Road and Subway Design and Construction
Years of war have left Afghanistan with damaged infrastructure. If a country was t body, its Roads would be its veins. Road designing entails topographic plans of two target points which the road is supposed to connect. Providing topographic plans is time-consuming and labor-intensive, however, the procedure is technically straight forward. The next stage is to find alternatives and determine the best alternative which can connect two target point with minimum earthworks and distance.
The next stage is calculating appropriate curves in accordance with sight distance, stopping sight distance, passing sight distance, braking distance, nonpassing sight distance, and sight distance along horizontal curves,. In curve the road might widen. In curves also superelevation should be considered to resist centrifugal forces drifting vehicle off the road.
Due to terrains and other vertical irregularity, the designing of vertical curves is inevitable. Factors required to be considered are: sight distance, sag vertical curves, headlight sight distance, and rider comfort.
After the completion of geometric design of road, a durable and strong pavement must be adopted. Several factors must be introduced in design procedure: pavement life, traffic, safety factor, moisture effect and frosting effect. Material used for base and sub base must be strong enough. One of the factors whereby the strength of material might be evaluated is CBR experiment.
Management is the most important factor in field operations. Because only with continuous monitoring can the idea design be implemented. Precise time, material, vehicle and workforce planning must be provided.
After the completion of pavement, the road is ready to operate. However, inspection on the quality of road must be restlessly continued. Where necessary, maintenance might seem necessary.
Our team has years of experience in designing and implementing many roads in Afghanistan. We feel obliged to play a constructive role in rehabilitating Afghanistan’s road.