预应力锚杆柔性支护在深基坑工程中的应用

Prestressed Anchor Flexible Retaining in Deep Excavation Engineering

预应力锚杆柔性支护技术广泛应用在深基坑工程中,为了研究其工作机理,对某一实际深基坑工程进行了数值模拟分析,并将预应力锚杆柔性支护和土钉支护两种方案进行了对比研究。分析结果表明:二维数值模型未考虑实际工程中基坑的空间效应,其数值计算结果偏安全;预应力在锚杆支护中起着重要作用,施加预应力可以明显减小基坑的变形;增加土钉长度或减小土钉间距,在一定程度上能减小基坑的变形,但很难控制基坑的整体稳定性;与土钉支护相比,预应力锚杆柔性支护可以有效控制基坑变形,从而保证基坑的整体稳定,能满足深基坑工程防护需求。

Prestressed anchor flexible retaining technique has been widely applied in the deep excavation engineering.To investigate its working mechanism,numerical simulation analysis of an actual deep foundation pit was conducted,and two schemes of prestressed anchor flexible retaining and soil nailing were compared in this paper.It is shown that numerical simulation results are conservative since the two-dimensional numerical model ignores the spatial effect in practical engineering.Prestress plays an important role in the anchor flexible retaining,and the deformation of foundation pit can be reduced by applying prestress on anchors.By increasing soil nail length or decreasing the spacing of soil nail,the deformation of foundation pit can be reduced,but it is difficult to control the overall stability of foundation pit.Generally,prestressed anchor flexible retaining method can effectively control the deformation of foundation pit and ensure overall stability of the foundation pit thus it can meet the demand for prorection in deep excavation engineering protection.