Soil Mechanics Exam 2 questions and answers latest 2023

Soil Mechanics Exam 2 questions and answers latest 2023 True T/F: Hydraulic gradient, i, is defined as the energy or head loss, h, per unit length, l. True T/F: Seepage velocity, the actual velocity of the water flowing in the voids, is greater than the discharge, or superficial, velocity and is related by porosity. Degree of Soil Saturation Void Ratio Grain size distribution Pore size distribution Hydraulic conductivity, or permeability, depends on the following: False T/F: There is a direct relationship between porosity and hydraulic conductivity. False T/F: Liquefaction, or quicksand, occurs when the effective stress is less than zero. True T/F: Seepage forces, which may cause quicksand to develop, are always present in soils where there is a gradient causing the flow of water. False T/F: The water level in a piezometer directly reads the total head at the point of interest. Secondary Settlement Immediate Settlement Consolidation Settlement The total settlement of a soil is made up of various components, which are...... False T/F: Most settlements that occur in fine-grained, clayey soils, are immediate. Compression of air and water in the voids Deformation of soil grains Squeezing out of water and air from the voids When a soil is loaded, it will compress because of... CR The slope of the normally consolidated portion (otherwise known as virgin compression) of the experimental laboratory consolidation curve in the vertical strain versus long effective consolidation stress realm is denoted as........ True T/F: A soil is normally consolidated (NC) when the preconsolidaton pressure (σ'p) just equals the currently existing effective vertical overburden pressure (σ'vo), that is σ'p = σ'vo. True T/F: When σ'v = σ'p, the soil is considered normally consolidated. True T/F: When σ'p is greater than σ'v, the soil is considered overconsolidated. True T/F: The increase in vertical stress due to a foundation load, Δσ, should be calculated at the same location within the clay layer that the pre-consolidation stress, σ'p, and vertical effective stress, σ'v, are calculated when determining settlement. False T/F: The increase in vertical stress due to a foundation load, Δσ, increases as the point of interest moves out away from the center of the foundation footprint. True T/F: The increase in vertical stress due to a foundation load, Δσ, is the highest it will be directly beneath the center of the foundation. non-dimensional time factor What is Tv? False T/F: We can increase the rate of settlement (e.g., how fast settlement occurs) by adding more surface load to the soil. True T/F: The coefficient of consolidation, cv, can be determined through graphical methods using the incremental oedometer data. Casagrande's Logarithm of Time-Fitting Method is used to determine the cv at the time at which 50% of the consolidation has completed. False T/F: The coefficient of consolidation, cv, can be determined through graphical methods using the incremental oedometer data. Taylor's Square Root of Time-Fitting Method is used to determine the cv at the time at which 50% of the consolidation has completed. False T/F: The coefficient of consolidation, cv, is a constant for a test on a given soil. Increasing the coefficient of consolidation Requiring a lower %Consolidation at the start of construction Decreasing the drainage path You can decrease the time rate of consolidation (i.e., make the settlement go faster) by......