Mechanical properties of soft rocks such as marls are strongly affected by suction, directly connected with wetting and drying cycles resulting from climate actions. An extensive experimental programme was carried out in order to characterize the physical and mechanical properties of Abadia marls, used in the A10 motorway near Arruda dos Vinhos (Portugal). The experimental programme consisted of laboratory unconfined compression and Brazilian splitting tests, oedometric tests and triaxial tests, all of them performed under controlled suction.