Development of External Prestressed Concrete with Large Eccentricities and Establishment of Its Design Method

大偏心体外预应力混凝土的研制及其设计方法的建立

• 批准号: 10555147
• 负责人: MUTSUYOSHI Hiroshi
• 金额: $ 3.78万
• 依托单位: Saitama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10555147/
• 关键词: PRESTRESSED CONCRETE; EXTERNAL PRESTRESSING; CONTINUOUS PC BEAMS; LARGE ECCENTRICITIES

Externally prestressed concrete has recently become popular in bridge structures. However, it has been known from past studies that the ultimate flexural strength of externally prestressed beams is comparatively lesser than that of similar internal bonded beams. One of the possible methods to enhance the flexural strength of externally prestressed beams is to place the tendons with large eccentricities. To verify the flexural behavior of such bridges, an experimental investigation was conducted using model test. In this study, a series of test was carried out on two span continuous beams consisting of different tendon layouts to obtain the fundamental mechanical behavior of such structures. The following conclusions are made from the test.1) The flexural behavior of the beams was not affected by the linear transformation of the tendon layout. The presence of confinement reinforcement did not influence the ultimate strength of these beams.2) The tendon stress increased proportionally to the midspan deformation until yielding of tendon. The type of loading arrangement influenced the rate of increase in external tendons. As such, the ultimate flexural strength of unsymmetrically loaded beams were reduced by about 20%.

外部预应力的混凝土最近在桥梁结构中变得流行。然而，从过去的研究中知道，外部预应力梁的最终弯曲强度比相似的内部粘结梁相对较小。增强外部预应力梁的弯曲强度的可能方法之一是将肌腱放置较大的偏心率。为了验证此类桥梁的弯曲行为，使用模型测试进行了实验研究。在这项研究中，对由不同的肌腱布局组成的两个跨度连续梁进行了一系列测试，以获得此类结构的基本机械行为。通过测试得出以下结论。1）梁的弯曲行为不受肌腱布局的线性变换的影响。限制强化的存在不会影响这些梁的最终强度。2）肌腱应力与中跨的变形成比例增加，直到肌腱产生。负载布置的类型影响了外部肌腱的增加速度。因此，不对称的梁的最终弯曲强度降低了约20％。

项目成果

S. Tamura, T. Aravinthan, H. Mikami and H. Mutsuyoshi: "Flexural Behavior of Two-span External PC Beams with Large Eccentricities"9ィイD1thィエD1 Symposium on Prestressed Concrete. 563-568 (1999)

S. Tamura、T. Aravinthan、H. Mikami 和 H. Mutsuyoshi：“具有大偏心率的两跨外部 PC 梁的弯曲行为”9iD1thieD1 预应力混凝土研讨会 563-568。

Aravinthan, T., Mutsuyoshi, H., Fujioka, A. and Hishiki, Y.: "Prediction of the Ultimate Flexural Strength of Externally Prestressed PC Beams"Proceedings of JCI. Vol.19, No.2 (in printing). (1997)

Aravinthan, T.、Mutsuyoshi, H.、Fujioka, A. 和 Hishiki, Y.：“外部预应力 PC 梁的极限弯曲强度的预测”JCI 会议记录。

T. Aravinthan, H. Mutsuyoshi, Y. Hamada, M. Watanabe: "Experimental Investigation on the Flexural Behavior of Tow Span Continuous Beams with Large Eccentricities"Proc. of the Japan Concrete Institute. Vol.21, No.3. 961-966 (1999)

T. Aravinthan、H. Mutsuyoshi、Y. Hamada、M. Watanabe：“大偏心距双跨连续梁弯曲行为的实验研究”Proc。

T. Aravinthan, H. Mutsuyoshi and Y. Hishiki: "Ultimate Strength and Ductility of PC Beams with External Tendons, IABSE SYMPOSIUM "Long-Span and High-rise Structures""Kobe, Japan. 191-192 (1998)

T. Aravinthan、H. Mutsuyoshi 和 Y. Hishiki：“带有外部筋束的 PC 梁的终极强度和延展性，IABSE 研讨会“大跨度和高层结构””日本神户。

Aravinthan,T.and Mutsuyoshi,H.: "Flexural Strength and Puctility of PC Beams with Extermal Prestressing" The 6th FASE C. 001.2. 805-810 (1998)

Aravinthan,T. 和 Mutsuyoshi,H.：“外部预应力 PC 梁的弯曲强度和塑性”第 6 届 FASE C. 001.2。