Background
GIP Grundwasser-Ingenieurbau-Planung GmbH Dresden has initiated an R&D project on soil liquefaction. The physical equations developed within the R&D project “Development of a practical prediction and visualization tool for mapping the thixotropic behavior of granular soils during temporary and local liquefaction” and the established material model are to be transferred into a suitable numerical calculation program.
The project has been designed as a follow-up to an already completed research project and includes, among other things, the performance of hydraulic engineering-geotechnical tests on a dike model on a semi-technical scale.
The verification of an already developed computational model is carried out on 2-dimensional embankment forms by means of physical experiments. For this purpose, model tests are to be carried out on a dike section in the experimental flume of the Hydraulic Engineering Research Laboratory of the TU Darmstadt. The experimentally observed embankment/soil movements of the model tests will then be compared with the calculated embankment/soil movements with respect to their temporal and local state changes. The goal is a successful evaluation and assessment of the developed prediction and simulation tool for the simulation of gravitational mass movements due to soil liquefaction considering the thixotropic behavior of the soil.
Hydraulic engineering-geotechnical experiments
At the TU Darmstadt, there is a deep gutter with a depth of 3 m, a length of 30 m and a width of 0.75 m suitable for carrying out the physical experiments. This is suitable for morphodynamic investigations. The filling of this flume is comparatively easy from the hall floor and the lateral glazing in some areas ensures the visual observation of the mass redistribution during the test runs.
The test setup and the test executions in the hydraulic engineering research laboratory are intended to represent the realistic behavior of partially water-saturated, loosely stored granulates during local liquefaction in the best possible way.
In order to record the relevant system variables and the parameters describing the flow behavior, a careful preparation of the measurement concept is required. In addition to test logistic requirements, the filling, preparation (construction of the layers and, if necessary, partial compaction) and removal of the relevant materials from the test facility must also be taken into account in the planning. The filling and preparation must be carried out in such a way that the soil conditions correspond sufficiently accurately to those of the dike systems.
The correspondingly required sensor technology will be taken over by an upstream R&D project and provided by GIP.
In the deep gutter of the hydraulic engineering research laboratory of TUDa, tests are to be carried out with installed dike bodies in each case. During the tests, the installed dikes are to be hydraulically loaded until partial or even complete soil liquefaction occurs. The data obtained will be further processed in the research project, e.g. in order to calibrate or validate numerical process simulations.
