A minimum mounting-height rough stone masonry guardwall was designed and successfully crash tested to meet Test Level 2 (TL-2) safety performance criteria found in NCHRP Report 350. Several design concepts were considered for providing shear transfer between the top capstones and the inner core wall. The new design uses steel angle segments anchored to the core wall with the upper leg recessed into saw-cuts placed in the capstones. LS-DYNA simulations were performed with varying barrier heights to evaluate the propensity for vehicular instabilities and barrier override. Two crash tests were performed. The first test was performed on a 22-in.-tall guardwall with a 2000P pickup truck impacting at a speed of 44.4 mph and at an angle of 24.2°. The second test was performed on a 20-in.-tall guardwall with another 2000P vehicle impacting at a speed of 43.6 mph and at an angle of 24.4°. Both crash tests provided acceptable safety performance. Although the 20-in.-tall parapet adequately contained and redirected the pickup truck at the TL-2 conditions, barrier performance was slightly degraded over that observed in the 22-in.-tall parapet. On the basis of the results of this study and for new construction, it is recommended that the rough stone masonry guardwall system be implemented using a nominal top mounting height of 22 in. relative to the traveled way. A significant benefit of this nominal height is that roadways requiring resurfacing could be accommodated using a 2-in. pavement overlay placed adjacent to the barrier system.
ASJC Scopus subject areas
- Civil and Structural Engineering
- Mechanical Engineering