Specialist Geotechnical Advice

New Cruise Terminal. – We were contacted to provide specialist geotechnical advice on the potential effects of noise and vibration caused by the installation of large diameter steel tubular piles for a new cruise terminal. Of particular concern was the potential effect on the marine life and over what area the marine life would be affected. Our findings recommended steps that could be taken to mitigate the levels of noise and vibration to reduce the risk of harm.   C Hobbs Associates were able to draw on experience gained in providing similar geotechnical advice on a review considering noise levels caused by the construction of a new loading berth in Bunbury Western Australia. 

Manchester Ship Canal. – In late December 2015 Storm Eva cause flooding in the canal which resulted in severe damage to about 160m of canal bank. Drilled ground anchors were needed to tie back a new combi pile wall stabilising the damaged bank. However, during the drilling of the anchors, movement was recorded beneath nearby structures and work was stopped. We were commissioned to provide specialist geotechnical advice about the cause of the movement and what changes could overcome these problems. Researching the probable cause of the movement, we highlighted changes ensuring that further movement could be kept to controllable levels. 

Chernobyl. – When building the sarcophagus over reactor number four, there were problems trying to build the CFA piles in the active zone. Bechtel contacted us to ask for our help to resolve the problems they were having on site. First, we reviewed the computer records for the pile installation and the test pile results. We identified where changes in construction method would significantly impact the quality and speed of construction. Seeing construction at the site quickly confirmed our findings. Finally we made recommendations to the construction team, resolving the problems that the site team were having.  Take some time to watch the arch being slid into place here.

Bishop Stortford. – A house builder called to say that their piling contractor was unable to form CFA piles on the site. Our role was to provide geotechnical specialist advice about the reasons why the piles could not be formed and what solutions could be implemented so the project could be completed.  First, we reviewed the site investigation documents, pile records and looked into previous projects close to the site and discovered there were dissolution features under the site preventing the formation of the piles. Our specialist advice was to scope further ground investigation that found the full extent of the features. Our specialist advice was to perform compaction grouting to stabilise the dissolution features thereby reducing the effects of ground movement on adjacent buildings during the successful completion of the piling.

Geotechnical Design and Innovation

Retaining Wall Design – C Hobbs Associates regularly prepare geotechnical design reports for the construction of embedded retaining walls to retain unstable slopes and for the construction of basement structures. Our more recent contracts include the design of a bored pile retaining wall at Cayton Stud near Reading; a piled basement retaining wall Bristol and a piled basement retaining wall in Abridge, London.

Bearing Pile Design – C Hobbs Associates prepare geotechnical design reports for bearing pile design from as little as 4 piles for a house extension to more than 1,000 piles for for much larger projects. Projects of note include the design of bearing piles to a new statue to Nehandu in Harare, Zimbabwe; designing bearing piles for a new hotel near Oxford and the design of steel cased driven piles for a new housing development near Welney, Cambridgeshire.

Ground Movement Analysis – Planning conditions for a new 24 storey tower block in South London required a ground movement assessment arising from the installation of the piled foundations. Using computer modelling techniques, we were able to show that the predicted induced strains surrounding the nearby tunnel would not be sufficient to cause any damage.

Differential Settlement – Heavily loaded centre core foundations near to more lightly loaded column foundations can give rise to high differential settlement and hence structural instability. Our analysis of a tall building’s foundations showed that there was a significant risk of large differential settlement occurring. By modelling the building foundations and structural loads, we modified the foundation design moderating the differential settlement to a level that the structure could sustain. 

Bid Management

Bauer. – We successfully led the bid for securing the £15m rotary piling project at Uskmouth as well as a £6.5m CFA piling project in Pembroke. 

Morgan Est. – C Hobbs took the role of Bid Director for the Crossrail Station boxes and LUL station upgrades for the BBMV JV. The projects required the construction of large diameter rotary piles, diaphragm walls and piled secant and contiguous walls.

Roy Hill. – C Hobbs oversaw the bids on three major sections for the Roy Hill mine project in North Western Australia. Of particular importance to the project was a new stockyard and car-dumper with piles and retaining walls. Secondly, a 6km conveyor to a new port facility over difficult marshy ground. Finally thirteen bridges on a new 350kM railway line needing heavy wall driven steel tubular piles. Overall, the project value was AU$35M and Avopiling were successful in securing the bridge piling for the 13 structures.

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Finally, if you want to learn more about any of these projects why not get in touch by clicking here and completing our contact form.