Demonstration and testing of a simple pneumatic slug-testing device for the determination of hydraulic conductivity

摘要

In the field of geotechnical engineering, hydraulic conductivity is an important parameter which is typically determined by sieve analysis or pumping tests. The characteristics of these two methods are diametrically opposed. Sieve analyses are inexpensive however the results are less representative. Pumping tests are often rather expensive but the results are highly representative. In this context, a geohydraulic test procedure is necessary that ensures representative results at low expense. From the authors' point of view, pneumatic slug-tests fit these requirements very well. A new experimental set-up for conducting pneumatic slug-tests was developed which uses a vertically movable seal to close the monitoring well in an airtight manner. Thus, the volume of the gas phase between the seal and the groundwater is independent of the depth to the groundwater table. The experimental set-up was tested on 38 monitoring wells and the results were compared with sieve analysis and pumping test results. The investigations demonstrated the representativeness as well as the cost efficiency of the pneumatic slug-tests.