|
|
|
| Influence of shallow soil improvement on vertical bearing capacity of inclined piles |
| HU Wen-hong1, 2, ZHENG Gang1, 2 |
| 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 |
|
|
|
|
Abstract The inclined pile under vertical load may yield large horizontal displacement, deflection and bending moment. Consequently, bending failure may happen before the ultimate bearing capacity of vertical pile provided by soils is fully mobilized. Based on the field test results, numerical simulations are carried out to analyze the influence of surface soil improvement on the behavior and capacity of inclined piles. The results indicate that the depth, area and location relative to the pile of the treated soil may affect the behavior and failure mechanism of inclined piles under vertical load. The improvement of shallow soils can provide significant lateral support to piles and thus reduce their horizontal displacement. In addition, the treated soils can reduce the rotation and deflection of piles. Both of the two effects can prevent the inclined piles from bending failure before penetration failure happens. Large elastic modulus of the treated soils can better reduce the horizontal displacement, deflection and bending moment of piles under vertical load. However, there is an optimum value, i.e., when the elastic modulus is larger than it, the reinforcement effect no longer increases.
|
|
Received: 09 July 2012
|
|
|
|
|
|
[1] JGJ 94—2008 建筑桩基技术规范[S]. 北京: 中国建筑工业出版社, 2008. JGJ 94—2008 Technical code for building pile foundations[S]. Beijing: China Architecture & Building Press, 2008.(in Chinese)
[2] 陈 剑,李 敏,杨蒙龙. 预应力混凝土管桩偏位和倾斜的分析与处理[J]. 山西建筑,2008, 3431:122-123. CHEN Jian, LI Min, YANG Meng-long.
Analysis and treatment of deviated and inclined PC pile[J]. Shanxi Architecture, 2008, 3431: 122-123. (in Chinese)
[3] 韩爱民,肖军华. 基坑开挖引起工程桩偏斜后的补强设计与施工监控[J]. 建筑技术,2006, 3712:913-915. HAN Ai-min, XIAO Jun-hua.
Reinforcement design and construction monitoring of deflected piles caused by pit excavation[J]. Architecture Technology, 2006, 3712: 913-915. (in Chinese)
[4] 蔡明兴. 倾斜预制方桩的承载力分析及处理[J]. 施工技术,2004, 339:35-37. CAI Ming-xing.
Analysis and treatment of the bearing capacity of inclined prefabricated square piles[J]. Construction Technology, 2004, 339: 35-37. (in Chinese)
[5] 赵宏华,韩选江. 某大厦裙楼桩基质量事故加固处理方案[J]. 南京建筑工程学院学报,2002, 601:74-78. ZHAO Hong-hua, HAN Xuan-jiang.
The strengthening method of a mansion's skirt-building pile foundation quality accident[J]. Journal of Nanjing Architectural and Civil Engineering Institute, 2002, 601: 74-78. (in Chinese)
[6] 任建国. 管桩施工质量事故的处理研究[J]. 中国高新技术企业,200915:163-164. REN Jian-guo.
Research on the handling of piles construction quality incident[J]. Chinese Hi-tech Enterprises, 200915: 163-164. (in Chinese)
[7] 朱进军,韩选江,朱连勇. 软土场地预应力管桩倾斜事故分析与处理[J]. 建筑技术,2007, 389:658-660. ZHU Jin-jun, HAN Xuan-jiang, ZHU Lian-yong.
Analysis and treatment of tilted PHC pile accident in soft ground[J]. Architecture Technology, 2007, 389: 658-660. (in Chinese)
[8] 郑 刚,王 丽. 竖向荷载作用下倾斜桩的荷载传递性状及承载力研究[J]. 岩土工程学报,2008, 303:323-330. ZHENG Gang, WANG Li. Load transfer and bearing capacity of inclined pile under vertical load[J]. Chinese Journal of Geotechnical Engineering, 2008, 303
[9] JGJ 79—2002 建筑地基处理技术规范[S]. 北京: 中国建筑工业出版社, 2002. JGJ 79—2002 Technical code for ground treatment of buildings[S]. Beijing: China Architecture & Building Press, 2002.(in Chinese)
[10] 郑 刚,焦 莹. 深基坑工程设计理论及工程应用[M]. 北京: 中国建筑工业出版社, 2010.ZHENG Gang, JIAO Ying. Design theory and practical applications in the deep excavation[M]. Beijing
[11] 蒋建平,李晓昭,罗国煜. 南京地铁地基土标贯与物理及力学参数关系试验研究[J]. 铁道学报,2010, 321:123-127. JIANG Jian-ping, LI Xiao-zhao, LUO Guo-yu.
Experimental study on correlativity between SPT and physical and mechanical parameters of foundation soil of Nanjing subway[J]. Journal of the China Railway Society, 2010, 321: 123-127. (in Chinese)
[12] HANNA A, NGUYEN T Q. Shaft resistance of single vertical and batter piles driven in sand[J]. Journal of Geotechnical and Geoenvironmental Engineering,2003, 1297:601-607.
[13] 王新泉,陈永辉,安永福,等. 塑料套管现浇混凝土桩倾斜对承载性能影响的模型试验研究[J]. 岩石力学与工程学报,2011, 304:834-842. WANG Xin-quan, CHEN Yong-hui, AN Yong-fu, et al. Model test study of effect of inclination on bearing behaviors of plastic tube cast-in- place concrete pile[J]. Chinese Journal of Rock Mechanics and Engineering, 2011, 304
[14] L Fan-ren, Y Ji-ming, J Yao-hua. Study on load- displacement of batter pile under vertical load by model experiments[C]//Proceedings of International Conference on Electric Technology and Civil Engineering, Lusan, 2011: 3506-3509.Study on load- displacement of batter pile under vertical load by model experiments[C]//Proceedings of International Conference on Electric Technology and Civil Engineering, Lusan, 2011: 3506-3509.
[15] 郑 刚,李 帅,杜一鸣,等. 竖向荷载作用下倾斜桩的承载力特性[J]. 天津大学学报自然科学版,2012, 457:567-576. ZHENG Gang, LI Shuai, DU Yi-ming, et al. Bearing capacity behaviors of inclined pile under vertical load[J]. Journal of Tianjin University, 2012, 457
[16] 郑 刚,李志伟,刘 畅. 型钢水泥土组合梁抗弯性能试验研究[J]. 岩土工程学报,2011, 333:332-340. ZHENG Gang, LI Zhi-wei, LIU Chang. Experimental study on flexural behavior of shaped steel reinforcedcement-soil composite beams[J]. Chinese Journal of Geotechnical Engineering, 2011, 333
[17] LEUNG C F, CHOW Y K, SHEN R F. Behavior of pile subject to excavation-induced soil movement[J]. Journal of Geotechnical and Geoenvironmental Engineering,2000, 12611:947-954.
[18] GB 50021—2001 岩土工程勘察规范[S]. 北京: 中国建筑工业出版社, 2009. GB 50021—2001 Code for investigation of geotechnical engineering[S]. Beijing: China Architecture & Building Press, 2009.(in Chinese)
[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] 郭婷婷,张伯平,吴 江. 二灰土工程特性的试验研究[J]. 西北水资源与水工程,2003, 142:21-23. GUO Ting-ting, ZHANG Bo-ping, WU Jiang. Experimental study on engineering characteristic of lime-flyash soil[J]. Northwest Water Resources & Water Engineering, 2003, 142
|
|
|
|
