Numerical Analysis of new Plate Load Tests on LWA

Student thesis: Master thesis (including HD thesis)

  • Brian Bjerrum
4. term, Structural and Civil Engineering, Master (Master Programme)
Light Weight Clay Aggregate, LWA, have been used for construction of buildings and infrastructures for many years. Especially Norway and Sweden have used LWA for railway and road embankments to reduce the the weight of the construction and to make frost protection of sensitive soils. In Denmark LWA has not been used in railway embankment because of strict rules in the national standards and because the risk of mechanical breakdown are concerning the Danish Railway Authority. Therefore, the desire of expanding the knowledge of the LWA has arisen. Several laboratory tests have been conducted, e.g. triaxial tests, oedometer tests and cyclic triaxial tests, but all are related with concerns to side and scale effects. This project has been investigating the material parameters of the LWA by using the Mohr-Coulomb and the GSK model implemented in the commercial software, Optum G2 where fits to triaxial tests have been conducted. Furthermore, plate load tests have been described and conducted in this project. The plate load tests took place in April 2018 where four tests were performed. The tests have been used to compare with Mohr-Coulomb and GSK model.

The fit of the triaxial tests showed that the GSK model describe the stress dependency of the friction angle in the LWA. However, calculations with the Mohr-Coulomb showed that fit to the load-displacement curve from the plate load tests gave the best fit, which states that the need of the GSK model is not necessary. Furthermore, the comparison with the plate load tests revealed that side and scale effects in the triaxial tests may not be significant and that a tendency has been shown.
LanguageEnglish
Publication date2018
Number of pages114
ID: 280599139