Criteria for Restoration of Longitudinal Barriers, Phase II (2021)

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417 CHAPTER 16 –FIELD GUIDE APPLICATION EXAMPLES The assessment procedures are designed to identify the types and levels of damage that will likely compromise the barrier’s crash performance in subsequent impacts on the unrepaired system. In other words, the assessment process is designed to determine if the damage warrants high priority for repair. When the damages do not meet critical damage conditions, then the damaged guardrail should be expected to perform effectively for a majority of impact conditions; therefore, the assessment process does not directly evaluate damages that have been classified as “medium” or “low” priority for repair. However, sound engineering judgment should always be used in making final repair decisions. A series of field assessments were performed using the on-line version of the Field Guide at http://www.roadsafellc.com/GCA/index.php to illustrate the basic assessment procedure. The example cases presented herein were based on damaged guardrails from actual crash sites in Oxford County, Maine. The on-line field guide was developed as a logic-based questionnaire; therefore, the specific questions asked for each example case below differ depending on the types and levels of damages identified. The format of the questionnaire was designed to be as user friendly as possible. For example, questions that have a limited number of response options are generally structured as multiple choice questions with radio buttons, yes/no questions with mouse-click response, or check-boxes to minimize and simplify the required inputs for the user. Further, the questionnaire was designed so that a “yes” response is expected whenever the level of damage meets a critical damage threshold to avoid confusion for new users, as well as, to allow experienced users to quickly speed through the assessment questions by relying on visual cues in the questionnaire (e.g., question title) for determining the proper response. Also, the answers for many of the questions are automatically pre-selected based on the most common responses, to help speed through the process. For questions that require numeric input or that require a response using check-boxes, leaving the answer-field blank indicates that the answer is “zero” or “none” (i.e., the default answer for those questions is zero).

418 Example 1 This example involves a modified G4(1S) guardrail with crash damage extending over two rail panels, including the w-beam splice, as shown in Figure 355. The following images show the step-by-step evaluation procedure using the on-line Guardrail Condition Assessment (GCA) program developed in Chapter 15. Figure 355. Photos of the crash site for Example 1. User Input for Question 1: Name, date, contact information, and crash site location was entered on the location information page.

419 User Input for Question 2: The damage was on the length-of-need section of the guardrail (i.e., not on the end-terminal), so the “yes” response was selected. User Input for Question 3: The default radio buttons were selected, which correspond to the components of the G4(1S) with 6’-3” post spacing . User Input for Question 4: The system in this case was the modified G4(1S) with W6x9 posts and composite blockouts.

420 User Input for Question 5: The rail height was 26.5 inches measured from the ground to the middle-point of the top w- beam corrugation, so the “No” response was selected. User Input for Question 6: The lateral deflection was less than 9 inches, so the “No” response was selected. User Input for Question 7: There was only moderate longitudinal displacement in the splice connection. The “No” response was selected.

421 User Input for Question 8: The extent of damage included two straight rail panels. The number “2” was entered in the appropriate text box; the other box was left blank. User Input for Question 9: The rail was free of horizontal holes and tears. The “No’ response was selected. User Input for Question 10: The damage included a 5.5 inch vertical tear on the top of the rail, so the “Yes” response was selected for this damage mode question.

422 User Input for Question 11: The posts experienced negligible deformations. No input is required on this page since the default values are “zero”. User Input for Question 12: The post-bolts did not have washers under the bolt-heads. User Input for Question 13: There was no soil erosion since the posts were all embedded in asphalt. No input was required, because the default response is “zero”.

423 User Input for Question 14: There were no damages noted for the upstream end-terminal. The response boxes were left “unchecked” (i.e., indicating no damage). User Input for Question 15: There were no damages noted for the downstream end-terminal. Again, the response boxes were left “unchecked”.

424 Assessment Results: The damage assessment is now complete. The results of the assessment are provided on the final page of the online guardrail condition assessment guide. The results are also sent to the e-mail address provided on the Question 1 page. The assessment results indicate that the guardrail is not likely to perform correctly if hit again, because of the vertical tear. It is recommended that the damages be repaired immediately. There may have been other critical damages on the system that were not evaluated in the assessment. According to the evaluation procedures, once the extent of damage to any aspect of the system has been shown to warrant repair, then no further investigations are necessary. It is only necessary to collect inventory of all components that will be replaced in the repair. Since the posts and connection hardware were not damaged, it is assumed that those components can be reused. The materials needed for the repair only include the two damaged w-beam rail elements.

