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 contiguous bored pile wall?

Contiguous piled walls consist of a row of successive unconnected cast-in-situ concrete piles constructed with small gaps between the adjacent piles, formed using CFA or rotary bored piles (replacement piles techniques). …

Why are contiguous piles used as dividing walls?

Contiguous piled walls are used in dry and cohesive soils and are often the quickest and more economic method of constructing retaining walls. In certain ground conditions it may be necessary for the design to incorporate temporary props or ground anchors to provide additional lateral support to the wall.

What is a secant pile wall?

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 the difference between Secant pile and contiguous pile?

Concrete @ your Fingertips The piles may be constructed so that they virtually touch each other (contiguous). The gaps between the piles can be grouted to form a watertight retaining wall. Alternatively (secant piles) every other pile may be constructed, with their centres less than two diameters apart.

Where is contiguous piling used?

The most common use of contiguous piling is for constructing basements or cellars, where the piles can be inserted and then used as a retaining wall already in place as the basement is excavated.

Are contiguous piles waterproof?

There is (technically) no structure, piles could have been chosen as the construction method for a number of reasons, such as a tight construction line or in order to achieve the desired depth. However, from a waterproofing perspective contiguous piles are not, and cannot be considered as, a structure.

What are contiguous piles?

Contiguous pile walls consist of piles arranged in a line typically with a 150mm gap between the piles. Where required the soil between the piles can be stabilised using grouting techniques if necessary, either before or after pile installation.

Is CFA bored piling?

Once the required depth is reached, the auger is removed, the reinforcement is added and the concrete is poured. When the concrete reaches the required level, the casing is removed, leaving the finished pile. Like CFA piles, rotary bored piles have their advantages and disadvantages.

What is contiguous piling?

Contiguous piling is a way of creating a retaining wall by inserting a row of augured piles that almost touch one another. The most common ways of inserting an augured pile are either: to bore a hole with continuous steel sections, which can then be removed and the hole filled with concrete, or.

What are the different types of piling?

How are piling types used in construction?

• Driven pile foundations. Concrete, steel and timber are the most common materials used to make piles for the driven pile foundation method.
• Cast-in-situ pile foundations.
• Combined pile foundations.
• End-bearing piles.
• Friction piles.
• Bored piles.
• Driven piles.
• Screwed piles.

What is the difference between contiguous and secant piling?

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. Secant piling is when there is no gap between piles as a wall is made of interlocking bored piles.

What is a bored pile wall?

A bored pile wall is when a wall is constructed using this method. There are three bored pile wall systems: The type of bored pile wall will depend on a variety of factors including surrounding soil type, construction time and cost. Here, we’ll look at each bored pile wall system in a little more detail.

What is contiguous wall piling?

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 Wall Piling – hard/soft or hard/firm Secant piling is when there is no gap between piles as a wall is made of interlocking bored piles.

What are the disadvantages of Secant pile walls?

The main disadvantages of secant pile walls are: More expensive compared to sheet pile walls: The main disadvantage of secant pile walls is that they are more expensive than sheet pile walls.