Shire Piling Approved
HB Jones (MIDLANDS) LIMITED have been using the shire piling method since the start of 2006. Before this a method called underpinning was most commonly used for stabilising structures affected by subsidence.
A traditional form of underpinning involves digging out around the existing foundations of a structure and making additional foundations to a suitable level underground to complement the original.
This method can be messy and disruptive to the structure which is why HB Jones (MIDLANDS) Ltd chose the new method, as it is more aesthetically pleasing and causes less destruction to the property.
SHIREPILES AND SHIRESTABILISERS
Helical Piling: Piles with helical projections have been used for hundreds of years. During the 19th and 20th centuries extensive use of helical piles was made for the construction of bridge and pier foundations. The early helical piles were Screw Piles. These piles had a small number of large helical fins and were twisted into the ground by applying a torque at the head of the pile. Small diameter helical supports are a more recent development. These have continuous small helical fins at the base and are driven into the ground. The driving force together with the shape of the helical fins generates the twist action. Shirepiles are small diameter steel piles with helical fins on the base section. The piles are driven into the ground using compressed air post drivers. With Shirestabilisers some reliance is placed on the existing structure. This could be to give a factor of safety or reduce the moment transferred into the support. Shirepiles are used where the entire load must be taken by the new support.
Remedial Scheme: With remedial schemes the support is not directly below the load and a moment is produced. It is important to keep the support as close to the wall as possible to keep the moment as small as possible.
Description of Operation - Remedial applications: The operation is performed to reduce the risk of future foundation movement.
The operation consists of installation of supports; tying in, or jacking - up of cracked wall and foundation to original level, formation of individual concrete pile caps or a concrete foundation beam over a group of piles to fix the wall in the final position, and transfer foundation loads onto the supports.
1. A helical lead end, 1.5m long is driven using a "Rhinotool PD140" post driver and diesel fueled air compressor, a pilot hole is provided in some ground conditions.
2. Trailing circular sections each 1.25M long are driven.
3. If necessary the piles are cut to length using an angle grinder.
4. Supports are filled with cementatious grout & reinforced with 1 no T12 bar, placed centrally.
5. The existing foundation is drilled and ties are grouted in using epoxy resin grout. The reinforcement is cut (using an angle grinder) and bent on site.
6. Individual in-situ concrete caps are formed, incorporating the tie to each support and the ties to the existing foundation.
Support Driver: A Rhino post driver is used to drive the piles into the ground.
Drive Speed: The drive speed is recorded as the support approaches the correct depth. The speed is measured as the time taken to drive 100mm.
Grout and Reinforce: After driving, the supports are cut to length (where required, if possible drive to depth) reinforced and the central core filled with a cement grout.
Trailing section screwed into lead end prior to driving (Step 2): The standard method of connecting to the building is a reinforced concrete cap. This method has the advantages of being adaptable to different foundation types and the rigidity formed reduces the rotation at the head of the support.
Minipile filled with cementatious grout, and reinforced (Step 4): Ties to existing foundation grouted with epoxy resin.
CORROSION
Corrosion in driven piles is unlikely to be significant due to the limited oxygen supply. After fabrication the steel is given an electrolytic zinc coating to give enhanced protection. After the zinc coating the surface is prepared and then given a further high slip powder barrier coat. This increases driving speeds, increases penetration depths in stiff clay and reduces negative skin friction on the shaft.
COMPONENTS
Head: The head consists of a steel circular hollow section. After driving the core is filled with a high strength cement grout and reinforced with a12mm steel rod.
In building repair situations the Shirestabilisers are generally only installed on one side of the existing foundation and this can result in a moment acting at the head. This moment reduces as it passes down the stem due to the lateral resistance of the soil. To resist this moment in some loading conditions it is necessary to reinforce the head with an external steel circular hollow section. A strengthening tube is driven around the main stem of the support and the gap between the sections filled with grout.
Stem: The stem transfers the load from the head to the base. The stem is constructed from steel circular hollow sections with screwed couplers. The stem has a high slip powder coat finish. This makes installation easier and reduces any negative skin friction.
Base: The base consists of a steel rod with external steel helical fins.
latest news
H B Jones ( MIDLANDS ) LIMITED have re-located offices, to a more suitable and modern environment, which is in-keeping with the company's vision of moving forward at all times. Our clients always prefer to work with forward thinking, dynamic companies and H B Jones ( MIDLANDS ) LIMITED look to portray this image to the many customers and clients that we work with. Details of our new premises are on the website
HB Jones (MIDLANDS) LIMITED are currently working through 2 fire damage claims at present. You will shortly be able to see the status of these jobs below or in our gallery section of the website.
High Street, Riddings, Alfreton : The whole property has been affected by fire damage and extensive reinstatement, including complete re-plastering, new staircase, replacement kitchen and bathroom suite plus redecorations and replacement UPVC door and windows throughout.
Wilmott Street, Long Eaton: Another property severely affected by fire. The roof is now completely removed and we are starting to fix the complete new roof shortly. Internal reinstatement of the property will follow, upon completion of the roofing works.
Subsidence & Escape of water
HB Jones (MIDLANDS) LIMITED are continuing to deal with the many Subsidence and Escape of Water claims, that come through on a daily basis from our clients, all over the Midlands region.
Miscellaneous
Carrington Day Nursery, Nottingham: Works are nearing completion, which involve extensive, internal alterations, refurbishment and decorations to this busy children's nursery.