基于拉-压杆模型的框架结构平移托换梁受剪承载力研究  

Research on shearing capacity of underpinning beams in frame structure moving based on strut-and-tie model

作　　者：岳庆霞 张鑫[2] 贾留东[2] 王恒[3] 

机构地区：[1]清华大学土木工程系,北京100084 [2]山东建筑大学建筑结构鉴定加固与改造山东省重点实验室,山东济南250101 [3]山东建筑大学工程鉴定加固研究所,山东济南250013

出　　处：《建筑结构学报》2012年第10期110-115,共6页Journal of Building Structures

基　　金：国家科技支撑计划项目(2006BAJ06A03-06);国家自然科学基金项目(51008184;51278287)

摘　　要：在16个框架结构平移托换节点试验研究基础上,根据托换梁的裂缝开展规律及破坏特点,并结合有限元分析结果,将托换梁的荷载等效为两点集中荷载,建立托换梁的拉-压杆模型。针对托换梁剪跨比较小的情况,在斜压杆的主压应力中考虑拉杆传来的应力分量。依据Kupfer-Gerstle的双向拉压应力关系考虑混凝土的软化效应,推导了托换梁的受剪承载力计算式,并与试验结果进行了对比。结果表明:不考虑拉杆分量的拉压杆模型的计算结果与试验值的相对误差均值为38.9%,考虑拉杆应力分量的拉-压杆模型的计算结果与试验值的相对误差均值为26.9%。Based on the research of crack development and the failure characteristics of the 16 underpinning joints tests, the strut-and-tie model （STM） was established with reference to the stress distribution of the finite element analysis results. In the STM, the underpinning beam was assumed to be loaded with two point concentrated load. Since the shear to span ratio of the underpinning beam is usually small, the stress component of the main longitudinal reinforcement in the direction parallel to the diagonal strut was considered in this paper. The shear capacity formulas were deduced based on the biaxial strength envelop of Kupfer-Gerstle to model the tension-compression nodal zones in STM, thus the softening effect of concrete compressive strength due to transverse tensile strain was taken into consideration. The STM was evaluated with the 16 underpinning joints test resuhs and the average relative errors were 26.9% and 38.9% , with and without the consideration of the stress component of the main longitudinal reinforcement in the direction parallel to the diagonal strut, respectively.

关 键 词：框架结构平移 托换梁 受剪承载力 拉-压杆模型 软化效应 

分 类 号：TU746.4[建筑科学—建筑技术科学] TU317.1