基坑钢管内支撑装拆过程中的相互影响研究

结合郑州地铁车站基坑工程实例,通过现场试验和理论分析,研究钢支撑安装和拆卸过程支撑轴力影响范围。第一道支撑安装时影响范围是:本层左右水平距离0～12 m,第二道支撑左右0～9 m,第三道支撑左右0~3 m。第二道支撑安装时影响范围是同道支撑面左右水平距离0～3 m,对第三道支撑无影响。支撑拆卸时轴力影响范围与安装时大体相同,但由于预应力损失,拆卸时的影响幅度小于安装时。按交叉梁系超静定模型分析支撑轴力在灌注桩、冠梁、钢围檩之间的分配与传递,可以得到钢管内支撑安装与拆除时的影响范围,理论计算结果与实测结果趋势相同,幅度相近。

Axial Forces Interaction between Steel Pipe Struts Used in Subway Station Pit during Setting-up and Removing

Based on Zhengzhou subway station foundation pit project, a field experiment and theoretical analysis are carried out, and the axial forces interaction between steel pipe struts used in subway station pit during setting up and removing is discussed. The influence scope during first layer struts setting up is 0~12 m in first layer, 0~9m in second layer and 0~3 m in the third layer. The influence scope during second layer struts setting up is 0~3m in second layer, and no influence in the third layer. The influence during removal stage is similar to that of setting up, but smaller than the former one because of axial force attenuation. The influence scope may be calculated by the hyperstatic crossing girder system algorithm. The analysis results on axial force dispensing and transmitting generally comply with the experiment one.