4.5.4 Confirmation of suitability for treatment
The builder shall obtain written confirmation from the engineer and specialist contractor that the site is suitable for the proposed ground improvement system.
NHBC should be notified prior to work starting, that the site is suitable for the proposed system. The engineer and specialist contractor should agree the following in writing before work commences on site:
- design objectives
- detailed schedule of work
- programme of work
- tests to be conducted on completion of the work
- responsibility for procedures and tests.
The following considerations should be taken into account:
- layout and depth of the stone columns and the accuracy to be achieved
- safety issues to be incorporated into the design to allow for unforeseen circumstances
- criteria for non-acceptance of the vibrating poker work tests to be conducted on completion of the work
- responsibility for procedures and tests
- calculations and case histories required to justify the ground improvement proposals together with the layout of the stone columns and details of the equipment and process to be used on site.
These written agreements should be made available to NHBC before work commences on site.
Last updated: 2nd January 2024