Numerical simulation using finite element (FE) software packages has been widely adopted to investigate the seismic performance of large-scale structures, recently.Among these, Open System for Earthquake Engineering Simulation (OpenSees), as an open-source FE software program, has increasingly become one of the most influential packages.However, the computational efficiency of the matrix solvers currently cannot satisfy the demand for numerical simulation of large-scale structures.Consequently, two new, parallel, iterative linear solvers are proposed and implemented in OpenSees based on two graphic processing unit-based (GPU-based) libraries.The time history analysis of two typical large-scale structures are performed using the proposed solvers.The speed-up ratio of the proposed solvers are up to 9 to 15 (achieved with high accuracy in results).The research outcome can provide an effective computing technology for further numerical analysis of the seismic behavior of large-scale structures.

The current investigations of building seismic damage are mainly dependent on manual work, leading to a low efficiency. To improve the efficiency of the investigation, a system for the investigation of building seismic damage based on smartphones and Web technique is developed. This system is made of three components: a server, smartphones and a web. In the server, a building-oriented database is built, which makes buildings become the basic elements for the data collection and management. In smartphones, an app for collecting data is developed, which builds a corresponding relationship between the collected multi-media data and buildings. In the web, the data collected by smartphones are analyzed and stored. In addition, these data are visualized on a GIS cloud platform. The system has been successfully applied in the investigation of building seismic damage in Tibet area in the 2015 Nepal earthquake.

To replay the process of bridge collapse scientifically and realistically and assist the technical appraisals for bridge collapse accidents, the scene simulation of bridge collapse on VR platform based on FEM is studied in this paper. By the data of FEM simulation of bridge collapse, the bridge scene model and the animation of bridge collapse are realized in 3D graphic engine OSG. Based on the model of bridge collapse, a scene walkthrough system with realistic graphics is developed in this paper. By comparing the animation of bridge collapse in OSG with the FEM simulation of bridge collapse, the methods of creating bridge scene model and realizing the animation of bridge collapse prove to be operative. This paper combines FEM simulation and VR simulation to provide a scientific and realistic virtual scene for the technical appraisals of bridge collapse accidents.