Film Thickness Formula for Thermal EHL Line Contact Considering a New Reynolds–Carreau Equation

Tribology Letters - Extreme pressure (EP) lubricant additives form protective tribofilms at the site of contact using the heat and pressure of contact and relative motion. Common EP additives...     

The residual shear strength of Neogene marly soils in the Granada and Guadix basins, southeastern Spain

The analysis of samples taken from the Neogene and Cretaceous marly series of the Granada and Guadix basins (south east Spain) shows an inverse correlation between the clay content and the residual friction angle. It has been verified that the carbonate fraction of the soil has a significant influence on the residual friction angle; there is a threshold of 25% carbonates, above which the value of φ′_r increases from 20 to 30°. It has been proved that the presence of smectitic clay as the dominant constituent produces a low value of residual shear strength, associated with high fragility in unconsolidated undrained tests. It has been proved that the degree of compaction of the soil and therefore the initial porosity, has a direct influence on the effective residual friction angle (φ′_r). Received: 2 February 1999 · Accepted: 31 March 1999     

Geotechnical map of Holocene alluvial soil deposits in the metropolitan area of Granada (Spain): a GIS approach

The results of a geotechnical research on Holocene alluvial deposits in 14 municipalities of the Granada basin are presented, and a procedure to draw a geotechnical map of foundation conditions, using ArcGIS 9.3 (ESRI 2009) is described. Three different alluvial soil units were distinguished: (1) cohesive soils; (2) cohesive and fine granular soil; (3) coarse granular soil, based on their properties concerning grain size, bulk density, cohesion, internal friction angle, and N_SPT value. The actual building structures have predominantly shallow foundations. The definition of the minimum depth to actual foundation level was based on the analysis of thickness of disturbed soils, man-made fillings, depth to the water table and bearing capacity. The depth to actual foundation levels varies from 0.5 to 4 m in the study area. Concerning the ground, the geotechnical data compiled on foundation conditions show a high heterogeneity expressed by the spatial distribution of the basic properties in the three distinguished units of cohesive, cohesive and fine-granular, and coarse granular soils, respectively. The fine-grained alluvial soil units (cohesive) have a low bearing capacity varying between 40 and 100 kPa and are associated with a shallow water table appearing near the surface. In contrast, across the wide extension of the coarse-grained alluvial soil unit, a bearing capacity ranging from 60 to 300 kPa is determined; this unit is associated with a deep water table appearing at more than 40 m below the surface. The usefulness of the obtained geotechnical map of foundation conditions extends to the analysis of further alternatives of urban expansion and for the delimitation of future trends for of land-use-development processes in the metropolitan area of Granada, mainly at local and regional scales.