Design of Retrofit Vehicular Barriers Using Mechanical Anchors

Retrofit barriers can be used to replace highway barriers damaged by vehicular collisions. The purpose of TxDOT Research Project 0-4823 is to develop retrofit designs of current TxDOT highway barriers using mechanical anchors. The retrofit designs should meet the TxDOT performance criteria for retrofit barriers as well as NCHRP Report 350 requirements.

Investigators for this project developed an impact pendulum test setup to represent a surrogate vehicle for Test Level 3 of NCHRP Report 350. They also developed retrofit designs for T203 and T501 barriers using mechanical anchors. Using the impact pendulum, tests were conducted on stand-alone cast-in-place and retrofit T203 and T501 barrier specimens. A quasi-static test was also conducted on the retrofit T203 barrier design. These designs met TxDOT performance criteria and NCHRP Report 350 requirements for Test Level-3.

Finite element models of the cast-in-place and retrofit T203 and T501 barrier specimens were developed using LS-DYNA, and they were validated using the pendulum impact tests. Using those models, vehicular crash simulations were conducted to NCHRP Report 350 Test Level-3 and Test Level-4 standards to predict the performance and robustness of the retrofit T203 and T501 barrier designs when subjected to large impact forces.

The retrofit barriers with mechanical anchors, while slightly inferior in performance to the cast-in-place barriers, did meet AASHTO and TxDOT requirements for new construction and are suitable for implementation by TxDOT.