Stabilisation of A-road in the South East of England

Geobear were recently contracted to deliver ground stabilisation works to a key  A road in South East England. Although the road is modern in construction, sections began to show signs of settlement and with the local county council keen to resurface they were concerned that any continued and future settlement would leave the road requiring more drastic remediation. Consequently they required a long-term solution that would mitigate against any asset degradation due to the ground conditions.

In addition, with the road a major network route, the council also required a solution that would be quick to install with the minimum of disruption to traffic.

Customer alternatives

Given the need to minimise disruption, yet also achieve a permanent solution to allow the resurfacing to be actioned confidently without further settlement, few options were available to the Council. The only real alternative would have been a full-depth reconstruction of the road. A task that would require full and lengthy road closure, it was not the most ideal solution, which prompted the Council to look to alternative methods.

Geobear was consulted by the Council about developing a scheme to stabilise the ground beneath the road.

Why Geobear

The solution proposed by Geobear to treat the road was vastly more appealing compared with the alternative and more complex construction option, which would not only have been considerably costlier, but would also have seriously impacted traffic with the road potentially requiring a lengthier period of full closure and during busy commuter periods.

Geobear’s geopolymer solution would be able to both stabilise and improve the ground beneath the road, permanently with the minimum disruption.

Geobear solution

Prior to engaging Geobear, the client commissioned ground investigation of the area to define the road’s makeup; the data from which was provided to Geobear to review, allowing it to develop its solution to the problem.

Seven areas of the road were identified as needing remediation, manifesting themselves through unevenness or ‘bumpy’ to the road user. A GPR utilities mapping company was on-site to survey any services that may have been present beneath the road and marking them for avoidance. Geobear remediated the issue by injecting a specific geopolymer resin at the seven areas identified treating some 16-1700 m2 in total. The resin was injected to a depth of 1m beneath the surface of the carriageway targeting the road’s sub-base and sub-grades stabilising the road and providing a firm foundation on which resurfacing could begin. Drain protection was also put in place by Geobear to ensure that there was no risk to the drains becoming blocked due to treatment and pre- and post-work dynamic cone penetration testing was undertaken to verify the effectiveness of the solution.

Work on the road commenced mid-August at night and under full road closure with work being completed, by three of Geobear’s crews in just three days.

For further information about this project please contact:

David Hedley, Highways Manager, South

[email protected]

07970 624 098