Bangladesh | Physical Protection System of Main & Auxiliary Facilities for Nuclear Power Plants – DSM

Project Overview

In 2022, Menard completed an important ground improvement project for a critical infrastructure site in Bangladesh. Our task was to enhance the foundation for a new nuclear power plant, ensuring the soil could handle seismic activity while maintaining stability. The chosen solution? Deep Soil Mixing (DSM)—a proven method for treating challenging soil conditions like silty sand. Over the course of seven months, Menard treated 19,015 m³ of soil, reinforcing the ground for the safe construction of this critical facility.

Ground Condition

The site was predominantly composed of silty sand, with occasional layers of loam and clay, which presented significant challenges in terms of soil liquefaction risk. The silty sand was prone to instability, especially in the event of seismic activity, making it necessary to strengthen the soil to support the plant’s large-scale infrastructure. The variability in soil types across the site required a flexible and robust approach to ground improvement.

Menard's Ground Improvement Solution

To address the instability of the silty sand and improve the overall bearing capacity, Menard employed Deep Soil Mixing (DSM). This technique involves mixing the in-situ soil with a binder, in this case, cement slurry, to create a solidified material with enhanced strength and deformation properties. DSM not only mitigated the risk of soil liquefaction but also improved the soil’s mechanical characteristics, making it capable of supporting the plant’s heavy infrastructure.

The DSM process for this project required variable column diameters ranging from 1 to 2 meters, with mixing depths reaching between 4 to 13.8 meters. Key performance targets included achieving unconfined compressive strength (UCS) greater than 1 MPa, a friction angle exceeding 30°, and a modulus of elasticity (E) greater than 80 MPa. These specifications ensured the treated soil met the strict structural requirements for the plant.

Menard's team worked in double shifts, 24 hours a day, 6 days a week, to complete the project on time, pooling resources from across three nationalities to bring expertise and precision to every stage of the process. By the project’s end in November 2022, we had successfully stabilized the ground, ensuring the site was prepared to support critical infrastructure safely and efficiently.