上覆土嵌岩桩抗拔受力性状离心模型试验研究
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摘要
上覆土嵌岩桩采用的形式主要为等截面桩和扩底桩,而目前扩底桩相对等截面桩承载力提高机制尚无理论研究,实际工程中现场试验往往限制因素太多,此方面在规范设计中也比较缺乏,对嵌岩桩的相关研究和现行规范不能完全应用于电力行业中。基于此,采用离心模型试验对等截面桩和扩底桩的抗拔承载特性进行研究,分析比较等截面桩和扩底桩在完整岩体中岩体破坏模式的差异,以及在竖向上拔荷载作用过程中的Q-s曲线、桩身轴力分布和桩侧摩阻力曲线。试验成果对我国西部输电线路工程中桩基优化设计具有工程意义和经济价值,能为类似工程提供参考依据。
Overburden rock-socketed pile with enlarged bottom and equal section were mainly used for the foundation of transmission tower in mountainous area of western China. Nevertheless, there is no theoretical research on mechanism of the enhanced bearing capacity of the pile with enlarged bottom. Compared to the pile with equal section, there are too many constraints for the pile with enlarged bottom in field test of practical engineering and few specifications in this aspect. Therefore, the research and current specification of rock-socketed piles can not be entirely applied to the power industry. Based on this, a centrifugal model test is proposed to study the bearing capacity of pile with enlarged bottom and equal section, analyze and compare the failure mode, Q-s curves, distribution of axial force and lateral friction curves of pile with enlarged bottom and equal section in intact rock mass under uplift load. Accurate knowledge of uplift bearing capacity behavior of pile with enlarged bottom and equal section is of great significance to engineering and economy in optimal design of pile foundation in transmission line engineering in western China and it's also a good reference for similar engineering.
Overburden rock-socketed pile with enlarged bottom and equal section were mainly used for the foundation of transmission tower in mountainous area of western China. Nevertheless, there is no theoretical research on mechanism of the enhanced bearing capacity of the pile with enlarged bottom. Compared to the pile with equal section, there are too many constraints for the pile with enlarged bottom in field test of practical engineering and few specifications in this aspect. Therefore, the research and current specification of rock-socketed piles can not be entirely applied to the power industry. Based on this, a centrifugal model test is proposed to study the bearing capacity of pile with enlarged bottom and equal section, analyze and compare the failure mode, Q-s curves, distribution of axial force and lateral friction curves of pile with enlarged bottom and equal section in intact rock mass under uplift load. Accurate knowledge of uplift bearing capacity behavior of pile with enlarged bottom and equal section is of great significance to engineering and economy in optimal design of pile foundation in transmission line engineering in western China and it's also a good reference for similar engineering.
引文
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[2]Deshmukh V B,Dewaiker D M,Choudhury D.Computations of uplift capacity of pile anchors in cohesionless soil[J].Acta Geotechnica,2010,5(2):87-94.
[3]Chattopadhyay B C,Pise P J.Uplift capacity of piles in sand[J].Journal of Geotechnical Engineering,ASCE,1986,112(9):888-904.
[4]Kulhawy F H,Kozera D W,Withiam J L.Uplift testing of model drilled shafts in sand[J].Journal of the Geotechical Engineering Division,ASCE,1979,105(1):31-47.
[5]Majer J.Zur berechnung von zugfundamenten[J].Ostereichische Bauzeitschrift,1955,10(5):85-90.
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[9]郭楠,陈正汉,黄雪峰,等.软岩地基中大直径布袋桩抗拔试验研究[J].岩土力学,2015,36(增2):603-609.GUO Nan,CHEN Zhenghan,HUANG Xuefeng,et al.Experimental study of large-diameter bag uplift pile in soft rock foundation[J].Rock and Soil Mechanics,2015,36(Suppl 2):603-609.
[10]张继红,朱合华.抗拔桩极限平衡方程及其应用[J].岩土力学,2015,36(8):2339-2344.ZHANG Jihong,ZHU Hehua.Limit equilibrium equation for uplift piles and its application[J].Rock and Soil Mechanics,2015,36(8):2339-2344.
