酸性大气环境下再生混凝土砖组合墙抗震性能试验研究及地震易损性分析

发布时间：2018-03-31 17:45

本文选题：再生混凝土砖　切入点：酸雨　出处：《西安建筑科技大学》2015年硕士论文

【摘要】：砌体结构是一种具有悠久历史的建筑结构形式,其在我国乃至世界各地均具有非常广泛的应用。改革开放以来,随着我国经济的迅速发展,环境的污染不可避免的造成了酸雨问题,而酸雨对建筑物造成的伤害已成为我国建筑物过早退役的罪魁祸首之一。随着酸雨对砌体结构腐蚀程度的加深,结构的整体承载力会下降,使用功能降低,这严重影响了其耐久性,砌体结构在酸雨环境作用下的性能退化研究势在必行。本文设计制作了8榀再生混凝土组合墙片,采用人工模拟酸雨腐蚀试验对墙片进行了不同程度的腐蚀。随后通过墙片的低周反复加载试验研究了再生混凝土砖组合墙抗震性能随酸雨腐蚀循环次数增加的退化规律。试验结果对比分析表明,随着试件受酸雨腐蚀程度的增加,试件的开裂荷载、极限荷载整体上呈现下降的趋势,而开裂位移、极限位移大致上呈增长的趋势,其初始刚度逐渐减小,试件的延性变差,耗能能力变弱。随后,简要分析酸性大气环境下墙体性能退化原理,由细观角度上来讲,墙体性能退化的原因为随着酸雨腐蚀,砂浆及砖的密实度持续加强直至达到饱和状态发生膨胀破坏,从而产生微裂缝降低砂浆与砖的强度;由宏观角度上来讲,酸雨腐蚀使得砂浆与砖的胶结面更容易产生微裂缝,甚至产生粘结面局部脱离,使得其抗剪强度的下降。在试验的基础上对带构造柱墙体极限荷载计算公式进行了修正并结合本文及国内诸多文献的试验值进行了对比分析,结果表明本文修正理论计算公式具有很好的精确性。随后,介绍了陆新征-曲哲恢复力模型及其关于砌体结构各参数的标定,针对个别参数进行了修正。接着,基于损伤理论建立了砌体结构损伤恢复力模型,并基于损伤恢复力模型在有限元软件MARC中利用三弹簧单元模型进行了有限元模拟。基于损伤的陆新征-曲哲模型可以很好的考虑砌体结构材料退化特性,同时也证明了三弹簧单元模拟砌体构件的滞回性能有很好的准确度。最后,本文选取了典型的在役砌体结构建筑并在有限元软件中进行了结构建模,对有限元模型中的不同的墙片进行了分类,并针对所有墙片代入基于损伤理论的陆新征-曲哲恢复力模型。随后,根据地震波选波原则选取12条地震波并对结构进行了IDA分析,最终建立了结构不同损伤程度的地震易损性曲线。易损性分析结果表明,随着结构损伤程度的增加,结构在各极限破坏状态对应的超越概率增大。计算结果可为既有的砌体结构抗震性能评估提供理论依据。
[Abstract]:Masonry structure is a kind of building structure with a long history, which is widely used in our country and all over the world.Since the reform and opening up, with the rapid development of China's economy, the pollution of the environment inevitably caused the acid rain problem, and the damage caused by acid rain to the buildings has become one of the main culprits of premature decommissioning of the buildings in our country.With the deepening of the corrosion degree of the masonry structure by acid rain, the overall bearing capacity of the structure will decrease, and the use function will be reduced, which seriously affects the durability of the masonry structure, so it is imperative to study the performance degradation of the masonry structure under the action of acid rain environment.In this paper, 8 pieces of recycled concrete composite wall were designed and manufactured, and the corrosion of the wall was carried out by artificial simulated acid rain corrosion test.Then the degradation law of seismic behavior of recycled concrete brick composite wall with the increase of acid rain corrosion cycle is studied by low-cycle repeated loading test.The comparative analysis of the test results shows that with the increase of the corrosion degree of the specimen by acid rain, the cracking load and the ultimate load of the specimen show a downward trend, while the cracking displacement and the ultimate displacement generally show an increasing trend.The initial stiffness decreases gradually, the ductility of the specimen becomes worse and the energy dissipation capacity weakens.Then, the principle of wall performance degradation in acidic atmosphere is briefly analyzed. From a meso point of view, the reason of wall performance degradation is that the compactness of mortar and brick continues to strengthen with acid rain corrosion until it reaches saturation state.From the macroscopic point of view, acid rain corrosion makes the cement surface of mortar and brick easier to produce micro-cracks, and even produces local detachment of bond surface, which makes the shear strength of mortar and brick decrease.On the basis of experiment, the formula for calculating ultimate load of wall with structural column is revised and compared with the experimental data of this paper and many domestic literatures. The results show that the modified formula has good accuracy.Then, the Lu Xinzheng-Quzhe restoring force model and its calibration about the parameters of masonry structure are introduced, and some parameters are modified.Then, based on the damage theory, the damage restoring force model of masonry structure is established, and the damage recovery force model is simulated by using the three-spring element model in the finite element software MARC.Luxin-Quzhe model based on damage can take into account the degradation characteristics of masonry structure materials, and it also proves that the three-spring element can simulate the hysteretic behavior of masonry members with good accuracy.Finally, this paper selects the typical in-service masonry structure building and carries on the structure modeling in the finite element software, has carried on the classification to the different wall piece in the finite element model.According to the damage theory, the model of Lu Xinzheng-Quzhe's restoring force is put into all the wall plates.Then, according to the principle of seismic wave selection, 12 seismic waves are selected and analyzed by IDA. Finally, the seismic vulnerability curves of structures with different damage degree are established.The results of vulnerability analysis show that with the increase of the damage degree of the structure, the corresponding transcendental probability of the structure in various ultimate failure states increases.The calculated results can provide theoretical basis for seismic performance evaluation of existing masonry structures.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU364;TU352.11

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