墩身偏位原因及纠偏加固方案数值模拟研究  

Numerical simulation study on the cause of misalignment of pier and the scheme of rectification and reinforcement

作　　者：陈洁金 董自行 胡敏 CHEN Jiejin;DONG Zihang;HU Min(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学土木工程学院,湖南长沙410114

出　　处：《交通科学与工程》2024年第3期128-134,共7页Journal of Transport Science and Engineering

基　　金：湖南省教育厅科学研究项目“优秀青年项目”(20B010)。

摘　　要：为探究某大桥墩身偏位的原因,在原位勘察结果的基础上,分析研究了导致墩身发生偏位的影响因素,这些因素包括桩底下卧软弱破碎带、桩侧及桩底岩层软化、桩侧钻孔、桩侧及桩底岩层在振动耦合作用下的加剧软化等。通过数值模拟发现,岩层软化对于墩身偏位的影响程度最大,桩底下卧软弱破碎带次之,桩侧钻孔对于墩身偏位的影响最小。在探明墩身发生较大偏位的主要原因后,针对补桩过程中墩身发生第二次较大偏位的现象,提出预注浆加固的方法进行纠偏加固。数值模拟结果表明,预注浆加固可使补桩引起的6#墩身偏位量减小80%。优化后的6#墩纠偏加固顺序为:原5#~8#桩底预注浆加固、补桩、增大墩身截面纠偏墩身。To explore the reasons for the deviation of a certain bridge pier,based on the results of in-situ investigation,it can be concluded that the main reasons for the deviation of the pier are that under the vibration coupling effect the characteristics of the weak and fractured zone beneath the pile,softening of the rock layers on the pile side and bottom,drilling on the pile side,and the rock layers on the pile side and bottom can exacerbate the softening,et al.Numerical simulation results indicated that the softening of the rock layers had the greatest influence on the displacement of the pier,followed by the weak and fractured zone beneath the pile,while the effect of drilling on the pile sides was minimal.After identifying the main reason for the large deviation of the pier,a method of pre-grouting reinforcement is put forward for the second large deviation of the pier in the process of pile patching.Numerical simulations demonstrated that pre-grouting reinforcement could reduce the displacement of pier 6#caused by pile repair by 80%.After optimization,the order of rectification and reinforcement of pier 6#is:pre-grouting reinforcement at the bottom of 5#-8#pile,patching pile,increasing pier section to modify pier.

关 键 词：墩身偏位 注浆加固 补桩 增大截面法 

分 类 号：U441[建筑科学—桥梁与隧道工程]