As part of its continued expansion programme, Advanced Mini Piling Systems, also operates in; Essex, Hertfordshire, Cambridgeshire, Bedfordshire, Northamptonshire, Buckinghamshire, Oxfordshire, Gloucestershire, London, Kent, Sussex, Surrey, Berkshire, Hampshire, Wiltshire, Somerset, Dorset, Devon, Cornwall, Wales.
We have also recently developed a rig to drive in solar panel posts, the posts are 2.8m long and are driven into the ground 1.8m, and will then have the photovoltaic panels attached, this method causes very little damage to the area and is very quick, no need for heavy ground works or unsightly tracks across farm land.
Sea Defences are new to us this year as we are undertaking a large Contiguous Piled wall in Devon, to protect a property from slipping into the sea, caused from weather damage and erosion of the sea.
At Advanced Mini Piling Systems we continually change our methods of piling and machines so we can compete in the modern construction industry, if we have a problem, or a job that requires a new piece of equipment to be developed, we will get it done.
Any job or any enquiry small or big, please contact us, we will help you.
Jurassic Coast, Contiguous Piled Wall, Branscombe, Devon
The site is situated on the side of Branscombe cliff, in Lyme bay. The cliff is made up of three strata, Chalk, Pre-Cretaceous Upper Greensand and Mercia Mudstone with gypsum from the Triassic era. Originally Branscombe grew from mining gypsum and the property we are working on was terraced workers cottages, with the look out on the end, a coastguard station.
The Jurassic coast is a world heritage site and the rock and cliff formations have been changing for millions of years, with land slip a very common problem. Only 1km down from the site is Hooken cliffs where in the 1800′s a landslip took place containing a few million tons of chalk slipping off the Triassic Mercia Mudstone, this continual changing coastline means we need to find modern answers to solve a very old problem.
This project comprise of installing a Contiguous Piled Wall in front of an old coastguards lookout, the lookout which is no longer used by H M Coast guard and is now part of private home and has been converted to suit the clients needs with a large decking, cantilevered over the cliff edge. In front of the building was mass poured concrete to retain the cliff edge and support the decking, unfortunately due to weather erosion the concrete has cracked up and is slowly slipping down the cliff, leaving the footings of the old lookout exposed.
In an attempt to prevent any further movement, the whole cliff has been rock anchored and netted down while works continue. With the original decking removed scaffolding had to be erected to allow for the piling rig to work in front of the building, the scaffolding had to support a 4t point load and every other support was placed on a rock anchor.
The machine we used for this job is a PPS Unwin Kitten Rig which is capable of working in restricted access conditions, and very powerful and able to bore through the tough layers of limestone. The Kitten is also able to install Temporary Cased Piles, which we are using for the bearing piles 1.5m from the centre of the Contiguous Piled Wall, this places them in the middle of the scaffolding, and any spoil or concrete would fall down the cliff causing a safety hazard. Site access and weather conditions also made this a challenging job for our team, All our equipment and reinforcement had to be delivered by 7.5t lorry as roads to site were very narrow. as the winter storms of 2014, with high tides and storm force 10 and 11, for some days the wind speeds reached 90mph with driving rain on the unprotected cliff face work had to stop as just standing up became a problem. Although we were unable to work on site, we helped clear debris from the road, restaurant and secured loose boats and peoples belongings. The high tides and high winds had washed most of the service road away which leads to several beach chalets, which were also damaged, and only 25m below our site.
Storm force 10 and abnormal high tides, cause major problems on the beach front.
The service road and some of the chalets have been washed away.
Scope of works:
* Site canteen and welfare facilities provided by main contractor.
* Protect all walls and drive where we are working.
* All services located and isolated.
* As we are working on a cliff face all safety handrails must be installed and checked.
* Mobilise PPS Unwin Kitten Rig, by 7.5t lorry.
* PPS Unwin Kitten Rig chained with tether while on scaffolding.
* Prefabricated 6H16 – H8 helicals @ 200mm pitch, delivered to site by us.
* Pile positions set out by main contractor.
* Safe route for concrete deliveries planned, and lorry walked to site by banksman.
The Contiguous Piled Wall continues along the front of the garden, although here we are working in between four cantilever beams which hold the decking over the cliff, so we are installing three Piles in each section.
