基于渐进破坏的路堤下刚性桩复合地基的稳定性分析及控制

郑刚; 杨新煜; 周海祚; 孙佳羽

doi:10.11779/CJGE201704001

基于渐进破坏的路堤下刚性桩复合地基的稳定性分析及控制 English Version

郑刚^{1, 2, 3},
杨新煜^{1, 2, 3},
周海祚^{1, 2, 3},
孙佳羽^{1, 2, 3}

1. 滨海土木工程结构与安全教育部重点实验室(天津大学),天津 300072;
2. 天津大学建筑工程学院,天津 300072;
3. 天津大学水利工程仿真与安全国家重点实验室,天津 300072

基金项目: 国家自然科学基金重点项目（41630641）; 国家自然科学基金项目（51378345）

详细信息

作者简介:
郑刚(1967- ),男,博士,教授,博士生导师,从事土力学及岩土工程教学与科研工作。E-mail: zhenggang1967@163.com。

计量
- 文章访问数: 0421
- HTML全文浏览量: 0
- PDF下载量: 0411
出版历程
- 收稿日期: 2016-06-21
- 发布日期: 2017-05-19

Stability and control strategy of ground improved with rigid piles to support embankments based on progressive failure

ZHENG Gang^{1, 2, 3},
YANG Xin-yu^{1, 2, 3},
ZHOU Hai-zuo^{1, 2, 3},
SUN Jia-yu^{1, 2, 3}

1. Key Laboratory of Coast Civil Structure Safety (Tianjin University), Ministry of Education, Tianjin 300072, China;
2. School of Civil Engineering, Tianjin University, Tianjin 300072, China;
3. State Key Laboratory of Hydraulic Engineering Simulation and Safety, Tianjin University, Tianjin 300072, China

摘要

摘要: 传统的刚性桩复合地基支承路堤的稳定分析方法均是假定滑动区内桩体发生同时破坏。在已有研究基础上,采用有限差分方法开展了考虑桩体破坏后的不同性状（post-failure behavior）和不同桩体破坏顺序的路堤稳定性分析,结果表明无筋刚性桩复合地基首先在局部位置发生脆性弯曲破坏,应力释放后引发相邻桩体的弯矩大幅度增加并发生弯曲破坏,从而产生由局部桩体的弯曲破坏引发不同位置桩体的渐进破坏,并最终导致复合地基发生失稳破坏。假定桩体同时发生破坏的复合地基支承路堤的稳定分析方法将显著高估路堤稳定性,路堤下复合地基的稳定性分析应考虑局部位置首先破坏并引发其它位置桩体的渐进破坏。基于复合地基中桩体渐进破坏控制的理念,提出了路堤下复合地基关键桩的概念和分区不等强设计的稳定性控制方法,通过提高关键桩桩体抗弯强度及延性的方法,可有效提高路堤整体稳定性。
- 刚性桩复合地基 /
- 破坏后性状 /
- 关键桩 /
- 稳定性 /
- 非等强设计
Abstract: The conventional stability design method for the composite ground improved with rigid piles (CGIRP) to support embankment assumes a simultaneous shear failure of the piles with the failure slip. Based on the previous studies, a finite difference method is adopted to analyze the stability of CGIRP by considering different simulation methods for post-failure behaviors and failure orders of piles. The analysis reveals that unreinforced rigid piles in the composite foundation firstly have brittle bending failure in local regions. The stress relief due to failure of pile leads to a significant increase of bending moment in the neighboring piles, causing the progressive bending failure of the neighboring piles. The progressive failure of piles finally triggers the catastrophic collapse of the CGIRP-supported embankment. The stability of CGIRP-supported embankments will be overestimated remarkably when assuming a simultaneous failure of the piles with the failure slip. The progressive failure caused by local failure of piles should be considered in practical design. Base on the progressive failure control method, the concept of key piles and the non-uniform strength design method are proposed. The stability of CGIRP can be improved efficiently and remarkably by increasing the strength and ductility of the key piles.
- composite ground with rigid pile /
- post-failure behavior /
- key pile /
- stability /
- non-uniform strength design

HTML全文

参考文献(24)

