为了对公路预应力混凝土空心板梁旧桥的承载力进行评定,采用单梁试验及承载力评价方法.选取病害较重、横向分布系数较大位置的空心板梁,按铰接板法计算空心板跨中的横向分布系数,按照形心高度、面积和惯性矩不变的原则,将空心板等效为工字形截面,计算出单梁承载力和相应的理论应力值及挠度值.对单梁进行试验加载并测试其应力和挠度,通过理论值与实测值的对比,评估单梁的结构性能.通过对一座13 m跨径预应力空心板梁桥单梁试验及受力性能进行评价,证明了单梁试验是一种实用有效的方法.%To evaluate the bearing capacity of old highway prestressed concrete (PC) hollow slab beam bridges, the method of testing and bearing capacity evaluation of single beam was employed. The hollow slab beams with severe deteriorations and at the locations where the transverse distribution coefficients were great were selected and the transverse distribution coefficients of midspans of the slab beams were calculated by the hinged slab method. The slab beams were firstly equalized as the I-shape cross sections on the principle that the centroid height, areas and moment of inertia remained unchanged and the bearing capacity of a single beam and the corresponding theoretic stress and deflection values were calculated. The single beam was then loaded, tested and its stress and deflection were measured. By comparison of the theoretic and measured values, the structural performance of the single beam was finally evaluated. The testing and evaluation of mechanical behavior of the single beam of a 13-m span PC hollow slab beam bridge proves that the method of testing and bearing capacity evaluation herewith is well practical and effective.
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