Fundamentals of Geotechnical Engineering - FE Civil Exam

Classify soils as cohesive or noncohesive, and explain how solids, water, and air relate in phase diagrams. Use void ratio, unit weights, and water content with examples.

Master field tests for soil quality by learning water content determination via oven drying, and computing relative density and relative compaction to guide foundation design and soil improvement decisions.

Explore sieve analysis for soil grading and size distribution, identify D10, D30, and D60 from the distribution curve, and calculate the uniformity and curvature coefficients.

Explore field tests using a 63.5 kg hammer and a borehole setup to count blows to 30 cm penetration, and review Atterberg limits and bearing capacity concepts.

learn to classify soils using the unified classification system (USCIS), separating green and fine-grained soils with sieve tests, liquid limit, plasticity index, and A-line curves to identify CH.

Classify soil using the AASHTO method, splitting into granular material and silt clay material based on the 200 sieve passing, then refine groups with liquid limit and plasticity index.

Compute the degree of saturation from the water volume and voids using the equation S = (Vw / Vv) × 100, yielding about 84%.

Calculate the saturated unit weight gamma_s using gamma_s = (Gs + e) * gamma_w / (1 + e) with void ratio e = 0.23 and Gs = 2.6, yielding about 23 kN/m^3.

Compute the water content of a saturated clay sample from total weight and solids weight, yielding a 34.6% water content (about 35%), as part of FE civil exam prep.

Calculate the void ratio for an undisturbed clay sample by deriving the solid volume from Gs, subtracting it from total volume to get voids, then compute e ≈ 0.40.

Apply the USGS method to classify soil from a 69% fines sample, with liquid limit 72 and plastic limit 48, using the USGS table to identify the soil type.

Compute the plasticity index from the liquid and plastic limits, then apply the group index equation to obtain about 7.85, the closest to eight (option d).

Compute the effective unit weight of soil using porosity 27% and specific gravity 3.11 by finding gamma saturated and subtracting gamma water.

Compute the saturated unit weight using gamma_sat = (Gs + e gamma_w)/(1+e) with e = 0.41, Gs = 3, and gamma_w = 10, yielding gamma_sat about 26.3.

Solve a geotechnical practice problem to determine the volume of air in a soil sample by calculating solids volume with gamma solids, then subtracting water volume from the voids.

Compute vertical stress from layer densities and depths, reflecting a triangular distribution. Subtract pore water pressure to obtain effective vertical stress, illustrated with a two-layer example.

Explore soil horizontal stress behind retaining walls, derive active and passive pressure coefficients, account for water pressure and vertical stress, and solve a sample active lateral force problem.

Analyze the stability of retaining structures by evaluating sliding and overturning failure mechanisms and bearing capacity, and compute active and passive pressures, friction, and adhesion for gravity and cantilever walls.

Compute footing effective stress by subtracting pore water pressure from stress; with 52 kilo scale stress and 2 m water head, sigma effective at point e is 32 kilo scale.

Compute active earth pressure on a 3.5 m retaining wall using ka = 0.27 for phi = 35°, gamma = 1834 kg/m^3, to determine the resultant per unit length.

Computes the factor of safety against sliding for a retaining wall, using active and passive earth pressures, weights, and friction, yielding a factor of safety of 2.4.

calculate the factor of safety against sliding for a retaining wall by evaluating active and passive earth pressures and the wall weight, yielding a factor of safety of 1.45.

Explore shallow foundations—isolated footing, combined footing, three footing, and draft foundation—and deep foundations like piles, and how they transfer loads to soil. Learn failure modes: bearing capacity and settlement.

Learn to compute bearing capacity for foundations, analyze general shear and punching shear failures, and apply the ultimate and net bearing capacity equations under varying water table conditions.

Explore soil consolidation in saturated clay, linking water seepage, void-ratio reduction, and settlement to virgin and recompression ranges, with cc and cr indices guiding analysis.

Compute the ultimate bearing capacity per meter length for a floating footing on sand using the given cohesion, gamma, density, and dimensions, approximately 840 kN/m.

Compute the primary consolidation settlement of a five-foot normally consolidated clay using cc 0.45, e0 0.92, P_A 1500, and ΔP 2500, yielding about 0.5 ft.

Calculate the primary consolidation settlement for a 15-ft clay layer under stress increase, using virgin compression and recompression with cc and cr from the liquid limit, approximately 1.15 ft.

Learn about shear strength in soils, its two components—cohesion and friction—how normal stress on a failure surface drives shear resistance, and how the circle representation (Moore Circle) illustrates failure.

Assess slope stability by analyzing a planner's surface under a slope, with weight components, mobilized and demobilized shear forces, friction, and cohesion to determine the factor of safety.

Learn soil stabilization techniques to improve properties for structural use, including cement and lime stabilization for clays in road projects, as well as bitumen and chemical stabilizers, grouting, and pre-loading.

Compute available shear resistance on a uniform-soil slope failure plane using cohesion 15, phi 15°, and 10 m height, concluding with a resisting force near 940.6.

Analyze a geotechnical problem on a soil slope, applying the equation for sliding force w sin alpha, with weight and slope angle, and determine the closest answer near 850.

Conclude this module by reviewing a quick example before the exam, and join the private Facebook group for fellow-student clarifications and support.