Dewatering Metro Tunnel Excavation – Bangkok, Thailand

Overcoming Subterranean Water Challenges

The Problem:

During the excavation phase of the Bangkok Metro Tunnel, significant groundwater seepage was encountered due to the city’s high-water table and soft soil strata. Constant inflow of water into the tunnel hindered progress, created unsafe working conditions, and required a dependable dewatering system to keep excavation areas dry and stable.

Impact:

The uncontrolled groundwater inflow resulted in:

Delays in excavation activities
Reduced construction productivity
Escalating project costs
Difficulty in maintaining safe working conditions

Without an effective dewatering solution, the project risked major timeline disruptions.

Pumps Used:

15 units – CDW 25 HP Submersible Pumps
10 units – CDW 35 HP Submersible Pumps

These high-performance pumps were chosen for their durability, high discharge output, and ability to operate reliably in deep excavation zones with continuous water inflow.

Objectives:

Ensure Rapid and Continuous Water Removal

2.Maintain Safe and Stable Excavation Zones

Prevent Construction Delays and Cost Escalation

4.Support Uninterrupted Tunnel Construction Progress

Solution Implemented

A tailored dewatering strategy was developed specifically for Bangkok’s challenging urban geological conditions.

Catchment Area Analysis

The technical team conducted a detailed assessment of groundwater behavior, soil permeability, and inflow volume to understand the exact dewatering requirements.

Deployment of High-Performance CDW Submersible Pumps

CDW pumps were strategically positioned across excavation points to maintain continuous water extraction and prevent buildup.

Robust, Continuous Dewatering Plan

A coordinated pump operation cycle was executed to ensure uninterrupted water removal—keeping the tunnel floor dry and stable for ongoing construction tasks.

Full Support Throughout the Turnkey Project

Our pumps remained on site for the entire duration of the excavation phase, ensuring complete dewatering reliability from start to finish.

Results

Excavation and construction continued without interruption
Significant reduction in delays and productivity losses
Stable and safe working environment within the tunnel
Project progressed efficiently according to planned timelines

The continuous dewatering operations ensured the site remained workable despite heavy groundwater seepage.

Project Outcomes & Strategic Insights

Project Outcomes and Strategic Insights

Long-term Benefits:

Enhanced Structural Stability

Steady groundwater control prevented soil weakening and supported a stronger, more stable tunnel foundation.

Improved Operational Efficiency

With water removed consistently, construction teams worked faster, safer, and with fewer disruptions.

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Conclusion:

Effective groundwater control was essential for the success of Bangkok’s Metro Tunnel excavation. Through the deployment of CDW high-performance submersible pumps and a meticulously engineered dewatering plan, continuous excavation progress was achieved, safeguarding both timelines and workforce safety.

Future Recommendations:

To maintain efficiency in similar urban tunneling projects, the following practices are recommended:

Real-time groundwater monitoring
Optimized pump staging for varying inflow conditions
Routine system checks to avoid downtime
Adoption of energy-efficient submersible pumping systems

These measures ensure dependable, long-term dewatering performance in complex underground construction environments.

Case Studies