In the construction of prestressed anchorage cables in Yinshuigou talus,according to the geological formation differences of every parts of the talus,the means of "pipe eccentrically follows upon" or "pipe concentrically follows upon" for boring holes are used respectively to different parts of the talus to improve the boring efficiency and quicken the stable equilibrium of the talus slide.

By the analysis of present drilling ways,and according to the characteristics of gravel strata,application feasibility is put forward for DTH hammer concentric simultaneous casing drilling tool in gravel strata,and analysis are made on the structure principle and characteristic of drilling tool.

Analysis and research on accessories intensity of DTH hammer drilling with concentric simultaneous casing;

The hole completion with eccentric casing,grouting test process and grouting effect inspection were adopted and presented as important reference for similar projects.