The Detection And Application Research Of Prestressed Concrete Continuous Girder Based On Loading Test

With the rapid development of traffic and the advancement of technology, the detection of bridge is considered to be more and more important. Its main signification expresses in the applications as follows: assess of actual carrying capacity of today's bridges, foundation of technical information of bridges, and developments of the assess theories of old bridges and design theories of new bridges. However, load test is an important testing method, which can provide advantageous and direct bases for administrators to evaluate carrying capacity of bridge. Especially for the new structure, bridge design theory and working techniques it can provide valid actual data. This paper tells the purpose, the theoretical analysis methods, main points, the principle of state evaluation in the load test of prestressed concrete continuous girder;based on the method of modern prestressed concrete continuous girder bridge, infinite element, random vibration, vibration testing and analysis technology, this paper studies and designs the detection of two project of WoXi Bridge and BaiNian River Bridge by summarizing the methods of several bridge detections. Static loading test of WoXi bridge's main span (prestressed concrete continuous box girder) is studies in the paper. Through investigating the locale and referring to the blueprint of WoXi bridge, considering the randomicity in bridge construction and the structural symmetry, therefore, the author chooses the 50m west span and 80m central span's1/2 beam as primary detection parts. This paper makes sure the controlling load and loading case under the condition of ensuring the load test efficiency. According to the results of comparison between the actual value and the theoretical value of the controlling section this paper makes clear the checkout coefficient and then confirms the actual carrying capacity of WoXi bridge. The problem of bridge vibration is very complicated and the analysis in theory still can not meet the requirement of the engineering application. In order to test the actual condition when BaiNian River bridge is forced by dynamical load. Before the detection, theoretical mode analysis calculation is made by assimilated vertical isomerism board theory (G-M), thus natural vibration frequency and mode shape of BaiNian River Bridge theoretically are concluded, then, braking test and jumping test are carried out respectively. With time draw-out measurement method this paper carries through parameter identification and tests the actual mode parameters (including mode shape andnatural vibration frequency).The comparison between actual results and those in theory indicates that this bridge is qualified with satisfactory dynamical peculiarity. Furthermore this paper analyses the causes that these mode shapes lie in according to the structure characteristic of continuous girder bridge, It brings forward beneficial advices for the road managing and maintaining department.