Corrosion Of Concrete Structures In Marine Environment Damage And Frame Structures In Earthquake Response Analysis

With the implement of our country’s basic national policy that explore and exploit marine resources, our marine engineering foundation construction has entered an unprecedented peak period. Meanwhile, the durability of concrete structures in marine environment appeals to be badly degraded, resulting the reduction of the structural seismic performance under earthquake response. Therefore, in order to improve the the security and reliability of engineering structures which was esposed to marine environment serving, as well as paying attention to the effect of seawater attack to concrete and reinforced material constitutive relation, This article use the CANNY software to discovery that the seismic response and seismic performance of reinforced concrete structures vary with time in marine environment. The main contents and conclusions are as follows:(1) Firstly, as a example that the extent of the corrosion (attack time) impact on the concrete’s constitutive relation in the process of sulfate attack, According to the law of strength degradation in the process of chemical corrosion and stress corrosion, it was gained the strength of concrete under a certain degree of corrosion, and basing on the strength, it was established the relationship between the strength of concrete and characteristic value of the stress-strain curve under different degree of corrosion, according to the correction of parameters of the concrete constitutive model, it was got the constitutive model of concrete with thinking of the influence of corrosion during the sulfate corrosion.(2)Then, as a example that the extent of the corrosion (attack time) impact on the steel’s constitutive relation in the process of chloride attack, according to the corrosion rate model that steel was affected by the under uniform corrosion, pitting corrosion, uniform corrosion and pitting joint action, by determining the parameters of model. According to the correction of parameters of the steel constitutive model, it was steel model of concrete with thingking of influence of corrosion during the sulfate corrosion.(3)Using the CANNY program, a finite element analysis model of the seismic analysis of concrete structures was established under corrosive conditions by considering the corrosion effects of concrete and steel material constitutive model, comparatively analysising elastic-plastic multi-process response of a five-story frame structure with corrosion in10years and with non-corrosive under in multi-case of earthquake, mainly researching horizontal schedule of displacement schedule the top layer, the maximum horizontal displacement of the layers, shear of the layers, displacement angle of the layers, and also studying the changes in seismic response of the structure with the growth of corrosion life.(4)Using the CANNY program, analysising the energy of a five-story concrete frame structure when rare case of earthquake is occurred at different corrosion life with multi-spring element model. one is for studying demanding distribution of hysteretic energy in the internal components of the structure at different corrosion life, the other hand is for studying changes of the energy transfer caused by the plastic damage in the internal components of the structure under different corrosion life, according to the time-history analysis result, time and location when the plastic hinge appearred in ends of the rod were get, researching changes of the energy distribution within the structure under different corrosion life after yielding with local members.