预应力锚杆柔性支护体系的锚杆抗拔力研究

预应力锚杆柔性支护体系是在锚杆支护基础上发展起来的，是用于深基坑支护或提高边坡稳定性的一种新技术，为深入了解其工作性能和作用机制，对其锚杆抗拔力进行了分析和研究，提出了摩擦型灌浆锚杆抗拔力的改进求解方法。研究表明，预应力锚杆柔性支护结构体系中锚杆所提供的抗拔力应由锚土作用抗拔力和土体自承作用抗拔力两部分组成；锚杆在支护体系中是作为传力构件传递土体自承作用抗拔力，通过锚土作用提供抗拔力。进一步分别对两部分抗拔力进行理论求解，给出了各自相应的理论计算公式，确定了预应力锚杆支护体系总的抗拔力。工程实例证明了所提出的锚杆抗拔力求解的合理性。依据改进求解方法所求得的锚杆极限抗拔力在数值上较传统方法结果大，改进求解方法后的抗拔力概念更加明确，这从理论上进一步充实了预应力锚杆支护体系的作用机制，为工程实践提供了科学依据。

Research on anti-pulling force of anchor of flexible supporting system with prestressed anchors

Flexible supporting system with prestressed anchors is a new technique developed from anchored retaining wall for retaining deep foundation pit or improving stability of existing slope.In order to further study the behaviors and working mechanism of the flexible supporting system with prestressed anchors,the anti-pulling force of anchor is analyzed and studied.The improved solution method of anti-pulling force of frictional grouting anchor is proposed.The study indicates that in the supporting system of flexible supporting structure with prestressed anchors,the anti-pulling force should be decomposed into two parts: the anchor-soil interaction and the soil self-supporting.In the supporting system,anchor,as a force transfer component,firstly transfers the anti-pulling force coming from the soil self-supporting;then provides other anti-pulling force by the anchor-soil interaction.The two anti-pulling forces are solved theoretically;and the theoretical calculation formulae are given respectively;then the total anti-pulling force of anchor is determined.Two case studies are introduced to prove the rationality of the solution of anti-pulling force of anchor.The values of limit anti-pulling force of anchor based on the improved solution method are larger than these of the traditional methods;and the concept of anti-pulling force solved according to the improved solution method is more clear,which further enriches the working mechanism of prestressed anchor supporting system from theoretical aspect and provides the scientific basis for engineering practices.