超高层矩形钢管混凝土柱太阳辐射下截面温度场分析

ANALYSIS OF SECTION TEMPERATURE FIELD OF CONCRETE FILLED RECTANGULAR STEEL TUBULAR COLUMNS FOR HIGHRISE STRUCTURES UNDER SOLAR RADIATION

超高层结构常采用矩形钢管混凝土柱,在超高层结构施工中,矩形钢管混凝土柱一般会受到太阳直晒,强太阳辐射下,钢管表面温度可达到50-70℃,由于截面尺寸通常较大,钢管壁的四面和核心混凝土温度极不均匀,会影响钢管混凝土柱的受力。为了明确太阳辐射下钢管混凝土柱的截面温度场分布,研究了超高层主体结构施工阶段,矩形钢管混凝土柱在太阳辐射作用下温度场分布、壁面和混凝土温度变化规律、温差变化规律。分析发现：核心混凝土与钢管四个壁面温度差最大可达35.6℃,东西面钢管壁温差最大达25.6℃,极值温度和温差随截面尺寸增加而增加,但是边长大于1 000 mm后,极值温度和截面温差增幅变缓。

Concrete filled rectangular steel tubular（ CFRST） columns are widely used in highrise buildings,in the period of construction,the steel tubes are always under high solar radiation,and the surface temperatures of the steel tubes reach 50 - 70 ℃. Because the section size of the columns are usually very large,there are significant differences between the temperatures of steel surfaces and that of inner concrete. The different temperatures on the cross section will influence the mechanical behavior of the CFRST columns. In order to find out the distribution of the temperature on the cross section,this paper studied the temperature field distribution,the changing laws of the steel tube surface temperature,the inner concrete temperature and the range of temperatures of CFRST columns in highrise buildings. The results showed that the max difference in temperature between the steel tube surface and inner concrete reached 35. 6 ℃,the one between the eastern and western sides was 25. 6 ℃. Additionally,with the increase of the section size of columns,the extreme temperature max difference in temperature were increased,but the increase range become gentle after the width is bigger than 1 000 mm.