Application Study On RC Plate-girder Bridge Strengthened With Prestressed High-strength Stainless Steel Wire

A further study is conducted on the performance of RC plate girder bridge strengthened with pre-stressed high-strength stainless steel wire on the basis of the existing tests,the result showed that the bearing capacity and stiffness improved obviously after strengthening. showed that this strengthening technique is suitable to plate girder bridge.Two reinforced concrete plate girder bridges were tested, through comparing the bridge strengthened with pre-stressed high-strength stainless steel wire with the bridge without strengthening in the dates of strain, displacement and natural frequency, the result showed that the two reinforced concrete plate girder bridge have existed some degree of damage, their load grade were lower than original design. the strain, displacement and natural frequency have improved obviously in same condition after strengthening. The midspan stress of the Sanfa bridge and Deqiangou bridge strengthened have decreased, the midspan deflection have decreased 19.8% and 16.7% respectively, natural frequency have improved. the result also showed that bearing capacity and stiffness of the two bridges have improved ,which can recover to the original design grade.The paper discussed the design formulas of strengthening reinforced concrete plate girder bridges with pre-stressed high-strength stainless steel wire. presented the formulas of bearing capacity, stiffness and deflection. Compared the result of formulas with result of finite element analysis software Midas. The results were reasonable, proved that the formulas of bearing capacity, stiffness and deflection were suitable to the strengthening engineering; The formulas can provide some reference for drawing criterion in similar engineering.In addition, combined with the experimental research paper, the author designed a suit of steel strand stretching set and process, and the construction of the need for attention are key link can be suitable to the construction site operation method. This device and construction technique is easy fabrication, tension accurate and easy to operate etc, The stretching set and process were suitable to the engineering. It will provide referenced value for the similar projects for construction, and provides better standardized formulated reference value.