Engineering Property and Its Significance of Alluvial Clayey Deposits

Abstract

Geological research on the subsurface alluvial deposits would be effectively promoted in combination with the investigation of civil engineering properties of these deposits.Judging from the soil technological investigation, the civil engineering properties of clayey deposits are largely controlled by both the inter particle forces acting among the clay particles and by the soil structure (arrangement of the clay particles) in the deposits. The inter particle forces and the soil structure are affected by the geological factors including the material factors and the environmental factors of the deposits.Two groups in the civil engineering properties are recognized: primary and secondary. The primary properties are concerned with the material factors of the deposits, such as clay content, composition of clay materials, and nature of pore fluid. The secondary properties are concerned mainly with the environmental factors of the deposits, such as sedimentary environment, post depositional overburden pressure, and geological history of the deposits. These secondary properties are important to reveal the geological evolution of the deposits.In this article the author discussed the bearing of indices of civil engineering properties on the geological factors, and he presented the methods in order to detect the geological factors which influenced the properties of the deposits. In the above methods, there have been used the correlation diagrams among the indices of civil engineering properties and the geological factors. Further detailed studies on this subject are under consideration.