Creep behaviour of upper globigerina limestone

Abstract

The upper layer of the Upper Globigerina Limestone is a complex material that is difficult to say whether it is a hard soil or a soft rock. This material has been studied from a geological point of view but no information currently exists on the geotechnical behaviour of this material. This material will be tested to find its one‐dimensional compressive behaviour, and check if the theories for soils are applicable. A block sample was obtained from a trial pit in Mellieħa in order to get specimen which could be tested in one dimensional compression. The specimen was machined using engineering tools such that it could be tested. Three specimens in total were tested, two in a high pressure oedometer, and one in a regular oedometer. The results obtained were then plotted on graphs and analysed. The results showed that despite the material is classified as a plasticity clay, Terzaghi’s theory for soils does not hold for the Upper Globigerina Limestone. It was also noted that the material changes behaviour depending on how long the load is applied. In the tests where the loading stages were left for a longer period of time, the specimen experienced a greater deformation and its behaviour was more similar to that of a soil. This change in behaviour occurs due to the breaking of the bonds between the soil particles.