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一、概述在我国林区公路桥梁中,小跨径钢筋混凝土简支梁桥为数较多。所占比例最大,中等跨径和大跨径的预应力混凝土梁桥也在迅速发展。在目前运营使用多年的桥梁中,已有若干桥梁存在基础冻胀,桥面破损,主梁混凝土表面裂缝,剥落及露筋等病害现象。这对现有桥梁正常发挥其承载能力与运营使用产生不利的影响。尤其近年来,运材车辆的荷载等级与运行速度均有明显提高,对运营桥梁的使用质量与承载能力提出了更高的
I. Overview In our country’s forest road and bridge, a small number of reinforced concrete simply-supported beam bridges are numerous. The proportion of the largest, medium span and long span prestressed concrete girder bridge is also rapidly developing. Among the bridges that are currently in operation for many years, there are already some bridges with some problems such as foundation frost heaving, devanning of the bridge deck, cracking of the concrete surface of the main girder, peeling and dewings. This adversely affects the normal performance of existing bridges and their operational use. In recent years, in particular, the loading grade and running speed of transported material vehicles have been significantly improved, and the use quality and carrying capacity of operating bridges have been raised.