|
|
|
| Effect of the strengthening area and the slope rate on bearing and deforming behaviors of CFG pile-geogrid composite foundations |
| ZHANG Shuming1，2，JIANG Guanlu1，2，LIAO Yilai1，2，DU Dengfeng1，2，HUANG Haowei1，2，LIU Yong3 |
(1. School of Civil Engineering，Southwest Jiaotong University，Chengdu，Sichuan 610031，China；2. Key Laboratory of High-speed Railway Engineering，Ministry of Education，Southwest Jiaotong University，Chengdu，Sichuan 610031，China；3. China Railway Eryuan Engineering Group Co.，Ltd.，Chengdu，Sichuan 610031，China)
|
|
|
|
|
Abstract In order to study the effect of the strengthening area and the slope rate on bearing and deforming behaviors of CFG pile composite foundations，centrifuge test with a similarity ratio of 1∶80 and numerical simulation were conducted. The results show that the vertical displacement has a significant increase during embankment fill period and a slow growth during the placement and operation periods. With decreasing the strengthening area，the increasing trend of the vertical displacement with a slope ratio of 1∶1.5 is greater than that of 1∶1.75，which indicates that a steeper slope results in more sensitivity of the strengthening area. The horizontal displacements at the toe of the slope and 5 meters away from the toe of the slope are greater than those at other places. When the strengthening area decrease，a anti-bend point of the horizontal displacement at the toe of the slope occurs at the soil interface，and the anti-bend rate increases with decreasing the strengthening area. Under the same load，the stress on the pile top in a half strengthening composite foundation is greater than that in a whole strengthening composite foundation，but the earth stress between piles shows a opposite pattern. The pile-soil stress ratio shows a increase trend with the decrease of the strengthening area with a same slope rate.
|
|
|
|
|
|
[1] 刘汉龙，赵明华. 地基处理研究进展[J]. 土木工程学报，2016，49(1)：96–115.(LIU Hanlong，ZHAO Minghua. Review of ground improvement technical and its application in China[J]. China Civil Engineering Journal，2016，49(1)：96–115.(in Chinese))
[2] 肖 宏，蒋关鲁，魏永幸. 遂渝线无碴轨道桩网结构地基处理技术[J]. 铁道工程学报，2006，94(4)：22–25.(XIAO Hong，JIANG Guanlu，WEI Yongxing. Discussion of Sui-Yu railway line ballastless track column-net structure[J]. Journal of Railway Engineering Society，2006，94(4)：22–25.(in Chinese))
[3] 詹永祥，蒋关鲁，魏永幸. 无碴轨道桩板结构路基在地震荷载下的动力响应分析[J]. 中国铁道科学，2006，27(6)：22–26.(ZHAN Yongxiang，JIANG Guanlu，WEI Yongxing. Dynamic response analysis on the pile-plank structure roadbed of ballastless track under earthquake load[J]. China Railway Science，2006，27(6)：22–26.(in Chinese))
[4] 丁小军，王 旭，张延杰，等. 大型油罐CFG桩复合地基变形与承载性能试验研究[J]. 岩石力学与工程学报，2013，32(9)：1 851– 1 857.(DING Xiaojun，WANAG Xu，ZHANG Yanjie，et al. Experimental study of bearing and deformation features of CFG-pile composite ground for large oil storage tanks[J]. Chinese Journal of Rock Mechanics and Engineering，2013，32(9)：1 851–1 857.(in Chinese))
[5] 蒋泽中，肖 宏，蒋关鲁，等. 桩网结构加固土质路基的离心机模型试验研究[J]. 铁道工程学报，2013，(11)：18–22.(JIANG Zezhong，XIAO Hong，JIANG Guanlu，et al. Centrifugal model test study on soil subgrade reinforced by column-net structure[J]. Journal of Railway Engineering Society，2013，(11)：18–22.(in Chinese))
[6] 肖 东，蒋关鲁，林展展，等. 过渡段地基加固作用对桥台桩工作性状的影响分析[J]. 中南大学学报：自然科学版，2017，48(3)： 820–829.(XIAO Dong，JIANG Guanlu，LIN Zhanzhan，et al. Analysis on working properties of abutment piles considering foundation reinforcement of approach embankment[j]. Journal of Central South University：Science and Technology，2017，48(3)： 820–829.(in Chinese))
[7] 刘飞成，张建经. 斜坡基底软土桩–网复合地基变形特性离心试验研究[J]. 岩石力学与工程学报，2018，37(1)：209–219.(LIU Feicheng，ZHANG Jianjing. Centrifuge test deformation characteristics of pile-geogrid composite foundation in soft soil under slope[J]. Chinese Journal of Rock Mechanics and Engineering，2018，37(1)：209–219. (in Chinese))
[8] 李连祥，符庆宏. 临近基坑开挖复合地基侧向力学性状离心试验研究[J]. 土木工程学报，2017，50(6)：85–94.(LI Lianxiang，FU Qinghong. Lateral mechanical behavior of composite ground due to adjacent excavation：centrifuge model test[J]. China Civil Engineering Journal，2017，50(6)：85–94.(in Chinese))
