空斗墙及HPFL加固空斗墙的抗震性能研究

发布时间：2018-01-19 01:17

本文关键词： 空斗墙高性能复合砂浆钢筋网加固抗震性能非线性有限元分析　出处：《湖南大学》2013年博士论文　论文类型：学位论文

【摘要】：综述国内外砌体结构抗震性能、结构加固和砌体结构有限元仿真分析的研究现状和发展趋势。在大量试验和有限元仿真分析的基础上，对空斗墙片和HPFL条带加固空斗墙片的抗震性能进行了较系统的研究。对砌体分离式有限元模型进行了研究。建立了考虑砂浆与砖块之间黏结作用和剪切滑移作用的双剪面单砖砌体试件的三维有限元模型。由于砖与砂浆之间的黏结滑移关系目前研究尚不成熟，本文提出了一种黏结滑移关系曲线，并以试件在剪压作用下的试验结果为目标函数，提出一种改进的遗传算法，通过APDL语言编制反演程序，在有限元软件ANSYS中实现黏结滑移关系曲线的参数反演。该分离式有限元模型和黏结滑移关系曲线能用于砌体墙片的有限元分析中。对24片空斗墙试件和3片实砌墙试件进行了拟静力试验。通过墙片的拟静力试验观察墙片的整个破坏过程，分析墙片的破坏形态和抗剪承载力、滞回曲线、骨架曲线、延性等抗震性能指标。建立了空斗墙分离式有限元模型。在试验结果和有限元分析的基础上，系统的研究了砌筑方式、砌筑材料强度、高宽比和竖向压力对空斗墙抗剪性能的影响。砌筑方式不同，对空斗墙抗剪性能有所影响，但影响不大，在实际工程应用中，，均可按全斗墙考虑，偏于安全。不同的砌筑材料强度对空斗墙抗震性能的影响较大。随着砂浆强度的提高，空斗墙的开裂荷载和极限荷载均提高。随着高宽比增大，墙体抗剪承载力减小。在相同条件，竖向压应力较小的情况下，随着竖向压应力增大，空斗墙的抗震承载力和变形能力均增大；当竖向压应力达到空斗墙竖向承载能力的0.6倍左右时，竖向压应力继续增大，空斗墙的抗震承载力反倒减小。依据库仑理论、主拉应力理论以及主压应力强度理论，首次提出了剪压状态下空斗砌体的破坏准则。提出了空斗墙的抗剪强度计算公式。对9片采用高性能复合砂浆钢筋网（HPFL）条带修复已损坏空斗墙和9片HPFL条带加固未损坏空斗墙与9片修复前的墙体和3片未加固墙体的对比墙体进行了拟静力试验，分析墙片的破坏形态和开裂荷载、极限荷载、滞回曲线、骨架曲线、刚度退化等性能指标。研究表明，采用HPFL条带修复的方法能恢复甚至提高受损空斗墙结构的抗震性能；采用HPFL条带加固无损空斗墙结构，能大幅提高墙体的极限承载力，改善墙体的延性和刚度退化。建立了HPFL条带加固空斗墙的分离式有限元模型。在试验结果和有限元分析的基础上，系统分析了加固条带宽度、加固面层砂浆强度、加固层钢筋网密度、砌筑砂浆强度、墙片高宽比和竖向压应力等因素对加固效果的影响。加固条带宽度对HPFL条带加固性能的影响很大，增大加固条带的宽度是提高墙体抗剪承载力的最有效方式。随着加固面层砂浆强度的提高，墙体的抗剪承载力随之提高。随着加固层钢筋网格尺寸加密，极限承载力略有增大，但提高效果不明显。不同砂浆强度砌筑的墙体，HPFL条带加固均能较大幅度的提高墙体的极限承载力；砌筑砂浆强度较高的墙体，加固后极限承载力的提高幅度略大于砌筑砂浆强度较低的墙体。经过HPFL条带加固的空斗墙的效果受高宽比变化的影响较小，HPFL条带圈梁构造柱式加固方式对各种高宽比的空斗墙都是有效的。HPFL条带圈梁构造柱式加固空斗墙，受竖向压应力大小的影响，条带的受力原理有所不同，但该加固方式对各种竖向压应力下的空斗墙都是有效的。提出了HPFL条带加固空斗墙的抗剪强度计算公式。
[Abstract]:Overview of seismic performance of masonry structure at home and abroad, the research status and development trend of structural analysis and finite element simulation of reinforced masonry structure. Based on the analysis of a large number of experiments and finite element simulation, the empty bucket wall and HPFL strip empty bucket wall seismic performance were systematically studied.
The masonry separated finite element model is studied. Considering the three-dimensional finite element model of the double shear test of single brick masonry bonding and shear slip effect between mortar and bricks. The relationship of bond slip between brick and mortar of the present study is not mature, this paper presents a bond slip relationship curve and, with specimens in the shear test results under pressure as the objective function, an improved genetic algorithm is proposed, through the APDL language program to realize parameter inversion inversion, bond slip relation curve in finite element software ANSYS. The separation type finite element model and bond slip relationship curve can be used to finite element masonry the wall was analyzed.
The 24 empty bucket wall specimens and 3 pieces of solid walls are tested by the pseudo static test. Through the whole failure process of wall pseudo static test observation of wall, analysis of failure mode of wall and the shear bearing capacity, hysteretic curve, skeleton curve, ductility and seismic performance index.
The establishment of the cavity wall separate finite element model. Based on the experimental results and finite element analysis on the system of construction, the strength of masonry materials, high aspect ratio and vertical pressure effect on the bucket wall shear capacity of masonry. In different ways, impact on the cavity wall shear performance, but the impact is not big, in practical engineering applications, can be considered as a full bucket wall, on the safe side. Construction material has great influence on the strength of different