外包砼加固的钢筋砼柱受力性能研究

A great many buildings need to be strengthened, but the present strengthening measures on these buildings depend mainly on the experiences from engineering practice for lack of systematic and thoroughgoing experimental investigation and theoretic analysis on them. This makes it very difficult to accurately appreciate the safety of building structures strengthened. Columns are most important members in building structures. The behaviors of reinforced concrete columns strengthened with concrete wraps were investigated by means of finite element analysis and experiment methods. Based on the previous research results, and a great deal theoretic calculation and comparative analysis, a total of 117 specimens were cast and tested. Through the testing results and corresponding calculation, many factors influencing the behaviors of reinforced concrete columns strengthened were examined. These factors include difference between gradual changing distribution damage and sudden changing distribution damage, loading level, eccentricity of loading, strengthened on specimen different surfaces, ratio of the strengthening to the strengthened section area, concrete different strength grades, property difference at interface between the strengthening and the strengthened concretes, and so on. General regularities of strengthened reinforced concrete columns were summed, and main influencing factors on specimens were determined. Based on these results, some necessary calculation simplification and hypotheses were put forward, then corresponding calculation formulas were given. It is shown that these formulas are simple, suitable, and they have a calculation accuracy better satisfying the requirements from the actual engineering and are convenient for designing engineers. These research results supply base information for the revision of the corresponding codes and make up absence of investigation on strengthening general changing distribution damage members, and they can be directly applied to calculate and design the damaged reinforced concrete columns which need to be strengthened.

许多建筑物需要进行加固，目前主要依靠工程经验决定加固措施，由于缺乏系统和深入的研究，加固后结构的实际安全度出入较大。通过有限元分析和试验研究外包砼加固的钢筋砼柱，确定其受力性能的一般规律和多种因素的影响，给出其加固的原则和计算方法，为结构的加固设计和加固后结构性能的评估提供必要的依据，具有重要的技术经济意义。