A Geotechnical Working Plan for a Thorough but Quick Assessment of Existing Slopes in Clay Mines

A Geotechnical Working Plan for a Thorough but Quick Assessment of Existing Slopes in Clay Mines

Bloem, Hugo (TU Delft Civil Engineering and Geosciences; TU Delft Geoscience and Engineering)

Ngan-Tillard, Dominique (mentor)
Schmitz, Robrecht (mentor)

Delft University of Technology

2017-07-14

In the Westerwald area clay quarries are in production. In order to assess the stability of the slopes the geotechnical characterisation of these quarries needs to be improved. This report provides the justification for a working plan for a thorough but quick assessment of existing slopes in clay mines. Literature is consulted for the information for the types of measuring and monitoring equipment for slopes, what instabilities look like in the field, how the safety factor are calculated, what information can be gathered outside the mine and what a field investigation should concern. To come to a working plan a field investigation was conducted to try out the different measurement equipment. For field testing, the needle penetrometer and hand vane shear came out as useful tools for correlating undrained shear strengths parameters of different layers. For thorough correlations, between layers and a dataset of geotechnical parameters, Atterberg limits are used to minimise the number of geotechnical parameters that have to be tested. The parameters are tested with different machines based on the timespan over which the slope has to be stable. Short-term slopes with insitu conditions are best tested with triaxial tests, but UCS and a theoretical strong shear box can provide useful data as well. Long-term slopes are better tested with either a shear box or ring shear because remoulded or weathered properties are needed. Monitoring is found to be done best by using InSAR monitoring provided a suggestion is added to increase the number of data points inside the mine. The working plan is presented as a flowchart for a good overview.

clay mines
geo-engineering
stability

http://resolver.tudelft.nl/uuid:fa4596e8-3c3d-495e-83e3-c1cdccdd6f75

Student theses

bachelor thesis

© 2017 Hugo Bloem