Shear Capacity & Seismic Resistance Of RC Beams With Large Web Openings Strengthened By Ribbed Steel Plate

Adhesive ribbed steel plate is an effective reinforcement method for RC beams with openings,which has the advantages of high strength,convenient construction and good stress performance.Ribbed steel plate reinforcement is also a new type of reinforcement method.In order to promote the application of ribbed steel plate reinforcement in the field of earthquake resistance,more in-depth research is needed on the basis of static tests.Based on the bending test results of the RC beam with a large opening at the web reinforced by the pasted steel plate/ribbed steel plate,the stress characteristics and failure mechanism of the reinforced beam are clarified through the test phenomenon and failure state of each specimen during loading,and the opening size,opening Influence of parameters such as hole position and anchor bolt structure on the shear capacity of reinforced web beams.The results show that the unreinforced open beams are all brittle shear failures.Although the plain steel plate reinforced specimens have greatly increased bearing capacity,the failure still shows brittle characteristics.The ribbed steel plate can restrain the steel plate from out-of-plane buckling and instability.The mode change is more ductile.The larger the opening size,the more significant the weakening effect of the test piece,but the more significant the mechanical performance improvement brought by the reinforcement of the pasted steel plate or ribbed steel plate.High hole openings,large bending moments and biased opening locations towards the compression zone all weaken the mechanical properties of the compression concrete at the entrance.Multi-hole test specimens have complex forces in the opening area,and it is preferable to take the multihole outer envelope as a boundary to approximate a single large hole.The anchor bolts around the opening can improve the integrity of the reinforcement system and restrain the stripping of the steel plate to a certain extent,but its contribution to the shear calculation should not be considered,and it should only be used as a structural measure.According to the experimental analysis results,a calculation model for the shear capacity of RC beams strengthened with ribbed steel plates was established,and the calculated results are in good agreement with the experimental results.According to the static loading test results of RC beams with web holes strengthened by ribbed steel plate,the finite element model of RC beams with web holes strengthened by ribbed steel plate was established by ABAQUS program according to its stress characteristics and failure mode,and the seismic behavior of RC beams with web holes strengthened by ribbed steel plate was studied.The main changing parameters in the study include the length of the opening,the height of the opening,the location of the opening,the number of openings,and the thickness of the steel plate.The results of simulation calculations show that the higher the opening height and the longer the opening,the lower the seismic performance of the opening beam,the horizontal sections of the skeleton curve of each opening beam decrease in sequence,the area surrounded by the hysteresis curve decreases,and the energy consumption capacity follows reduce.The farther away the opening is from the loading end,the greater the superimposed effect of bending moment and shear force on the opening area,the more obvious the stress concentration effect caused by the opening,the faster the cracks are generated and developed at the opening,and the seismic performance of the specimen Weaken.The hysteretic performance,energy consumption capacity and bearing capacity of open double-hole beams are lower than those of single-hole beams,but the ductility coefficient is slightly higher than that of single-hole beams with the same opening area.The opening of the tunnel is shifted in the beam height direction,and the height of the concrete section of the upper limb is small,which adversely affects its seismic performance.The opening beam is reinforced with ribbed steel plates,which effectively inhibits the occurrence and development of cracks at the corners of the opening,improves the integrity of the concrete in the opening area,and prevents the component from losing its bearing capacity due to the premature crushing of the concrete in the opening area.Improved seismic performance of the beam.The influence of the thickness of the steel plate on the reinforcement effect is also discussed.The seismic resistance and the economics of the materials should be considered comprehensively,and the thickness of the reinforced steel plate should be selected reasonably.