Why might contiguous piles have been used as dividing walls instead of secant piles?
Why might contiguous piles have been used as dividing walls instead of secant piles?
The presence of footings of adjacent buildings and underground utilities on a site make contiguous pile wall the ideal choice for supporting an excavation. Contiguous piled walls have a faster speed of installation when compared with secant piled walls.
What is Secant piles?
A Secant Piled Wall is a retaining wall constructed for ground retention prior to excavation. The wall is formed by constructing alternating primary (female) and secondary (male) piles where the secondary piles partially cut into either side of the primary piles in order to form a continuous impervious structure.
What is secant pile?
A secant pile wall consists of overlapping (secant) piles to form structural or cutoff walls and achieve the required water tightness. The design can incorporate steel bar or beams for reinforcement and anchors can provide additional lateral support, if needed.
What is a cased pile?
Cased piles consist a shell around it and these piles when casted in site are called cased cast-in-situ concrete piles. In case of cased cast in situ piles, the shell is usually made of steel. This type of piles is suitable for any types of soils.
What are Secant piles used for?
Secant Pile Walls are usually installed as retaining structures and support systems for deep foundations, retaining elements and at the same time load-bearing walls and deep foundations for engineering constructions (e.g. walls and foundations of underground storeys, stand-alone and framed bridgeheads, etc.).
What’s the difference between secant and contiguous piles?
If the piles are constructed so that they are touching they are called contiguous piles, and they can then be grouted to form a watertight wall. Secant piling is when there is no gap between piles as a wall is made of interlocking bored piles.
When to use secant piling in a wall?
Secant piling is when there is no gap between piles as a wall is made of interlocking bored piles. This method is a cost-effective and fast solution for when short-term water retention os required. Firstly, primary piles are constructed using a ‘soft’ or ‘firm’ concrete mix.
What kind of equipment is used for secant piles?
The equipment used to construct secant piles generally comprises a heavy duty CFA auger with rotary cutting heads. A secant pile wall when completed is a cost effective alternative to diaphragm wall construction. Click on images below to enlarge.
How are contiguous piles used in retaining walls?
Contiguous Piling When rows of piles are inserted close together they can be used to form retaining walls. This is common when constructing basements, underpasses or cut and cover tunnels. If the piles are constructed so that they are touching they are called contiguous piles, and they can then be grouted to form a watertight wall.