Podcast
Questions and Answers
What is a major advantage of steel piles?
What is a major advantage of steel piles?
What is a disadvantage of steel piles?
What is a disadvantage of steel piles?
What is the purpose of a composite pile?
What is the purpose of a composite pile?
How do end bearing piles transmit loads?
How do end bearing piles transmit loads?
Signup and view all the answers
When are friction piles used?
When are friction piles used?
Signup and view all the answers
What is the conventional method of pile driving?
What is the conventional method of pile driving?
Signup and view all the answers
What restricts the length of a pile?
What restricts the length of a pile?
Signup and view all the answers
What is the main advantage of driven piles?
What is the main advantage of driven piles?
Signup and view all the answers
What is the purpose of using piles in structures like transmission towers and off shore platforms?
What is the purpose of using piles in structures like transmission towers and off shore platforms?
Signup and view all the answers
What type of soil may require the use of piles to transfer the load below the active zone?
What type of soil may require the use of piles to transfer the load below the active zone?
Signup and view all the answers
What is the primary reason for using piles in areas where the soil condition is poor?
What is the primary reason for using piles in areas where the soil condition is poor?
Signup and view all the answers
How are piles classified?
How are piles classified?
Signup and view all the answers
What is the maximum load that a timber pile can typically carry?
What is the maximum load that a timber pile can typically carry?
Signup and view all the answers
What is an advantage of using timber piles?
What is an advantage of using timber piles?
Signup and view all the answers
What is a disadvantage of using timber piles?
What is a disadvantage of using timber piles?
Signup and view all the answers
What type of concrete piles can be used?
What type of concrete piles can be used?
Signup and view all the answers
What is a crucial consideration for the suitability of driven piles in certain soils?
What is a crucial consideration for the suitability of driven piles in certain soils?
Signup and view all the answers
What is the first step in the construction process of driven cast in-situ concrete piles?
What is the first step in the construction process of driven cast in-situ concrete piles?
Signup and view all the answers
What is the purpose of using bentonite in bored piles construction?
What is the purpose of using bentonite in bored piles construction?
Signup and view all the answers
What is the primary function of the grout pipes in a screw pile?
What is the primary function of the grout pipes in a screw pile?
Signup and view all the answers
What is the purpose of the temporary casing in bored piles construction?
What is the purpose of the temporary casing in bored piles construction?
Signup and view all the answers
What determines the length of the temporary casing in bored piles construction?
What determines the length of the temporary casing in bored piles construction?
Signup and view all the answers
What is the primary load that bored piles are designed to resist?
What is the primary load that bored piles are designed to resist?
Signup and view all the answers
What is the purpose of the rotary drill rigs in bored piles construction?
What is the purpose of the rotary drill rigs in bored piles construction?
Signup and view all the answers
Study Notes
Pile Foundations
- Piles are used for foundations of structures like transmission towers and offshore platforms that are subjected to uplift.
- Piles are used to transfer the load below the active zone in expansive soils like black cotton soil that swell or shrink with water content changes.
- Piles are required when soil conditions are prone to washout, erosion, or scour underneath shallow foundations.
Classification of Piles
- Piles are classified according to materials used, mode of load transfer, method of installation, and use.
- Materials used: timber, steel, concrete, and composite piles.
Timber Piles
- Timber piles are made from tree trunks, trimmed of branches, and designed for a maximum load of 15 to 25 tons/pile.
- Additional strength can be obtained by bolting fish plates to the sides.
- Timber piles last for about 30 years and are used for structures with moderate loads and temporary structures.
- Breadth of timber piles ranges from 12 to 16 inches.
Advantages of Timber Piles
- Low cost per running length of the pile.
- Suitable for impact absorption due to timber's resilience.
- Easy to install and uninstall if necessary.
Disadvantages of Timber Piles
- Small bearing capacity.
- Untreated timber piles above groundwater may last more than 25 years but are not permanent.
- Prone to damage by hard driving.
Concrete Piles
- Can be pre-cast or cast in-situ, and are generally reinforced.
- Driven cast-in-situ concrete piles are constructed by driving a permanent pile casing, followed by reinforcement and concrete pouring.
Bored Piles
- Constructed by boring through overlying soils to find a bedrock strata or remain in the soil to act as shaft friction and end-bearing piles.
- Piles are designed to resist axial compressive loads.
- Construction involves rotary drill rigs, temporary casing, and bentonite for unstable subsoil conditions.
Screw Piles
- Equipped with internal grout pipes extending downwardly through the tubular pile shaft.
- Grout pipes connect with side-opening ports in the shaft side wall to inject fluid grout into the surrounding ground.
- Pile length is restricted depending on the mode of transportation available.
Steel Piles
- Have a large bearing capacity and can penetrate through stiff layers or boulders.
- Less soil displacement during driving.
- Can withstand rough handling.
Disadvantages of Steel Piles
- High possibility of damage from corrosion and electrolysis.
- Relatively expensive unless the bearing stratum can develop large pile capacity.
- Less effective than friction piles.
Composite Piles
- Made by driving two different materials one over the other to achieve economy in piling work.
Mode of Load Transfer
- End-bearing piles transmit the load through the bottom tips to a firm stratum below.
- Friction piles transfer the load through skin friction between the embedded surface and surrounding soil.
Classification by Method of Installation
- Driven piles
- Driven and cast-in-situ piles
- Bored and cast-in-situ piles
- Screw piles
- Jacked piles
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers the uses of piles in construction, including their application in foundations for structures like transmission towers and offshore platforms, as well as in expansive soils and unstable soil conditions.
