Real-time Stress Data Acquisition System For Safe Bridge Construction

The data acquisition system in the bridge construction decide whether the structure,internal force,line style of the bridge meet the need of the design when it is built and whether the bridge can work safe after it is put into use. At the same time the measurement of every stress of the bridge is the main task of the construction monitoring system. The stress data main include the concrete stress of the prestressed concrete beam bridge and the cable stress of the cable–stayed bridge. The stress data of every designated point changes along with the constructing progress, by inspecting the loading state of the bridge, the control system can alarm in advance immediately and give the control instruction to guide the following construction. So the real-time stress data acquisition plays the key role. Now the main method that gains the stress data is: technical persons measure the stress of the bridge regularly and then input it to the computer. Because other cables stress change when one cable stress is adjusted, the cable stress measurement in the construction of cable-stayed bridge is very frequent and complicated; and the method of measurement make the builders can't know the change of the stress, so builders can't know whether the bridge is safe or not in time. The main limitation of this method is to measure the different points at the different time, so they can't acquired the real-time data and the loading state of the bridge so as to can't give alarm and adjustment controlling instruction in time.First, the theory of construction control,the stress data acquisition of long span prestressed concrete bridge and cable-stayed bridge are discussed. Second, a bridge stress data acquisition system is put forward, the real-time stress data of the local multipoint can be acquired in the system and then transmitted to the controlling computer. After calculated by the computer, the stress data,the error between the measured stress on the spot and the designed stress,whether the error overrun the safe range or not are showed throw the man-machine interface on the computer. Alarm would be given if it's necessary, at the same time the computer provide the parameter that need to be adjusted and the cable adjusting order based on the appointed control arithmetic.