Soil Mechanics and Foundation Engineering Questions

• Soil Mechanics – Moisture Content from Pycnometer with Wet Soil and Known Specific Gravity A 260 g sample of wet soil is placed in a pycnometer jar (empty pycnometer weight = 400 g) to determine the water (moisture) content. The specific gravity of soil solids is 2.75. The combined weight of the pycnometer with the wet soil and water added to remove all air is 1415 g. The weight of the pycnometer filled with water only is 1275 g. Calculate the moisture content of the soil sample (in %).
• Consolidation Theory – Name of the Ratio s(t)/s(final) In one-dimensional consolidation of soils, the ratio of settlement at any time t to the final settlement is termed as which parameter?
• Expansive Clay Minerals – Identify the Incorrect Property of Montmorillonite-Rich Soils Which of the following statements about soils containing significant montmorillonite (smectite) minerals is incorrect?
• Water Content Determination for Coarse-Grained Soil – Preferred Practical Method When a soil sample contains coarse grains (sands/gravels) and you need to determine its water content efficiently, which method is generally preferred in practice?
• Soil Behavior Terms – Thixotropy, Sensitivity, Remoulding Loss, and Dilatancy Choose the correct statement(s) regarding common soil behavior terms used in geotechnical engineering.
• Slope Stability – Critical Height from Stability Number for Purely Cohesive Clay For a clay slope (cohesive soil) with cohesion C = 2.5 t/m^2, unit weight γ = 2.0 t/m^3, and stability number Sn = 0.05, compute the critical height Hc of the slope at limiting equilibrium.
• Soil Genesis – Water-Formed Transported Soils (Identify the Best Example) Which of the following is a soil type predominantly formed and transported by running water?
• Triaxial Shear Test – Reasons for Its Suitability for Shear Strength Evaluation Why is the triaxial shear test widely regarded as the most suitable laboratory test for determining shear strength parameters of soils?
• Granular Soils – Name of the Void-Ratio–Based Measure (e_max, e, e_min) The quantity defined as (e_max − e) / (e_max − e_min), where e is the natural void ratio, is generally termed as:
• Mohr–Coulomb Failure – Orientation of Failure Plane Relative to Major Principal Plane According to Mohr–Coulomb theory, the angle between the failure plane and the major principal plane is equal to:
• Earth pressure at rest K₀: For a cohesionless soil (φ = angle of internal friction), identify the correct proportional expression for the at-rest earth pressure coefficient. If none of the listed tan-based forms is valid, choose ‘‘none of these’’.
• Clay mineralogy (illite vs. kaolinite vs. montmorillonite): choose the correct statements about bonding strength, swelling, and layer structure.
• Foundation classification by geometry: identify which statements correctly define shallow vs. deep, spread, and strip foundations using depth/width and length/width ratios.
• Soil moisture terminology: The portion of soil moisture that is driven off by oven heat (standard water-content determination) is called:
• Volume change upon drying: As water content decreases, the volume of a cohesive soil reduces in which consistency states?
• Compaction effects: identify the incorrect statement about how compaction influences soil structure and behavior.
• Soil three-phase system: select the correct statements about voids in saturated and dry conditions.
• Pile load terminology: The maximum load that a pile carries while it continues to sink without any further increase of applied load is termed as:
• Maximum shear orientation: The plane (or filament) on which maximum shear stress occurs makes what angle with the horizontal plane?
• Standard oven-drying for water content: Water content is determined as the mass loss after drying the sample for about 24 hours at which temperature range?