SANRAL Completes R424 Million Sinkhole Repairs on N1 and R21 in Centurion

SANRAL CEO Reginald Demana emphasized the technical complexity of the project, particularly given the dolomitic nature of Pretoria’s terrain.

The South African National Roads Agency SOC Limited (SANRAL) has announced the completion of repairs to the sinkhole on the N1 near the Flying Saucer Interchange in Centurion, Gauteng. This milestone comes shortly after the repair of another sinkhole on the nearby R21, with the combined projects costing R424 million. Key Highlights of the Repairs:

Cost Breakdown: R280 million was allocated to the N1 sinkhole repair, while R144 million was spent on the R21 sinkhole.

Timeline: Work on the N1 sinkhole began in September 2023 and is now 99.9% complete.

Strategic Importance: The Flying Saucer Interchange connects the N1 and R21, two vital routes for Pretoria’s economy and South Africa’s overall infrastructure network.

Complex Geotechnical Challenges

SANRAL CEO Reginald Demana emphasized the technical complexity of the project, particularly given the dolomitic nature of Pretoria’s terrain.

“Pretoria is prone to sinkholes due to its dolomitic foundation. The heavy rains of late 2021 and early 2022 exacerbated the risk, causing depressions and cracks on critical sections of the N1,” Demana explained.

He noted that sinkholes are unpredictable and require extensive excavation, drilling, and concrete piling to address the damage effectively.

Timeline and Safety Measures

The sinkhole on the N1 was first identified in January 2022. SANRAL promptly closed the affected lanes and redirected traffic to ensure user safety while repairs were carried out.

The scope of work included:

• Stabilizing the ground to prevent further collapse.
• Reconstructing damaged road sections.
• Ensuring long-term resilience against future sinkhole formation.

Economic and Social Impact

Demana highlighted the critical nature of these repairs for maintaining the connectivity and economic vitality of Pretoria and surrounding areas. “The N1 and R21 are lifelines for Pretoria’s economy and a significant part of the national road network. Minimizing traffic congestion during peak hours was a top priority during construction.”

Additional Information

As part of SANRAL’s broader efforts, the agency is implementing long-term measures to monitor and mitigate the impact of Pretoria’s dolomitic terrain on its road infrastructure. This includes geotechnical assessments, early-warning systems, and enhanced drainage systems to reduce the risk of future sinkholes.

By completing these repairs, SANRAL reaffirms its commitment to providing safe, efficient, and sustainable road infrastructure for South Africa.