将钢夹梁和钢梁间的砖砌体等效为组合梁, 基于Timoshenko 弹性梁理论, 建立了钢梁-砖砌体组合梁弯曲变形的控制方程, 给出了钢梁-砖砌体组合梁弯曲变形的解析解. 在此基础上, 考虑砖砌体墙的拱效应, 研究了砖砌体墙的基础托换问题, 得到了不同型号工字钢夹梁的钢梁-砖砌体组合梁最大挠度和最大应力, 以及基础单段托换的最大长度. 研究结果表明: 钢梁-砖砌体组合梁挠度和应力随着工字钢型号编号的增加而减小, 但钢梁承担的荷载以及锚栓承担的压力不变. 同时, Timoshenko模型的组合梁挠度大于Euler模型的组合梁挠度, 但两种模型的应力及紧箍压力相同. 因此, Euler 组合梁模型可用于基础托换设计中的强度分析, 而刚度分析建议采用Timoshenko 组合梁模型.
Regarding the steel clamping beams and brick masonry between them as a composite beam and based on the Timoshenko elastic beam model, the governing equation for bending deformation of composite beam is established. The analytical solution for bending deformation of the composite beam of steel and brick masonry is presented. Considering the arch effect of the brick masonry, the foundation underpinning of the brick wall of masonry structure is investigated. The maximum deflection and maximum stresses of the steel-brick masonry composite beam for different models of H-type steel clamping beam are obtained, and the maximum length of the foundation underpinning for single stage is given. It is shown that deflection and stresses of the steel-brick masonry composite beam decrease with the model number of the H-type steel beam increasing, but the load held by the steel beam and the confining pressure of the steel-brick masonry composite beam are unchanged. Furthermore, the deflection of the Timoshenko composite beam is larger than that of the Euler composite beam, but the stresses and confining pressure are the same. Therefore, in the foundation underpinning design, the model of an Euler composite beam can be used for strength analysis, and the Timoshenko composite beam model can be used for stiffness analysis.
[1] 张立人, 卫海. 建筑结构检测、鉴定与加固[M]. 武汉: 武汉理工大学出版社, 2012.
[2] 欧阳煜, 刘能科. 外包钢加固轴心受压砖柱的受力性能分析[J]. 建筑结构, 2006, 36(11): 27-29.
[3] 欧阳煜, 龚勇. 碳纤维布加固破损木柱偏心荷载作用下的性能试验[J]. 上海大学学报: 自然科学版, 2012, 18(2): 209-213.
[4] Corradi M, Borri A, Grazini A. Confinement of brick masonry columns with CFRP materials [J]. Composites Science and Technology, 2007, 67(9): 1772-1783.
[5] Alhayek H, Svecova D. Flexural stiffness and strength of GFRP-reinforced timber beams [J]. Journal of Composites for Construction, 2012, 16(3): 245-252.
[6] 卢欣, 杨骁, 宋少沪. 纤维增强聚合物布加固木梁的非线性弯曲分析[J]. 上海大学学报: 自然科学版, 2012, 18(6): 634-639.
[7] Hardy S J. Design of steel lintels supporting masonry walls [J]. Engineering Structures, 2000, 22(6): 597-604.
[8] Maria E S, Vagelis B L. Dynamic analysis of a masonry wall with reinforced concrete lintels or tie-beams [J]. Engineering Structures, 2012, 44(11): 23-33.
[9] 童敏, 彭少民. 钢-砌体组合结构在砖混建筑改造中的应用[J]. 武汉理工大学学报, 2007, 29(S2): 152-156.
[10] 赵考重, 王莉, 夏风敏. 钢-混组合结构在砖混建筑拆墙改造中的应用[J]. 建筑结构, 2003, 33(4): 28-35.
[11] 敬登虎, 曹双寅, 石磊, 等. 钢板-砖砌体组合梁、柱静载下性能试验研究[J]. 土木工程学报, 2010, 43(6): 48-56.
[12] 敬登虎, 曹双寅, 郭华忠. 钢板-砖砌体组合结构托换改造技术及应用[J]. 土木工程学报, 2009, 42(5): 55-60.
[13] Gere J M, Timoshenko S P. Mechanics of materials [M]. 2nd ed. New York: Van Nostrand Reinhold, 1984.
[14] 中国建筑东北设计研究院有限公司. GB 50003—2011 砌体结构设计规范[S]. 北京: 中国建筑工业出版社, 2011.
[15] 沈祖炎, 陈扬骥, 陈以一. 钢结构基本原理[M]. 北京: 中国建筑工业出版社, 2005.
[16] Cowper G R. The shear coefficient in Timoshenko’s beam theory [J]. Journal of Applied Mechanics, 1966, 33(2): 335-340.
