Modelling of Moisture Effect in Safety Evaluation of Soil-Interacting Masonry Wall Structures

This paper deals with analytical models of retaining walls interacting with soil, whose mechanical properties are influenced by penetrating moisture. Specifically, urban masonry walls are here considered. The proposed simplified procedure takes rainfalls as the intensity measure dependent on rain duration and return period. Growing levels of imbibition of the soil behind the wall determine a de-crease of the strength parameters of the soil. A geometry of the section at each step of imbibition is analyzed considering a set of soil layers with modified properties over time. The method is applied to a section of the Volterra historical urban walls named "Sperone" which was affected by a relevant collapse occurred in March 2014: a back analysis of the soil-structure section is also proposed to re-place the collapse.