Plate load testing : Effects of in situ conditions, test procedure and calculation method

• Main Author: Andresdottir, Herbjörg
• Other Authors: Mork, Helge, Aksnes, Jostein
• Format: Master Thesis
• Language: English
• Published: Statens vegvesen 2019
• Subjects: Analyse; Platebelastning; Vegkonstruksjon; Materiale; Resultater; Statens vegvesen Vegdirektoratet; Norway; Iceland
• Online Access: http://hdl.handle.net/11250/2621551

Master Thesis in Roads, Transportation and Geomatics. NTNT - Norwegian University of Science and Technology Department of Civil and Environmental Engineering. The plate load test is a widely used and important test method to determine the bearing capacity of unbound granular materials in the superstructure of a road. The test is based in Boussinesq’s formula, which makes general assumptions that are not reasonable when considering the materials used for road construction. The test is thus very dependent on the test procedures, as well as the conditions in the field. The Norwegian Public Roads Administration has defined the plate load test as the only method for final documentation of the quality of compaction of unbound materials, and has defined a set of requirements that every measured point must fulfil. However, a number of contractors have experienced unexplained difficulties with fulfilling the requirements, even after repeated compaction efforts. This thesis aims to assess to what extent the in-situ condition of the road, the superstructure materials and their in-situ state, as well as the test procedure and calculation method affect the results of the plate load tests. In order to answer the research questions, a document analysis, a case study and a field test were conducted. In the document analysis, national standards and regulations regarding requirements and test procedures for plate load tests from Norway, Sweden, Iceland and Germany were analysed and compared. The case study compared four different road construction sites; (1) a tunnel based project, (2) an urban road project, (3) a new motorway project and (4) a motorway upgrading project, by conducting semi-structured interviews on representatives from the constructor and/or owner builder, collecting measured results from plate load tests conducted on the site, and conducting observations in the field. Additional interviews with individuals with experience from multiple different construction sites, as well as results from plate load test ...