The section of NH-4 connects the thickly populated regions of Tumkur and Chitradurga in Karnataka. The National Highway Authority of India adopted this section for widening to six lanes.

Considering the terrain and sub-soil conditions, designing and constructing the approaches on filled up / raised foundations was necessary. The conventional solution of RCC retaining walls was costlier and time-consuming, besides possible disruption of traffic.

Strata’s geosynthetic experts suggested RS wall construction using non-plastic soils available in the region, StrataGrid™ PET knitted geogrid soil reinforcement and StrataBlock™ precast segmental concrete blocks as fascia. The founding levels of these walls had to be raised to meet technical requirements and economise the construction cost. The reinforced soil material was also used for these berms. Construction of both, RS walls and berms was carried out with stringent quality control.

The use of StrataGrid™ and StrataBlock™ fascia resulted in a cost reduction compared to the conventional RCC retaining walls. The system also facilitated easy construction of roads within minimum time.