Summary

Ground movement beneath a 30m section of track at Beech Hill, Northeast Bristol, led to line closure and disruption to rail operations.

Mainmark was engaged by Balfour Beatty, on behalf of Network Rail, to strengthen the ground and enable rapid reopening. Using its non-intrusive Teretek engineered resin injection solution, Mainmark delivered a fast and controlled programme that reduced downtime and returned the line to service with minimal delay.

Challenge

Weak underlying soil strata caused settlement and loss of track performance, requiring urgent remediation. Key challenges:

• Restore traffic safely and as quickly as possible

• Work within restricted possession windows

• Strengthen soil beneath live rail infrastructure

• Avoid track removal and extended closures

• Deliver a proven solution under time pressure

Solution

Teretek resin injection was used to strengthen the ground beneath the track without excavation. This enabled fast, controlled ground improvement within a constrained rail environment. Scope included:

• DCP testing to confirm ground conditions

• Injection through ballast to depths up to 4.5m

• Targeted strengthening of weak and voided zones

• Post treatment verification testing

Outcome

Ground conditions were successfully strengthened, allowing:

• Re-levelling of the track

• Safe reopening of the line

• Restoration of rail services within a shortened programme

Rail Sector Value

•             Faster line reopening, reducing passenger and freight disruption

•             Shorter possession periods compared to traditional methods

•             No track removal or reconstruction required

•             Reduced risk of repeat speed restrictions or future closures

•             Improved track geometry and ride quality

•             Lower whole life maintenance requirements

•             Increased network reliability and asset availability

Sustainability & Asset Performance

• No excavation or waste removal

• Reduced plant, transport and carbon impact

• Lower embodied carbon than reconstruction

• Extended service life of the existing track asset

• Strengthened ground to support long term performance.