Research On Construction Monitor And Control For Pre-stressed Continuous Rigid-Framed Bridge With Long Spans And High Piers

Long-span prestressed concrete continuous rigid frame bridge as a routine form is widely used in engineering. It has the ability to cross great distance, no expansion joints, driving smoothly, without large bearing characteristics and adapted to the needs of the construction and development of the bridge.Long-span prestressed concrete continuous rigid frame usually adopt the cantilever method. With the increasing span of the cantilever and the continuously reducing of cross section of the beam, the vertical load is increasing, considering the temperature and load factors, the flexibility in construction, the change of the line, location and stress in the bridge, it is difficult to achieve design results. As bridge construction process is accumulating deviation, if not to be effective controlled, it will effect the bridge in safety, line, economy, and the lately use. To avoid these adverse situations, the process of the construction must be monitored and control.The main content of this article:1. Study the construction methods and technology of continuous girder bridge, comprehend the characteristics and the application of the construction method. Analysis the causes of the bridge engineering accident at home and abroad, this paper has discussed how to avoid this kind of accident, as to carry out effective control in the process of the construction of the bridge. Throughout the construction control field at home and abroad in the current situation of the development, predict the development trend of construction.2. This paper introduced the content and method of control in construction. The main control work is:(1)Control of the linear to meet the requirement of design, and guarantee the smooth bridge spans folded into a bridge, linear smoothly.(2)Monitoring the stress of bridge structure, ensure that the internal force was reasonable distributed, the bridge operations healthy.(3)Control the structure to make it stable and safe. This article lists the prediction control method, adaptive control method and the largest tolerance method, the method of control theory. The analysis of the structure of the commonly used method also made a detailed description.3. With the highway engineering background, this article described the basic situation of the project and recorded the detail of the main process of model setting.4. According to the engineering examples, the introduction of the adaptive control method for the project of the structure calculation model parameters are fixed, make the structure model utmost close to the engineering practice, instruct on-site construction. This process in the bridge in the linear control have been very good expression. Using this method to set the arch degrees also has a good effect.5. The steel string strain gauge is used to control of the internal force of the bridge structure. According to the frequency-strain relationship of gauge can get real strain of concrete structure, then, use the stress-strain relationship of the concrete structure to calculate the internal force. Stress tests also contains a variety of factors affecting, in the calculation of the stress, the cause of the error factors has been detailed analyzed and eliminated with reasonable method. It makes the calculation results and the structure of the actual status more identical.