Laboratory and Field Tests
Laboratory and Field Tests
Learning Objectives:
- Gain an understanding of the various laboratory and field tests used in civil engineering, including their purposes and applications.
- Differentiate between laboratory tests conducted in controlled environments and field tests conducted on construction sites.
Some sample lab and field tests include:
- The California Bearing Ratio (CBR) test is a standardized test used to evaluate the mechanical strength of subgrade soils and their suitability for road construction and pavement design.
- Sp. gravity of solids : Pycnometer Method: The Pycnometer Method is a laboratory technique used to determine the density and specific gravity of soil and aggregate materials. It is an essential test in geotechnical and materials engineering.
- Sp. gravity of solids : Density Bottle Method The specific gravity of solids is a measure of the relative density of a solid material compared to water. The Density Bottle Method is a laboratory technique used to determine the specific gravity of soil and other solid materials.
- Dry-Density of Soil: Water replacement method: Dry Density ($\rho_d$) represents the mass of dry soil per unit volume. It is typically expressed in grams per cubic centimeter (g/cm$^3$) or pounds per cubic foot (lb/ft$^3$). Dry density of soil samples is essential for geotechnical engineering, construction materials testing, and compaction quality control.
- In-Situ Dry Density: Sand replacement method
Solved Example: 9072-01
In order to obtain a good quality of undisturbed soil the area ratio of the sampling tube should be:
A. 8%
B. 16%
C. 24%
D. 32%
Correct Answer: A
Solved Example: 9072-02
Shelby tube is one of the most widely used devices for:
A. Drilling rocks and cobbles
B. Measuring effective stress
C. Wash borings
D. Collecting undisturbed soil samples
Correct Answer: D
Solved Example: 9072-03
The type of soil sample collected using wash boring technique is:
A. Representative
B. Zero-representative
C. Undisturbed
D. Zero disturbed
Correct Answer: B
Solved Example: 9072-04
Auger boring is suited for which of the following exploratory strata?
A. Partly saturated sands, silts and medium to stiff cohesive soils
B. All types of soils and rocks except fissured rocks
C. Practically all types of soils except hard and cemented soil or rock
D. All types of soils and rocks except loose sands and soft sticky clays
Correct Answer: A
Solved Example: 9072-05
Undisturbed soil samples are obtained by:
A. Thick-walled samplers
B. Direct excavations
C. Thin-walled samplers
D. Augers
Correct Answer: C
Solved Example: 9072-06
What should be the minimum depth of exploration below an isolated footing?
A. Equal to width of footing
B. One and half times the width of footing
C. Three times the width of footing
D. Three times the depth of footing
Correct Answer: B
Solved Example: 9072-07
The degree of disturbance of the sample collected by the sampler is expressed by a term called the 'area ratio'. If the outer diameter and inner diameter of the sampler are D$_o$ and D$_i$ respectively, the area ratio is given by:
A. $\dfrac{{D_o^2 - D_i^2}}{{D_i^2}}$
B. $\dfrac{{D_o^2 - D_i^2}}{{D_i^2}}$
C. $\dfrac{{D_o^2 - D_i^2}}{{D_o^2}}$
D. $\dfrac{{D_i^2 - D_o^2}}{{D_o^2}}$
Correct Answer: A
Solved Example: 9072-08
For sampling saturated sands and other soft and wet soils satisfactorily, the most suitable soil sampler is:
A. Open drive thin-walled sampler
B. Standard split-spoon sampler
C. Stationary piston sampler
D. Rotary sampler
Correct Answer: A
Solved Example: 9072-09
Los Angeles testing machine is used to conduct:
A. Attrition test
B. Impact test
C. Abrasion test
D. Crushing strength test
Correct Answer: C
Solved Example: 9072-10
Which of the following tests is not a field test?
A. SPT
B. CPT
C. Vane Shear Test
D. Proctor Compaction Test
Correct Answer: D
Solved Example: 9072-11
A hydrometer analysis is used to determine:
A. Particle shape
B. Organic content
C. Grain size of fine soils
D. Moisture content
Correct Answer: C
Solved Example: 9072-12
Which test gives the coefficient of consolidation (Cv)?
A. Unconfined Compression Test
B. Proctor Compaction Test
C. Consolidation Test
D. Sieve Analysis
Correct Answer: C
Solved Example: 9072-13
The permeability of a clayey soil is best determined by:
A. Constant Head Test
B. Falling Head Test
C. Sieve Analysis
D. SPT
Correct Answer: B
Solved Example: 9072-14
Vane shear test is commonly used in:
A. Hard rocks
B. Loose sand
C. Soft clay
D. Dry gravel
Correct Answer: C
Solved Example: 9072-15
The main advantage of triaxial testing over direct shear is:
A. It's quicker
B. Drainage can't be controlled
C. Uniform stress conditions
D. Less equipment required
Correct Answer: C
Solved Example: 9072-16
A triaxial test can be performed under:
A. Only unconfined condition
B. Drained and undrained conditions
C. Fully saturated only
D. Partially dried samples only
Correct Answer: B
Solved Example: 9072-17
The Cone Penetration Test (CPT) is mostly suitable for:
A. Very coarse gravels
B. Dense rock
C. Fine-grained and sandy soils
D. Organic peat
Correct Answer: C
Solved Example: 9072-18
Which test uses a split-spoon sampler and measures resistance to penetration?
A. Triaxial Test
B. Standard Penetration Test (SPT)
C. Unconfined Compression Test
D. Hydrometer Test
Correct Answer: B
Solved Example: 9072-19
Which field test is best suited for determining in-situ soil density?
A. Cone Penetration Test
B. Sand Cone Test
C. Vane Shear Test
D. Permeability Test
Correct Answer: B
Solved Example: 9072-20
A consolidation test is primarily conducted to determine:
A. Shear strength
B. Water content
C. Settlement characteristics
D. Specific gravity
Correct Answer: C
Solved Example: 9072-21
Which of the following tests provides $c_u$ and $\phi$ values?
A. Permeability Test
B. Direct Shear Test
C. Liquid Limit Test
D. Hydrometer Analysis
Correct Answer: B
Solved Example: 9072-22
The unconfined compression test is primarily applicable to:
A. Dense sands
B. Cohesive soils
C. Granular soils
D. Gravels
Correct Answer: B
Solved Example: 9072-23
The Standard Proctor Test is used to determine:
A. Shear strength
B. Compaction characteristics
C. Permeability
D. Consolidation
Correct Answer: B
Solved Example: 9072-24
Which of the following tests is used to determine Atterberg limits?
A. Standard Proctor Test
B. Casagrande Cup Method
C. Triaxial Test
D. Consolidation Test
Correct Answer: B