Research On The Load Test Method Of Simply Supported T-shaped Girder Beam

T-shaped girder usually has high section and wide flange plate which can sufficientlyexert the compressive performance of the concrete above and the tensile property of the steelbars below. When it’s subjected to external load, it can produce good resisting momentwhich can improve the bearing capacity. The simply supported T-shaped girder bridgecombines the characteristics of the T-shaped girder bridge and the simply supported beambridge, which has clear mechanical behaviors. When it’s subjected to temperature load andbridge foundation displacement, it has no additional internal forces in the structure. Thesimply supported T-shaped girder bridges are easily precast by factories. This kind ofcontainerization construction can greatly shorten the construction period and save theconstruction cost.On the one hand, with the extension of the bridge service period, this kind of bridgewill encounter many different kinds of diseases, which will lead to the decline in the carryingcapacity of the bridge itself. The main disease types of this kind of bridge are concretecracks in girders, steel corrosion, concrete carbonation and diaphragm damage, on the otherhand, with the continuous improvement of the traffic load grades, the simply supportedT-shaped girder beams built early have already failed to meet the needs of the modern traffic.Regarding the problem of carrying capacity shortage of the simply supported T-shapedgirder bridges, one way to deal with is to dismantle all and build new, which is unreasonablein technology and infeasible in economy. One effective processing method is to make clearthe actual carrying capacity of the bridge structure and according to the existing carryingcapacity of the bridge to conduct maintenance, reinforcement, limiting load and rebuilding.In order to master the actual carrying capacity, the most effective method is to detect thebridge structure and accurately assess the carrying capacity of the bridge based on thedetected data.At present, the bridge detection method can be divided into nondestructive testingmethod, static load testing method and dynamic load testing method three categories. Thenondestructive testing much relies on the experience of the detection personnel. So it’s not easy to assess the carrying capacity accurately and objectively. While the static load testingmethod and the dynamic load testing method assess the carrying capacity respectively basedon the static responses and the dynamic responses of the bridge structure, so the assessmentresults are much more accurate and objective.To the simply supported T-shaped girder bridges, now there is no specialized andeffective static load testing and dynamic load testing method. Therefore, it’s of greatmeaning to conduct researches on the static load testing and the dynamic load testing methodof the simply supported T-shaped girder beams.Based on the project of Mingshui Western Bridge in Hinggan League of NeimengProvince, the paper mainly conducts the following researches:1. Based on the fundamental principle and solving process of the finite element, itbuilds the theoretical analysis model of the simply supported T-shaped girder beam by meansof grillage method. And it clears the general method and the basic solution process ofbuilding the theoretical analysis model of the simply supported T-shaped girder beam bymeans of grillage method.2. It discusses the general process and the special matters of the dynamic load testing ofthe simply supported T-shaped girder beam, and relying on one simply supported T-girderbeam, clears the excitation method and the dynamic response collection method. Accordingto the characteristics of the dynamic responses collected, it presents the dynamic parameterdetection method combining the NEXT and ERA. Then it applies the above method into thedynamic load test of one simply supported T-shaped girder beam bridge, includingmeasuring the dynamic responses, analyzing the dynamic parameters and assessing theservice state based on the dynamic parameters.3. It discusses the general process of the static load tests of the simply supportedT-shaped beam bridges and the assessment method for this kind of bridge based on the staticload testing data. According to the theoretical calculation, the test load of this bridge iscleared. According to the testing purpose, the static measuring point arrangement method ofthis bridge is cleared. According to the static load test data measured, the carrying capacityof this bridge is assessed combining the checking method of bridge structures.