[1]	龚晓南. 广义复合地基理论及工程应用[J]. 岩土工程学报, 2007, 29(1): 1-13. (GONG Xiao-nan. Generalized composite foundation theory and engineering application[J]. Chinese Journal of Geotechnical Engineering, 2007, 29(1): 1-13. (in Chinese))
[2]	郑刚, 龚晓南, 谢永利, 等. 地基处理技术发展综述[J].土木工程学报, 2012, 45(2): 127-146. (ZHENG Gang, GONG Xiao-nan, XIE Yong-li, et al. State-of-the- arttechniques for ground improvement in China[J]. China Civil Engineering Journal, 2012, 45(2): 127-146. (in Chinese))
[3]	郑刚, 刘力, 韩杰. 刚性桩加固软弱地基上路堤的稳定性问题（I）——存在问题及单桩条件下的分析[J]. 岩土工程学报, 2010, 32(11):1648-1657. (ZHENG Gang, LIU Jie, HAN Jie. Stability of embankment on soft subgrade reinforced by rigid piles (Ⅰ)—background and single pile analysis[J]. Chinese Journal of Geotechnical Engineering, 2010, 32(11): 1648-1657. (in Chinese))
[4]	郑刚, 刘力, 韩杰. 刚性桩加固软弱地基上路堤的稳定性问题（II）——群桩条件下的分析[J]. 岩土工程学报, 2010, 32(12):1811-1820. (ZHENG Gang, LIU Jie, HAN Jie. Stability of embankment on soft subgrade reinforced by rigid inclusions (Ⅱ)—group piles analysis[J]. Chinese Journal of Geotechnical Engineering, 2010, 32(12): 1811-1820. (in Chinese))
[5]	莫景逸, 黄向平. 某矿料堆场地基失稳原因分析[J]. 水运工程, 2013, 10: 212-217. (MO Jing-yi, HUANG Xiang-ping. Analysis of foundation failure of mineral ore yard[J]. Port and Waterway Engineering , 2013, 10: 212-217. (in Chinese))
[6]	JGJ 79—2012 建筑地基处理技术规范[S]. 北京: 中国建筑工业出版社, 2012. (JGJ 79—2012 Technical code for ground treatment of buildings[S]. Beijing: China Architecture & Building Press, 2012. (in Chinese))
[7]	李帅. 刚性桩复合地基支承路堤的失稳破坏机理及其稳定分析方法研究[D]. 天津: 天津大学, 2012. (LI Shuai. Research on failure mechanisms and stability analysis method of embankment supported on composite ground reinforced with rigid piles[D]. Tianjin: Tianjin University, 2012.(in Chinese))
[8]	KITAZUME M, MARUYAMA K. Internal stability of group column type deep mixing improved ground under embankment loading[J]. Soils and Foundations, 2007, 47(3): 437-455.
[9]	TERASHI M, TANAKA H, KITAZUME M. Extrusion failure of the ground improved by the deep mixing method[C]// Proceedings of the 7th Asian Regional Conference on Soil Mechanics and Foundation Engineering. Haifa, 1983: 313-318.
[10]	郑刚, 李帅, 刁钰. 刚性桩复合地基支承路堤破坏机理的离心模型试验[J]. 岩土工程学报, 2012, 34(11): 1977-1989. (ZHENG Gang, LI Shuai, DIAO Yu. Centrifugal model tests on failure mechanisms of embankments on soft ground reinforced by rigid piles[J]. Chinese Journal of Geotechnical Engineering, 2012, 34(11): 1977-1989. (in Chinese))
[11]	黄俊杰. 路堤下素混凝土桩复合地基变形失稳机理及注浆加固试验研究[D]. 成都: 西南交通大学, 2014. (HUANG Jun-jie. Study on failure mechanism and grouting reinforcement of composite foundation with plain concrete piles under embankment[D]. Chengdu: Southwest Jiaotong University, 2014. (in Chinese))
[12]	HAN J, CHAI J C, LESHCHINSKY D, et al. Evaluation of deep-seated slope stability of embankments over deep mixed foundations[C]// GeoSupport 2004: Drilled shafts, methods, and specialty foundation systems. Orlando, Florida, 2004.
[13]	ZHANG Z, HAN J, Ye G B. Numerical analysis of failure modes of deep mixed column-supported embankments on soft soils[J]. Ground Improvement and Geosynthetics, 2014, 168: 78-87.
[14]	CHAI J C, SHRESTHA S, HINO T. 2D and 3D analyses of an embankment on clay improved by soil-cement columns[J]. Computers and Geotechnics, 2015, 68: 28-37.
[15]	NAVIN M P, FILZ G M. Numerical stability analyses of embankments supported on deep mixed columns[J]. ASCE GSP 152, Ground Modification and Seismic Mitigation, 2006: 1-8.
[16]	赵尚毅, 郑颖人, 时卫民, 等. 用有限元强度折减法求边坡稳定安全系数[J]. 岩土工程学报, 2002, 24(3): 343-346. (ZHAO Shang-yi, ZHENG Ying-ren, SHI Wei-min, et al. Analysis on safety factor of slope by strength reduction FEM[J]. Chinese Journal of Geotechnical Engineering, 2002, 24(3): 343-346. (in Chinese))
[17]	LADD C C. Stress-strain modulus of clay in undrained shear[J]. Journal of the Soil Mechanics and Foundations Division, 1964, 90(5): 103-132.
[18]	CHENCY. Numerical analysis of slope stabilization concepts using piles[D]. Los Angeles: University of Southern California, 2001.
[19]	GB 50010—2010 混凝土结构设计规范[S]. 北京: 中国建筑工业出版社, 2010. (GB 50010—2010 Code for design of concrete structures[S]. Beijing: China Architecture & Building Press, 2010. (in Chinese))
[20]	ZHANG Z, HAN J, YE G B. Numerical investigation on factors for deep-seated slope stability of stone column- supported embankments over soft clay[J]. Engineering Geology, 2014, 168: 104-113.
[21]	LARSSON S, MALM R, CHARBIT B, ANSELL A. Finite element modelling of laterally loaded lime-cement columns using a damage plasticity model[J]. Computers and Geotechnics, 2012, 44: 48-57.
[22]	TASSIOS T P, VINTZĒLEOU E N. Concrete-to-concrete friction[J]. Journal of Structural Engineering , 1987, 113(4): 832-849.
[23]	MOHAPATRA SR, RAJAGOPAL K, SHARMA J. Direct shear tests on geosynthetic-encased granular columns[J]. Geotextiles and Geomembranes, 2016, 44: 396-405.
[24]	易耀林, 刘松玉. 路堤荷载下复合地基沉降计算方法探讨[J]. 工程力学, 2009, 26(10): 147-153. (YI Yao-lin, LIU Song-yu. Settlement calculation method of composite foundation under embankment load[J]. Engineering Mechanics, 2009, 26(10): 147-153. (in Chinese))