Standardization of DTH drilling as a geotechnical survey method

Important results from the project

Purpose: To develop DTH, down the hole drilling, into a swedish geotechnical standard technique, enhancing quality in difficult and deep conditions. Goal: To implement DTH as a standard method by SGF, Swedish Geological Society and to be the first on the market. Fullfillment: We have provided data to support a standard technique descriprion. We can offer the market Jb-S but we have not been able to implement into SGF standard.

Expected long term effects

Quality improvement: Deeper sounding retrieves better values and, in turn, higher security in evaluation. Hard conditions that reduce quality with top hammer, will be retained with DTH. Environment / Work Environment: The noise level is reduced.Ground impact is reduced. The method presents three implementations 1) Jb-S as a complement for traditional Jb-2 Sounding. 2) Can be used for BIPS ( Borehole Imaging Processing System) 3) Can be used in bedrock permeability measurments.

Approach and implementation

The work has followed swedish geotechnical standard technique for Jb-2. We have implemented an already existing method to an evaluative geotechnical field method. In order to get results following SGF, we have carried out a number of trails that were set in line-up for already implemented methods. From the results, we can see that the method lives up to the theoretical advantages. Also, the method is comparable to conventional methods.