Development of MASH TL-3 Deflection Reduction Guidance for 31-inch Guardrail
| 项目名称： | Development of MASH TL-3 Deflection Reduction Guidance for 31-inch Guardrail |
| 摘要： | In the design and installation of guardrail systems, there routinely exists a need to provide a stiffening mechanism to locally reduce the lateral deflection distance where there is an area of concern such as bridge piers, poles, and other rigid objects located near roadway shoulders. Various means of providing reduced deflections have been made with past systems that have included nesting of guardrail and the reduction of guardrail post spacing. With the adoption of the American Association of State Highway and Transportation Officials (AASHTO) 2016 Manual for Assessing Safety Hardware (MASH), there is currently little to no guidance on the use of deflection limiting techniques for MASH compliant guardrail installations and their necessary transitions. Thus, a need exists to provide guidance for the use of stiffening mechanisms that will reduce the deflection distances behind guardrail while maintaining the integrity and safety performance. This research will continue the development of guidance for the design and installation of reduced deflection guardrail systems that are MASH compliant. Most research on guardrail used the NCHRP Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features testing criteria. The AASHTO and Federal Highway Administration’s (FHWA) Joint Agreement for the Implementation of MASH requires the use of MASH compliant hardware. Further research is needed and should be conducted using the most commonly used 31 in. generic guardrail system, the Midwest Guardrail System (MGS). The objective of this research is to develop guidance for the practical and cost effective use of stiffening mechanisms to locally reduce the deflection for MASH TL-3 compliant 31-in. MGS installations or equivalent guardrail including any needed transition from the standard system to the stiffened system while maintaining its integrity and safety performance. The guidelines are to consider the effects of dynamic deflections and working width, fill condition behind the system, post spacing, post length and embedment depth, nested rail, block-out depth, barrier offset, and full development length of the stiffening mechanism. It is anticipated that a combination of previous research, computer simulation modeling, and full-scale crash testing conducted by an ISO 17025 certified crash laboratory will be required to develop and verify the guidance to demonstrate MASH compliance. |
| 状态： | Active |
| 资金： | 499429 |
| 资助组织： | National Cooperative Highway Research Program<==>American Association of State Highway and Transportation Officials (AASHTO)<==>Federal Highway Administration |
| 项目负责人： | Jared, David M |
| 执行机构： | Texas A&M Transportation Institute (TTI) |
| 开始时间： | 20190708 |
| 预计完成日期： | 20220108 |
| 主题领域： | Design；Highways；Safety and Human Factors |
相关文献
- Pooled Fund for the Design, Development and Testing of a Box Beam Approach Guardrail Transition and an MGS Approach Guardrail Transition to a MASH TL-4 Three Steel Tube Bridge Rail
- Midwest Guardrail System (MGS) Thrie Beam Approach Guardrail Transition (AGT) Retrofit to Existing Concrete Parapets and Bridges
- Pooled Fund for the Design, Development and Testing of a Box Beam Approach Guardrail Transition and an MGS Approach Guardrail Transition to a MASH TL-4 Three Steel Tube Bridge Rail
- Pooled Fund for the Design, Development and Testing of a Box Beam Approach Guardrail Transition and an MGS Approach Guardrail Transition to a MASH TL-4 Three Steel Tube Bridge Rail
- Develop Transition for MASH Test Level 4 (TL-4) Compliant Guardrail System
- Roadside Barrier Designs Near Bridge Ends with Restricted Rights of Way
检索历史
应用推荐