[11]罗少锋.抗拔桩的承载力与变形研究[D].西安:西安建筑科技大学,2014.LUO Shaofeng.Study on deformation and capacity of uplift piles[D].Xi’an:Xi’an University of Architecture and Technology,2014.
[12]赵彤,杨海松,王向军.扩底抗拔桩在天津于家堡南北地下车库中的应用[J].岩土力学,2014,35(增2):359-363.ZHAO Tong,YANG Haisong,WANG Xiangjun.Application of pedestal uplift piles to Yujiapu north-south underground garage in Tianjin[J].Rock and Soil Mechanics,2014,35(Suppl 2):359-363.
[13]鲁先龙,乾增珍,崔强.黄土地基掏挖扩底基础抗拔试验研究[J].岩土力学,2014,35(3):647-652.LU Xianlong,QIAN Zengzhen,CUI Qiang.Experimental investigation on uplift behavior of belled piers in loess[J].Rock and Soil Mechanics,2014,35(3):647-652.
[14]胡琦,凌道盛,孔令刚,等.超深开挖对抗拔桩承载力影响的离心机试验研究[J].岩土工程学报,2013,35(6):1076-1083.HU Qi,LING Daosheng,KONG Linggang,et al.Effects of deep excavation on uplift capacity of piles by centrifuge tests[J].Chinese Journal of Geotechnical Engineering,2013,35(6):1076-1083.
[15]钱建固,马霄,李伟伟,等.桩侧注浆抗拔桩离心模型试验与原位测试分析[J].岩土力学,2014,35(5):1241-1247.QIAN Jiangu,MA Xiao,LI Weiwei,et al.Centrifuge model test and in-site observation on behaviors of side-grouting uplift pile[J].Rock and Soil Mechanics,2014,35(5):1241-1247.
[16]杨军,张大峰,李连友,等.高液限膨胀性黏土基桩工作性状的离心机试验研究[J].岩土工程学报,2017,39(10):1770-1776.YANG Jun,ZHANG Dafeng,LI Lianyou,et al.Centrifuge modelling of working performance of foundation pile embedded in high liquid limit expansive clay[J].Chinese Journal of Geotechnical Engineering,2017,39(10):1770-1776.
[17]袁文忠,于志强,谢涛.岩基强度对嵌岩抗拔桩承载力影响的试验研究[J].西南交通大学学报,2003,38(2):178-182.YUAN Wenzhong,YU Zhiqiang,XIE Tao.Vertical bearing capacity of rock-socketed piles influenced by batholith strength[J].Journal of Southwest Jiaotong University,2003,38(2):178-182.
[18]JGJ 94-2008,建筑桩基技术规范[S].JGJ 94-2008,Technical code for building pile foundations[S].
[19]鲁先龙,乾增珍,童瑞铭,等.戈壁地基扩底掏挖基础抗拔试验及其位移计算[J].岩土力学,2014,35(7):1871-1877.LU Xianlong,QIAN Zengzhen,TONG Ruiming,et al.Uplift field tests and displacement prediction on belled piers in gobi[J].Rock and Soil Mechanics,2014,35(7):1871-1877.
[20]JGJ 106-2014,建筑基桩检测技术规范[S].JGJ 106-2014,Technical code for testing of building foundation piles[S].
[2]Deshmukh V B,Dewaiker D M,Choudhury D.Computations of uplift capacity of pile anchors in cohesionless soil[J].Acta Geotechnica,2010,5(2):87-94.
[3]Chattopadhyay B C,Pise P J.Uplift capacity of piles in sand[J].Journal of Geotechnical Engineering,ASCE,1986,112(9):888-904.
[4]Kulhawy F H,Kozera D W,Withiam J L.Uplift testing of model drilled shafts in sand[J].Journal of the Geotechical Engineering Division,ASCE,1979,105(1):31-47.
[5]Majer J.Zur berechnung von zugfundamenten[J].Ostereichische Bauzeitschrift,1955,10(5):85-90.
[6]Clemence S P,Veesaert C J.Dynamic pullout resistance of anchors in sand[C]//Proceedings of International Symposium on Soil Structure Interaction.India:Roorkee,1977:389-397.
[7]Murray E J,Geddes J D.Uplift of anchor plates in sand[J].Journal of Geotechnical Engineering Division,ASCE,1987,113:202-215.
