The effects of seawater and site conditions on the seismic response of the isolated continuous girder bridge are evaluated in this study. The seawater‐muddy soil‐isolated bridge coupling model is built in the dynamic analysis software ADINA, and the external seismic wave input is realized by the seismic wave motion analysis program. The influences of seawater and muddy soil on the seismic response of isolated continuous girder bridges are determined by comparing different offshore site models. The results indicated that the seawater and the muddy soil magnify the displacement of the seabed. The existence of seawater increases the longitudinal relative displacement of piers by 20%–40% but has limited influence on the bending moment and shear force of piers. The muddy soil can increase the longitudinal relative displacement and internal force of the piers remarkably. Moreover, the displacement of bridge bearings increases significantly under the combined influence of muddy soil and seawater. In the seawater‐muddy soil‐isolated bridge coupling model, the seawater and site condition can influence the seismic performance of sea‐crossing bridges obviously.

During the service process, piers are often in harsh chloride ion erosion environments. The failure mode evolution of reinforced concrete (RC) piers may occur under the action of continuous corrosion. Accurately identifying the failure mode types and evolution characteristics of corroded RC bridge piers is a prerequisite for the lifetime seismic performance evaluations of bridges. First, based on Fisher’s theory and 174 RC pier columns as the analysis samples, a two-stage discrimination formula for the pier failure modes was established and compared with the existing theoretical discrimination methods. Then, based on Fisher’s discriminant grouping, and combined with Bayes’ formula and chloride erosion theory, a failure mode discrimination method for corrosion-damaged bridge piers that considers probability was developed. Finally, taking a medium-span concrete bridge as an example, the failure modes of the corroded pier in different service periods were predicted, and the influences of the various parameters on the failure mode evolution process of the corroded pier were studied. The results show that the accuracy of the proposed discriminant model was significantly improved compared with those of previous theoretical studies. The development of the failure mode features depends on how the distinct RC pier material qualities degrade under the influence of chloride ions. The degradation of the stirrups and concrete accelerates the nonductile failure of RC bridge piers, while the degradation of the longitudinal reinforcements delays it.

The recent earthquakes have caused serious damage to Chinese rural houses. Research on the seismic performance and reinforcement for traditional rural houses is strongly needed. In this study, the seismic performance of traditional brick‐wood structural houses in Jiangxi province and surrounding areas is analyzed and confirmed by site investigation and numerical simulation. And, the traditional constructions, such as the purlin roof and the cavity wall, are considered. These construction types can reduce the seismic behavior of rural houses, and limited research has been carried out. This study found that the structure will produce plastic deformation and local damage above 6‐degree earthquake fortification action. The damage positions occurred in the walls close to purlins and the walls close to doors and windows. Given the above seismic safety problems, a reinforcement method of reinforced cement mortar strip and mesh surface is proposed, which is suitable for engineering applications for traditional rural houses. The seismic strengthening effect is analyzed by numerical simulation. Comparing the calculation results, it is found that the seismic performance of the structure after reinforcement is significantly enhanced, and the stress concentration of the walls is improved.