Abstract: Main types of the pier，abutment and foundation in substructure of ＲC or PC bridges in China were summarized respectively． It was pointed out that the main diseases in substructure of concrete bridges were differential settlement of foundations， insufficient carrying capacity，durability diseases of reinforced concrete，cracking of concrete pier columns，bent caps and abutments etc． ． In allusion to the concrete pier，abutment and foundation，the causes and mechanisms of these diseases were analyzed from the design，construction，maintenance and operation of bridges． The relevant maintenance and strengthening methods were also discussed，such as the foundation enlargement method，adding pile method and artificial foundation reinforcement method for concrete and ＲC pier or abutment foundation; the method of ＲC columns reinforced by reinforced concrete hoop or FＲP for piers，the reinforcement method of pasting steel strips or plates，the method of external prestressed reinforcement and additional support method，etc． for ＲC bent caps; the method of reducing load，the method of reducing filling height by adding approach spans，the support beam method and the reinforcement method of installing auxiliary retaining wall，etc． for ＲC abutments．

Key words: bridge engineering, concrete pier and abutment, pile foundation, disease analysis, reinforcement

摘要： 概述了国内混凝土桥梁下部结构中桥墩、桥台与基础的主要类型，指出混凝土下部结构出现的主要病害，即地 基不均匀沉降、承载力不足、钢筋混凝土耐久性病害、混凝土墩身、盖梁及桥台的开裂等;从桥墩、桥台、基础，以及桥 梁设计、施工、养护、运营等方面分析了病害成因与机理;讨论了养护加固方法，如:基础加固的扩大基础法、增设桩 基法、人工地基加固法，桥墩加固的钢筋混凝土套箍法、FＲP(纤维增强塑料)加固法、盖梁加固的粘贴钢板法、体外 预应力法、增设支撑法等，桥台加固的减轻荷载法、扩孔降低填土高度法、支撑梁法、辅助挡土墙加固法等。

关键词: 桥梁工程, 混凝土桥墩及桥台, 桩基础, 病害分析, 加固