螺旋锚极限抗拔承载力的回归分析

目的分析砂土中单锚片螺旋锚的工作性状及破坏模式，给出上拔极限承载力计算公式，为指导工程实践提供理论依据．方法通过室内试验获得试验数据，选定拟合函数对试验数据进行拟合，用回归分析的方法进行分析；绘制出相同直径锚片在不同埋深时的SQ曲线及不同直径的锚片在同一埋深时的S，Q曲线，通过对比找出锚片直径、埋深等因素对上拔极限承载力的影响．结果在相同埋深的条件下，上拔极限承载力随锚片直径的增加而增加；在锚片直径不变的情况下，浅埋时承载力随埋深的增加而增加，但当埋深达到临界埋置深度后，承载力不再随埋深的增加而明显增加，而趋于稳定．结论可以通过增大锚片直径提高承载力，也可通过增加埋深提高承载力，但最大埋深不宜超过临界埋置深度。

Regression Analysis on the Ultimate Up-lift Bearing Capacity of Screw Anchor

This article aims to study how single-screw anchor works in sand through indoor test,gives the calculation formula of critical embedded depth and provides theoretical basis for the instruction of engineering practice.The method of regression analysis is used to cope with testing data.What else are obtained are displacement-force curves of anchors with different diameter and identical embedded depth and anchors with different embedded depth and identical diameter.The effect of blade diameter and embedded depth on the ultimate up-lift bearing capacity of single-screw anchor is studied through comparing these curves.Then some conclusions are drawn: the greater the diameter of anchors with identical embedded depth is,the greater the value of ultimate up-lift bearing capacity gets;also the deeper the anchors are embedded,the greater the value gets before embedded depth reaches the critical embedded depth,and the value doesn't change along with embedded depth when it is equal or larger than critical embedded depth.Theoretical models were developed to predict the ultimate up-lift bearing capacity of single-screw anchor in sand,and the calculating formula of them are given.The calculating results are in good agreement with testing results.