CASE STUDY: Structural Expansion Joint Replacement DLR | Civils

Project Overview:

Client: TFL

Duration: Phase 1 (April 2022 – July 2023)

Project Description and Scope Location: DLR Shadwell to Tower Gateway, West India to South Quay & Royal Albert to Beckton

Scope of Work: 

Replacement of 32 structural expansion joints 
Baseplate and anchor replacement 
Percussion drilling and diamond over-coring 
Resin fixing new anchors and grout pad installation 
Slab repairs, re-railing, welding, negative return bonding 
ETE 3rd Rail Re-Gauging

Project Challenges

Elevated Track Access:

• Working at heights required strict safety protocols.
• Limited access points meant innovative logistics were needed, including craning RRVs on and off-site.

Operational Constraints:

• Frequent DLR service schedules necessitated precise coordination.
• Night-time and weekend work minimized disruption.

Technical Complexity:

• Specialised equipment was required for drilling and over-coring in reinforced concrete.
• Accurate installation of grout pads was essential for long-term stability.

Execution Strategy

Pre-Construction Planning:

• Conducted comprehensive site surveys and structural assessments.
• Developed detailed schedules to align work with minimal service disruption.

Precision Drilling and Coring:

• Used advanced percussion drilling and diamond over-coring to create precise openings for new expansion joints.
• Monitored drilling in real-time to ensure accuracy and avoid structural damage.
• Managed dust and debris with vacuum systems and water suppression for enhanced safety.

Installation:

• High-strength Sika Rail Fast grout secured the new expansion joints and baseplates.
• Laser levelling and inclinometers ensured exact tolerances for track alignment.

Conclusion

•  On-Schedule & On-Budget: All expansion joints, rails, and baseplates were replaced within the set timeline and budget.
• Improved Performance: The new joints reduced maintenance needs and extended service life.
• Minimal Disruption: The project caused minimal interference with DLR services due to meticulous planning and execution.
• Enhanced Safety: Advanced techniques and strict safety standards ensured long-term reliability and safety for the DLR infrastructure.