In-situ loading test and analysis on large-span steel truss structure
During the construction stage of an 85m span steel truss some diagonal web rods experienced global buckling and the lower chord experienced local deformation,and the corresponding diagonal web rods were replaced immediately.In order to evaluate the reliability of the repaired steel truss,in-situ loading tests were conducted.The water loading method was employed to apply a load of 9kN/m to the steel truss.The test results indicate that the stress and displacement of the steel truss change approximately linearly with the load,and the values of stress and displacement are small,which all meet the requirements of relevant codes.The finite element analysis of the steel truss in the in-situ loading stage was carried out.The results show that the finite element analysis results of the in-situ loading stage are in good agreement with the test results.Considering that the steel truss has already bored most of the dead load prior to in-situ loading,the whole construction process simulation of the steel truss was conducted to obtain the stress state of the bars during the whole construction process.Compared to the designed ideal state,the axial forces in the lower chords near the jacking point is close to the ideal values,but the bending moments increase.Additionally,after construction,the steel truss exhibits slight deviations in its shape,with a slight bulge near the jacking point.The results of in-situ test and structural analysis show that the replacement of the diagonal web rods has no significant effect on the overall structural stress performance,and the structure is safe and can be used normally after the replacement of the diagonal web.
steel trussin-situ loading testconstruction process analysisdisplacementstress
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