Because the spacing between the Cantilever beams was to small, the third Pile was installed behind the face of the wall giving it the same lateral restraint.
Reinforcement, consists of two 6H16 – H8 @ 200mm pitch prefabricated cages, which are spliced together and then lowered in safely, with our specially designed cage lowering frame and winch.
The Contiguous Piled Wall is installed at 600mm from the centre of the piles, to the face of the Look Out, top of reinforcement is finished at 1200mm from piling platform to allow for protrusion into 600mm x 600mm R/C capping beam.
Installing 300mm dia Temporary Cased Piles here with the Kitten Rig Prevents the spoil and concrete from falling down the cliff face, and means no operatives need to come off the scaffold.
Casing is socketed into the clay to form a seal and the pile is then formed with the casings extracted straight after concreting. These piles will have pile caps formed on top of them, which will support the new decking.
Site is left clean and tidy after each day, with the access to the main house kept open and the drive power washed.
Mini Piling and Remediation, Cheltenham, Gloucestershire:
This project comprises of the remediation of two luxury apartments in Cheltenham, Gloucestershire. The two apartments are part of a luxury complex, and were originally a stable block and mews for the main house, which was also converted into apartments at the same time. Once the present home owners were moved into temporary accommodation, the main contractor who acquired the responsibility of the buildings in a company take over, removed all fixings, fittings, kitchens and bathrooms. Advanced Mini Piling Systems took over the site and protected all internal walls, drive way and lawn. We then removed all the floor screed and insulation and found that all the internal walls, that had been added to the properties were built upon a wooden parquet floor straight on to the old stable block concrete floor, which had cracked and subsided under the weight of second floor apartment. With the floor screed and old concrete floor removed the next step was to excavate the the clay underneath to the underside of our collapsible material, ( Cellcore Hex ). This also gives us a working height from floor to ceiling of 3.0m, enabling us to install all the 250mm O/D Rotary bored cast in situ piles, with the PPS/Unwin Kitten rig which has a minimum working height of 2.8m, and a width of 0.7m allowing us to move from room to room with ease. Once we have bored enough piles for a lorry load of concrete, the anti heave sleeve is inserted, the piles are then filled with concrete via wheel barrow and the steel reinforcement installed. All piles are left up 250mm above our cut of level (COL) allowing for the poor concrete on top to be removed and we get a clean cut keeping the steel of the 300mm RC slab nice and flat. The property will be divided into 3 stages the middle of the house will be completed first, once the needles ( Needles are 500x500mm holes taken out the external walls which have steel from the slab continued into them which intern picks up the load from the wall transferring the load onto the piles), have been broken out and all internal walls put onto jacks at 1.0m centers, allowing the steel reinforcement to continue across the width of the building, the concrete is then pumped in and left to cure. Then the other two stages will be completed one after the other, keeping stress on the building to a minimum. With the 300mm R/C slab installed through out the building, the internal walls have their jacks removed, because there must be total isolation from the heaving clay beneath the Cellcore Hex. The internal walls are then rebuilt onto the new slab with a new damp course. Because this property requires total isolation, we must excavate round the whole of the property to remove all the remaining footing of the external walls, all excess material is disposed of and the void is closed off, preventing any material coming between the old footing and new R/C slab, the excavation is back filled and compacted in layers. Once we have cleaned all the walls and driveway, we then hand the property back to the main contractor, where they will put all the fittings and fixtures back in and make ready for the owners to move in.
Scope of works;
*Welfare facilities provided by main contractor.
*All services isolated and removed.
*Temporary 110v supply installed, and lights.
*Drive way and garden protected with DPM and ply wood.
*Wooden flooring and screed removed.
*Concrete removed and clay excavated 1.0m.
*All 250mm O/D Rotary Bored Cast Insitu Piles installed.
*Piles cut off to (COL) and Needles and footings of internal walls jacked and removed.
*Steel reinforcement installed.
*Concrete pumped in by mobile line pump.
*Stage 1, 2 and 3 completed in succession.
*Jacks removed and internal walls made good.
*All remaining external footings removed from outside.
*External excavation back filled.
*Outside walls washed and made good.
*Site made clean and tidy and ready to hand over to main contractor.
