【摘要】 预应力在大跨度曲线桥梁中的使用,给预应力的分析研究以及张拉施工提出了新的问题,尤其是施工中的一些问题亟待解决,如摩擦系数、曲率等的改变,都会给预应力的分布带来不利的影响。现有的力学模型又无法满足解决这些问题的需求,建立一种适用于大跨度曲线预应力桥梁预应力钢束张拉施工的新模型是必要的。本文给出了预应力钢束张拉的控制模型,并在施工中得以验证,取得了令人满意的效果。该模型不仅可以解决一些诸如摩擦系数这类可确定因素的变化问题,亦可处理一些不确定因素给施工所带来的影响。按照这一模型所规定的方式进行施工,大大改善了预应力在钢束中的分布情况,提高预应力的使用效果是显著的。更多还原

【Abstract】 The use of prestressing in curved large span bridges results in new problems to analysis and construction. Especially, some problems in construction have to be solved, for example, friction coefficients and curvature change, which would affect significantly the distributing of prestressing in tendons. The available mechanics models are helpless to solve these problems. It is necessary to establish a new model that is applicable to the tension of tendons in curved prestressed large span concrete bridge girders. The model of tension under control given in this paper can deal with the above problems, and has been validated in practical engineering. The results are satisfactory. The model can not only solve the problems of friction coefficients and curvature change in practice but also deal with some uncertainties. Constructions with reference to the model have improved the distributing of prestressing in tendons.更多还原