique,1981,31(2):247 − 259.
[13] 国家铁路局. 铁路路基支挡结构设计规范: TB 10025—2019[S]. 北京: 中国铁道出版社, 2019
Code for design of retaining structures of railway earthworks: TB 10025—2019[S]. Beijing: China Railway Publishing House, 2019. (in Chinese)
[14] 熊治文. 深埋式抗滑桩的受力分布规律[J]. 中国铁道科学,2000,21(1):48 − 56. [XIONG Zhiwen. Force distribution rule of deeply buried anti slide pile[J]. China Railway Science,2000,21(1):48 − 56. (in Chinese with English abstract) doi: 10.3321/j.issn:1001-4632.2000.01.007
[15] 雷文杰. 沉埋桩加固滑坡体的有限元设计方法与大型物理模型试验研究[D]. 武汉: 中国科学院武汉岩土力学研究所, 2006
LEI Wenjie. Study on design method of deeply buried piles stabilizing slides and large scaled model tests[D]. Wuhan: Wuhan Institute of Geotechnical Mechanics, Chinese Academy of Sciences, 2006. (in Chinese with English abstract)
[16] 郑颖人, 赵尚毅. 用有限元强度折减法求边(滑)坡支挡结构的内力[J]. 岩石力学与工程学报,2004,23(20):3552 − 3558. [ZHENG Yingren, ZHAO Shangyi. Calculation of inner force of support structure for landslide/slope by using strength reduction fem[J]. Chinese Journal of Rock Mechanics and Engineering,2004,23(20):3552 − 3558. (in Chinese with English abstract) doi: 10.3321/j.issn:1000-6915.2004.20.029
[17] 宋雅坤, 郑颖人, 雷文杰. 沉埋式抗滑桩机制模型试验数值分析研究[J]. 岩土力学, 2007, 28(增刊1): 63 − 68
SONG Yakun, ZHENG Yingren, LEI Wenjie. Analysis of the experimental mechanism of deeply buried anti-slide pile by FEM[J]. Rock and Soil Mechanics, 2007, 28(Sup 1): 63 − 68. (in Chinese with English abstract)
[18] 申永江, 黄立, 严克伍. 悬臂双排桩桩排距的计算方法研究[J]. 水文地质工程地质,2012,39(5):59 − 63. [SHEN Yongjiang, HUANG Li, YAN Kewu. Calculation method of the piles row distance of cantilever double-row anti-slide piles[J]. Hydrogeology & Engineering Geology,2012,39(5):59 − 63. (in Chinese with English abstract)
[19] 张玲, 朱幸仁, 欧强. 考虑桩桩相互作用的双排支护桩受力变形分析[J]. 水文地质工程地质,2019,46(5):72 − 80. [ZHANG Ling, ZHU Xingren, OU Qiang. Analysis of forced deformation of double row support piles considering pile interaction[J]. Hydrogeology & Engineering Geology,2019,46(5):72 − 80. (in Chinese with English abstract)
[20] 肖世国, 何洪. 双排抗滑桩上滑坡推力近似解析方法[J]. 岩土力学,2015,36(2):376 − 380. [XIAO Shiguo, HE Hong. An approximate analytical method for calculating thrust on double-row stabilizing piles[J]. Rock and Soil Mechanics,2015,36(2):376 − 380. (in Chinese with English abstract)
[21] 胡峰. 基覆式滑坡中双排全长式与沉埋式抗滑桩受力规律研究[D]. 成都: 西南交通大学, 2010
HU Feng. Research on the mechanical features of double-row anti-slide piles with tops exposed or embedded in bedrock-overburden landslide control[D]. Chengdu: Southwest Jiaotong University, 2010. (in Chinese with English abstract)
[22] 徐骏, 李安洪, 肖世国. 折线型滑面滑坡桩排推力分布规律研究[J]. 岩土力学,2012,33(11):3479 − 3482. [XU Jun, LI Anhong, XIAO Shiguo. Study of landslide thrust distribution law of row of piles in reinforced landslide with polygonal line slip surface[J]. Rock and Soil Mechanics,2012,33(11):3479 − 3482. (in Chinese with English abstract)
-
图(13)
表(4)
计量
- 文章访问数: 746
- PDF下载数: 23
- 施引文献: 0