大跨PC箱梁桥腹板裂缝的控制研究

Research on web cracking control of long span PC box girder bridge

本文对大跨预应力砼(PC)箱梁桥从设计和施工两方面对如何有效地控制腹板裂缝进行了讨论,并给出了在建的连续刚构桥纵向筋的部分预应力测试结果,现有夹片式预应力群锚张拉工艺和张拉设备存在着亟待改进的地方,无粘结竖向预应力技术将成为确保竖向短力筋有效预应力的有效措施.

How to control the web cracking of long span prestressed concrete(PC) box girder bridge from two aspects of design and construction effectively is discussed in this paper, and the partial test results of prestressing on longitudinal strands of continuous rigid frame bridge under construction is given out. It is urged to improve the prestressing procedure of jaw vice anchorage and the defects of prestressing facilities. The technique of unbonded tendons on vertical prestressing becomes an effective method of retaining prestressing in short tendons.