The Application of Self Drilling Anchor Bolt in Abutment Accumulation in Xiaowan Hydropower Project

Xiaowan Hydropower Project is located in Xiaowan town which is at the border of Nanjian county and Fengqing county and along the middle and lower reaches of the Lancang in Yunnan province. It is also designed as the second stage in the eight steps hydropower stations.

The rock is relatively complete under the deep dam area, while engineering geology condition on the surface is definitely worse: the rock is weathered and broken into small pieces, deep unloading belt and joint fissures developed, and there are lots of empty holes inside. In all, big collapse accumulations exist in both sides of the dam area. The whole stability of the slope is relatively worse. Therefor, to find an practical, effective and economical supporting method is the key point in the slope protection of Xiaowan Hydropower Project.

As an efficient anchoring method, self drilling anchor bolt is used in complicated, loose and broken geological condition. It is mainly used for slope stabilization, foundation with micropiles and tunneling, it is also applied in the railway system, metro project, etc. It can be installed in sites with weak rocks, loose soil, weathered layer, sand with stone layer and so difficult to create a hole in complex formation. The unconsolidated ground condition favor the self drilling anchor bolt technique for fast and simple method of installed compared to the traditional method.

  • Features:
  1. It is easy to penetrate various rocks.
  2. It can be elongated by using couplers.
  3. Unnecessary to be pulled out.
  4. The hollow bar can be used as grouting channel.
  5. Drilling, grouting and anchoring can be finished at the same time.
  •  Technical Parameters

The engineering quantity of the left dam abutment is 36052 and the right is 74413.

(mm) Thickness(mm) Ultimate Load (Mpa) Weight(kg/m) Thread(L/R) Length(m) Thread Pitch(mm)
GM25 25 5.5 600 2.5 L 2.0 12.7
GM27 27 6.0 600 3.0 L 3.0 12.7
GM32 32 6.0 600 3.6 L 4.0 12.7