体外预应力石结构抗震性能研究

发布时间：2018-06-30 08:47

本文选题：体外预应力 + 粗料石砌体墙　；参考：《东南大学》2016年硕士论文

【摘要】：我国东南沿海地区(尤其是福建地区)盛产石材,该地区村镇建筑以石砌体结构为主,具有浓厚的建筑特色和悠久的历史。然而,调研发现,该地区石结构大多未设置圈梁、构造柱,抗震性能较差,存在“小震成灾、大震大灾”的隐患。为提出合理的提高粗料石砌体抗震性能方法,本文开展了体外预应力粗料石砌体墙抗震性能试验研究。通过7片粗料石砌体墙的水平低周反复荷载试验,研究了体外预应力大小、预应力钢筋布置形式、窗洞口等不同参数对体外预应力粗料石砌体墙的受力过程、破坏形态、抗剪强度、滞回曲线、骨架曲线、变形能力、耗能能力以及刚度退化等抗震性能的影响。研究结果表明：体外预应力粗料石砌体墙的破坏过程可近似划分为弹性阶段、弹塑性阶段和摩擦耗能阶段;体外预应力不仅大大提高了墙体的开裂荷载和极限荷载,又能显著改善墙体的变形能力、延性和耗能能力;墙体开裂荷载和极限荷载随着体外预应力的增加而增大,体外预应力改变了墙体破坏形态和裂缝分布,使破坏时裂缝分布更加均匀,石砌体墙“裂而不散”；墙体滞回性能和耗能能力都随着体外预应力的增加先逐渐增强后逐渐降低,在0.3MPa体外预应力作用下达到最大；体外预应力钢筋能够延缓墙体刚度退化,对墙体倒塌起“二道防线”作用；相比在墙体两端和中间同时布置体外预应力钢筋,预应力钢筋全部布置在墙体两端可以提高墙体开裂荷载,但会降低墙体极限荷载,以及滞回性能、能量耗散系数、刚度退化等抗震性能,在实际工程中建议采用分布式预应力钢筋布置形式；窗洞口对墙体整体性能和抗震性能削弱非常明显,在实际结构中应尽量避免开过大的门窗洞口。根据试验及理论分析,提出了体外预应力粗料石砌体墙的抗剪承载能力理论公式和设计计算公式,该公式与非预应力粗料石砌体墙抗剪承载力计算公式平滑过渡,不仅可用于体外预应力粗料石砌体墙的抗剪承载能力计算,还适用于普通粗料石墙的抗剪承载能力计算。通过计算发现,地震设防烈度低于7度(0.10g)时,粗料石砌体房屋可以不采取任何抗震构造措施,结构抗震承载力可满足要求；对墙体施加0.2MPa体外预应力,可以使粗料石砌体结构抗震性能满足8度(0.2g)时的抗震设防烈度要求；对墙体施加0.3MPa的体外应力,可以使粗料石砌体结构抗震性能满足8度(0.3g)的抗震设防烈度要求。对于我国东南沿海地区(尤其是福建地区)村镇建筑,施加0.2 MPa体外预应力(同时在墙体中间和两端布置预应力钢筋),可以满足该地区粗料石砌体结构的抗震性能要求。本文结合试验施工经验及国内外研究现状,总结了一些有关体外预应力粗料石砌体结构设计和施工方面的建议,可以作为体外预应力粗料石结构设计和施工甚至石结构加固工作的参考。
[Abstract]:The southeast coastal areas of China (especially in Fujian area) are rich in stone production. The village and town buildings in this area are mainly stone masonry structure, with strong architectural features and long history. However, it is found that most of the stone structures in this area have not been set up and the structural columns have poor seismic performance, and the hidden danger of "small earthquake disaster and big earthquake disaster" is put forward. In order to improve the aseismic behavior of the coarse material masonry, the seismic performance of the external prestressed coarse material masonry wall is studied in this paper. Through the horizontal low cycle cyclic loading test of 7 coarse material masonry walls, the size of the external prestressing force, the layout of the prestressed reinforcement and the different parameters of the window hole, etc., are studied. The effect of the stress process of the body wall, the failure form, the shear strength, the hysteresis curve, the skeleton curve, the deformation capacity, the energy dissipation capacity and the stiffness degradation. The results show that the failure process of the external prestressed coarse material stone masonry wall can be approximately divided into elastic phase, elastoplastic stage and friction energy dissipation stage, and external prestressing force can not be used. The cracking load and ultimate load of the wall can be greatly improved, and the deformation capacity, ductility and energy dissipation capacity of the wall can be greatly improved. The cracking load and ultimate load of the wall increase with the increase of the external prestress, and the external prestress changes the damage form and the distribution of the cracks in the wall, so that the distribution of the cracks is even more uniform when the wall is destroyed. "Split but not scattered"; the wall hysteresis performance and energy dissipation capacity are gradually increased with the increase of external prestress, and then gradually decrease and reach the maximum under the effect of 0.3MPa external prestress; the external prestressed reinforcement can delay the wall stiffness degradation and play the role of "two lines of defense" on the collapse of the wall; compared to the two ends and middle walls of the wall. Layout of external prestressed steel bar, the layout of prestressed reinforcement at both ends of the wall can increase the cracking load of the wall, but it will reduce the wall limit load, hysteresis performance, energy dissipation coefficient, stiffness degradation and so on. In practical engineering, it is suggested that the distribution of distributed pre stress reinforcement is adopted in the actual project, and the whole performance of the window hole is on the wall. It is very obvious that the seismic performance is weakened, and the open door and window openings should be avoided in the actual structure. According to the experimental and theoretical analysis, the theoretical formula and calculation formula of the shear bearing capacity of the external prestressed coarse material stone masonry wall are put forward. The formula is smooth transition from the calculation formula of the shear bearing capacity of the non prestressed coarse stone masonry wall. It can be used not only for the calculation of the shear bearing capacity of the external prestressing crude stone masonry wall, but also to the calculation of the shear bearing capacity of the ordinary coarse stone wall. It is found that when the seismic fortification intensity is less than 7 degrees (0.10g), the masonry building of the coarse material can not take any seismic construction measures and the structural seismic bearing capacity can meet the requirements; The application of 0.2MPa external prestress can make the aseismic performance of the masonry structure meet the seismic fortification intensity requirements of 8 degrees (0.2g), and the external stress of 0.3MPa on the wall can make the aseismic performance of the masonry structure meet the seismic fortification intensity of 8 degrees (0.3g). For the southeast coastal areas of China (especially in Fujian area) The construction of village and town, applying 0.2 MPa external prestress (at the same time placing prestressed reinforcement in the middle and both ends of the wall), can meet the seismic performance requirements of the coarse material stone masonry structure in this area. This paper summarizes the construction design and construction of the masonry structure with external pre stress coarse material stone, combining the experience of the construction of the area and the present situation at home and abroad. It can be used as a reference for the design and construction of external prestressed coarse aggregate structure and even for the reinforcement of stone structures.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU363;TU352.11

【参考文献】