As you can see from the photo there is no steel connecting the pile to the beam, and because of the heave here it would of just lifted the beam from the pile. Also the pile is a steel cased driven pile and would not of had sufficient shaft length to anchor it past the heaving clay, so whole system would have risen up and down with the changes in moisture in the clay.
The Cellcore is sealed with tape to prevent grout loss and internal jacks are encased with clay master which will prevent them from being concreted in, allowing for them to be removed, isolating the building from the ground beneath.
H16′s at 150 centers are laid on 50mm spacers and are tied together creating a reinforced mat, pile bars are bent down so they sit between the top and bottom mat, connecting the piles to the R/C slab, steel spacers are tied onto the bottom mat which hold the up the top layer of H16′s.
From the photo you can see the concrete does reach the top some needles, because this building is old the brick work can only be removed at the joints, and the joints do not relate to the finish concrete level, once the concrete is cured the brick work will be dry packed or removed and rebuilt.
Once stage 1 has cured, the needles are then broken out in stage 2, the process is repeated and then the same for stage 3.
Stage 3, this is the end wall of the building, and the wall sits on the boundary preventing us from excavating externally, so the only way to achieve total isolation is to leave three sections unconcreted, allowing us, once the concrete is cured to remove the remaining brick work, so all the footing is removed from inside the building.
This is a before and after of the brickwork once the R/C slab is installed.
With the internal work completed the external perimeter is excavated.
The Cellcore hex has taken the load of the concrete and created a void between the clay and R/C slab, this material is 225 mm deep and will achieve a void of 150mm.
The walls are washed, and the site is cleared ready to hand over to client.
Clapham common Basement:
This was a very challenging site, with tight access on a small street, and a very small open site. The property is a modern three storey town house which was built in 2006 and was built off piled block and beam foundations. A single storey extension to the side of the property was demolished, and the piles and beams removed, to allow for the installation of a Contiguous piled retaining wall, to be installed around the perimeter of the garden, once excavated this would give the client a basement and access to excavate under the rest of the house.
Because the property is built off piled reinforced beams, these would support the building while the R/C works are taking place, and removed once the transfer slab is completed. Although the site was very narrow about 4.0m we managed to complete the piles using are largest piling rig, this allowed us to work more efficiently, as we could have the reinforced cages fabricated on site, to the required length of 10.0m, which could then be winched in to the open bores in one lift. Also our daily meter rate is higher and it requires less labour than smaller rigs keeping down costs.
Scope of works;
*Mobilise to site 14.0 t Doosan Kelly bar rig on a low-loader.
*Welfare facilities provided by main contractor.
*Loading plan put in place, with protection to the drive way.
*Safe working zone for steel fixers.
*Site marked out by main contractor using 500mm pins with caps on.
*Required number of piles installed and concreted.
*Site, pavement and road cleaned on a daily basis.
Brent knoll, Somerset
To provide 220 steel cased bottom driven piles to a pre designed set, and fabricate and cast 450 x 350mm R/C beams, for a detached garage, office and utility room. The main property is located on the Somerset levels, and surrounded by land drains which prevent the main river from flooding and carry away excess water from the farm land.
When we started the project the level of the drain was 0.6m below commencing surface level, and all piles were driven to their pre designed set, and were then concreted. After waiting for the piles to cure we then proceeded to excavate for the beams, and because of the heavy rainfall the drain level rose to 0.1m below commencing surface level, which unfortunately was 0.5m above our bottom of dig, so all the beams flooded, and we were unable to continue with work until the water level of the drains fell. We returned a month later once the water level had receded, and completed excavating the ground beams, we used a mobile line pump to concrete the beams as the access to site would not allow larger vehicles onto the driveway.
Scope of works;
*Welfare facilities provided by client.
*Check for services.
*Install 220 Steel cased bottom driven piles.
*Fabricate and install steel reinforced beams.
*Pour beams with C35 concrete.
*Clear site and leave tidier then when we arrived.
Unfortunately the perimeter of the new extension, came parallel to the bank of the land drain which had been built up by the previous owners, so as soon as we disturbed the ground near the bank, it breached the drain flooding the excavated beams. Because of the abnormal weather conditions that had been taking place, the drains were full and we left site until the water level had receded and would could continue with works.
