酸雨环境腐蚀下钢管混凝土构件抗震性能研究

钢管混凝土结构作为一种新型组合结构，充分发挥了钢结构与混凝土的各自受力特性，因而得到了广泛应用。钢管混凝土构件在服役过程中，不但要承受车辆、设备等使用荷载和大风大浪、冰雪、地震等自然荷载，有时还要遇到大气、海洋、酸碱盐等环境腐蚀。中国既是地震多发区，又是酸雨频现区，因此研究酸雨环境腐蚀下钢管混凝土构件的抗震性能，对提高钢管混凝土结构的耐久性和安全性具有重要的学术价值和实践指导意义。 项目以钢管混凝土构件为研究对象，选取合适的酸雨模拟参数，通过快速酸雨腐蚀试验和损伤力学方法，建立考虑耐久性腐蚀损伤的钢管混凝土应力-应变关系，配合抗震试验和数值分析模拟酸雨地区钢管混凝土结构的地震反应过程，得出构件受力形式；研究应力和塑性变形集中的部位，继而判明结构屈服机制，研究构件弯矩-曲率和载荷-位移滞回关系特征，延性系数，得到其恢复力模型，为酸雨地区钢管混凝土结构抗震性能评估和抗震设计奠定理论和试验基础。

Concrete filled with steel tubular structures, as a new kind of composite structures which fully come into respective load characteristics of the steel and concrete, have been widely used. Over the service period of concrete filled with steel tubular structures, they usually not only bear occupancy loads such as vehicles, engineering machineary, etc and natural loads such as wind, waves, snow, earthquakes and so on, but sometimes also encounter such corrosion conditions as atomosperic environmen, marine envronment, industrial acid salt envireonment. China is not only an earthquake-prone area but also a acid- rain-frequent area. Therefore, the study on the seismic properties of concrete filled with steel tubular members under acid rain attack has great academic value and practical significance in improving the safety and durability of concrete filled with steel tubular members. In prsent application program, concrete filled with steel tubular members are used as the object of study. Proper test parameters to simulate acid rain environment are first selected. Consequently, a stress-strain constitutive relation considering corrosion damage evolution of durability for concrete filled with steel tubular members is constructed by using rapid acid rain corrosion test and damage mechanics method. In conjunction with numerical method of finite elements and seismic tests to simulate the earthquake response process of concrete filled with steel tubular structures, the mechanical behavior of the structures are investigated. The position for stress and plastic deformation concentration is examined to identify the yield mechanism of the structures. The hysteretic characteristics of moment-curvature and load-displacement are studied, and thus a simplified formulation for ductility factor as well as a hysteretic model are derived. Present research achievements will lay a theoretical and experimental foundation for the evaluation seismic performance and seismic design of concrete filled with steel tubular members.