【作者】 何涛；

【导师】 柴金义；

【作者基本信息】 内蒙古大学 ， 环境工程（专业学位）， 2015， 硕士

【摘要】 本文分析寒冷地区桥墩周围冻融冰水界面下静冰压力对桥墩的剪切破坏机理,以内蒙古鄂尔多斯市乌兰木伦河3号坝钢筋混凝土桥为例,通过建立冻融冰水界面桥墩受力模型,并运用有限元分析软件ANSYS数值分析静冰压力对桥墩的剪切作用。在我国北方气候寒冷地区,由气温变化和冻融循环作用对水工结构的危害较为显著。无论是流冰压力还是静冰压力均会对水中桥墩产生不利影响,对桥墩的刚度、稳定性甚至整个上部结构的安全运营构成威胁。本文首先综述国内外静冰压力及其对桥墩影响的研究现状,并指明研究方法与技术路线。其次从冰的微观结构、静冰压力的产生与消退、冰的强度及力学性能方面,分析静冰压力产生原理。在此基础上,选取典型简支梁桥跨,运用MIDAS CIVIL计算上部结构产生的竖向荷载,运用ANSYS建模分析桥墩在竖向荷载和静冰压力共同作用下墩柱-盖梁及墩柱承台连接处的主应力,并将其与材料的设计强度加以比较,从而判断结构的安全性。计算结果表明,冰盖受温度升高膨胀而产生静冰压力,在墩柱—承台连接处、墩柱—盖梁连接处形成应力集中,在上部荷载和静冰压力组合作用下导致桥墩剪切破坏,建模分析结果与现场检测结果基本一致。同时提出静冰压力的防范措施,为预防此类事件的发生提供技术支持,具有实际意义。更多还原

【Abstract】 This paper examines the mechanism of shear failure of piers under the static ice pressure at ice-water interface around the piers in the cold area,which was cased by the ice cover body due to the alternation of freezing and thawing.Taking the Trestle Bridge across the Ulan Moron River at No.3 Dam in Erdos City,Inner Mongolia as a case,the numeric analysis of static ice pressure on the piers at ice-water interface was made through modeling of forced piers and using of finite element software ANSYS.The temperature variation and freezing thawing cycles causes many problems,which is harmful to the hydraulic structure more significant in northern area of our country.Both floating ice pressure or static ice pressure will have an adverse impact on the piers in the water,which leads to the piers vibration,the stiffness,the stability and threats safety operation of upper structure.Firstly,this paper states the research status of static ice pressure and its effect on bridge piers at home and abroad and points out the research methods and technical route.Secondly,it analysis the principle of the static ice pressure from the ice microstructure, produce and fadeaway of static ice pressure, strength and mechanical properties of ice.On this basis,this paper chooses the typical bridge span then calculates vertical loads of superstructure generated by MIDAS CIVIL calculation and analysis principal stresses of the connections of pier column-pile cap,pier column-bent cap under the combination action of loads from the superstructures and the static ice pressure by ANSYS so as to judging the security of the structure.The results have shown that,the oblique shear failure occurred under the combination action of loads from the superstructures and the static ice pressure,which caused the stress concentration at the connections of pier column-pile cap,pier column-bent cap,the expansion of ice cover would produce the static ice pressure due to the ricing of its temperature.The results of modeling analysis are basically consistent with the measured ones on-site test.It has practical significance through puts forward to the static ice pressure measures at the same time, provides technical support for the prevention of the occurrence of such incidents.更多还原