当今国内外既有建筑物的加固改造业发展非常迅速，其中混凝土结构的加固理论与技术的研究与应用是结构工程学科的重要研究课题之一，我国属于多地震的国家，加固后的结构抗震性能研究更是重中之重。 本研究课题根据外包钢加固法的构造作法及受力特点，研究分析了外包钢加固混凝土柱的工作机理，采用结构低周反复加载试验研究了两种类型试件的动力性能，并由数值模拟方法进行了验证，得到了外包钢法加固钢筋混凝土柱的破坏形态、滞回曲线、骨架曲线、延性系数、耗能指标，分析了加固后的混凝土柱抗震性能；并通过数值模拟方法，分析和研究了湿式外包钢加固混凝土柱的工作性能。由此得出了几点研究结论：采用湿式外包钢加固混凝土柱，其延性较普通混凝土柱较好；外包钢加固混凝土柱的耗能性能与普通混凝土柱相比提高不大；外包钢的缀板承受拉应力，对混凝土起到约束作用，使核芯混凝土处于三向受压应力状态，提高了混凝土的抗压强度，从而提高了加固后混凝土柱的承载力；应适当加密柱端处的缀板间距，且第一缀板应布置在柱端处；采用水泥浆和G型灌浆料两种灌浆料加固混凝土柱，根据试验及以往工程实例，提出G型灌浆料作为结合剂的施工工艺。 上述研究成果对外包钢加固结构及其受力性能的进一步深入研究，对完善混凝土结构加固设计规范有一定的参考价值，并可供混凝土结构加固改造工程设计和施工参考。

As the development of reinforcement and reconstruction of buildings rapidly, the study and application on the reinforcement theory and technology of concrete structures become the one of most important research tasks of structure engineering.It is especially the top priorities about strengthening the structure after seismic studies in our country such a multiple earthquake zone. According to construction practices and the characteristics of bearing laod about strengthening method with wet encased steel, the paper issue analysis and study the work mechanism of strengthening reinforced concrete column with wet encased steel . According to tests of low cyclic reversed loading, the dynamic Performance about the two type specimens has been studied,and also been tested and verified by numerical simulation methods . Failure patterns, hysteretic curves, skeleton curves, ductile coefficients, energy dissipation of reinforced concrete column strengthened with wet encased steel are obtained.The seismic performance of strengthened concrete columns is studied.Throughout the numerical simulation methods,the work performance is analysised and studied about strengthening reinforced concrete column with wet encased steel. So some conclusions are made: the ductility of strengthening reinforced concrete column with wet encased steel is better than ordinary concrete columns. The energy performance of strengthening reinforced concrete column with wet encased steel compared with ordinary concrete columns do not improve. The batten plates of encased steel bear tensile stress ,and constraint the concrete. The stress of strengthening reinforced concrete column with wet encased steel is three-dimensional compression which can increase the compression strength of concrete,so the loading capacity of the strengthening concrete column is increased. The spacing of batten plates should be reduced at the bottom of column, and the first batten plates should be layed at the bottom of column. Concrete column is strengthened using cement slurry and G-type grouting material.According to the test and the past working examples, the G-type grouting material is regarded as the combination during the construction process. The research in this paper have some value to the study on property of envelope iron structures more and the perfect of reinforcement code of concrete structure, and it can provide reference for the design and construction of reinforcement and reconstruction of concrete structures.