The smaller tie beams which can be seen are 350 x 350mm these will carry very little load; the one furthest away will carry the rear of the garage wall, which is timber, and closest one in the photo will support the the block and beam floor.
Advanced mini piling systems was contracted to provide piling services for a local Property development company, based in Bath; The site is at the top of Bath over looking the whole city. There are 5 plots on the site, each with a 4-5 bedroom luxury home, 3 of the plots were based on traditional foundations, because they were on the crest of the hill and based into the natural layer of brash (local stone).
The 2 remaining properties are located on the bottom of the site below the crest of the hill, and both have basements in the their designs, so the commencing surface level would be below the layer of Brash and into the fullers earth, which meant that these 2 properties would require piling, because lateral and vertical loads could not be gained via traditional strip footings.
Our engineer choose to use 220mm dia Steel cased bottom driven piles, with a 300mm thick reinforced concrete slab. One of the problems we came across while driving the piles, was that they hit softer layer of stone which made the piles bend off vertical, this happened in every location we tried; So to save the client time and money, and as the access to the site was restricted, the option for a bigger CFA rig was out of the question. The solution we came up with, was to base the piles in the soft stone, which meant they were shallower, and double up all the heavily loaded piles.
Scope of works
*Mobilise D1000H to site.
*All 220mm dia steel cased tube delivered to site in two loads.
*Install all piles to engineers specifications.
*Reinforcement for piles.
*Set up safe location for mobile boom pump.
*Concrete all piles.
The 3.0m firsts plugged up, and ready to be driven in plumb; The D1000H can lift its driving hammer over 3.0m which means the rig can drive, while other casings are being welded together which gives us a higher productivity.
We achieved very close centres to the temporary retaining wall.
All piles concreted with a mobile boom pump and a C35 pump mix.
To Provide 21 piles to rebuild a garden wall; the existing wall had fallen down due to the tree roots, and the weight of the garden it had been retaining for many years. As we were working on the party wall, permission had been granted from both sides to gain access to work. All materials and machinery would be brought through the garden, of the property at the top side of the wall, and a safe working area would be made in the garden of the bottom property.
Before work could commence trial pits had to be dug, by hand to find out where the roots of an oak tree with a TPO (Tree Preservation Order) on it were, which prevented damage to the tree roots while removing the existing wall, and while piling. The piles, beams and beam heights were determined by the location of the tree roots, the beams will bridge the roots so no piles or excavations would damage them.
Although this is not a Contiguous Piled retaining wall, which would of been more expensive, the engineer choose to design the piles to take a hollow block wall, which would be slotted onto reinforcement cast int the beam, and then filled with concrete. The piles were placed in pairs and will take lateral and vertical load, tied together with a 600×400 capping beam.
Due to ground conditions here, the decision was taken to Tremmie all piles rather than use Hollow Stem flights, as this would help to reduce mess from waste water in the cleaning process after every pile, and the clay was stiff enough to stand open while grouting.
Scope Of Works
*Site health and safety and welfare facilities provided by main contractor.
*Mobilise Kitten Piling Rig to site with grouter.
*Garden protected and ramp made to remove spoil.
*Safe working area set up for Steel fixing and use of grouter,
*All cement and sharp sand to be moved by hand to the rear of the property.
*Garden of bottom property fenced off and piling mat installed.
*Piles and pile heights set out by main contractor.
*Install all 21 piles to engineers specifications.
*Clean and clear site, demobilise rig.
All cages tied and protection boards taken up every night to prevent killing the grass.
The grout hose is placed to the bottom of the pile, which brings the water and debris out of the top, the cages are then plunged into the pile.
All piles complete and left at differing heights to allow easier cut off for the client.
With this project we were contacted firstly, in an advisory capacity by the architect and his engineer. Their original plan consisted of an extension to the property and too remove the roof, and build an additional storey.
The existing foundations were exposed, to verify their suitability to carry the additional load. Although the footings complied with width and depth, the ground underneath was very wet, and the clay soft and silty. Further testing was then carried out by way of two bore holes, and the results were handed over to us.
Due to the poor ground conditions, and since the existing schemes involved alterations to the ground floor layout, the client after consultation with her architect, decided upon an alternative scheme, of complete demolition and constructing a new dwelling off, Piled foundations. The house footprint will also be shifted to avoid removing the original footings.
