The Application Of Moses Algorithm On The Identification Of Axle Weigts Of Moving Vehicles On Wide Bridge

Generally, weigh-in-motion (WIM) systems are divided into pavement WIMsystems and bridge WIM (BWIM) system. BWIM system uses instrumented bridge asa large sensor to identify axle weights of heavy vehicles passing the bridge. Basically,BWIM system takes the influence line (IL) of the mid-span bending monments as areference to calculate axle weights. Therefore, to obtain an IL which is closer to theactual condition of the instrumented bridge is substantially important for improvingthe accuracy of the identified axle weights. Commercial BWIM systems usuallyassume the ILs along the transversal direction of bridge are identical, and the bridge isconsidered as a one-dimensional structure. It is reasonable for the case that the bridgedeck is not wide and the number of bridge girder is less. However, when the bridgedeck is wide and there are a large number of girders, the successful application ofBWIM technology in this type of bridge needs further investigation. Based on fieldtests on an approach span of the Fifth Huaihua Bridge located in Huaihua, Hunanprovince, China, the application of Moses algorithm together with the Tikhonovregularization technique was investigated on the identication of axle weigts of movingvehicles on wide bridge. The fomula was derived, the algorithms are implementedwith computer program developed in MATLAB software, and the identified axleweiths are verified by the field test results. Emphasis of this thesis was put on thefollowing aspects:(1) To derive the corresponding formulae of the calibration of IL, theidentification of axle weiths with traditional Moses algorithm, and the application ofthe Tikhonov regularization technique in BWIM system as well.(2) To calibrate the bending-moment ILs of each lane based on the field-test data,and to compare the calibated ILs of different lanes. The results indicate that thecalibrated ILs of each lane is different in wide bridge. IL of each lane, therefore,should be calibrated respectively, and the axle weights of passing vehicles along alane should be calculated base on the IL calibrated from vehichles passing along thisspecific lane when applying BWIM technology to wide bridges.(3) To identify the axle weights of vehicles along different lanes with traditionalMoses algorithms based on the calibrated ILs. Comparsison analysis indicates that theidentified axle weights for vehicles along a specific lane exhibits more accetable accuracy by taking the calibrated IL from that very lane as a reference.(4) To optimize the identified axle weights with the application of Tikhonovregularization techinique. Field test results verify that Tikhonov regularizationtechnique can effectively improve the accuracy level of the identified axle weightswith the application of BWIM technology to wide bridges.