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Questions and Answers
What is the primary function of a foundation in construction?
What is the primary function of a foundation in construction?
Which factor is NOT considered when selecting a foundation type?
Which factor is NOT considered when selecting a foundation type?
What is one of the structural requirements for a foundation system?
What is one of the structural requirements for a foundation system?
How can geotechnical investigation impact project costs?
How can geotechnical investigation impact project costs?
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What is an important constructional requirement for foundations?
What is an important constructional requirement for foundations?
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What is the primary consideration before selecting bearing capacities for soil conditions?
What is the primary consideration before selecting bearing capacities for soil conditions?
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Which of the following is NOT a type of shallow foundation?
Which of the following is NOT a type of shallow foundation?
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What formula represents allowable soil bearing capacity?
What formula represents allowable soil bearing capacity?
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What does the variable $q_{u}$ represent in the allowable bearing capacity formula?
What does the variable $q_{u}$ represent in the allowable bearing capacity formula?
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Which type of foundation is characterized by supporting loads over a large area?
Which type of foundation is characterized by supporting loads over a large area?
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What design solution is suggested when an edge column is closer to the boundary?
What design solution is suggested when an edge column is closer to the boundary?
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What does the comparison $N_A = N_B$ indicate in the context of combined footings?
What does the comparison $N_A = N_B$ indicate in the context of combined footings?
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In soil pressure distribution for combined footings, which scenario leads to varying pressure?
In soil pressure distribution for combined footings, which scenario leads to varying pressure?
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What does the expression $L imes b imes q_{m,m,m,m,m,m} = N_A + N_B$ represent?
What does the expression $L imes b imes q_{m,m,m,m,m,m} = N_A + N_B$ represent?
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Which parameter is NOT directly involved in estimating the dimensions of a combined footing?
Which parameter is NOT directly involved in estimating the dimensions of a combined footing?
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What is the primary purpose of taking the first moment of area about the left-hand edge of the footing?
What is the primary purpose of taking the first moment of area about the left-hand edge of the footing?
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When constant pressure is applied to a combined footing, what is likely true about the footing?
When constant pressure is applied to a combined footing, what is likely true about the footing?
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Which statement correctly describes the line of the reaction force in combined footings?
Which statement correctly describes the line of the reaction force in combined footings?
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What should generally be avoided when using prefabricated shoring systems?
What should generally be avoided when using prefabricated shoring systems?
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Which of the following is a disadvantage of sheet pile walls?
Which of the following is a disadvantage of sheet pile walls?
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What materials are typically used for soldier pile walls?
What materials are typically used for soldier pile walls?
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Which condition is best suited for the use of soldier pile walls?
Which condition is best suited for the use of soldier pile walls?
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How are sheet pile walls typically secured?
How are sheet pile walls typically secured?
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Which option best describes a major drawback of soldier pile walls?
Which option best describes a major drawback of soldier pile walls?
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What is a notable advantage of using sheet pile walls?
What is a notable advantage of using sheet pile walls?
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Which type of shoring system is generally not suitable for retaining soil below the water table?
Which type of shoring system is generally not suitable for retaining soil below the water table?
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What factors primarily influence the settlement of a pile?
What factors primarily influence the settlement of a pile?
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Which statement accurately describes pile group settlement?
Which statement accurately describes pile group settlement?
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What is the main function of piles in bridge construction?
What is the main function of piles in bridge construction?
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What is the primary source of pile resistance?
What is the primary source of pile resistance?
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Why are driven piles often preferred over cast-in-place piles?
Why are driven piles often preferred over cast-in-place piles?
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In what conditions would cast-in-place piles be more advantageous than driven piles?
In what conditions would cast-in-place piles be more advantageous than driven piles?
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What are driven steel H-piles specifically noted for?
What are driven steel H-piles specifically noted for?
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What is a limiting factor of driving stresses on driven steel H-piles?
What is a limiting factor of driving stresses on driven steel H-piles?
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What characterizes trench-box excavation shoring systems?
What characterizes trench-box excavation shoring systems?
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Which material is primarily used to construct gabions?
Which material is primarily used to construct gabions?
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What is the maximum wall height mentioned that structures built under AS 4678:2002 can typically achieve?
What is the maximum wall height mentioned that structures built under AS 4678:2002 can typically achieve?
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Which type of soil is characterized by its dependence on friction between particles?
Which type of soil is characterized by its dependence on friction between particles?
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What classification applies to structures where failure results in minimal damage and their wall height exceeds 1.5 m?
What classification applies to structures where failure results in minimal damage and their wall height exceeds 1.5 m?
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Which of the following soils is described as sticky and strength dependent on capillary water?
Which of the following soils is described as sticky and strength dependent on capillary water?
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What is the AS 4678:2002 standard primarily applicable to?
What is the AS 4678:2002 standard primarily applicable to?
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Which clause specifies the requirement for obtaining accurate data from the site geotechnical report?
Which clause specifies the requirement for obtaining accurate data from the site geotechnical report?
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What characteristic differentiates cohesive soil from cohesionless soil?
What characteristic differentiates cohesive soil from cohesionless soil?
