ASBOG - Engineering Geology Exam Review Qs&As 100% Verified

ASBOG - Engineering Geology Exam Review Qs&As 100% Verified Strain - ANS-An alteration in the shape or volume of a soil related to stress. It is calculated as the ratio of the new shape compared to the original shape Effective Stress - ANS-The total amount of stress placed on a soil minus the pore-water pressure Normal Stress - ANS-The component of total stress that acts perpendicular to the plane. Shear stress - ANS-The component of total stress that acts parallel to any point in question. Dilatancy - ANS-Tendency of a material to increase in volume when subjected to a shape change. Assume a closed-packed structure from an open-packed structure Quick Condition - ANS-Tendency of some soils that lack cohesion to allow water to flow rapidly between grains and to liquefy the material. Soil does NOT possess significant bearing capacity Elastic Modulus - ANS-Measure stiffness in a material (bulk, shear, Young's(Elastic)) Triaxial Test - ANS-Test for mechanical properties of deformable solids. Direct Shear test - ANS-Measure shear strength when sample is surrounded withstand subjected to mechanical stresses. Unconfined compressive strength test - ANS-Similar to triaxial but without external confining pressure. Consistency - ANS-General amount of cohesion in soil particles Critical void ratio - ANS-Void ratio of soil that stays the same even during shearing events. Mohr circle - ANS-Graph showing stresses that act on a single point on a plane. The x-axis - normal stress. Y-axis - shear stress Seepage - ANS-The flow of a fluid through soil pores. 4-inch diameter; three lifts; 25 blows by 5.5 lb hammer; falling 12-inches - ANS-Proctor Test five lifts; 10lb hammer; 18-inches - ANS-Modified Proctor Test Differentiate between the three different types of modulus: bulk (incompressibility) modulus, shear (rigidity) modulus, Young's (elasticity) modulus. - ANS-There are three different kinds of modulus, or ways to measure the stiffness of the material: • bulk modulus (K; otherwise known as incompressibility modulus): a measure of a substance's resistance to uniform compression. It is defined as the pressure increase needed to affect a given relative decrease in volume • shear modulus (G; also known as rigidity modulus): refers to the deformation of a solid when exposed to a force parallel to one of its surfaces as its opposite face is exposed to an opposing force. This will cause an object that is shaped like a rectangular prism to be deform into a parallelpiped • Young's modulus (E; also known as the modulus of elasticity): a measure of the stiffness of a given material. Defined as the ratio, for small strains, of the rate of change of stress with strain Define the terms used to describe volume changes in soils: dilatancy, dry strength, quick condition. - ANS-The following terms are used to describe volume changes in soils: dilatancy: the tendency of a material to increase in volume when subjected to a shape change. Also refers to material which can assume a close-packed structure from a openpacked structure...