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Further Processes of CFA piles

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Casting of the Shaft and Pile Base

When the auger reached the necessary depth then it is necessary to eject temporary plug from hollow stem which is actually meant for preventing soil to enter the hole. It is possible to easily accomplish this by lifting the auger slightly and then injecting concrete. This is the time when soil decompression is something unavoidable and is also found as a common practice to reinsert rotating auger when concrete is made injected. This is the method that minimizes to some of the degree of the decompression at bottom of pile but quantitative effect is that difficult for assessing. There are chances for the individuals to easily make things better. There are chances for the individuals to easily make use of the things so that it can minimize the degree of auger. There are chances for this to easily make the piles to come in good form.

Once when grout head gets establishes then extraction starts at a rate that is consistent with the grout supply. Positive rotation of auger is required for retaining drilling spoil and for ensuring that grout can fill in the whole cross section of the secant pile wall. The grout pressure need to be high enough and auger need not be extracted in much faster pace. If it happens fast then it can lead to a pile shaft that is soil contaminated as the drilling soil may enter to the grout that is freshly placed.

Placing Reinforcement

With the diameter there is a small stem which cannot be commonly used. It can be reinforcement that has got installed after auger and it has been withdrawn. It can be used when concrete or grout is the one with still fluid. It is something that is soil decompression that is unavoidable. It is good to reinsert rotating auger when concrete gets injected. This is the method that can be used for minimizing the compression to some degree at bottom of pile but the quantitative effect with it is really difficult for assessing.

Placing the longer reinforcement cage to uncased hole can pose so many practical problems and it can even lead to contamination of concrete shaft with soil that is eroded. It is very important to ensure that cage is stiff and is welded properly. It is something necessary for overcoming the problem related with the proper placement of reinforcement. Augers that has got larger stem are used and then the reinforcement can be installed inside before auger is extracted.


CFA pile is a pile that comes under the category of non displacement. This makes this pile pose very less risk for damaging the adjacent foundations and also underground utilities from ground displacement. It is possible for installing these piles with less noise or vibration. A major factor that is associated with the CFA piles is the usage of some flow meter that is reliable for monitoring and also recording while process associated with the construction of this kind of piling. The major items recorded include injection pressure, uplift using placing, concrete supply per increment etc.


Facts You Should Know About CFA Piles

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CFA piles are the ones which are much popular for around 50 years in North America since it was introduced in the place. These are the pile types which are considered cheaper compared to the alternatives available in the market. It is possible for achieving much higher production rates by making use of proper designing, planning, experienced personal and also efficient equipment. These piles are easily available in various diameters that include 0.9 m,.75m,0.6m,0.45 m and 0.3m. These are the piles which can be considered to depths to an excess of about 30 meters. It is always good for considering to buy such kind of an equipment for your purpose so that things can really become much easier for you.

CFA Equipment

CFA equipment is the one that comprises of various things which are really necessary for making CFA piles. There are certain things that can really make things much better for you. The first equipment that you need to have is a base machine which has got swinging, hanging or fixed lead associated with it. It is also necessary to have an auger drive unit which is usually hydraulic. This should come with adequate power for advancing CFA to the depth that you need with less amount of decompression to surrounding soil. It is always good for making use of such equipments so that things can really work well for you. CFA with the required diameter and length that have got auger cutting heads equipped in it can be suitable for the material to be penetrated. If you are going to make use of continuous flight augers then it is necessary for you to make use of the equipments.


Installation Process

Continuous flight auger piles are usually formed by the process of drilling continuous flight auger to the ground. Both the sides of the piles are usually supported by auger that is filled with soil. This makes it easy to do the pile and also there is no necessity for using temporary casing or betonite slurry. When the pile is made with the necessary depth then the concrete or sand cement grout can be pumped to the hollow stem as this auger can be withdrawn steadily. Reinforcement is usually done immediately when the auger is withdrawn.

The settlement behavior and also the bearing capacity that is associated with these retaining walls is usually influenced to a larger extend by the experience of operator and also the equipment that is used for making the pile. The major issues that are associated with this pile is when the importance of these two aspects are overlooked or underestimated by the people during design phase. It is necessary to consider this as they do play major role for performance of the CFA piles. There are many possibilities for the individuals to have the best possible piles if they are able to consider these aspects well and make the pile as per the requirement.


Things to Know About Secant Piles

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Secant piles are constructed to have intersection between piles. Usual practice is that alternative piles are constructed along the wall and then leave a clear space of which is very little under diameter of the required piles that are there as intermediates. The exact spacing is usually determined by construction tolerances that are easily achieved. These piles that are placed initially need not have to be constructed to same depth like that of intermediate piles that follow as per the way in which walls are reinforced and designed.

Concrete us added and then before it is set completely set holes are drilled intermediately so through a parallel but a bit offset lines so that holes cut to the first piles. Intermediate piles are usually placed through heavy casing that has got cutting edged which is toothed and which also makes the casing to cut inside concrete of initial piles on both side. When concreting is done subsequently then it can result in a wall that is normal. The concrete that is used for secant pile usually come with the property of slowly setting as it can really make it possible for cutting one pile to another in much easier way.

