摘要: |
The objective of this research was to design a tie-down system for temporary concrete barriers for use on asphalt road surfaces, and then apply that tie-down system to the design of an approach transition from free-standing to rigid barriers. The tie-down and transition systems were to be evaluated according to the Test Level 3 (TL-3) safety performance criteria set forth in NCHRP Report No. 350. For the asphalt tie-down system, three steel pins were installed in holes on the front face of the barrier. The new tie-down design was crash tested according to NCHRP Report No. 350 test designation 3-11. The test was judged acceptable, barrier deflections were reduced, and all of the barriers in the system were safely restrained. The approach transition to rigid barrier was developed through strategic application of the previously designed asphalt tie-downs. Computer simulation with LS-DYNA was used to locate the critical impact point for the full-scale crash test. The system was tested according to NCHRP Report No. 350 test designation 3-21. The results showed that the vehicle was safely redirected, and the test was judged acceptable. |