cavity wall seismic performance. With the improvement of mortar strength, cavity wall cracking load and ultimate load are increased. As the aspect ratio increases, the wall shear stress decreased. In the same conditions, the vertical compressive stress is smaller, with the vertical compressive stress increases, the empty bucket wall seismic bearing capacity and deformation capacity are increased; when about 0.6 times the vertical compressive stress reaches the cavity wall of vertical bearing capacity, vertical compressive stress to In addition, the seismic bearing capacity of the bucket wall decreases.
Based on Coulomb theory, principal tensile stress theory and principal compressive stress strength theory, the failure criterion of hollow bucket masonry under shear pressure is first put forward. A formula for calculating shear strength of hollow bucket wall is put forward.
The 9 sheets with high performance ferrocement (HPFL) strip to repair a damaged wall of an empty bucket and 9 pieces of HPFL strip without damage of cavity wall and 9 pieces of repair before the wall and 3 pieces of unreinforced wall between the wall of the pseudo static test, analysis of failure modes and the cracking of wall load, ultimate load, hysteretic curve, skeleton curve, stiffness degradation and other performance indicators. The results show that the method of HPFL strip repair can restore and even improve the seismic performance of damaged air bucket wall structure; using HPFL strip lossless cavity wall structure, wall can significantly improve the ultimate bearing capacity, improve the wall the ductility and stiffness degradation.
The establishment of the HPFL strip cavity wall of the separate finite element model. Based on the experimental results and finite element analysis, systematic analysis of the reinforcement strip width, the strength of mortar layer reinforcement, reinforcement layer steel mesh density, strength of masonry mortar, influence of wall aspect ratio and vertical stress and other factors on the effect of reinforcement. The reinforcement strip width of HPFL strip reinforcement effect properties and reinforcement increases the width of the strip is to improve the shear capacity of the most effective ways. With the strength of mortar surface layer reinforcement, shear strength increases with the increase of the wall. With the reinforcement of reinforced mesh size encryption. A slight increase of ultimate bearing capacity, but the improving effect is not obvious. Different mortar strength of masonry wall strengthened with HPFL strips can greatly improve the ultimate bearing capacity of the wall; the wall masonry mortar with high strength, reinforcement of the ultimate bearing capacity The increase is slightly larger than the low strength mortar wall strengthened with HPFL strips. After the empty bucket wall by the effect of the ratio of height to width smaller changes, HPFL strip pillar reinforcement ring beams and constructional way are effective.HPFL strip pillar reinforcement cavity wall beam structure of high aspect ratio of cavity wall. The vertical compressive stress influence the size of the strip force principle is different, but the way of strengthening of the vertical stress of the cavity wall are effective.
A formula for calculating the shear strength of a HPFL strip reinforced empty bucket wall is proposed.

【学位授予单位】：湖南大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU352.11;TU364

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