大直径深层钻孔灌注桩拔除工艺研究
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摘要
结合郑州南站连接线明挖隧道(拔桩区间)拟拔桩基直径大、桩长的特点,对桩体受力特征和拔桩工艺进行了研究。通过拔桩过程中桩周土破坏模式和桩体自身的抗拉强度分析计算,选取有效的减阻方法并应用于工程实践,取得良好效果。最后总结出大直径深层钻孔灌注桩拔除工程中桩身局部扩大、桩侧摩阻力过大和断桩等问题及相应的解决方法,供今后类似工程借鉴。
According to the characteristics of long and large diameter pile to be pulled out in the open-excavated tunnel( pile-puling interval) in Zhengzhou,the force on pile body and the pile-pulling technology are studied. Through the analysis and calculation on failure mode of soil around the pile and tensile strength of the pile body in pulling-out process,the effective method of resistance reduction is selected to be applied in the engineering practice,and good results are achieved.The solutions of pile body partial enlarged,too large pile lateral friction and pile broken in pile pulling-out operation are summed up,which can serve as reference for the same projects.
According to the characteristics of long and large diameter pile to be pulled out in the open-excavated tunnel( pile-puling interval) in Zhengzhou,the force on pile body and the pile-pulling technology are studied. Through the analysis and calculation on failure mode of soil around the pile and tensile strength of the pile body in pulling-out process,the effective method of resistance reduction is selected to be applied in the engineering practice,and good results are achieved.The solutions of pile body partial enlarged,too large pile lateral friction and pile broken in pile pulling-out operation are summed up,which can serve as reference for the same projects.
引文
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[5]Parry R H,Swin C W.Effective Stress Methods of Calculating Skin Friction on Driven Piles in Soft Clay[J].Ground Engineering,1997,10(3):24-26.
[6]Rao K S,Venkatesh K H.Uplift Behavior of Short Piles in Uniform Sand[J].Soils and Foundation,1985,25(4):1-7.
[7]戴金林.钻孔灌注桩侧壁摩阻力极限值计算[J].建筑结构,2007,37(8):85-87.
[8]刘杰.浅谈对如何减小桩侧摩阻力的拔桩方法[J].中华民居(下旬刊),2012,(6),127-128.
[9]Meyerhof G G,Adams J I.The Ultlmate Uplift Capaeity of Foundation[J].Canadian Geotechnical Journal,1968,(4).
[10]何思明.抗拔桩破坏特性及承载力研究[J].岩土力学,2001,22(3):309.
[11]JGJ 94—2008,建筑桩基技术规范[S].
[12]GB 50010—2010,混凝土结构设计规范[S].
[2]吴林峰.射水造孔法拔除混凝土预制桩施工技术[J].人民黄河,2010,32(11):150-151.
[3]宋辉.套管法拔桩对既有大直径地下污水管的影响[J].上海大学学报(自然科学版),2011,17(3):321-324.
[4]Ramanathan T S,Ganapathy A P.Pull out Resistance of Piles in Sand[J].Indian Nat Soc Soil Mech Found Eng,1970,9(2):189-202.
[5]Parry R H,Swin C W.Effective Stress Methods of Calculating Skin Friction on Driven Piles in Soft Clay[J].Ground Engineering,1997,10(3):24-26.
[6]Rao K S,Venkatesh K H.Uplift Behavior of Short Piles in Uniform Sand[J].Soils and Foundation,1985,25(4):1-7.
[7]戴金林.钻孔灌注桩侧壁摩阻力极限值计算[J].建筑结构,2007,37(8):85-87.
[8]刘杰.浅谈对如何减小桩侧摩阻力的拔桩方法[J].中华民居(下旬刊),2012,(6),127-128.
[9]Meyerhof G G,Adams J I.The Ultlmate Uplift Capaeity of Foundation[J].Canadian Geotechnical Journal,1968,(4).
[10]何思明.抗拔桩破坏特性及承载力研究[J].岩土力学,2001,22(3):309.
[11]JGJ 94—2008,建筑桩基技术规范[S].
[12]GB 50010—2010,混凝土结构设计规范[S].