Is top-down cracking critical on airfield rigid pavements?

This paper identifies the key slab loading locations for inducing critical bottom and top tensile stresses on airfield rigid pavements servicing the A-380 aircraft. Finite element simulations were conducted for the A-380's individual triple dual tandem (TDT) gear and all its main landing gears for a given slab geometry and pavement material properties. The numerical results show that the ratio between the top and bottom tensile stresses of the slab were significantly higher for the main landing gear analysis relative to the individual gear analysis and could be 1.0 for some cases. Furthermore, this initial finite element analysis has shown consideration of the entire main landing gear of the aircraft is necessary if the top tensile stresses are going to be accurately predicted.