As the important model basis of smart city and digital twin city, CIM is becoming increasingly important in the context of "New Infrastructure Construction". Based on the domestic and foreign research literature, this study summarizes the development process of CIM, elaborates the main research directions and technical implementation platforms of CIM, and introduces its typical applications, which provides an important reference for the research of CIM.

With the development of urban construction, the increase of project scale has brought about the problem of increasing management difficulty. By integrating the Revit, ArcGIS, CityGML, database and Web technology, this paper integrates BIM and GIS data to form City Geography Markup Language (CityGML) data, completes the database design of Engineering multi-source data, designs and develops an intelligent management system for urban engineering projects based on BIM and GIS.The system realizes project schedule management, quality management, engineering measurement and safety management.It can greatly simplify the management process, effectively improve the efficiency and quality of management, and save the cost of management.It can effectively solve the problems of poor information communication, time-consuming and inefficiency in the use of traditional management methods in engineering projects.

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 software on simulation of building fire and the software on simulation of structural response due to fire both have good performance in their respective fields, but they are not good at the synchronous simulation between building fire and structural response due to fire. In this paper, the synchronous simulation above is made in the virtual reality system based on Vega. This system is a post-processing platform based on a fire simulation software FDS and a FEM software MSC. MARC. FDS and MARC provide scientific results for synchronous simulation, while this virtual reality system shows these results in a visual and lifelike way. This system reveals the link between building fire and structural fire response. In virtual training, this system can help people judge the structural safety by the situation of building fire.

The development of virtual reality (VR) technology makes it possible for users to improve the understanding of dangerous scenes from computational simulations.A prototype system-AutoEscape based on the integration of virtual reality visualization and numerical simulation, was developed for human evacuation in fire scenarios.FDS was selected to simulate the fire growth and an evacuation computational engine was designed and implemented based on GIS technology.A VR representation module was constructed, which develops a comprehensive representation for the distributed scenario variables according to numerical results.The case study indicates that the system can help users to form a deep full-scale understanding of fire evacuations, and therefore provide a virtual training environment for emergency evacuation drills and fire rescue command.

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.