一种无粘结预应力混凝土设计方法的研究

发布时间：2018-08-07 19:25

【摘要】：无粘结预应力混凝土目前正在被广泛的应用于连续梁等土建结构中,是建筑工程不可缺少的一种新型技术。它不仅使结构性能优越适应性好,而且能发挥材料的潜能,加快了施工进度,节约了成本具有较高的经济效益。尽管预应力混凝土连续梁结构具有跨高大,相对截面小,控制截面的内力显著大于同规格普通钢筋混凝土连续梁的特点,采用一定量的预应力筋,仍无法避免支座的控制截面非预应力钢筋用量大,导致钢材浪费,施工难度大的问题。目前广泛应用于预应力混凝土结构的塑性设计方法均是基于有粘结预应力混凝土结构特点所建立,其适用性具有一定的局限性。因此,开展无粘结预应力混凝土结构连续梁结构截面曲率延性系数定量定性的研究,并建立适于该结构的塑性设计方法,具有重要的理论及现实意义。本文以预应力混凝土结构设计的常用方法为理论基础,选取张拉引起次弯矩secM与外载弯矩设计值loadM之和为超静定预应力混凝土结构弯矩调幅对象;应用试验数据和计算机模拟技术,构建了无粘结预应力混凝土连续梁弯矩调幅系数和无粘结预应力混凝土受弯构件截面曲率延性系数计算模型,同时对等效塑性铰的长度的度量方法进行了完善和改进;提出了适用于无粘结预应力混凝土连续梁结构的塑性设计方法。本研究成果能够对无粘结预应力混凝土连续梁的塑性设计提供有力的理论依据和技术支持,具有广阔的推广和应用前景。
[Abstract]:Unbonded prestressed concrete (unbonded prestressed concrete) is widely used in civil structures such as continuous beams, which is an indispensable new technology in building engineering. It not only makes the structure superior and adaptable, but also can give full play to the potential of materials, accelerate the construction progress and save the cost with high economic benefit. Although the prestressed concrete continuous beam structure has the characteristics of large span and small relative section, the internal force of the control section is significantly larger than that of the common reinforced concrete continuous beam of the same specification, and a certain amount of prestressed tendons are used. It is still impossible to avoid the problem of steel wastage and construction difficulty caused by the large amount of non-prestressed steel bar used in the control section of the bearing. At present, the plastic design methods widely used in prestressed concrete structures are based on the characteristics of bonded prestressed concrete structures, and their applicability is limited. Therefore, it is of great theoretical and practical significance to study the quantitative qualitative analysis of curvature ductility coefficient of unbonded prestressed concrete continuous beam structure and to establish a plastic design method suitable for the structure. Based on the common methods of prestressed concrete structure design, this paper selects the sum of the secondary moment secM caused by tensioning and the design value of external load moment loadM as the amplitude modulation object of the moment of statically indeterminate prestressed concrete structure. Based on the experimental data and computer simulation technology, the calculation models of moment amplitude modulation coefficient of unbonded prestressed concrete continuous beam and curvature ductility coefficient of unbonded prestressed concrete flexural members are established. At the same time, the method of measuring the length of equivalent plastic hinge is improved, and the plastic design method suitable for unbonded prestressed concrete continuous beam structure is proposed. The research results can provide a strong theoretical basis and technical support for the plastic design of unbonded prestressed concrete continuous beams, and have a broad prospect of popularization and application.
【学位授予单位】：石家庄铁道大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU378.2

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