西部盐渍土地区混凝土桥墩柱抗震性能腐蚀劣化机理的研究

西部盐渍土地区包括内蒙古、宁夏、青海、新疆、甘肃等地区，主要特点是土壤中含有多种类高浓度腐蚀性离子，对混凝土结构使用性能具有很强的腐蚀劣化作用。同时，西部大部分地区属于地震频发地区，地震对混凝土结构具有毁灭性的破坏作用。随着西部大开发战略的实施，西部地区桥梁工程大量兴建，混凝土桥梁结构抗震性能面临着盐渍土环境的腐蚀劣化作用，尤其是与盐渍土壤接触的混凝土桥墩柱，受到的腐蚀作用最显著。因此，本项目拟以混凝土桥墩柱为研究对象，根据西部盐渍土壤中的化学成分，配制试验溶液，采用干湿循环腐蚀方式，研究不同干湿循环阶段混凝土桥墩柱的抗震性能，分析混凝土保护层和钢筋的腐蚀劣化规律；同时，采用结构地震损伤理论和可靠度理论，进行西部盐渍土地区混凝土桥墩柱地震损伤分析和抗震性能时变可靠度分析，评价西部地区盐渍土环境对混凝土桥墩柱抗震性能的影响。为西部盐渍土地区桥梁工程建设和抗震防灾提供必要的研究背景和理论基础。

western saline soil area includes Inner Mongolia, Ningxia, Qinghai, Xinjiang, Gansu, and so on. Many types of corrosive ions exist in the western saline soil area, their concentrations are higher, and their corrosive deterioration for service performance of reinforced concrete structure is stronger. At the same time, frequent earthquake seriously threatens reinforced concrete structure in the western saline soil area. A large number of bridge construction is started during the implementation of the western great exploitation strategy, and bridge structures are faced with corrosive action of saline soil environment. Especially the bridge pier is corroded strongly because it is directly contacted with saline soil.So reinforced concrete bridge pier is selected as research object in this project. The experimental solution will be prepared according to the chemical constituents of saline soil and bridge pier will be corroded in the dry/wet cycle method. The research contents include corrosive deterioration of steel bar and concrete cover, seismic performance of bridge pier in the various cycle stage, earthquake damage analysis of bridge pier and time-dependent seismic reliability of bridge pier in this research program. Seismic damage theory and reliability theory are applied. Influence of corrosive environment on seismic performance of bridge pier is evaluated. The available results will provide research background and theoretical basis for the construction and earthquake disaster prevention of bridge structures.