Author(s)

J. Estaire & C. Olalla

Abstract

In this paper an analysis of the shear strength of armourstone is made based on the results obtained in 16 direct shear tests made in a 1 m 3 box, belonging to CEDEX, in which 68 probes were broken. The tests were performed with seven types of armourstone coming from different quarries and with different characteristics. The material was placed in the shear box by simple dropping, in some tests, and with light mechanical compaction in other ones. The vertical stresses used in the tests varied from 50 to 800 kPa. The results of the tests were analysed with three different criteria: using the Mohr-Coulomb strength model, with and without cohesion and using parabolic fitting curves. Keywords: shear strength, armourstone, shear test. 1 Introduction Armourstone, as construction material, has a relevant role in the design of coastal structures, such as breakwaters, and of foundation structures such as the ones used in the foundation of caissons. A good design of these structures requires the knowledge of the mechanical properties of the armourstone. The difficulty comes from the great size of the grains or pieces of these materials, which need both test equipment of great dimensions and heavy weight samples. Equipment that fulfils the requirements to perform tests to determine armourstone shear strength is the direct shear test with box of great dimensions, as the one belonging to CEDEX. Due to this difficulty, the aim of this paper is to collect all the results obtained in the direct shear test of 1 m 3 , since its construction, performed with

Keywords

shear strength, armourstone, shear test.