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Abstract
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Five full-scale dynamic impact tests were made on two basic geometric designs and one trial design of bridge barrier rails.
The three geometric designs included a standard California Type 1, a standard California Type 2, and a modified Type 1 bridge barrier rail. Each was tested utilizing extruded aluminum pipe rail and cast aluminum posts mounted on a concrete parapet, Figure 1. The concrete parapet used for the aforementioned Type 1 test was repaired and the rail design was modified for two additional tests, one with steel pipe railing on welded steel plate posts (Type 1-A) and one with extruded aluminum pipe railing on malleable iron posts (Type 1-B).
This report describes the test procedures, instrumentation and test results based on the data secured from five high-speed oblique angle impacts on the five bridge barrier rail designs. The test results indicated that all of the bridge barrier rails tested could effectively withstand the impact of a 4300-pound passenger vehicle at speeds in excess of 75 m.p.h. Minor cracking and spalling of the concrete portion of the Type 1 barrier was successfully repaired with epoxy/aggregate patches for use in two additional tests.
Specific recommendations are made for a balanced design bridge barrier rail system.
These vehicle barrier tests were also used by the California Highway Patrol for comparisons of various lap belt-shoulder harness restraining systems. Accident reports involving patrol officers have indicated that partial ejection during oblique angle collision or roll-over has been a serious hazard, and every effort is being made to reduce injuries incidental to this type of accident. An anthropometric dummy was, therefore, placed in the driver's seat for these tests to simulate a highway patrol officer involved in an oblique angle impact during a high-speed chase. |