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Study Notes
Foundations and Retaining Walls
- Foundations transmit building loads to the underlying soil.
- Foundation type selection depends on ground conditions, water level, site environment (nearby buildings), and structure type.
- Foundations need to transfer loads safely to undisturbed soil and provide sufficient structural safety.
- Construction requires minimal resources, minimal cost, and time-efficient techniques.
- Geotechnical investigation can optimize foundation design, costing 0.5%-5% of the project but significantly saving money.
Introduction to Foundations
- Foundations support the structure's weight and transmit load to the soil or rock.
- Knowledge of geology, soil mechanics, rock mechanics, and structural engineering is applied.
- Foundations are often expensive and complex to repair. Poor design or construction can lead to building demolition.
- Mistakes can occur due to construction or geotechnical errors.
Before Excavation
- Subsurface exploration is essential.
- Previous developments (buildings) and geological maps need to be considered.
- Exploration targets soil/rock strata, engineering properties, and groundwater levels.
Bore Holes
- Bore holes are used for subsurface exploration to understand soil/rock conditions.
Core Logging
- Core logging is a process that collects soil and rock samples from bore holes.
Types of Foundations
- Shallow foundations (e.g., spread footings, strip footings, combined footings, slab on grade, mat foundation).
- Deep foundations (e.g., piles, piers, caissons, raft foundations, basement foundations).
Shallow Foundations
- Pad footings support single column loads in the footing center.
- Strip footings are long, reinforced concrete members supporting load-bearing walls consistently.
- Combined footings are rectangular/trapezoidal reinforced concrete members supporting multiple columns.
- Slab on grade is a continuous reinforced concrete foundation.
- Mat/Raft foundations are large, thick concrete structures supporting the entire structure.
Types of Deep Foundations
- Piles can be driven into the ground using wood, steel or precast concrete.
- Piers are similar to piles but have larger diameters.
- Caissons are large piers that act as watertight structures for construction work.
Bored Pile Construction
- Augured and CFA (Continuous Flight Auger) methods are common.
Pile Caps and Spread Footings
- Proper detailing of pile caps is crucial.
Numerical Methods
- Used to study the load-deformation responses of piles.
- Charts are used to evaluate pile settlement based on soil and pile geometry/stiffness parameters.
Pile Function
- Piles transfer loads from the bridge to the foundations.
- Pile loads are pre-calculated during the bridge design process.
Pile Resistance
- Pile resistance results from friction along the pile sides and bearing on the bottom of the pile.
- Driven piles are used where driving allows for achieving the required resistance or reaching rock.
- Cast-in-place piles are used in situations with proximity to rock or where vibration from the driven piles is undesirable.
Driven Steel H-Piles
- Suitable for rural applications, but careful consideration is needed given the limitations imposed by driving stresses and conflicting views on strength.
Trench-box Excavation Shoring Systems
- Suitable for shallow and stable excavations where water is not an issue.
- Prefabricated walls and connected braces are used.
Sheet Piling and Excavation
- Thin steel sheets are used as continuous barriers and retaining walls for excavation and construction purposes.
Sheet Pile Excavation Shoring Systems
- The system uses steel or vinyl sheet piles when groundwater is an issue. Installation can only be used in areas where it doesn't damage adjacent structures.
Sheetpile Walls
- Temporary shoring and retention of deep soil, often above and below the water table.
- Often connected by multiple anchors or bracing/struts.
- Relatively low cost and can be reused.
Soldier Pile Walls
- Used for vertical excavations in stiff clay or weak rock.
- Often feature bored concrete piles or piers with infill shotcrete panels.
- Can potentially have "tie-back" ground anchors to aid in restraint.
- Relatively low cost, and can often be set to integrate into rock.
Contiguous Pile Walls
- Used to reinforce earth retention in dry soil situations.
- Formed from bored or CFA piles, often placed in such a way that they are close to each other.
- Minimal shotcrete is required.
Secant Pile Walls
- Used for watertight basement foundations in soil below the water table..
- Formed by CFA piles.
- Can be hard-soft or hard-hard piles (primary/secondary, reinforced/unreinforced).
Diaphragm Walls
- Permanent retaining wall typically placed below the water table.
- Stiff retention system, fewer anchors usually needed.
- Can be installed into rock, for cut-off purposes.
- Ideal for depths greater than 30m, with good verticality control.
Types of Retaining Walls
- Gravity – rely on weight for stability
- Embedded – mobilize surrounding earth pressures to resist loads
- Categories of retaining walls, such as gravity walls, gabion walls, crib walls, and cantilevered walls are presented.
- Buttress walls, reinforced earth walls, and bridge abutments are additional types explained.
Abutments in Bridges
- Form the connection between the bridge deck and the approach roads.
- Support vertical and horizontal loads from the superstructure.
Different soil types and their properties are presented, as well as typical design sections and failure modes for specific structures.
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Description
Test your knowledge on the critical aspects of foundation types in construction. This quiz covers fundamental principles, structural requirements, and factors affecting foundation selection. Delve into the importance of geotechnical investigation and various types of foundations to enhance your understanding.
