44
施工技术
CONSTRUCTION TECHNOLOGY
IⅡI型钢板在桥梁加固工程中的应用
胡庆安，张同舟，邬晓光，史建朋
安710064)
（长安大学公路学院，陕西西安
2011年2月第40卷第3期
[摘要］针对南方某些省份大批在役桥梁现存病害利用增加主梁抗弯、抗剪刚度可大幅度提高桥梁承载能力的原理首次提出I型钢板加固方法并利用ANSYS程序进行有限元数值模拟。对ⅡI型钢板与粘贴钢板加固的主梁进行加固结果比较分析最大竖向挠度前者低于后者约18.85%顶板处最大主压应力、腹板处最大主拉应力底板处最大主拉应力前者分别低于后者约17.05%15.87%15.67%因而发现ⅡI型钢板加固效果高于粘贴钢板加固
进一步对比分析ⅡI型钢板助板高度、厚度对加固效果的影响发现ⅡI型钢板助板高对加固效果影响较大，[关键词】桥梁工程；ⅡI型钢板；助板高度；挠度；主应力
[中图分类号］U447
[文献标识码］A
[文章编号】1002-8498(2011) 03-0044-04
The Il-type Steel for Strengthening Deficient Bridge Structures
Hu Qing'an ,Zhang Tongzhou Wu Xiaoguang ,Shi Jianpeng( School of Highaay , Chang' an Unizersity Xi' an Shaanxi 710064 ,China)
Abstract: Based on diseases for some of the existing bridges in service in some southern provinces , using the principle that increasing bending and shear stiffness can enhance the carrying capacity of bridge , the authors firstly propose the II-type steel strengthening technology , and carry out the finite-element numerical simulation by means of ANSYS. The effects of the II-type steel strengthening technology and that of the sticking steel slab technology are compared , which can make some conclusions as follows: the maximum vertical deflection of the former is about 18. 85% less than that of the latter; the maximum main compressive stress in the top slab , the maximum main tensile stress in web plate and the maximum main tensile stress in the bottom slab of the former are about respectively 17. 05% ,15. 87% and 15. 67% less than that of the latter. So the strengthening effect of the Il-type steel strengthening technology is better than that of the sticking steel slab technology. The authors also research the influence of the height and thickness of the ribbed slab on the strengthening effect , and find that height of ribbed slab has a significant impact over the thickness on the strengthening effect.
Key words: bridge; Il-type steel; height of ribbed slab; deflection; the main stress
钢板是桥梁加固中最常用的加固材料。目前，
使用钢板进行加固常采用粘贴钢板加固法。由于粘钢加固法用的钢板很薄，未能明显增大主梁抗弯剪能力因而其加固效果并不理想
ⅡI型钢板加固板梁是本文首先研究的一项新型补刚加固技术，它是指沿主梁纵向利用ⅡI型钢板把相邻主梁连接起来山型钢板与主梁之间采用胶粘剂、膨胀螺栓连接继而可以把荷载传递到钢板使钢板与混凝士主梁协同工作这样充分发挥了钢的材料特性混凝土主梁的刚度与强度得到了提高。该加固方法施工快速简便、经济可靠并能有效提高[收稿日期]2010-1-40
[作者简介］胡庆安,长安大学公路学院教授,陕西省西安市
710064 ,电 话: 13060426795 E-mail: tongxhou321@ 126. com 万方数据
主梁的抗弯、抗剪能力。 1计算理论
.d_M(x)I
取梁变
梁曲线近似微分方程为：
dx2
EI
形前的轴线为x轴其中：w为梁横截面形心在垂直于梁轴方向的线位移M(x）为该点处横截面上的弯矩为梁截面的惯性矩,E为材料的弹性模量1]。由上式可知梁的变形与抗弯刚度E成反比,而截面形状是影响惯性矩「的主要因素在截面面积定的情况下采用合理的加固途径增大截面惯性矩 I的数值，减小梁的变形,不仅可以提高梁的刚度，同时也能提高梁的强度。
弯曲变形还与材料的弹性模量E有关,为了提高梁的刚度，可以选择弹性模量E较大的材料，但