UPPC梁的开裂截面惯性矩及挠度计算研究

发布时间：2018-03-03 10:49

本文选题：预应力混凝土　切入点：无粘结筋　出处：《工程力学》2014年02期 　论文类型：期刊论文

【摘要】：为满足无粘结部分预应力混凝土(UPPC)梁正常使用极限状态的设计要求,必须合理估算使用荷载下构件的挠度。由于预应力筋与其周围混凝土没有粘结,加之部分预应力混凝土梁的中性轴随外荷载而动,开裂截面形心轴及开裂截面惯性矩也跟着变,这给UPPC梁的挠度计算带来了困难。该文建立了一个UPPC梁的开裂截面惯性矩计算方法,在此基础上,可以按Branson方法很容易地计算出截面有效惯性矩。该有效惯性矩与按《混凝土设计规范》(GB50010-2010)方法所得的有效惯性矩较接近,前者与后者之比在0.89~1.10。计算挠度与3个不同研究者的试验对比表明所建立方法是正确的并具有较广泛的适用性,可用于无粘结预应力筋为纤维复合材料的混凝土梁,而目前的混凝土结构设计规范方法则无法应用于此类构件。
[Abstract]:In order to meet the design requirements of the normal service limit state of unbonded partially prestressed concrete (UPPC) beams, the deflection of members under load must be reasonably estimated. In addition, the neutral axis of partially prestressed concrete beams moves with external loads, and the center-axis of cracking section and the moment of inertia of cracking section also change. This makes it difficult to calculate the deflection of UPPC beam. In this paper, a method for calculating the moment of inertia of cracking section of UPPC beam is established. The effective moment of inertia of the section can be easily calculated according to the Branson method, which is close to the effective moment of inertia obtained by the method of concrete Design Code (GB50010-2010). The ratio of the former to the latter is 0.891.10.The comparison of the calculated deflection with that of three different researchers shows that the proposed method is correct and widely applicable, and can be used in concrete beams with unbonded prestressed tendons as fiber composites. However, the present code method of concrete structure design can not be applied to this kind of component.
【作者单位】：北京交通大学桥梁工程系;香港大学土木工程系;
【基金】：香港研究资助局基金项目(RGC Project No.HKU 710111E)
【分类号】：TU378

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