01707640

Monograph

http://www.trb.org/Main/Blurbs/179167.aspx

Each year hundreds of bridges are rebuilt or are entirely replaced as part of highway construction projects. Bridge reconstruction or replacement work often entails demolition of part or all of the bridge structure. This synthesis documents practices used by bridge owners to manage and administer bridge demolition in construction projects. Information used in this study was gathered through a literature review, a survey of state departments of transportation, and follow-up interviews with selected agencies and bridge construction contractors for case examples. The literature review found that available manuals and specifications used for bridge design and construction provide limited criteria for bridge demolition activities. The rigorous requirements for demolition plans were found to be from railroad owners and, in cases where highway bridges cross railroads, those requirements will normally control the demolition. Limited research or technical information was found that addresses bridge demolition practices other than specific demolition techniques. The literature consists of project descriptions with minimal technical content. The few technical papers available and the Occupational Safety and Health Administration (OSHA) accident reports stress the need for an engineering evaluation of demolition activities and good field oversight. A review of various state DOT specifications shows a range of requirements for demolition. Requirements for partial demolition of bridge decks are provided and sometimes contain detail on equipment limitations and construction practices, particularly to limit damage to the remaining structure. For extensive demolition or total removal, a demolition plan is requested, but only a few states provide specific requirements on what the plan is to include. Provision of specific design criteria for conducting a structural assessment of the demolition sequence is rarely provided. Forty-two states responded to the survey of practice. All but two survey respondents have specifications or special provisions addressing bridge demolition, and 83% require submittal of a demolition plan. Most agencies provide field oversight of demolition using either in-house staff or a consultant. Less than one-half of the agencies indicated that they provide training in demolition activities to field staff. The case examples illustrate the use of both standard specification and special provisions for demolition projects, as well as varying submittal requirements. The case examples show that unintended events may occur and that agencies do revise their requirements based on past experiences.

Project 20-05, Topic 49-03

English

95p

2019

NCHRP Synthesis of Highway Practice

9780309480376

Digital/other

Figures; Glossary; Photos; References; Tables

Construction projects; Demolition; Highway bridges; Specifications

Bridges and other structures; Construction; Highways

TRIS, TRB, ATRI

Jun 4 2019 10:46AM