Applications for secant pile wall

Secant walls are usually utilized for transfer vertical, lateral or both the kinds of the load through weak layers of soil to the bearing layer that is very suitable. They can easily be drilled in various kinds of the configurations that can form a wall which is interlocking and watertight. It may also be providing with structural overlapping wall. These kinds of walls are mainly used for the purpose of transfer of foundation load and also with the earth retention systems. They are usually made used with subway structures,cofferdams, top-down tunnel and also land based structures in which the surface soil do not have the capacity for bearing the load. They are also utilized much with the structures related with marine and also dames.

secant piling is a most economical method that can be used for controlling water effectively for building the structural walls, dams and also top down tunnel. They are the finest solution in such construction where dewatering and water tables are creating issues. There are so many varieties of drilling techniques which can be used for constructing overlapping concrete cylinders through the saturated rock soil which extend below the water seepage.

Method for Secant Piles

Secant piling can be done either by making use of simple drilling techniques or with the usage of CFA techniques. The secant piles include reinforced primary piles and also secondary piles. The secondary piles can easily overlap primary piles and primary piles can act as concrete lagging. Reinforcement that is associated with the secondary piles comes with rebar cages and also steel beams. The diameter of secant piles can come to such a way that it can be in a distance of 30 inches. This can make the piles overlap each other which is what is the requirement.


Understanding Different Piling Processes with a focus on secant piling

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For any concrete structure to be well constructed, it needs to have a firm foundation with a very firm underground structural base. This is to make sure that the heavy building is supported adequately. Piling processes are responsible for this firm structural base.

Piling processes are techniques used by contractors to create deep structural / building foundations. During these processes, wood piles, steel or concrete are driven and embedded into the soil deep in the ground. Eventually, the foundation levels of buildings are made very strong to offer maximum support.

Before the processes begin, factors such as project scope, size and capacity, under the ground soil condition, rigging space need to be considered. A deep foundation requires strong soil layer for it to have the capacity to offer the best support.

Precast concrete piles, steel sheet piles, vertical wood columns and timber piles are the most common piling materials.

Piling processes involve driving or drilling your preferred type of piles into the ground in order to set up a firm foundation, able to support the intended building’s load. Civil engineers should play their roles in construction by engaging piling processes which result to firm foundations and therefore firm structures.

There are piling processes of different kinds. Which kind is undertaken is a question of which specific project is underway. Civil Engineers, housing developers and contractors use different piling processes for establishment of housing development projects, big commercial projects, marine projects and road / retail projects among others.

Piling processes differ from each other on the basis of the chosen material and the process used. As mentioned above the two main techniques are mainly drilling and driving piles.

Directional Drilling technique: This technique uses boring method to drill into hard ground to insert piles. These piles are also referred to as CIDH meaning Cast-in-Drilled-Hole piles. Drilled piles are: under-reamed piles, Auger Cast piles, pier & grade beam foundation, mini piling and tripod piling.

Driving technique: It is done by a pile driver which is a mechanical device utilized to drive or insert your preferred piles into the ground. There is also a new state-of-the-art hammer utilized to insert or drive piles, mostly timber or pipes into the soil.

Bored piles are cost effective and efficient in construction of long-term or short-term walls for retention. They are used during construction of building basements, substructures near existing structure which may require restraining. Piling helps to reduce too much excavation and helps in regulating ground shaking or movement.

Discussed below are the three piling processes

Secant Piling

This type of piling is the most functional and efficient of them all. This is because the constructing equipment used for secant piling include heavy-duty CFA auger featuring rotary cutting heads. The piling process is similar to the one for interlocking piles. The difference is that secant piling engages strong concrete mix just as the one for primary piles. The soft or secondary piles are reinforced in the same way the primary piles are.


When secant piles are embedded together, the end result is a well formed retaining wall for terraces or excavation pits. Secant piling can be applied with different requirements of diameter, material, placement, formation to meet different unique construction needs.

Civil engineers can use secant piling to construct ground water barriers, foundations and retaining walls.


It has various advantages over other piling processes namely:


– Improved structural toughness compared to others constructed through other processes.

– Improved flexibility in terms of construction alignment

– Can be set up on difficult / hard ground

– Good closely installed columns like 3 – 5 inches from already existing structures

– Usable in areas with high water table conditions

– Reduced noise during construction

– Contiguous Piling

This process is preferable for retention of cohesive and sub-soil and in places where the level of underground water is lower past the ultimate excavation depth. In contiguous piling, the piles diameters fall between 450mm to 900mm and are inserted at the middle of piles with the range of 50 and 1000mm. This means that gaps measuring around 15mm to 100mm are left after installation.

Interlocking Piling

This process is almost the same as contiguous piling but here the gap between piles is occupied by soft piles of non-reinforced not-so-strong concrete mix placed a layer below the eventual excavation depth level. This type of piling ensures that less amount of water goes past subsequent excavation.


Generally, piling processes are important for structural support purposes. Specifically, secant piling is a crucial economical solution for most civil structural shoring walls offering unmatched support of structural foundations as well as ground water regulation problems. In other words, secant piling process has several civil applications among them structural walls and dewatering solution and shoring.