改性夯土墙体结构的有限元数值模拟分析

发布时间：2018-10-15 13:29

【摘要】：近年来,由于人们的环保意识开始觉醒,对绿色建筑的追求也开始显现,于是对于生土建筑的研究也逐渐增多。虽然生土建筑拥有诸如节能环保、造价低廉、保温隔热等优点,但由于土体本身力学性能差,再加上施工缺乏相关的规范,使得其在承载力与抗震性能方面都无法与现代建筑结构相比。本文则重点着眼于传统夯土墙农房在力学性能上的缺陷,通过实地调研和力学试验并利用数值模拟的方法对改性夯土墙体的力学性能和抗裂性能进行了分析,并对整体夯土农房抗震性进行了分析。本文首先对西南地区的生土结构农房进行了调研,归纳总结与分析了该地区的生土结构农房的主要结构形式、破坏特征与抗震性能。以调研过程中出现比例较高的单层对称夯土农房为例,通过在土体中加入纤维、固化粉末及石子的改性方式,以探究出一种能够有效提高夯土墙体力学性能的夯土改性方案。通过力学试验以确定备选方案中最优的夯土改性方案。力学试验通过对不同改性材料在抗压强度、抗剪强度与抗拉强度上的对比试验最终确定了1%纤维5%石子(5mm、10mm、15mm等比均分)质量比的改性方案为备选方案中的最优方案。通过有限元数值模拟的方法,对素夯土与改性夯土这两种材料进行对比分析。分析包括:单片墙体在竖向荷载与单调水平荷载下的位移、开裂和破坏情况;整体夯土农房在地震作用下,关键节点的地震时程反应分析。分析结果表明1%纤维5%石子的夯土改性方案,在提高夯土农房的承载力与抗震性能方面均有显著效果。
[Abstract]:In recent years, due to people's awareness of environmental protection began to wake up, the pursuit of green buildings also began to appear, so the study of raw land architecture has gradually increased. Although raw soil buildings have the advantages of energy saving and environmental protection, low cost, thermal insulation, etc., but due to the poor mechanical properties of the soil itself and the lack of relevant specifications for construction, It can not compare with modern building structure in carrying capacity and seismic performance. This paper focuses on the defects of mechanical properties of traditional rammed earth walls, and analyzes the mechanical properties and crack resistance of the modified rammed earth walls by means of field investigation, mechanical tests and numerical simulation. The seismic resistance of the whole rammed soil farm house is analyzed. In this paper, the main structural forms, damage characteristics and seismic behavior of the raw soil structure agricultural houses in Southwest China are summarized and analyzed. Taking the monolayer symmetrical rammed soil farm house with a high proportion in the investigation process as an example, by adding fiber, solidified powder and stone to the soil, a modified scheme of rammed soil can be found out, which can effectively improve the mechanical properties of rammed soil wall. The optimum tamped soil modification scheme was determined by mechanical test. Through comparing the compressive strength, shear strength and tensile strength of different modified materials, the modification scheme of 1% fiber 5% stone (5 mm / 10 mm / 15mm) was determined as the best option. The finite element numerical simulation method is used to compare and analyze the two kinds of materials: the modified rammed soil and the plain rammed soil. The analysis includes the displacement, cracking and failure of monolithic wall under vertical load and monotone horizontal load, and the seismic time history analysis of the key nodes of the whole rammed soil farm house under earthquake. The results show that the modified scheme of 1% fiber 5% stone has remarkable effect on improving the bearing capacity and seismic performance of the rammed soil farm house.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU361

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