Primary Research On 3-D Masonry Structure Model And Realization Technology Of 3-D Disaster Scene

Earthquake emergency rescue service is one of the important part of earthquake prevention and disaster reduction. It is a necessary behavior for the government to reduce the casualties to the minimum degree when the earthquake happened. The earthquake emergency rescue service is a very professional work. Over the years, the domestic and foreign experiences show that it plays a crucial role for the effectiveness of an emergency earthquake relief if the rescuers can get a competent understanding of the environment of rescue site,the type of building structure and the form of structural damage.There is a little probability for the occurrence of a destructive earthquake. Rescuer,engineer and technician rarely have the chance to arrive at the real earthquake site. So they can not be well acquainted with disaster scenes and the form of structural damage. With the development of the virtual reality and system simulation technique, more and more examples successfully applied in the area of disaster prevention and reduction. However, it is rare for research of the visible model of building seismic damage and earthquake disaster scene demonstration in the three-dimensional terrain situation.Masonry Structure is one structure form used frequently and widely in China. The damage of masonry structure during the earthquake is an important factor leading to casualties and economic losses. Thus, the task of conducting"Primary Research on 3-D Masonry Structure model and Realization Technology of 3-D disaster scene", with simulating the damage state of masonry structure and earthquake disaster scene using computer technique, will be helpful for advancing the accuracy of rescue team member and engineering technicians'rescue training, making them be familiar with the earthquake disaster scene they will experience. It is also good for increasing the rescue effective and decreasing the casualties. This paper discussed two problems: how to realize the 3-D visible model of masonry structure's earthquake damage with the software of 3DS Max and ArcGis, and the method of realizing the earthquake disaster scene together with 3-D terrain. The specific works are as following:By referring to the former earthquake damage data of masonry structure, and investigating the Wenchuan Ms8.0 Earthquake, this paper analyzed systematically the damage location, damage form and damage causation of the typical damage of masonry structure. According to the fortification feature of the masonry structure in China, this paper analyzed the damage difference between seismic fortification and non-seismic fortification, and the damage difference between high and low intensity region, which showed the importance of seismic fortification.By the 3-D modeling technique of 3DS Max, using importing graphics from AutoCAD, jointing and Boolean operation, wall squeezing, material pasting, mapping and arraying, etc, this paper completed the perfect task of 3-D modeling, including the model of rectangle, L-shape, groove-shape, slope roof model, residence, school, etc. Because of the great difference of damage form between under the mid-level and over the serious-level, there are two modeling method to form the 3-D damage model of masonry structure. One basically uses the jointing method. The crack on the masonry structure caused by earthquake effect is the primary feature of mid-level and below. This method first extracts the damage information from pictures by Photoshop, then combines the information with the building materials, generating the Earthquake Damage Feature Pictures, then pastes these pictures on the surface of buildings with bitmap method, and finally completes the mid-level damage model. The other one focuses on the damage features of serious-level and above, such as deep crack of building components, dropping, and falling. This method changes the damaged members, adds shivers, and finally completes the falling model, which was proved by experience.Upon the serious damage of Wenchuan Earthquake with severe casualties and economic loss, based on the Digital Elevation Mode data and Remote Sensing data, this paper established the 3-D terrain in the ArcGis9.2 software, laid a foundation for the geological hazard simulation. Meanwhile, the modal of ArcCatalog and ArcMap were used to edit the building and road point data, and the modal of ArcScene was used to create the 3-D deserter scene. The method of establishing disaster scene was proposed. In this scene, the 3-D building blocks with different color presents different damage levels, which were obtained from Earthquake damage prediction method. Finally, this paper take the Shishi city as an example to introduce the produce steps and feasibility of 3-D disaster scene based on the ArcScene modal combined with 3-D terrain.According to the Similarity Theory and Building Code of Masonry Structure, this paper proposed a displace criteria and a displace method of 3-D model and 3-D modal of masonry structure, initially realized 3-D building scene and 3-D disaster scene of Shishi City based on ArcScene modal. Also this paper introduced the 3-D demonstrating function, including building inquiry, dynamic roaming, etc. The observer can check the damage level of buildings, inquiring the basic property, and zoom, rotate the scene, observe the damage form. Meanwhile, the observer can fly through the disaster scene.