一、前言 目前我国无论是公路、铁路还是城市立交桥梁,多采用“后张预应力箱梁结构”,在设计、施工及验收质量标准方面,都积累了相当宝贵的经验。 近几年,建筑市场竞争激烈。相当一部分施工企业采用粗放经营,扩大外延的办法增加在施面积。这种方法使得企业的整体素质、管理水平很难提高。由于企业不善于技术积累和技术跟踪,很难形成具有本企业特色的综合配套技术。为此,建设部于1989年 I. Preface At present, no matter whether it is a highway, a railway or an urban overpass bridge, most of the time, the “post-tensioned prestressed box beam structure” has accumulated considerable valuable experience in the design, construction and acceptance quality standards. In recent years, the construction market is highly competitive. A considerable part of the construction enterprises using extensive management, expansion of the extension of the measures to increase the area in the facilities. This method makes the overall quality of enterprises, the management level is difficult to improve. Because enterprises are not good at technology accumulation and technical tracking, it is difficult to form a comprehensive supporting technology with the characteristics of this enterprise. To this end, the Ministry of Construction in 1989