Grundomat Pile Driving Hammer
Before beginning on any piling task, the location and ground condition must have been thoroughly researched to make sure that it is safe to proceed. Prefabricated ERW steel tubes are used to install piles and additional tubes can be added if needed. Dry concrete mix, or driving plug, is inserted into the starter tube, which is the initial tube with a pointed end.
Resistance is created at the driving end by electrically welding additional tubes to the original tubes. The resistance needed is calculated and measured in millimetres movements per second (the piling set.) The piles are then put into place from the pile head with a self-compacting concrete mix.
Grundomat piles can be used for a range of applications including underpinning, foundation piles for lightweight structures i.e. extensions, conservatories, fence post foundations and instrumentation holes
What is Piling?
Piling is the initial support that is implemented to form the foundations for a construction project, such as a building or another type of structure. It is vital that you have the correct piling equipment before beginning construction work. The most common materials which are used for piling are wood, steel or concrete. All of these materials are solid and substantial which is crucial to ensuring that a structure has safe foundations that will support it and not move or collapse.
The process of piling consists of driving large pieces of your chosen material – wood, steel or concrete – into the ground to a suitable depth. This creates a sturdy platform on which the structure will rest. The piling needs to be carried out correctly, to ensure that the foundations of the structure are secure.
There is also a lot of initial planning and measuring to be done before construction can even begin. For instance, the condition of the ground needs to be taken into consideration. There is no point in driving piles into wet, loose soil as they will not stay in place. Piling is an extremely skilled job and should only be undertaken by a qualified piling contractor.
Piling Methods
The purpose of pile foundations is to transfer the weight of a structure to the bearing ground which is located beneath the surface. The key components of pile foundations are the piles themselves and the pile caps which are connected when the piles are driven into the ground.
There are several factors which need to be considered when choosing the method of pile installation in order to avoid causing any damage to the piles. The size and weight of the pile, the resistance that occurs when driving the pile, the amount of space and headroom on the site, access to cranes and any possible noise restrictions all need to be taken into account.
Pile driving methods can be split into two categories; displacement piles and non-displacement piles. Displacement piles can be driven using dropping weight, explosion, vibration, jacking (micro piling only) or jetting. Non displacement pile methods are continuous flight auger (CFA), underreaming and C.H.D.P.
Mini Piling
The process of mini piling consists of the pile being driven by an internal drop hammer. A wooden pile tip is fitted to a steel casing which contains a long concrete plug. The casing can be rather tenuous as there will only be tension forces that occur when driving the mini pile. The pile is driven to a specified depth at which point the steel casing is filled with concrete and then is installed with reinforcement. When this has been completed the casing is then extracted from the ground.
There are different ways of driving mini piles into the ground. One such way is using an explosive pile. The explosive charge is put into the casing at the bottom once it has reached the required depth. As the casing is removed the charge is detonated, increasing the size of the pile base. The benefit of this is that the bearing capacity is increased when the soil becomes greatly compacted by the force of the explosion. However, this is not always an ideal technique to use as soil compression and displacement is not always easy to predict.
Economic Recovery having positive effect on Construction Companies
Now that the economic situation in the UK is beginning to improve, construction companies are already seeing the benefits. Many businesses were being forced into insolvency but now the numbers have begun to drop. In the third quarter of last year 16% which is more than any other business sector. However this number is 18% lower than the previous quarter and 29% less than it was during the same time period last year.
It is not all good news however, as the Government’s plans to make heavy cuts on the public sector which will have major effects on many businesses. The construction industry will as suffer as a high proportion of contracts come from this area of business.
Improvements in property development have also fallen rapidly but it has been reported that this is due to support from banks and investors rather than the upswing of the real estate industry. Property values have not increased but actually declined, particularly in the case of secondary properties.
Composite Ground Anchors
Ground anchors are what stabilise steep slopes or slopes that are made up of loose soils as well as preventing erosion and landsides. Ground anchors are made up of a bearing plate with connecting cables or rods.
There are many advantages of using ground anchors which consist of reinforced composite materials such as improved durability and therefore less need for maintenance. These ground anchors are much more light weight than conventional steel versions meaning that it is much easier to transport them to the site as well as enabling contractors to place them more accurately. They are much safer to install due to increased tensile strength coupled with them being lightweight.
Composite ground anchors are made up of three parts:
• The composite cable runs through an anchor nut or plate on a steel sheath. This is called the anchorage and it fastens the ground anchor to the structure. Cement mortar fills the anchorage in order to prevent slippage.
• The cable either has just a singular rod or several which are separate or braided together.
• A polyethylene or PVC sheath fits round the free anchor length of cables.
Advantages of a Continuous Flight Auger (CFA) System
There are several reasons why the use of a CFA system is beneficial. They can be installed quickly and quietly, with low levels of vibrations and are also an environmentally friendly option. Unlike displacement type piles, CFA piles have a very low risk of ground displacement or loose soil that becomes solid causing damage to any neighbouring foundations or utilities.
Another advantage of using a CFA system is that it is possible to monitor the entire installation process of the piles. A flow meter provides accurate data that is then recorded and can be analysed. Information that is collected includes penetration/uplift per revolution, auger depth and injection of pressure at the head of the auger.
The CFA system also has an excellent rate of installation success so it is definitely an option worth considering.
Sheet Pile Driving Methods
There are three methods of sheet pile driving the use of which depends on the conditions of the ground that is being built upon.
The first method is pitch and drive which is appropriate for when using short piles and on loose soils. Each pile needs to be driven into the ground to its full depth before beginning to pitch the next pile.
Panel driving is a method which ensures that each pile is aligned properly and with good vertical positioning. This technique decreases the possibility of driving difficulties and any issues with de-clutching. The advantages of using this system of sheet pile driving is that piles can be left without being fully driven in and work can continue without any disruptions.
If your site is located on difficult ground conditions such as dense sand, gravel or rock then staggered driving is ideal. This involves driving the piles between guide frames and installation is split into steps. For example, begin by driving piles 1, 3 and 5 followed by 2 and 4. Piles 1, 3 and 5 can be reinforced at the toe.
Piling Contractors
Piling contractors are employed to implement extra support at the foundations of a new building. This support comes in the form of large, robust columns that are driven into the ground. Piling is usually only required when the site on which a building is being constructed is uneven. Seek advice from the architect or whoever is in charge of the build to confirm whether or not piling is needed to be done.
Construction piling and any other type of construction work should only be undertaken by qualified piling contractors. It is crucial that piling is completed to a safe standard. There are many piling options available which you can discuss with your piling contractor. Make sure that you are clear about what exactly you are looking for and agree exactly what costs are involved in the piling project and how long it will take to complete. Do this before the work is underway so that both sides know where they stand.
iPhone App for the Construction Industry
The company, SmartBuild Software, have developed an iPhone application which enables construction site managers to monitor the clean-up of their sites by sub-contractors. There is a wide spread problem of sub-contractors being either very slow when cleaning-up or simply leaving the site without doing it. This can result in the contractor incurring additional costs by employing extra staff to do the cleaning work.
The software was designed after research was carried out and it emerged that there was significant demand for a technological solution to the ongoing problem. The software is suitable for construction companies of all sizes. The app capabilities include recording and actioning a clean-up by a specific date or penalties are issued, sending warning notifications to workers and reporting on the performance of workers. The dashboard displays issues that are pending, late and resolved.
SmartBuild Software headquarters are at NovaUDC, Innovation and Technology Transfer Centre at University College Dublin. They are marketing their new products at the UK, UK and Irish market.