[9] 黄生根. 柔性荷载下带帽CFG桩复合地基承载性状的试验研究[J]. 岩土工程学报，2013，35(增2)：564–568.(HUANG Shenggen. Experimental Study on bearing behaviors of composite foundation with CFG piles with caps under flexible loads[J]. Chinese Journal of Geotechnical Engineering，2013，35(Supp.2)：564–568.(in Chinese))
[10] 左 珅，王 敏，徐林荣，等. 高速铁路中低压缩性土桩–筏(网)地基加固效果研究[J]. 中南大学学报：自然科学版，2014，45(5)：1 590–1 597.(ZUO Shen，WANG Min，XU Linrong，et al. Research on reinforce effect of high-speed railway low and medium compressible soil pile-raft(net) foundation[J]. Journal of Central South University：Science and Technology，2014，45(5)：1 590–1 597.(in Chinese))
[11] 李 懿，王连俊，栾光日，等. 高速铁路站场咽喉区复合地基的工程特性研究[J]. 铁道学报，2014，36(12)：90–96.(LI Yi，WANG Lianjun，LUAN Guangri，et al. Research on consolidation characteristics of composite foundation in the throat area of high- speed railway station[J]. Journal of the China Railway Society，2014，36(12)：90–96.(in Chinese))
[12] 沈宇鹏，毛远凤，荆 鹏，等. PHC与CFG桩复合地基在高速铁路基底中处理效果试验对比[J]. 岩石力学与工程学报，2014，33 (增2)：4 174–4 180.(SHEN Yupeng，MAO Yuanfeng，JING Peng，et al. Experimental effect contrast between PHC and CFG pile-raft composite foundation in high speed railway base treatment[J]. Chinese Journal of Rock Mechanics and Engineering，2014，33(Supp.2)： 4 174–4 180.(in Chinese))
[13] 张 爽，唐春安，张向东. 季节性冻土地区高铁路基沉降研究[J]. 东北大学学报：自然科学版，2013，34(8)：1 202–1 205.(ZHANG Shuang，TANG Chun?an，ZHANG Xiangdong. Subgrade settlement of high-speed railway in seasonal frozen soil area[J]. Journal of Northeastern University：Natural Science，2013，34(8)：1 202–1 205. (in Chinese))
[14] 张 峰，刘 莹，许兆义，等. 武广高铁CFG桩复合地基工后沉降影响因素[J]. 西南交通大学学报，2015，50(5)：783–788. (ZHANG Feng，LIU Ying，XU Zhaoyi，et al. Factors Influencing subgrade post-construction settlement of CFG pile composite foundation in Wuhan-Guangzhou high-speed railway[J]. Journal of Southwest Jiaotong University，2015，50(5)：783–788.(in Chinese))
[15] 高广运，李绍毅. 列车运行引起的CFG桩复合路基动力响应分析[J]. 振动与冲击，2015，34(24)：135–143.(GAO Guangyun，LI Shaoyi. Dynamic response of CFG pile composite subgrade induced by moving train loadings[J]. Journal of Vibration and Shock，2015，34(24)：135–143.(in Chinese))
[16] 刘 杰，张可能. 复合地基荷载传递规律及变形计算[J]. 中国公路学报，2004，17(1)：20–23.(LIU Jie，ZHANG Keneng. Load transfer law and deformation calculating of the composite foundation[J]. China Journal of Highway and Transport，2004，17(1)：20–23.(in Chinese))
[17] 马明正，海振雄，叶阳升，等. 高速铁路CFG桩复合地基沉降计算适用方法研究[J]. 中国铁道科学，2014，35(2)：7–13.(MA Mingzheng，HAI Zhenxiong，YE Yangsheng，et al. Applicable method for settlement calculation of CFG Pile composite foundation for high speed railway[J]. China Railway Science，2014，35(2)：7–13. (in Chinese))
[18] 赵明志，罗 强，崔维孝，等. 高速铁路深厚地层CFG桩复合地基变形计算经验系数分析[J]. 铁道学报，2015，37(1)：69–76.(ZHAO Mingzhi，LUO Qiang，CUI Weixiao，et al. Analysis on deformation calculation empirical coefficient of CFG pile composite foundation of deep layer in high-speed railway[J]. Journal of the China Railway Society，2015，37(1)：69–76.(in Chinese))
[19] 罗 强，陆清元. 考虑桩土滑移的路堤下刚性桩复合地基沉降计算[J]. 中国公路学报，2018，31(1)：20–30.(LUO Qiang，LU Qingyuan. Settlement calculation of rigid pile composite foundation considering pile-soil relative slip under embankment load[J]. China Journal of Highway and Transport，2018，31(1)：20–30.(in Chinese))
[20] 王占江，白建波，卢萍珍. CFG桩布桩范围对路基水平位移影响数值分析[J]. 路基工程，2011，(1)：94–96.(WANG Zhanjiang，BAI Jianbo，LU Pingzhen. Numerical analysis on the influence of CFG Pile layout on subgrade horizontal displacement[J]. Subgrade Engineering，2011，(1)：94–96.(in Chinese))
[21] CRAIG W H. Edouard phillips and the idea of centrifuge modeling[J]. Geotechnique，1989，(39)：679–700.
[22] 冯 振，殷跃平. 我国土工离心模型试验技术发展综述[J]. 工程地质学报，2011，19(3)：323–331.(FENG Zhen，YIN Yueping. Statw of the art review of geotechnical centrifuge modeling test in china[J]. Journal of Engineering Geology，2011，19(3)：323–331.(in Chinese))
[23] 邢建营，邢义川，梁建辉. 土工离心模型试验研究的进展与思考[J].水利与建筑工程学报，2005，3(1)：27–31.(XING Jianying，XING Yichuan，LIANG Jianhui. Development and thoughts of geotechnical centrifuge modeling[J]. Journal of Water Resources and Architectural Engineering，2005，3(1)：27–31.(in Chinese)) |
|
|
|
2019, Vol. 38 
