山区公路重力式U型高桥台受力分析及施工技术研究

发布时间：2018-05-03 14:28

本文选题：高填方 + 重力式U型桥台　；参考：《重庆交通大学》2014年硕士论文

【摘要】：重力式U型桥台因其取材方便且施工简单等优点在桥梁工程中备受青睐,现行的U型桥台标准图的高度在8米以下,宽度在12米之内,难以满足实际设计需要。通过对已有与在建桥台的调查表明,填土高度大于8米或宽度大于15米的桥台多有开裂现象,桥台整体性被破坏。本文通过有限元分析模拟实验以及现场工程测试,对不同高度、不同宽度、不同工况下的高填方重力式U型桥台台身应变-应力规律进行研究,寻求高填方重力式U型桥台的受力特点,提出有利于高填方桥台预防或缓解开裂病害及使得结构受力更为稳定的设计方法。取得如下研究成果：(1)分析了不同高度下台身应力-应变分布规律及其随高度增加的变化。将离心模型试验与有限元分析模拟的结果相互验证,台身竖向压应力呈上小下大的分布规律,且随高度增加,压应力整体增大。台身横向应力呈上拉下压的分布规律,侧墙自由端顶部为拉应力集中区域。(2)分析了不同宽高比下台身应力一应变分布规律,高窄桥台台内填土体积较小,填土重量较难维持桥台稳定；宽大桥台内大量填土对侧、前墙产生了较大的水平压力,造成墙身变形。将离心模型试验与有限元分析结果对比,得出高填方桥台易破坏位置：侧前墙隅角处向侧墙中部的裂缝、前墙自由端墙踵处轻微碎裂以及基底的下沉现象。(3)分析了不同工况下台身应力-应变分布规律。重力式桥台的前墙作为主要承重结构承受竖向压力,在设计施工过程中需注意台身偏心受压发生倾覆。特别是在桥台形态高窄时,需保证台内填土有足够的质量,以维持台身平衡。(4)根据数值模拟计算结果初步研究了高桥台的稳定性验算方法和施工工艺与质量控制方法。
[Abstract]:Gravity U-abutment is very popular in bridge engineering because of its advantages of convenient material selection and simple construction. The current U-abutment standard chart is below 8 meters in height and less than 12 meters in width, so it is difficult to meet the actual design needs. Through the investigation of existing abutments and abutments under construction, it is found that most abutments with filling height greater than 8m or width larger than 15m have cracking phenomenon, and the integrity of abutments is destroyed. Through finite element analysis simulation experiment and field engineering test, the strain-stress law of high fill gravity U-abutment with different height, width and working condition is studied in this paper. The stress characteristics of high fill gravity U type abutment are sought and the design method is put forward which is helpful to prevent or alleviate cracking disease of high fill abutment and to make structure force more stable. The following research results are obtained: (1) the stress-strain distribution and its variation with the height increase are analyzed. The results of centrifuge model test and finite element analysis show that the vertical compressive stress of the abutment is larger than that of the upper one, and with the increase of height, the compressive stress increases as a whole. The lateral stress of the abutment is distributed under upward pull-down compression, and the top of the free end of the side wall is the tensile stress concentration area. (2) the stress-strain distribution of the abutment with different width-height ratio is analyzed. The volume of the fill in the high narrow abutment is relatively small. The fill weight is difficult to maintain the stability of abutment, and a large amount of fill in the opposite side of the bridge abutment produces a large horizontal pressure on the front wall, resulting in the deformation of the wall body. By comparing the results of centrifuge model test and finite element analysis, it is found that the breakage position of high fill abutment is the crack in the corner of the front wall toward the middle of the side wall. The stress-strain distribution of the free end wall heel of front wall and the subsidence of the base are analyzed. The front wall of gravity abutment, as the main bearing structure, is subjected to vertical pressure. During the design and construction, the eccentric pressure of abutment should be overturned. Especially when the abutment shape is high and narrow, it is necessary to ensure that the fill in the abutment has enough quality to maintain the balance of abutment. (4) based on the results of numerical simulation, the stability checking method, construction technology and quality control method of high bridge abutment are preliminarily studied.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U445.559

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