【摘要】 旨在论述超长混凝土框架结构温度(及混凝土收缩)应力的计算原理及其实用简化计算方法。以往大多把钢筋混凝土框架视为弹性体的计算方法既不正确,又会给出过大的温度(收缩)应力(内力)值,以致不得不加大柱截面尺寸,但截面加大后又将进一步增大温度(收缩)应力……,.如此往复,产生难以破解的矛盾。正确计算框架结构温度(收缩)应力应充分考虑钢筋混凝土框架柱列所具有不同的弹塑性性质。但在温度(收缩)变形作用下,却难以确定各框架柱柱列所具有的不同弹塑性抗侧移刚度。本文计算的特点在于提出了框架柱柱列不同抗侧移刚度的确定方法,并导得了温度(收缩)应力(内力)的简化计算公式,由此还提供了确定超长框架总长度的控制验算方法。工程应用表明,该计算方法快捷而简明,经济而有效,在确定超长结构方案时尤为适用。更多还原

【Abstract】 The purpose of this paper is to discuss the thermal and shrinkage stress computational principle and a simplified method of stress analysis for ultra-long concrete frames. Usually, the computational method of concrete frames is regarded the same as that of an elastic structure, which was incorrect and the analysis results appeared to be overestimated. As a result, the cross section of a column must be increased which will, in return, lead to higher stresses in the structure. Instead, the elastoplastic characteristic of reinforced concrete materials should be taken into consideration while calculating the thermal and shrinkage stresses of columns. However, it is generally difficult to determine the elastoplastic lateral stiffness of concrete frame columns under the action of thermal and shrinkage stresses. The computational method in this paper is as the following:(1)mathematical formulation on various elastoplastic lateral stiffnesses of concrete frame columns is presented; (2)then a simplified computational method of thermal and shrinkage stresses is deduced; (3) a computation formula for controlling the total length of ultra-long framework is also included. Application of the methodology to engineering problems has shown that the computational method proposed is concise and effective, especially for determining the deflections and stresses of ultra-long concrete frames.更多还原