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OCR for page 29
29 Figure 20. Test 07-3: detailed view of impact location (left), post damage at splice (center), and non-splice location (right). the splice bolts pulling through holes in the rail with none of the individual splice bolts fracturing. At both the splice and non-splice location, the post bolt pulled through the rail ele- ment. The splice failure and post damage is shown in Figure 22. 5.3 Recommendation Pendulum tests show that horizontal tears less than 306 mm (12 inches) in length and 13 mm (0.5 inches) in width do not significantly alter the performance of the barrier. In the 29.3 km/hr (18.2 mph) test, the damaged barrier was able to 0.02 s 0.06 s contain the impacting pendulum mass. In the higher speed 31.2 km/hr (19.4 mph) test, a splice failure was observed, although there was no evidence of rail rupture near the loca- tion of the horizontal tear. A pendulum test (18.2 mph impact speed) of a strong-post w-beam barrier section with a 12-inch horizontal (longitu- dinal) tear (0.5 inches wide) resulted in successful contain- 0.10 s 0.14 s ment of the pendulum mass. For this test, the horizontal tear was located at the impact location in the upper fold of the w-beam in order to represent a practical worst case. The performance of this damaged barrier section was virtually identical to that of the undamaged strong-post barrier section tested at the 17.5 mph impact speed. In a slightly higher speed 31.2 km/hr (19.4 mph) test, a splice failure was observed, 0.18 s 0.22 s although there was no evidence of rail rupture near the loca- tion of the horizontal tear. As a result, the research team has recommended that the repair threshold for horizontal tears be those exceeding a length of 12 inches and a width of 0.5 inches. The rationale for the width specification is that horizontal tears with suf- ficient width reduce the tensile capacity of the rail through 0.26 s 0.30 s a reduction in available cross-section area in the area of the Figure 21. Sequential overhead photographs tear. The research team's recommendation is that larger for 29.3 km/hr pendulum impact of barrier with horizontal tears should be repaired with a medium priority horizontal tear damage (Test 07-3). (Exhibit 2.0).
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30 Figure 22. Test 02-1: detailed view of splice failure (left), post damage at splice (center), and non-splice location (right). Exhibit 2.0. Recommendations for horizontal tear damage repair. Damage Repair Threshold Relative Mode Priority Horizontal Horizontal (longitudinal) tears greater than 12 in. long or greater Medium tears than 0.5 in. wide should be repaired with a medium priority. Note: for horizontal tears less than 12 in. in length or less than 0.5 in. in height, use the non-manufactured holes guidelines.