考虑二阶效应的火灾后不等肢L形型钢混凝土异形柱偏心距增大系数的研究  

Research on eccentricity magnified coefficient of L-special-haped SRC columns with unequal limbs after fire considering second-order effect

作　　者：高立堂[1] 王都[1] 王万敏 GAO Litang WANG Du WANG Wanmin(School of Civil Engineering, Qingdao Technological University, Qingdao 266033, Chin)

机构地区：[1]青岛理工大学土木工程学院,山东青岛266033

出　　处：《四川建筑科学研究》2016年第5期1-4,共4页Sichuan Building Science

基　　金：国家自然科学基金(51178232)

摘　　要：为了研究考虑二阶效应的火灾后不等肢L形型钢混凝土异形柱的偏心距增大系数,选取4种偏心距,按照两种加载角度,对受火1 h后的8根不等肢L形型钢混凝土异形柱进行了常温下的静力加载试验。由于型钢混凝土异形柱含钢量较高,将L形截面按照等形心轴惯性矩的原则等效成矩形截面,计算出偏心距增大系数η矩,并与异形柱的偏心距增大系数η异进行了对比分析,比较两种计算方法,为火灾后异形柱偏心距增大系数的计算提供参考和依据。研究表明:1不等肢L形型钢混凝土异形柱在X、Y两方向抗侧刚度不同导致两方向柱中挠度不同;2矩形柱与异形柱偏心距增大系数η的差值与矩形柱η的比值均在10%以内,计算结果比较接近,其中比值绝对值最大为9.901 8%,出现在BL6的Y方向,其余比值均在5%以内。Adopting 4 kinds of eccentricity,2 kinds of loading angles,static load tests of 8 L-special-shaped steel reinforced concrete columns with unequal limbs were done after 1 hour of fire to analyze the second-order effect. Because of the higher amount of steel,the L-shaped cross-section was converted into a rectangular cross-section,eccentricity magnified coefficients of rectangular columns were calculated to make a comparison with eccentricity magnified coefficients of shaped columns. The applicability of the two calculation methods was analyzed to provide reference and basis for the calculation of eccentricity magnified coefficients for shaped columns after fire. Test results show that： ① unequal lateral stiffness in L-special-shaped steel reinforced concrete columns with unequal limbs X,Y two different directions result in different deflections; ② the ratio of the difference between the two coefficients and η of rectangular columns is less than 10%,the ratio of the maximum absolute value is 9. 901 8%,others are less than 5%.

关 键 词：不等肢L形型钢混凝土异形柱 二阶效应 偏心距增大系数 火灾后 

分 类 号：TU398.9[建筑科学—结构工程]