基于现场试验的预制拼装式挡墙变形特性的数值模拟研究

发布时间：2018-01-10 21:38

本文关键词：基于现场试验的预制拼装式挡墙变形特性的数值模拟研究　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着社会的发展,人们对于工程建筑的景观要求也越来越重视,预制拼装式植生挡土墙是一种新型的挡土墙,具有施工快捷、质量稳定性高、生态环保等特性,因此,预制拼装式绿色挡墙将是未来挡土墙形式的发展方向之一。目前,国内铁路领域对预制拼装式绿色植生挡土墙的受力与变形特性研究极少,因此对此课题开展研究很有必要。针对此课题,本文结合相关的论文文献,对于预制拼装式挡墙的现场试验,采用有限元软件进行数值模拟研究。结合理论分析,对比讨论了现场试验与数值模拟两种研究方法所得到的挡墙的受力和变形特性。进一步,通过有限元软件研究了填土内摩擦角,墙土外摩擦角,墙体刚度,墙体倾斜坡度,基础尺寸等参数对于该新型预制墙体受力与变形及挡墙整体稳定性的影响。得到如下结论:1)基础底部各处土压力随填高增大的数值模拟计算值与现场实测值的变化规律基本吻合,其中墙踵处竖向土压力随填高的增大先增大后减小,墙趾处竖直土压力值随填高的增大逐渐增大,竖直侧土压力值大于倾斜侧;凸榫底部竖向土压力随填高的增加先增加后略微减小,竖直侧土压力值大于倾斜侧;凸榫前沿的水平土压力数值计算值随填高的增加逐渐增加,但增加的速率逐渐降低。倾斜侧基地应力较竖直侧分布更均匀。2)墙体的变位模式为平移、绕墙底某点转动、墙身挠曲三者的共同作用,墙后土压力分布呈不规则曲线。3)墙体水平位移数值计算值随填高的增大逐渐增大,填高4m后水平位移迅速增大,与实测数据变化规律一致,竖直侧水平位移大于倾斜侧。4)采用增大填土的内摩擦角,增大墙土外摩擦角,增加墙体坡度三项措施之一均可以减小墙后水平土压力合力值,减小墙体水平位移,增大墙体的整体稳定系数。5)增大墙体刚度可显著降低墙体的水平位移,而对挡墙的稳定系数无影响。6)不同墙高的基础尺寸理论计算所求得的稳定系数与采用数值模拟求得的稳定系数匹配度很高,可用有限元法辅助预制拼装式挡墙的设计。
[Abstract]:With the development of society, people pay more and more attention to the landscape requirements of engineering buildings. Prefabricated planting retaining wall is a new type of retaining wall, which has the characteristics of fast construction, high quality stability, ecological environmental protection and so on. Therefore, prefabricated green retaining wall will be one of the development directions in the future. At present, there is very little research on the force and deformation characteristics of prefabricated green green retaining wall in the domestic railway field. Therefore, it is necessary to carry out research on this subject. In view of this topic, this paper combines the relevant papers and literature, for the field test of prefabricated retaining wall. Finite element software is used for numerical simulation research. Combined with theoretical analysis, the stress and deformation characteristics of retaining wall obtained by field test and numerical simulation are compared and discussed. The internal friction angle, the external friction angle, the stiffness of the wall and the slope of the wall are studied by the finite element software. The influence of parameters such as foundation size on the force and deformation of the new precast wall and on the overall stability of the retaining wall are obtained as follows: 1). The numerical simulation results of the earth pressure around the bottom of the foundation with the increase of the filling height are in good agreement with the field measured values. The vertical earth pressure at the heel of the wall increases first and then decreases with the increase of the filling height, and the vertical earth pressure increases gradually with the increase of the height of the wall toe, and the value of the vertical earth pressure is larger than that of the inclined side. The vertical earth pressure at the bottom of the convex tenon increases first and then decreases slightly with the increase of filling height, and the vertical earth pressure is larger than that on the inclined side. The numerical value of horizontal earth pressure at the front of the tenon increases gradually with the increase of filling height, but the increasing rate decreases gradually. The displacement mode of the inclined side is more uniform than that of the vertical side. 2) the displacement mode of the wall is translation. The earth pressure distribution behind the wall is irregular curve. 3) the numerical value of horizontal displacement of the wall increases with the increase of the filling height. The horizontal displacement increases rapidly after the filling height of 4 m, which is consistent with the measured data. The vertical horizontal displacement is larger than the inclined side. 4) the internal friction angle of the fill is increased and the external friction angle of the wall is increased. One of the three measures to increase the slope of the wall can reduce the resultant value of horizontal earth pressure behind the wall, reduce the horizontal displacement of the wall, increase the overall stability coefficient of the wall. 5) increase the stiffness of the wall can significantly reduce the horizontal displacement of the wall. But the stability coefficient of the retaining wall has no effect on the stability coefficient. 6) the stability coefficient obtained by the theoretical calculation of the different wall height and the stability coefficient obtained by the numerical simulation is very high. The design of prefabricated and assembled retaining wall can be aided by finite element method.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU476.4

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