Before being given the the contract, we helped with pricing the ground beams and Piling. Which enabled the client to understand where her budget would be going, even before they had decided to demolish the property. Due to the nature of the ground, the high water table/springs, and the loadings of the Piles, 220mm dia Steel Cased Bottom Driven Piles were the best option.
Poor access was also an issue on this site, as it was in the middle of the New Forest, and we had to negotiate fording a river, and 2 miles of rough track, which made our steel tube, and concrete deliveries challenging.
Scope of works:
*Piling mat, Pile positions and welfare facilities, were the main contractors responsibility on this project.
*Mobilise D500 and D1000h with 7.5t lorry suited to smaller access sites.
*Locate steel tube delivery and escort them to site.
*Install 32 No 220 Steel Cased Bottom Driven Piles to design depth.
*Cast all completed Piles with C35 concrete and reinforcement to our engineers design specifications.
*Place safety tops on all reinforcement.
*Clear site of rubbish and demobilise Rigs.
The D1000h Driven Piling Rig allows us to lift the driving weight over 3.0m, this means we can weld the tubes up in front, and can continually drive Piles without stopping.
This property has 2 fire places; when we arrived onsite, 2 of the piles in the fire place were too close together, so with a quick call to our engineer we were able to move the piles apart, so they were 3.5 times the diameter away from each other.
The first load of concrete is in, reinforcement inserted and safety caps placed on all protruding steel reinforcement.
All our sites are left clean and tidy, which makes the next stage of the project a lot easier for the next contractor.
As main Piling contractor on this project we were required to provide a Contiguous Piled retaining wall, around the perimeter of the property. The property is a five storey, end terraced house in the heart of Nottinghill. The side access to the garden, was 2.5m wide which, restricted the size of Piling rig we could use onsite.
The basement on this project, will be two levels, with the first level as living quarters, and the second as plant and storage rooms. This meant that the retained depth changed where we stepped down for the double basement, so our Contiguous Pile depth ranged from 8.0 – 15.0m. And as we are a smaller company, with a hands on attitude our engineer was onsite to over see most of the Piling works which enabled us to sort out any problems quickly keeping the programme within time scale.
The whole house is to be put on a transfer slab extending the basement, beyond the footprint of the house. Which required us to install temporary Bearing Piles to take the load of the house while the basement is being excavated. There are also a number of internal and external Tension Piles and internal Compression Piles to take loadings of 200kn at sub basement level.
Scope of works:
*Site welfare and Health and Saftey set out by Main contractor.
*Mobilise T5000 Auger Rig and 300mm dia solid stem augers to reach design depth.
*Steel and safe area for making cages was set up.
*Dumper for concrete with a chute.
*Lifting frame with 110v winch to safely lower cages for Internal Piles with minimum headroom of 2.3m.
*Complete all external Contiguous piles and Tension Piles.
*Install Contiguous Piles to form sub basement, which will join up with deeper external piles.
*Install Temporary Piles which will support the transfer slab while Sub basement is being excavated.
*Install Bearing Piles with a design depth to take 200kn.
*Clear site and demobilise T5000 Auger Rig and all other equipment.
On our first visit to site our engineer checks access, and the centre lines of piles so we can decide which Rig would be most efficient onsite.
T5000 Auger Rig with outriggers and 300mm dia lead flight with a cutting head for London clay and mudstone.
All the walls had been underpinned by the main contractor, the Contiguous Piled wall had to continue between the remaining walls supporting the house which proved to be very challenging. Especially underneath the stairs to the front door, where we had to install 4 Piles, at our minimum working headroom 2.25m, which meant boring and casting 2 Piles a day.
All of the steel reinforcement for the Contiguous Piled retaining wall had, 6H16 @ 2.2m long in a H8 helical – 200mm O/D (overall diameter) and pitch of 150mm (distance between helix). The design depth for these Piles was 15.0m so we had to connect and lower 10 cages, in each open bore before casting the Pile. Our custom winch and lifting frame has a SWL of 500kg and makes this job very safe.
Contiguous Piles installed, cut and broken down ready for capping beam.
