DEVELOPMENT OF DATABASE OF HEAVY TRUCK LOAD DATA IN PESHAWAR, PAKISTAN

The objective of this research project is to develop an indigenous solution that should be efficient and cost effective for determining truck loads passing from Peshawar. As heavy vehicles impacts road most, therefore small vehicles are put in one category and trucks are divided into two, three, four, five and six axles to give clear interpretation of each type of truck. To determine load data, a portable weighing station was designed keeping in view the size of each truck tire, the maximum deflection and economy. Weighing plates were made of steel which is easily available, cheaper as compare to the aluminum plates that are being employed in most of the weighing machines. Movable weighing station comprises of two rectangular steel plates of sizes 28” x 21” and thickness 1” considering the dimensions of loaded trucks tires and AASHTO specification. The thickness is taken as 1” as the deflection produced by the heaviest truck tire was less than 0.5”. General purpose strain gages were installed on front and back side of each plate in full wheat stone bridge form and were connected to Data acquisition system (DAQ) to record deflection. Lab calibration was carried out to determine the value of strain for each load applied through Universal testing machine (UTM). Load verses strain graph was developed for each load cell which was used to interpret the value of load exerted by each pair of tire to produce strains. By adding the strains from each plate, axle load and similarly by adding axles, the load of the complete vehicle can be determined. Field calibration was carried out to check the precision of plates and was found in close agreement. Axle wise load of around 200 vehicles were taken randomly and were found that more than 80% of the vehicles of each category are overloaded. This sample survey of load can be implemented across the country as it is the representation of the loaded vehicles moving in the country.