The Challenge
The site is a former quarry that had been infilled with construction & demolition (C&D) waste prior to operation as a contractor’s yard. Site preparation & remediation works were required to address large soil bunds containing demolition materials, asbestos fragments, other deleterious materials and localised Japanese Knotweed infestation. Made ground beneath the site was geotechnically poor and the required significant re-grading to achieve required development formation levels.
Our Solution
A ‘suitable for use’ Remediation Strategy was agreed with the EA / Local Authority, and Soilfix designed and implemented a remediation & enabling works scheme, fully in accordance with CL:AIRE Code of Practice, which included:
- Targeted excavation and off-site disposal of Japanese Knotweed contaminated hotspots;
- Modular processing of bunds and shallow made ground for recovery of deleterious, materials (including asbestos cement fragments) and aggregates for processing; / re-use
- Controlled breakout of concrete slabs & shallow sub-structures, processing to 6F2 specification for re-use;
- Decommissioning / removal of interceptors & an underground storage tank (UST);
- Remediation of made ground containing unforeseen fragments of Asbestos Insulation Board (AIB) under Licensed Works, fully in accordance with CAR2012;
- Cut & fill reprofiling the site to required development platform levels, carrying out further processing and quicklime modification of made ground, as well as cement stabilisation of soft underlying formations to achieve a suitable bearing capacity prior to filling; and,
- Additional cement stabilisation below buildings and road corridors, capping site with a running layer of site-won crushed material to form a ‘suitable for use’ Development Platform to carry out safe piling operations and timely, cost effective infrastructure construction.
All works were completed with a staged handover to facilitate the client’s piling works to commence on programme. In spite of exceptionally inclement winter weather and highly challenging Made Ground, Soilfix achieved 99% materials re-use in accordance with the MMP.