Advanced Mini Piling Systems operative, with a concrete dumper, is far more efficient than using wheel barrows, and a lot cleaner than using a concrete pump which requires a lot of water to clean, which we don’t need in the winter.
As you can see from the photo the reinforcement has not been cut down, saving the main contractor time and money when casting the capping beam. which shows we care about what we do, and we work with the client, not for them.
Part of the finished retaining wall to the basement, underneath the bay window, also acting as a fire escape.
Dunkeswell Bridge, Devon is an old stone built bridge which has become structurally unstable caused by the increased weight and traffic of this small arch based bridge. Unfortunately the road was closed until all works had been completed, the contract had to be finished in a short time, scale safely and without causing further damage to the bridge while it was being used as a work platform.
Scope of works:
*Install 12 No. 273mm dia Steel Cased Bottom Driven Piles to a designed set.
*Insert 12 No. 150mm dia 6mm walled steel Reinforcement.
*Concrete all piles to top of capping beam.
*Leave one chosen Pile up 500m from CSL to be tested by request of main contractor.
The road to Dunkeswell in closed untill all works are complete, by main contractor South West Highways allowing only pedestrians and cyclists safe passage. Which is why barriers and welding screens were used to prevent harm to the public.
The arch of the bridge is supported temporarily, while work goes ahead on top. And once the slab is cast over the piles the load will be transferred to them via the capping beam. Leaving the stone arch and sides of the bridge untouched.
The D1000H with built in hydraulic welder, and out riggers make for a very safe machine while operating over an excavated pile position.
All 12 piles installed to design depth, some of the driven piles had to be moved due services running under the road surface. The piles either side of the bridge, as they were being driven displaced the ground and put pressure on the sides this was also taken into account by moving them inwards.
A 150mm dia steel tube with a 6mm thick wall was inserted into each completed pile. Special skid spacers were welded to the sides of the reinforcement tube giving the correct concrete cover.The reinforcement goes top to bottom and is left 500mm below CSL which is top of capping beam, the piles were then filled with high slump, high strength concrete.
No pictures were taken of finished piles as heavy showers in the afternoon caused flash floods resulting in the road turning into a river which consequently ended in a number of piles filling with water, these were pumped out and were then ready for concreting.
3 Bedroom mid terrace house in Weston-Super-Mare,
with subsidence to the front and rear of the property. The house is positioned between a block of 5 flats and another 3 bedroom house, and on removal of the plasterboard inside it was found that the property was built with no cavity on the party wall adjacent to the flats. Both party walls are built off piled beams and the front and rear of property is built off standard footings.
Externally there are major cracks to front and rear of the brickwork and internally the aerated concrete blocks are all loose and cracked on both the first and second floor of the house.
Scope of works:
*Remove reinforced concrete floors and excavated down to bottom of slab before Piling work commences.
*Resin bond all cracks with Heli bar.
*Mobilise T5000 Rotary Bored Auger Rig which will bore 250mm dia to 5.0m reducing vibration and taking us past any obstructions before Driven Piling starts.
*Demobilise T5000 and mobilise D500 Piling Rig to drive 17 No 220 Steel Cased Bottom Driven Cast Insitu Piles.
*Demobilise D500 and concrete all Piles with reinforcement.
*Break out needles in walls front and back.
*Fabricate 250mm reinforced concrete slab.
*Remove jacks for total isolation and clear site.
While removing the reinforced concrete floors we found that the footings at the rear of the house were found to be alot wider than anticipated and 2 Piles were redesigned and placed outside.
With all 17 No. 220 Steel Cased Bottom Driven Piles, installed to designed depth and concreted, the underside of the reinforced concrete slab is blinded ready for laying out the steel reinforcement. As there is no Heave involved in this job just insufficient footings, we are not using any void forming collapsible materials and no Anti Heave Sleeve around our Piles (Which where there is Heave involved allows the top stratum of clay to move with the changing variables of weather).
The Reinforced steel slab has been fabricated insitu and 500 x 250 needle beams have been inserted into the walls, picking up the front and rear walls and preventing them from sinking by transferring the load through the entire 250mm deep Reinforced concrete slab.
We have a H12 top and bottom mat with H16 bar’s running side by side and top and bottom around all Piles locations. The project is now ready for concreting.
All concreted and job finished.