Chapter 79: Sequencing of geotechnical works

To achieve the safety and technical requirements of geotechnical works, it is imperative that a sequence of working is agreed prior to commencement and is subsequently adhered to by all the organisations working on a project at the same time. The roles for planning, managing, and coordinating the construction works are set out under the Construction Design and Management regulations 2015 (CDM 2015 - see Chapter 8 Health and safety in ground engineering). When the construction works involve more than one contractor, a CDM Client must appoint an organisation (or individual) to plan, manage, monitor and coordinate each of the phases of the work. Under the CDM Regulations these roles are referred to as the Principal Designer and the Principal Contractor. There is a key link between the Principal Designer, who plans, manages, monitors and coordinates health and safety in the pre-construction phase and the Principal Contractor who executes these items in the construction phase. When agreeing the sequencing of the geotechnical works, the role of the Principal Contractor is crucial - they are likely to be the only party with an understanding of the overall construction sequence and the roles and responsibilities of each organisation on site. The Principal Contractor needs to understand each organisation's ideal method of working to achieve their own particular safety and technical requirements. If, as is common, many organisations on a site interact with each other or are reliant on one another, the Principal Contractor must help these organisations to modify their ideal method of working without compromising safety or technical requirements. Geotechnical design often requires a particular construction sequence to be followed or else the design is invalidated and the geotechnical works may not progress to plan; this would introduce another complication which would need to be managed by the Principal Contractor.