土层锚杆的常见病害及防治对策研究

Study of the common deflects of the anchors in clay and the controlling measures to be taken

为了深入研究土层锚杆可能出现的各种病害及原因,有针对性地提出防治措施,进行了室内模型试验。根据试验结果分析了在水的作用下土层锚杆破坏时的应力传递过程,提出土层锚杆发生破坏时所遵循的逐次破坏的突破观点。首先失效的是坡顶锚杆,其次是坡脚的锚杆,最后才是坡体中部的锚杆。并对破坏时土层锚杆发生的6种病害形式进行了详细论述及原因分析:灌浆体和土体界面的破坏、土体的破坏、锥体-黏结复合破坏、锥体破坏、灌浆体的拉裂和压碎、灌浆体与杆体之间的黏结破坏。在综合分析的基础上,提出了土层锚杆常见病害防治的几个关键性对策。

The paper is engaged in the study of the failures or defects of anchors with our analysis of the likely causes of such failure in ad- dition to the introduction to effective measures on their prevention. In proceeding with our study, we have done a series of room model tests in this way in hoping to thoroughly study the common cases of such failure with corresponding control measures put forward. In the pa- per, we have first of all introduced our design and test process, with the focus of our study laid on the strain figure of the end of anchorage segment, slip surface and slope for the same row anchors. The exper- imenta｜ results of ours prove that the stress transmission of destructive process tends to account for such failures of the anchors in clay with water. Here we have put forward a breakthrough brink point of view for the successive destruction, saying that the primary failure is likely to take place just over a hill, followed by the foot of the slope, and finally by the central slope. The author has also made a discussion in detail on six kinds of likely failure modes and their causes： the de- struction in the interface for grouting and soil mass, the destruction of soil mass, cone-shape bonded compound damage, cone-shape dam- age, grouting fracture and crushing, bonded damage in the interface for grouting and bolting. The conclusion has been made on the key causes leading to the defects is the action of water and internal stabil- ity of the anchors in clay, and in turn a few corresponding counter- measures proposed, such as reduction of the water influence, length of the anchor, improvement of the anchor＇s pullout resistance and higher strength of the construction quality.