复合支护体系中土钉的受力特点

Axial force in soil nails of composite supporting system

结合郑州一基坑工程项目,利用分布式光纤应变传感技术监测基坑开挖过程中及开挖后排桩预应力锚杆复合土钉支护体系中土钉的轴力。在试验基础上,利用ABAQUS有限元分析软件建立排桩预应力锚杆复合土钉支护体系的三维基坑开挖模型,研究土钉在复合支护体系中的作用。结果表明,这种复合支护体系中土钉和预应力锚杆能很好地协同工作,充分发挥二者锚固和支护的作用。排桩能有效降低土钉的轴力,显著改善预应力锚杆复合土钉支护结构的整体受力状态。

The axial force in soil nails of composite supporting system of soldier pile with prestressed anchors and soil nails during and after pit excavation is monitored by distributed optical fiber sensing technology in a foundation pit engineering project in Zhengzhou. Based on the test,the function of soil nails in this system is studied by using a threedimensional excavation model which is established by ABAQUS. The results show that soil nail and prestressed anchor can work cooperatively and give full play to the role of anchoring and supporting in the composite supporting system. The soldier pile can effectively reduce the axial force as well as notably improve the entire stress.