Esfuerzos de preconsolidación y su importancia en la determinación del coeficiente lateral de presión de tierras en reposo (Ko) en suelos arcillosos sedimentarios

Abstract

Preconsolidation pressure is known as the maximum geotechnical effort that has supported a particular soil along its geological history. The concept is especially important for sedimentary soils. A soil is preconsolidated or overconsolidated when currently effective stresses are below those historical values, deducting these in oedometer or isotropic conditions. The main factors determining the origin of preconsolidation on a sedimentary soil, there are geological processes are associated with loading stress paths and subsequent unload processes caused by erosion (physical removal of material by some geological agent), desiccation (loss of moisture) with in-depth of the water table and antropic unloads (man made excavations). Lacustrine clay of Bogota (Colombia), is a material that has been subjected to sedimentation processes in the last 3 million years and dessication processes in surficial layers in the last 100 years. This material has undergone all the processes described above. The preconsolidation stress is closely linked to the value of the coefficient of lateral earth pressure at rest (Ko), this value determines the lateral forces of buried infrastructure. There is still a lack of data about the values of Ko in Bogota Clay, especially in surface layers in which paved roads, foundations and other structures are supported.