基于三维扫描的预应力混凝土梁预应力储备无损评估方法

大型预制构件是大型基建项目必不可少的基础构件,而其中预制构件的预应力储备是否满足要求又直接关系到预制构件的健康程度和生命周期。以新疆葫芦沟特大桥某跨预制箱梁为依托,针对目前预应力混凝土构件预应力张拉控制指标的单一性以及由于内部应力集中导致的数据不可靠性等问题,提出了一种基于三维扫描的预应力储备检测评估新方法,通过算法获取实测连续变形曲线,并与有限元理论变形值对比分析,以变形反向评估各部位预应力储备状态。结果表明：该实验研究对于提高预制构件预应力检测的准确性以及可靠性提供了一种新方法、新思路,对于预制构件出厂检验以及新建混凝土桥梁预应力检测评估具有重要意义。

Nondestructive evaluation of Precast concrete beam prestress reserves by 3D scanning

Large prefabricated components are essential foundations for large-scale infrastructure projects, and whether the pre-stressed reserves of prefabricated components meet requirements is directly related to the health and life cycle of prefabricated components. A new method to test and evaluate prestressing force reserves via 3D scanning is proposed based on a pre-fabricated box girder of Hulugou Bridge in Xinjiang; this method considers the single index of prestressed tension control of prestressed concrete members and the problem of data unreliability caused by internal stress concentration. The measured continuous deformation curve is obtained by the algorithm and compared with the value obtained through finite element theoretical deformation. The prestress reserve state of each part is evaluated by the deformation. This experimental study provides a new method and ideas for improving the accuracy and reliability of expected component prestress detection, which is important for pre-fabricated factory inspection and new concrete bridge prestress detection and evaluation.