The displacement of structures founded on expansive soils – unapparent causes

Abstract

Determining the causes for the displacement of damaged structures located on expansive soils often requires meticulous and individual analyses of many factors. The sensitivity of the expansive subsoils to environmental changes in humidity, activating its volume changes, requires a careful and comprehensive monitoring of structures susceptible to deformation. The article presents the method of the diagnostics of structures, located on an expansive subsoil in Poland. The methodology and preliminary results of the measurement of the vertical displacements of a building structure founded on expansive subsoil were presented. During field measurements, periodic geodetic measurements of structural displacements were carried out using classical precision levelling and the coordinate method of the Leica TDRA 6000 laser station. At the same time, geotechnical investigations were carried out describing the condition of the ground on which the structure is located. An analysis of the obtained results allowed determining the existing soil and water conditions and drawing unapparent conclusions regarding the causes of damage to the tested structure. On this basis, a further structures monitoring program was established.