Cambodia | New Chroy Changvar Bridge – CMC

Facing challenging ground conditions with weak clay and sand layers, Menard implemented Controlled Modulus Columns (CMC) technology. This innovative approach resulting in substantial cost and time savings for the client.

Project Overview

The project consists in building an Extra Dossed Bridge across Tonle Sap River in Phnom Penh to connect the National Road 5 and the National Road 6 In Chroy Changvar district, Phnom Penh, Cambodia Capital City.

This project requires access roads (ramps) to be built with embankment up to 6m. Menard has been contacted by the Client in order to propose its soil improvement solutions under the access roads like it has been done earlier that year on NR5 Fly Over Project.

Ground Condition

The subsoil is composed of:

• 22m thick of weak clay layer
• 7m of loose clayed sand layer
• Sandstone

Menard Solution

Due to heavy trapezoidal loading coming from embankments, pavements and traffic loads, CMC grid has been designed following different square spacings from 2,5m x 2,5m to 1,3m x 1,3m and the diameter was 320mm. CMC have been drilled down to 30m to reach the sandstone layer.

For the second time with our client, we have applied Controlled Modulus Columns technology as valuated engineered solution for their project: Indeed, CMC allowed our client to delete the initially designed RC ground slab on piles.

In addition, CMC solution has been combined with Reinforced Earth Wall (REW), which is lighter than conventional RC Retaining Wall and allowed our client to extend the access ramps and save 2 spans on their bridge (one span each side).

This solution has obviously allowed significant costs and timesaving to our client.