新型预应力锁定钢支撑施工工艺研究

Study on Construction Technology of New Prestressed Locking Steel Braces

深基坑施工过程中的钢支撑普遍采用钢楔铁塞紧,以确保支撑轴力达到设计值。由于采用多块楔铁塞紧,楔铁间不可避免地存在间隙,在后期难免出现由于楔铁挤密或窜出而造成轴力损失。基于此,本文对新型预应力锁定钢支撑施工工艺进行研究,在地铁基坑施工过程中进行可控试验,有效解决基坑施工过程中支撑轴力损失问题,减少了轴力附加环节,降低了基坑开挖风险,对基坑周边建筑抗变形保护效果明显。保载钢支撑结构简单、操作简便、稳定性好,不额外占用施工场地,在城市施工条件较差的地下工程施工中具有明显应用优势。

In the process of deep foundation pit construction,iron wedge is generally used to plug the steel braces so that the axial force of bracing reaches the design value.Due to the use of multiple iron wedges in plugging,there is inevitably a gap between each wedge iron,the loss of axial force in the later is caused by unavoidable wedge iron compaction or wedge iron channeling.Based on this,the construction technology of the new prestressed locking steel braces is studied in the paper.The controllable test is carried out during the process of deep foundation pit construction,it is found that the problems of lossing axial force are effectively avoided,and the axial force additional process is reduced.It reduces the risk of foundation pit excavation and the anti-deformation protection effect is obvious for the surrounding buildings of foundation pit.The load-keeping steel braced structure is simple,easy to operate and with good stability,and does not take up additional construction site.It has obvious application advantages in the urban construction of underground engineering with poor construction conditions.