桥梁桩基不对称直桩的计算与补桩施工应用  

Calculation of asymmetric straight piles for bridge pile foundation and application of supplement pile construction

作　　者：叶坤[1] 李兆军 陈鹏飞[2] 李征 丁杰 廖立坚 YE Kun;LI Zhao-jun;CHEN Peng-fei;LI Zheng;DING Jie;LIAO Li-jian(CCCC Second Highway Engineering Bureau Co.,Ltd.,Xi’an,Shaanxi 710065,China;The Fourth Engineering Co.Ltd.of China Zhongtie Major Bridge Engineering Group,Nanjing,Jiangsu 210031,China;Xi’an Huachuang Civil Engineering Technology Co.,Ltd.,Xi’an,Shaanxi 710075,China;China Railway Design Corporation,Tianjin 300308,China)

机构地区：[1]中交第二公路工程局有限公司,陕西西安710065 [2]中铁大桥局集团第四工程有限公司,江苏南京210031 [3]西安华创土木科技有限公司,陕西西安710075 [4]中国铁路设计集团有限公司,天津300308

出　　处：《岩土力学》2025年第4期1278-1285,共8页Rock and Soil Mechanics

基　　金：国家重点研发计划(2022YFB2603400)。

摘　　要：补桩是桥梁施工中常见的一种补救措施,由此产生的不对称桩基按照现行公路规范计算,结果不闭合也不稳定。在m法的基础上提出了不对称直桩的计算方法,首先计算单桩刚度,在承台底处汇总成群桩刚度;然后建立纵横向关联的平衡方程,承台底荷载按不对称结构重新进行荷载组合,代入平衡方程求解出承台位移;再依次计算出每根桩的桩顶外力,接着按现行规范进行后续计算;最终实现不对称桩基的计算。经验证,该方法计算准确、快捷、便于操作,可纳入规范。工程应用表明,承台四周补桩法受力合理且容易施工,具体操作是:边桩损坏时,在承台最近侧对称地补打2根桩;角桩损坏时,在承台两端各补1根桩;中间桩损坏时,在承台最近侧补打1根桩。为节省成本,可在废桩1~2倍桩径范围内坏1补1,但因不满足最小桩间距要求,应慎用。The use of supplement piles is a common remedial measure in bridge construction.The resulting asymmetric pile foundation is calculated according to current highway specifications,which is not closed and unstable.A calculation method for asymmetric straight piles is proposed based on the m-method.Firstly,calculate the stiffness of a single pile and summarize the pile group stiffness at the base of the pile cap.Then establish a balance equation related to the longitudinal and transverse directions.The load at the base of the pile cap is recombined according to the asymmetric structure,and the displacement of the pile cap is determined by solving the equilibrium equation.Next,calculate the external force at the top of each pile in sequence.Then,carry out subsequent calculations according to the current specifications,and finally achieve the calculation of asymmetric pile foundation.It has been verified that this method is accurate,efficient,and easy to operate,making it suitable for inclusion in specifications.Practical engineering applications have demonstrated that the approach of using supplement piles around the bearing platform is structurally sound and straightforward to implement.In case of damage to a side pile,two symmetrically placed piles should be added adjacent to the affected side of the pile cap;for a corner pile damage,one pile should be added at each end of the pile cap;if the middle pile is damaged,one pile should be added to the closest side of the pile cap.To save costs,one pile can be damaged and replaced within a range of 1-2 times the diameter of the abandoned pile.However,as it does not meet the minimum pile spacing requirement,it should be used with caution.

关 键 词：公路桥梁 不对称直桩 M法 群桩平衡方程 补桩原则 

分 类 号：TU473[建筑科学—结构工程]