Assessment of the Internal Instability for Granular Soils Subjected to Seepage

摘要

The knowledgeof the internal stability of granular soils is a key factor for the design of granularand filter for the geotechnical infrastructures such as dykes, barrages, weirs androads embankment. To evaluate the internal instability of granular soils differentcriteria are generally used in the practice. However, the results of these criteriaon the same soil may lead to different evaluations of the internal instability.In this paper the common criteria used for the internal instability have been presentedand compared as far as possible. It was found that the most internal instabilitycriteria define a limit value for the secant slope of the grain size distributioncurve of the granular soils. Based on this finding an own criterion for the evaluationof the internal instability of granular soil has been developed and compared tothe common criteria. A very good agreement between some criteria was found. Furthermore,a site specific assessment for the evaluation of the internal instability of granularsoil has been proposed in order to get more confidence in this evaluation.