TUDa Geotechnical Test Pit

Scope

The TUDa Geotechnical Test Pit (GTP) is a testing facility mainly for studying soil-pile interaction, although in principle, investigation of other geotechnical problems is also possible. The facility allows for near to full-scale testing (e.g., micropiles), as well as medium to large-scale model testing, thus being able to close the gap between small-scale testing, on one hand, and very rare and expensive in-situ testing, on the other. The facility also overcomes some of the limitations of centrifuge testing such as scalability of the soil/soil grain. As such, phenomena that are usually difficult to observe, as for instance soil-water interaction, can be better investigated. With its capability, the GTP can provide valuable contribution in the testing and validation of existing physical theories and numerical models, as well as in the development of new ones.

Specifications

Located in a 23 m x 23 m x 7 m (L x W x H) experimental hall of the Institute of Geotechnics, GTP has a total length and width of 19.5 m and 5 m, respectively. It consists of a stiff concrete box caisson, the lateral and bottom boundaries of which are rigid. It has two parts: a 6 m deep pit with plan dimension of 5 m x 4.35 m and a shallower pit 3 m in depth and plan dimension of 14.5 m x 5 m. In the latter pit, mobile walls can create smaller sections to allow for smaller-scale tests. In addition, a 4.3 m x 3 m (diameter x height) steel cylinder is available that has water connections at the bottom and thus where saturated testing can be performed.

The facility is equipped with vertical and horizontal actuators that can transmit static and dynamic force or displacement to the pile/foundation. Both the vertical and horizontal loading frames are movable and can be positioned at various places across the pit to accommodate different test and loading conditions. Below table gives further details on the technical specifications of the GTP.