Some very interesting contracts have been recently awarded and have involved us travelling to many parts of England. Notable recent contract wins include the following together with a large number of Phase I Desk Studies and Coal Mining Risk assessments.
We were procured by Mansell Plc to establish ground conditions alongside the existing John Lewis building in central Liverpool. Due to the proximity of a large number of services a detailed Method Statement, and coal mining risk assessments needed to be presented and a rigorous induction process attended.
We were instructed by a local land owner for an investigation on the site of a former notorious public house in Heaton Mersey, for a proposed new Morrison’s food retail store.
We were very proud to have received an instruction from British Land for the investigation and assessment of ground conditions on a very busy car-park adjacent to a shopping centre. The work was conducted in accordance with strict health and safety conditions and within a live shopping centre car-park. The report provided recommendations for a new cinema complex and restaurants including shallow pad foundations to support column loads, no ground gas mitigation or soil/groundwater contamination measures.
A recent instruction has involved us conducting a site investigation for a new luxury housing development on a greenfield site near Blackpool. Ground conditions proved to be difficult due to the presence of very weak organic silts and clays, so much so that SPT N values were regularly between 0 and 1!
Recommendations will include transfer of foundation loadings onto a competent glacial clay horizon and improvement of ground conditions along roadways and parking areas by use of geogrids and importation of suitable sub-grade capping material.
We have been instructed to conduct a site investigation on part of a former paper mill site adjacent to a canalised river to assess ground conditions for three proposed high rise apartment blocks.
The site investigation consisted of a series of trial pits and cable percussion boreholes extending through a sequence of dense fluvial flint gravel underlain by putty chalk.
We were very careful to work closely with the site vendor and our client to assess the location of all services across the site. A large number of services including two culverts, electricity cables, gas pipes, were delineated and the area secured to ensure good health and safety practices.
Ground gas monitoring and chemical testing of soils and groundwater proved an absence of significant concentrations.
Recommendation’s included the adoption of shallow foundations bearing on the river gravels, avoiding the use of costly driven piles in a sensitive residential area, and the decommissioning of a former groundwater abstraction borehole near to the site entrance.
We are currently assisting a national groundwater specialist remediation contractor in a programme of remediation on a former bus station site in South London. In the recent past a diesel spill occurred emanating from a rupture below ground pipe leading to a fuel delivery point.
Our work has involved us advising our client of the extent of diesel impacted soils and groundwater, the derivation of remedial targets and monitoring of groundwater quality.
The remedial works consists of a combination of the use of Dual Phase Vapour Extraction and Air Sparging within a shallow unconfined flint sand/gravel horizon. The work is planned to continue until February 2014.