Projects approved and funded by the Ministry of Finance:
Ultrasonic defect location and analysis technology of welding lines related to "T, K, Y" intersecting joints of large-scale spatial grid steel structures—
In 2004, the Ministry of Finance of People's Republic of China (PRC) supported Baoye Construction Company as a sub-project of the project "Research on New Technology of Design, Installation and Construction of Long-span Spatial Grid Steel Structure".
Mainly for large-scale spatial grid steel structures, the welds of "T, K, Y" joints of pipeline branches intersect in space, and the main pipe is directly connected with the branch pipe and welded on one side. In the process of ultrasonic flaw detection of intersecting welds, the included angle between the weld and the axis of the steel pipe changes continuously along the circumference of the weld, so the section where the axis of the ultrasonic beam is located is an ellipse, and the contact surface between the probe and the steel pipe is a spatial curved surface. The variable curvature of the thin wall makes it difficult to locate and calculate the ultrasonic flaw of T, K and Y welds. In this paper, the ultrasonic defect location technology of "T, K, Y" intersection line is studied, and the computer analysis and calculation program of ultrasonic defect location of "T, K, Y" intersection line is developed. Through research and experiments, according to the structural characteristics of TKY pipe joint and the principle of space geometry, the mathematical model of parametric formal equation of intersection line of weld section and the calculation model of defect position are established. The technological process of ultrasonic detection, calculation, analysis and evaluation of weld defects in T, K and Y tubular joints is formulated. This technology has reached the leading level in China.
As one of the key technologies of Shanghai Baoye Construction Co., Ltd.' s "New Technology Development of Design, Manufacture, Installation and Construction of Large-scale Spatial Grid Steel Structure", the achievement of "Ultrasonic Defect Location and Analysis Technology of T, K, Y Pipe Joints Related Lines" has passed the project acceptance of the Ministry of Finance.
First prize in the 19th Shanghai Excellent Invention Competition in 2005. It has been successfully applied to the fabrication and installation of steel structures such as the Bird's Nest of Beijing National Stadium and Nanjing Olympic Gymnasium.
Research on Damage Detection and Bearing Capacity Evaluation Method of Building Structure after Disaster—
In 2005, it won the technical development project of "Research on Damage Detection and Bearing Capacity Evaluation Method of Post-disaster Building Structures" funded by Ministry of Finance. The main task is to study the damage detection and bearing capacity evaluation methods of building structures and components after common disasters. Combined with Tongji University in Shanghai and the State Key Laboratory of Civil Engineering Disaster Prevention, according to the long-term strategy of disaster prevention and relief in modern civil engineering in China, a series of experimental studies were carried out on the detection and identification methods of post-disaster building structures. It mainly includes: 1, research on fire damage mechanism and detection method of concrete buildings; 2. Study on the mechanism and detection method of wind and earthquake damage of concrete buildings: 3. Study on the fire damage mechanism and detection method of steel structure buildings: 4. Theoretical study on wind and earthquake damage and its mechanism of steel structure buildings: 5. Study on the failure mechanism and detection method of steel structure during snowstorm: 6. Study on the safety detection and evaluation method of the whole process of high-altitude mobile transportation of super-large steel structure for Baosteel's short-term overhaul project.
At present, it has been applied to a number of post-fire building structure detection and evaluation work, such as a cold rolling factory building, gymnasium, iron-making project frame steel structure, civil residential buildings and so on.
Core technology:
1. Study on fire damage mechanism and detection method of concrete buildings: The changes of macro-properties of concrete materials after different fire temperatures are analyzed and judged by scanning electron microscope (SEM) and X-ray diffraction (XRD). The calculation model of bearing capacity of concrete members is established. The evaluation method of concrete structure performance after fire is established by combining qualitative and quantitative methods.
2. Research on the mechanism and detection method of wind disaster and earthquake damage of concrete buildings —— A rapid assessment method for the safety of concrete structures after earthquake disaster: The main forms of concrete structure damage after earthquake and wind disaster are structural settlement, inclination, deformation of components, cracking, peeling and fragmentation of components, and whether reinforcement bars are exposed or broken. Formulate the rapid assessment process and specific methods for the safety of concrete structures after earthquakes and wind disasters;
3. Research on fire damage mechanism and detection method of steel structure building: According to the characteristics of steel structure building, firstly, the fire characteristics and the change characteristics of steel properties under fire high temperature conditions are analyzed; Then, the material properties of the main components of the steel structure building after the fire were tested and analyzed, and the calculation and evaluation method of the residual bearing capacity of the steel structure was formulated. Combining with the existing detection methods and adopting new analysis and calculation techniques, a new method for post-fire detection and evaluation of steel structures was developed, and the Technical Specification for Post-fire Detection and Evaluation of Steel Structures was formed.
4. Research on the detection and bearing capacity evaluation method of steel structure after earthquake and wind disaster: Through research and analysis, it is considered that the building steel structure mainly produces low-cycle fatigue failure under the action of earthquake or wind. That is to say, under cyclic load, the damage keeps accumulating and the performance keeps declining until it can't resist the external load and finally breaks. It is the calculation method and evaluation standard for damage detection and evaluation, structural reinforcement and bearing capacity evaluation of building structural members after disasters.
Major achievements:
1, "post-fire assessment method for steel structure buildings" has applied for national invention patent, with application number:
2, "a stress evaluation method of building components in migration" has declared the national invention patent, application number:
3. The Technical Specification for Detection and Evaluation of Building Structure after Snow Disaster and the Technical Specification for Detection and Evaluation of Building Structure after Fire were formed.
4. Completed the research on the method of damage detection and bearing capacity evaluation of building structures after the disaster, and won the gold medal in the 2008 Shanghai Excellent Invention Selection Competition.