425 Example 2 This example also involves a modified G4(1S) guardrail with crash damage extending over two rail panels on the length-of-need section of the guardrail, as well as a portion of the end-terminal, as shown in Figure 356. The following images show the step-by-step evaluation procedure using the on-line GCA program. Figure 356. Photos of the crash site for Example 2. User Input for Question 1: Name, date, contact information, and crash site location was entered on the location information page.

426 User Input for Question 2: The damage was extended over a portion of the end-terminal and onto the length-of-need section of the guardrail, so the “yes” response was selected. User Input for Question 3: The radio buttons corresponding to components of the G4(1S) with 6’-3” post spacing were selected (i.e., default options) User Input for Question 4: The system was the modified G4(1S) with W6x9 posts and composite blockouts.

427 User Input for Question 5: The rail height was 28 inches measured from the ground to the middle-point of the top w-beam corrugation, so the answer was “No”. User Input for Question 6: The lateral deflection was only 4 inches, so the “No” response was selected. User Input for Question 7: The damage was limited to flattening with moderate longitudinal displacement in the splice connection. The “No” response was selected.

428 User Input for Question 8: The extent of damage included two straight rail panels on the length of need section and one rail panel on the end- terminal. The number “3” was entered in the appropriate text box; the other box was left blank. User Input for Question 9: The rail was free of horizontal holes and tears. The “No’ response was selected. User Input for Question 10: The rail was free of vertical tears. The “No’ response was selected.

429 User Input for Question 11: There are a total of 3 posts that need replacement. Two line posts were damaged and one CRT post. User Input for Question 12: One of the composite blocks on the line posts need replacement and the wooden blockout on the CRT post needs replacement (see photo above). User Input for Question 13: Two post bolts are needed. The post-bolt for one line-post and one CRT was damaged.

430 User Input for Question 14: The post-bolts did not have washers under the bolt-heads. User Input for Question 15: There was no soil erosion since the posts were all embedded in asphalt. No input was required, because the default response is “zero”. User Input for Question 16: There were no damages noted for the upstream end-terminal. The response boxes were left “unchecked” (i.e., indicating no damage).

431 User Input for Question 17: There were no damages noted for the downstream end-terminal. Again, the response boxes were left “unchecked”. This completes the damage assessment. Click the “Results” button to continue.

432 Assessment Results: The results of the assessment are provided on the final page of the online guardrail condition assessment guide. The results are also sent to the e-mail address provided on the Question 1 page. The assessment results indicate that the guardrail is not likely to perform correctly if hit again, because of the damaged line post. It is recommended that the damaged section of guardrail be repaired immediately. Although the guardrail condition assessment does not yet include damage assessments for CRT posts, the broken CRT post, blockout and damaged rail panel on the end-terminal section were included in the inventory of materials needed for the repair.

433 Example 3 This example also involves damages to a FLEAT guardrail end-terminal section, as shown in Figure 357. The following images show the step-by-step evaluation procedure using the on-line GCA program. Figure 357. Photos of the crash site for Example 3. User Input for Question 1: Name, date, contact information, and crash site location was entered on the location information page.

434 User Input for Question 2: The damage was located at the last CRT post of the end-terminal section, so the “no” response was selected. User Input for Question 3: The GCA field guide does not currently include assessment criteria for this section of the end-terminal, and the user is referred to the manufacturer’s recommendations for repair. By clicking on the “Continue with Damage Assessment” button, the assessments for the end-terminal head and anchor system are then evaluated. User Input for Question 4: The lag screws fastening the terminal head to the end-post were pulled out of the post. Damaged Section CRT Post Line Post Damage Length of need

435 User Input for Question 5: The downstream end-terminal was not an energy absorbing terminal and thus the assessment criteria is not applicable. However, there were no visual damages to the system. . This completes the damage assessment. Click the “Results” button to continue.

436 Assessment Results: The results of the assessment are provided on the final page of the online guardrail condition assessment guide. The results are also sent to the e-mail addressed provided on the Question 1 page. The assessment results state that the damage is part of the end-terminal and instruct the user to see the manufacturer’s recommendations for repair. The general assessment of the terminal head, however, indicated that the end-terminal was compromised and needs to be repaired.