月別アーカイブ: 2017年9月

In order to ensure the construction safety and quality, ​self drilling anchor bolt​ is largely applied to the side wall and arch part of the tunnel excavation project. Self drilling anchor bolt can farthest ensure the grouting efficiency, completely solve the defects of traditional bolts. In the excavation process of Dongyangguan tunnel of Changhan highway, a large number of self drilling anchor bolts were used for supporting surrounding rocks and received good effect. It not only ensured the quality of the project, but also ensured the construction period of the tunnel.
​Self drilling rock anchor system​ is a new type of anchoring technology, which is used in foundation pit, highway, tunnel, slope support and other engineering fields. Self drilling anchor system integrates drilling, grouting, installing and anchoring processes in one operation. It has the advantages of simple process, high construction efficiency, good economic benefit, etc. This system will overcome the problems of narrow aperture, hole collapse and hole forming during drilling hole in loose broken rock and soil and sandy gravel layer and have a good anchoring effect. 
One open pit of iron mine had always been downward creep deformation. The upper landslide body was backfilled and sandy gravel layer of 24m thickness. While the lower was iron ore and gneiss of 56m thickness. The original design of the upper landslide body used 2m full-length bond anchor bolt and C20 shotcrete reinforcement. In the course of drilling hole by the full-length bond anchor bolt, it appeared hole shrinkage and hole collapse. After drilling, it’s hard to install and grout in anchor bolt, which caused that it was impossible to construct. Afterwards, self drilling anchor system is designed to replace full-length bond anchor bolt. The landslide body was effectively anchored and got obvious effect. 
Self drilling anchor system has solved the problems of hole shrinkage and hole collapse caused by drilling in sandy gravel layer, which played a good anchoring effect, achieved a purpose of supporting sandy gravel layer in the slope. It can be extensively applied in other loose rocks and soils.