Daniel Arias

Finite elements analysis of an underground collector installed by pipe-jacking method

Using the commercial software RS2, a 2D finite-element program for soil and rock application, the ground response to pipe jacking in pipeline installation in Avilés (north coast of Spain) was analysed. The geology of the location comprises Quaternary deposits on both flanks of the Avilés estuary and includes different highly variable geotechnical behaviour. Both axisymmetric and plane strain analyses were carried out in RS2 to simulate in 3D the ground response to pipe advancement. The results demonstrate that the vertical displacements at specific positions in the immediate vicinity of the pipeline were small. The maximum deformation at ground surface was shown to be less than 1.5 mm, which was still safe. However, the displacements were found to vary depending on the local properties of the materials drilled. Stress distributions were also computed.

Geotechnical map of a coastal and industrialized urban area (Avilés, NW Spain)

ABSTRACT Geotechnical mapping of urban environments is usually constrained by the scarcity of outcrops during fieldwork. Such is the case of Avilés, a coastal Spanish city that has been heavily industrialized since the middle of the last century. This research approaches the study of its urban subsoil through the development of a Geographical Information Systems-based relational database containing thousands of unpublished ground data, partially extracted from geotechnical reports. This allowed analysing the distribution and changes of thickness of the superficial deposits and lithostratigraphic formations as well as the evaluation of their main geotechnical properties. Thus, 14 geotechnical units were differentiated (hierarchically displayed in three categories) depending on lithological, geotechnical and constructive criteria. As a result, this investigation provides a geo-engineering map at scale 1:25,000.