已服役20年预应力结构现存预应力的试验研究

发布时间：2018-04-29 02:00

本文选题：在役预应力简支梁 + 应力释放　；参考：《哈尔滨工程大学学报》2014年10期

【摘要】：为了探讨在役预应力混凝土梁中现存预应力值,利用应力释放法对已经服役20年的预应力空心板梁进行切槽法试验。研究了不同的切割位置,切割缝间距对测点应力释放速度的影响;分析了切槽法释放混凝土工作应力随切槽深度、切割缝间距的变化规律,得到了梁体混凝土工作应力得以全部释放的切槽深度;利用数值分析软件建立切割深度与测点残余应力之间的拟合函数,从而推断出梁底表面的初始应力;根据推导的混凝土现存预应力的计算公式,将推导得到的初始应力代入计算公式,获得梁体现存预应力,通过这种方法实现对梁现存预应力的准确预估,以期对混凝土结构有效预应力的评估和桥梁结构评定方法提供一定的参考。
[Abstract]:In order to study the existing prestress value of prestressed concrete beams in service, the slabs with prestressed hollow slabs which have been in service for 20 years have been tested by means of stress release method. In this paper, the effect of cutting seam spacing on the stress release rate of measuring points at different cutting positions is studied, and the variation law of the working stress of concrete released by the notch method with the depth of the slot and the spacing of the cutting joint is analyzed. The cutting depth of beam concrete working stress is obtained, and the fitting function between cutting depth and residual stress of measuring point is established by numerical analysis software, and the initial stress on the bottom surface of beam is inferred. According to the calculation formula of the existing prestress of concrete, the initial stress is substituted into the calculating formula, and the existing prestress of beam body is obtained. Through this method, the accurate prediction of the existing prestress of beam is realized. In order to provide a certain reference for the evaluation of effective prestress of concrete structure and the evaluation method of bridge structure.
【作者单位】：福州大学土木工程学院;福建船政交通职业学院;
【基金】：国家自然科学青年基金资助项目(51108092) 福建省交通科技资助项目(201336)
【分类号】：U441.5

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