Piles foundation and CFA piling system - At a glanceFoundations offer support to various structures. They operate generally by transferring the load of the structure or the building to layers of rock and soil having enough bearing capacity. There are a number of types of foundations available for construction which depends on various conditions of the ground, structure and applications etc. Some of the considerations are:
· The ground or soil condition · Noise and vibration sensitivity · Presence of water · Nature of load distributing support · Nature of adjacent structures or buildings etc. Pile foundations are generally made from reinforced concrete, steel and sometimes timber. They are deep foundations. According to Atkinson stated in the year of 2007, a support structure like this can only be considered as pile when the proposed depth is more than or equal to three times of the structure’s breadth. Piles are usually used to transfer the load from a heavy structure or a superstructure. They shift the load from weak base to more stiff and compact layer of soil or rocks. They are extensively used for larger structures which are supposed to withstand huge amounts of load and human workforce and are made or structured around or near a more volatile and softer surface. Piles are basically categorized as: · Friction piles · End bearing piles Most piles fall under the category of end bearing piles. The common piles are driven piles which are made somewhere else and then placed in the ground of the site. When the pouring and boring of the piles happen simultaneously, these sorts of special piles are called as Continuous Flight Augured Piles or most commonly CFA Piles. Continuous Flight Augured Piling is almost vibration free and one of the most noise free form of piling. The technique of CSA piling is very economical. This particular process is environment friendly and is popular among the residents near the construction site for the noiseless operations. The basic equipments used for CFA piling are as follows: · An auger unit for driving which is generally hydraulic in nature · A machine for the base which comprises of a fixed, swinging or hanging lead · Flight augers which are continuous in motion suitable for material penetration. The introduction of CFA Piles offered a great alternative of the more orthodox procedure of using bored piles and driven piles. CFA piling system can be used for weight transfer underneath structural fundamentals and in addition for adjacent and secant pile wall. The building sequence of CFA piling usually consists of the following processes: 1. Drilling a complete length auger by means of a void stem (provisionally plugged) into the earth using a steady penetration rate. 2. After attainment of the blueprint’s primary stage, concrete is supplied through the unfilled stem of the auger as the auger is removed. It is significant that the auger constantly remains entrenched into concrete https://en.wikipedia.org/wiki/Continuous_flight_augering 3. An optimistic concrete force is maintained all through the assignment of concrete. CFA piles need to be dispensed to base level to aid reinforcement setting up and shun the possibilities of any kind of pile necking 4. After the conclusion of concrete placement procedure, the reinforcement confine is thrust into the liquid concrete and thus completing the whole procedure of CFA piling. |
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