钢板-混凝土组合加固预应力混凝土箱梁

为了研究钢板-混凝土组合加固技术在桥梁加固工程中的应用,提出了钢板-混凝土组合加固预应力混凝土箱梁的抗弯极限承载力计算公式,采用ANSYS软件选用合理单元类型和材料本构关系,对采用钢板-混凝土组合加固的某火灾受损预应力混凝土箱梁桥进行了非线性有限元数值模拟分析对比,并做了加固后效果验证性荷载试验,还对组合加固和粘钢加固效果进行了对比。结果表明：简化公式计算结果与数值分析结果偏差在5%以内;加固后结构关键截面抗弯极限承载力提高30%以上,应变校验系数降低为0.57～0.70,挠度值减小明显,结构基频提高了19%,横向分布系数理论值与实测值比值为0.93～1.05,吻合良好;组合加固梁体校验系数降低为0.66～0.82,较合理且相对均匀,结构受力协同性较好,更有利于提高结构整体受力性能。

Prestressed concrete box girder strengthened with comsposition of steel plate and concrete

In order to study the application of steel plate and concrete composite strengthening(SPCCS) technology in bridge reinforcement,a formulation for calculating ultimate bearing resistance of prestressed concrete box girder was presented.A nonlinear finite element model was established using ANSYS with right material parameters for a prestressed concrete box girder bridge which was damaged in a fire and strengthened with SPCCS.A comparison was made between numerical analysis results and function formula data.A loading test was carried out to verify the effect,the results of SPCCS and steel plate strengthening were compared.The results show that the deviation of numerical analysis results and function formula data is within 5%,the ultimate bending capacity of important section is improved over 30%,the verification coefficient of strain is reduced to the one from 0.57 to 0.70,the bending deflection is decreased significantly,the fundamental frequency of structure is improved by 19%,the ratio of theoretical and observed value of the load distribution coefficient is from 0.93 to 1.05,the strain verification coefficient of beams which is reinforced with SPCCS is reduced to the one from 0.66 to 0.82,it is more reasonable and relatively homogeneous.The collaboration of structure become better than before,it is helpful to improve the structural force performance.