What does soil classification primarily help determine?
A Soil’s texture and properties
B Soil’s color
C Soil’s depth
D Soil’s moisture content
Soil classification groups soil based on its texture (sand, silt, clay) and other properties. It helps determine how soil will behave under load, moisture, and stress, essential for engineering and agricultural applications.
Which soil type typically has high permeability?
A Clay
B Sand
C Silt
D Gravel
Gravel has large particles with significant voids between them, which allows water to flow easily. This high permeability makes gravel ideal for drainage and reducing water retention in construction projects.
What does consolidation of soil result in?
A Soil shrinkage
B Increase in soil volume
C Decrease in soil volume
D Increase in permeability
Consolidation is the gradual decrease in soil volume under a sustained load, primarily due to the expulsion of pore water. This process is essential for understanding settlement and is most significant in fine-grained soils like clay.
What does shear strength in soil indicate?
A Soil’s ability to resist deformation
B Soil’s ability to resist deformation
C Soil’s moisture retention capacity
D Soil’s permeability
Shear strength is the ability of soil to resist shear stress. It helps in determining how soil will behave under load, ensuring structures like foundations are stable and safe from deformation or failure.
What is the purpose of the Proctor test?
A Measure shear strength
B Determine optimal moisture for compaction
C Measure soil permeability
D Evaluate soil’s plasticity
The Proctor test identifies the moisture content at which soil achieves maximum compaction. This ensures that the soil density is high, leading to stable and strong construction foundations that resist settling.
What happens when soil is compacted?
A Soil density increases
B Permeability increases
C Soil plasticity increases
D Shear strength decreases
Compaction reduces voids between soil particles, increasing its density and strength. This process improves the soil’s ability to support structures, reducing settlement and providing better support for buildings and roads.
What does the CBR test measure?
A Soil moisture
B Soil’s compaction
C Soil’s resistance to penetration
D Soil’s permeability
The California Bearing Ratio (CBR) test measures how much force a soil can resist before failing under penetration. It is used to assess soil for road construction to ensure it can handle traffic loads without failure.
What is the main characteristic of expansive soils?
A High permeability
B High swelling potential
C High shrinkage
D High plasticity
Expansive soils, like certain clays, swell significantly when wet and shrink when dry. This swelling can cause severe structural problems, such as foundation cracking, especially if the moisture content fluctuates.
What does effective stress influence?
A Soil permeability
B Soil strength
C Soil compaction
D Soil shrinkage
Effective stress refers to the stress that contributes to the soil’s shear strength. It is calculated by subtracting pore water pressure from total stress, and it is crucial for understanding how soil behaves under load.
What does soil-structure interaction refer to?
A Interaction between soil and groundwater
B Interaction between soil and construction materials
C Interaction between soil and external forces
D Interaction between soil and plants
Soil-structure interaction involves understanding how soil and structures (like buildings and roads) respond to external forces. This helps design foundations that can handle loads and environmental conditions safely and efficiently.
What happens to clay when it absorbs water?
A It expands
B It shrinks
C It compacts
D It becomes impermeable
Clay expands significantly when it absorbs water due to its fine particle size and high plasticity. This expansion can cause structural problems, such as cracking in foundations and roads built on clayey soils.
What is capillary action in soils?
A Water moving downward through soil
B Water flowing horizontally through soil
C Water rising through small pores against gravity
D Water evaporating from the soil
Capillary action occurs when water moves upward through soil due to surface tension between the water molecules and soil particles. This is especially noticeable in fine-grained soils like clay, affecting moisture availability.
What is the purpose of the triaxial test?
A Measure soil’s shear strength
B Measure soil compaction
C Measure soil permeability
D Measure soil shrinkage
The triaxial test measures the shear strength of soil by applying stress in all directions. It simulates real-world conditions, providing valuable data for understanding how soil will behave under different loads.
What does consolidation cause in soil over time?
A Volume increase
B Increase in permeability
C Decrease in volume
D Increase in moisture
Consolidation causes a decrease in soil volume as pore water is expelled under pressure. This process is particularly important for fine-grained soils and can result in settlement as soil compresses over time.
What is the effect of soil erosion?
A Increased fertility
B Loss of topsoil
C Increased shear strength
D Decreased soil strength
Soil erosion removes the fertile topsoil, which is essential for plant growth. Water and wind are the main causes, leading to land degradation, reduced agricultural productivity, and instability in construction areas.