基于数字图像相关技术的非均匀受限状态下土遗址的锚固性能

Anchorage performance of bolts under non-uniform restricted condition in earthen sites via digital image correlation technology

为研究锚固工程中处于非均匀受限状态锚杆的锚固特性,利用数字图像技术建立室内缩尺半锚模型.基于拉拔试验,研究锚固系统的荷载位移关系及破坏模式,在观察面上布设横向、纵向测线,分析夯土的位移情况.结果表明,锚固系统的极限锚固力为1.3 kN/m,锚固系统表现为弹脆性破坏;横向测线各点的位移呈现围绕锚杆轴线对称的分布特征;脱黏前,距锚杆较近的纵向测线位移自上而下递减,此后呈单峰形分布,随着荷载增加峰值下移.在此特殊受限状态下,锚杆的锚固性能主要取决于锚固系统的弹性变形,锚杆变径特征对锚固性能的增强作用不明显.

In order to study the anchoring characteristics of anchors in a non-uniform restricted state,which often exists in anchoring engineering, the digital image correlation technology was used to establish an indoor half-anchor model, and the load-displacement relationship and failure mode in a pull-out test were studied, while horizontal and vertical measuring lines were set on the observation surface to analyze the displacement of the rammed soil. The test results showed that the ultimate anchoring force of the anchorage system was 1.3 kN/m, and the elastic-brittle failure occurred. The displacement of points in the horizontal measuring lines was symmetrically distributed around the axis of the bolt. Before debonding,the displacement of the vertical measuring points near the anchor showed a decreasing feature from top to bottom, and a single peak distribution after that and the peak value moved down with the increase of the load. In this special restricted state, the anchoring performance of bolts mainly depended on the elastic deformation of the anchoring system, and the diameter-changing characteristics of anchor had no obvious enhancement effect on the anchoring performance.