[8]Balla A.The resisitance to breaking out of mushroom foundation for pylons[C]//Proceedings of the 4th International Conference on Soil Mechanics and Foundation Engineering,1961:69-76.
[9]郭楠,陈正汉,黄雪峰,等.软岩地基中大直径布袋桩抗拔试验研究[J].岩土力学,2015,36(增2):603-609.GUO Nan,CHEN Zhenghan,HUANG Xuefeng,et al.Experimental study of large-diameter bag uplift pile in soft rock foundation[J].Rock and Soil Mechanics,2015,36(Suppl 2):603-609.
[10]张继红,朱合华.抗拔桩极限平衡方程及其应用[J].岩土力学,2015,36(8):2339-2344.ZHANG Jihong,ZHU Hehua.Limit equilibrium equation for uplift piles and its application[J].Rock and Soil Mechanics,2015,36(8):2339-2344.
[11]罗少锋.抗拔桩的承载力与变形研究[D].西安:西安建筑科技大学,2014.LUO Shaofeng.Study on deformation and capacity of uplift piles[D].Xi’an:Xi’an University of Architecture and Technology,2014.
[12]赵彤,杨海松,王向军.扩底抗拔桩在天津于家堡南北地下车库中的应用[J].岩土力学,2014,35(增2):359-363.ZHAO Tong,YANG Haisong,WANG Xiangjun.Application of pedestal uplift piles to Yujiapu north-south underground garage in Tianjin[J].Rock and Soil Mechanics,2014,35(Suppl 2):359-363.
[13]鲁先龙,乾增珍,崔强.黄土地基掏挖扩底基础抗拔试验研究[J].岩土力学,2014,35(3):647-652.LU Xianlong,QIAN Zengzhen,CUI Qiang.Experimental investigation on uplift behavior of belled piers in loess[J].Rock and Soil Mechanics,2014,35(3):647-652.
[14]胡琦,凌道盛,孔令刚,等.超深开挖对抗拔桩承载力影响的离心机试验研究[J].岩土工程学报,2013,35(6):1076-1083.HU Qi,LING Daosheng,KONG Linggang,et al.Effects of deep excavation on uplift capacity of piles by centrifuge tests[J].Chinese Journal of Geotechnical Engineering,2013,35(6):1076-1083.
[15]钱建固,马霄,李伟伟,等.桩侧注浆抗拔桩离心模型试验与原位测试分析[J].岩土力学,2014,35(5):1241-1247.QIAN Jiangu,MA Xiao,LI Weiwei,et al.Centrifuge model test and in-site observation on behaviors of side-grouting uplift pile[J].Rock and Soil Mechanics,2014,35(5):1241-1247.
[16]杨军,张大峰,李连友,等.高液限膨胀性黏土基桩工作性状的离心机试验研究[J].岩土工程学报,2017,39(10):1770-1776.YANG Jun,ZHANG Dafeng,LI Lianyou,et al.Centrifuge modelling of working performance of foundation pile embedded in high liquid limit expansive clay[J].Chinese Journal of Geotechnical Engineering,2017,39(10):1770-1776.
[17]袁文忠,于志强,谢涛.岩基强度对嵌岩抗拔桩承载力影响的试验研究[J].西南交通大学学报,2003,38(2):178-182.YUAN Wenzhong,YU Zhiqiang,XIE Tao.Vertical bearing capacity of rock-socketed piles influenced by batholith strength[J].Journal of Southwest Jiaotong University,2003,38(2):178-182.
[18]JGJ 94-2008,建筑桩基技术规范[S].JGJ 94-2008,Technical code for building pile foundations[S].
[19]鲁先龙,乾增珍,童瑞铭,等.戈壁地基扩底掏挖基础抗拔试验及其位移计算[J].岩土力学,2014,35(7):1871-1877.LU Xianlong,QIAN Zengzhen,TONG Ruiming,et al.Uplift field tests and displacement prediction on belled piers in gobi[J].Rock and Soil Mechanics,2014,35(7):1871-1877.
[20]JGJ 106-2014,建筑基桩检测技术规范[S].JGJ 106-2014,Technical code for testing of building foundation piles[S].