This project included ground improvement below the reinforced soil wall at National Highway 30A, Nalanda, Bihar. This district has the ancient Nalanda University, a UNESCO World Heritage site. NH 30A is entirely within the state of Bihar and covers 65 km (~40 miles). This location has historical importance making it imperative to awe world-class infrastructure.

There were many challenges for the project. The site consisted of locally available sand up to a depth of 4 m below ground, leading to low bearing capacity. The structure was unsafe for rotational and translational stability for both static and seismic loading. The soil bearing capacity required was low for constructing a safe structure.

The conventional method would have been soil replacement. However, the soil replacement that needed to be done at a depth of 4 m was highly time-consuming, tedious, and expensive.

Strata’s team of specialists provided a design in which a basal reinforcement combination consisting of biaxial geogrids and StrataWeb® geocells was used for ground improvement. The well-graded sand was used as StrataWeb® infill material.

The use of Strata geogrids saved up to 25% of the total cost. The solution made the structure extremely stable along with faster construction compared to conventional methods.