M25 Clearmount Bridge Demolition

The demolition of a steel and concrete bridge over the M25 with significant time and stakeholder pressure due to the first full weekend closure of one of the busiest parts of the UK road network to facilitate the work.

Client: National Highways

Principal Contractor: Balfour Beatty

Demolition Contractor: TRU Demolition (formerly Clarke Demolition Company)

Project Overview

The demolition of a combined steel and concrete road bridge between J10 and J11 of the M25. The demolition of the bridge required the planned closure of the section of the M25 between J10 and J11 from 9pm on a Friday until 6am on Monday morning.

This was the first full daytime closure of the M25 since it opened in 1986, which received significant media attention as part of the National Highways effort to mitigate the inevitable traffic disruption.

Due to the closure, an 11.5-mile diversion route was created to direct traffic along A roads. However, traffic jams were not as bad as many feared.

Key Project Constraint

The demolition needed to be carried out within a tight timeframe to minimise disruption, with a strong public and media focus on the potential traffic impacts.

Service and Road Protection

The demolition of the bridge was relatively straightforward. However, several services needed to be protected, including the road surface, which was protected using Navvy matts.

Demolition Process

Initially, machines up on the abutments broke out what they could reach, and then machines on the deck broke out the rest of the concrete deck. The steel beams were then cut free and lifted out with a crane. 

The piers were then broken down, the remaining elements tidied up, and the abutments broken out.

Outcome and Sustainability

The bridge was successfully demolished and the M25 could open at 10 pm on Sunday evening; 8 hours ahead of schedule. 

When announcing the successful completion of the demolition, the demolition contractor confirmed that all the granular material was recovered for potential reuse on future projects and all the steel work was sent for recycling.