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Structural Behavior of Integral Abutment Bridge Approach Slabs
Structural Behavior of Integral Abutment Bridge Approach Slabs
상세정보
- 자료유형
- 학위논문 서양
- 최종처리일시
- 20260209102836
- ISBN
- 9798314842539
- DDC
- 620
- 저자명
- Liu, Gaoyu.
- 서명/저자
- Structural Behavior of Integral Abutment Bridge Approach Slabs
- 발행사항
- [Sl] : University of Illinois at Urbana-Champaign, 2023
- 발행사항
- Ann Arbor : ProQuest Dissertations & Theses, 2023
- 형태사항
- 253 p
- 주기사항
- Source: Dissertations Abstracts International, Volume: 86-11, Section: B.
- 주기사항
- Advisor: Fahnestock, Larry A.;LaFave, James M.
- 학위논문주기
- Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2023.
- 초록/해제
- 요약Integral abutment bridges (IABs) have gained increasing popularity in the United States due to their relatively low cost, simpler construction, greater service life, and better seismic performance - compared to stub abutment bridges. However, elimination of joints in IABs raises concerns about distress of the structural system induced by live load and thermal effects. IAB concrete approach slab cracking has been a frequent example of such distress in Illinois, and in other states, based on a conducted agency survey. Thus, there is a need for thorough study of approach slabs at IABs to elucidate fundamental structural behavior and determine the influence of key parameters on demands that develop in approach slabs due to traffic loading and thermal effects. This research employs field monitoring and numerical simulation of approach slabs to provide a comprehensive assessment of their response and inform future decisions about approach slab design and maintenance.A four-lane cast-in-place concrete approach slab and a three-lane precast concrete approach slab were instrumented during construction and subsequently monitored for 2.5 years. The field results suggest strong linear correlation of slab deformation and stress with temperature. Nonlinear relationships between slab stress and temperature were also observed, which can be attributed to boundary condition evolution over time. Field data suggest several locations at the bottom of the slabs with a potential risk of cracking. Static truck load tests were conducted at various traffic lane and shoulder locations on each of the instrumented approach slabs. Finite-element models were developed to simulate slab behavior under controlled live loading and thermal effects. Numerical modeling of slabs subjected to truck loads is used to estimate the modulus of subbase support under the approach slab. A data driven method using Multilayer Perceptron (MLP) neural networks to help efficiently estimate approach slab support conditions is proposed. A nonlinear thermal gradient profile is used to improve the ability of the finite element models to properly capture slab behavior under thermal effects. Solar radiation is found to introduce peak stresses greater than the live load stresses. It is also observed that simplified structural analysis in practice (neglecting parapets) can significantly underestimate stresses in slab edge regions.A parametric study is then carried out, which uses validated numerical simulations of IAB concrete approach slabs in Illinois based on typical design and construction practices. From the parametric study, it is suggested that such approach slabs would generally not be prone to cracking from truck live loads, although certain skews and widths can increase the chances of cracking. When an approach slab is subjected to the combined effects of low temperature and solar radiation, the principal stress can reach the concrete modulus of rupture, and its distribution confirms some crack patterns observed in the field, especially for highly skewed approach slabs. Increasing the slab thickness and/or releasing restraint at the approach slab-abutment interface may be able to mitigate structural distress from live load and/or thermal effects for IAB approach slabs in Illinois. In addition, lateral restraint from the abutment can be partially released by introducing new details that allow the approach slab to expand and contract with less restriction. This "breathing room" in the transverse direction is expected to reduce the potential risk of cracking due to thermal loads.
- 일반주제명
- Engineering
- 일반주제명
- Computer engineering
- 키워드
- Approach slab
- 키워드
- Truck loads
- 키워드
- Thermal analysis
- 키워드
- Machine learning
- 기타저자
- University of Illinois at Urbana-Champaign Civil & Environmental Eng
- 기본자료저록
- Dissertations Abstracts International. 86-11B.
- 전자적 위치 및 접속
- 로그인 후 원문을 볼 수 있습니다.
MARC
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■020 ▼a9798314842539
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■035 ▼a(MiAaPQ)httphdlhandlenet2142120105
■040 ▼aMiAaPQ▼cMiAaPQ
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■1001 ▼aLiu, Gaoyu.
■24510▼aStructural Behavior of Integral Abutment Bridge Approach Slabs
■260 ▼a[Sl]▼bUniversity of Illinois at Urbana-Champaign▼c2023
■260 1▼aAnn Arbor▼bProQuest Dissertations & Theses▼c2023
■300 ▼a253 p
■500 ▼aSource: Dissertations Abstracts International, Volume: 86-11, Section: B.
■500 ▼aAdvisor: Fahnestock, Larry A.;LaFave, James M.
■5021 ▼aThesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2023.
■520 ▼aIntegral abutment bridges (IABs) have gained increasing popularity in the United States due to their relatively low cost, simpler construction, greater service life, and better seismic performance - compared to stub abutment bridges. However, elimination of joints in IABs raises concerns about distress of the structural system induced by live load and thermal effects. IAB concrete approach slab cracking has been a frequent example of such distress in Illinois, and in other states, based on a conducted agency survey. Thus, there is a need for thorough study of approach slabs at IABs to elucidate fundamental structural behavior and determine the influence of key parameters on demands that develop in approach slabs due to traffic loading and thermal effects. This research employs field monitoring and numerical simulation of approach slabs to provide a comprehensive assessment of their response and inform future decisions about approach slab design and maintenance.A four-lane cast-in-place concrete approach slab and a three-lane precast concrete approach slab were instrumented during construction and subsequently monitored for 2.5 years. The field results suggest strong linear correlation of slab deformation and stress with temperature. Nonlinear relationships between slab stress and temperature were also observed, which can be attributed to boundary condition evolution over time. Field data suggest several locations at the bottom of the slabs with a potential risk of cracking. Static truck load tests were conducted at various traffic lane and shoulder locations on each of the instrumented approach slabs. Finite-element models were developed to simulate slab behavior under controlled live loading and thermal effects. Numerical modeling of slabs subjected to truck loads is used to estimate the modulus of subbase support under the approach slab. A data driven method using Multilayer Perceptron (MLP) neural networks to help efficiently estimate approach slab support conditions is proposed. A nonlinear thermal gradient profile is used to improve the ability of the finite element models to properly capture slab behavior under thermal effects. Solar radiation is found to introduce peak stresses greater than the live load stresses. It is also observed that simplified structural analysis in practice (neglecting parapets) can significantly underestimate stresses in slab edge regions.A parametric study is then carried out, which uses validated numerical simulations of IAB concrete approach slabs in Illinois based on typical design and construction practices. From the parametric study, it is suggested that such approach slabs would generally not be prone to cracking from truck live loads, although certain skews and widths can increase the chances of cracking. When an approach slab is subjected to the combined effects of low temperature and solar radiation, the principal stress can reach the concrete modulus of rupture, and its distribution confirms some crack patterns observed in the field, especially for highly skewed approach slabs. Increasing the slab thickness and/or releasing restraint at the approach slab-abutment interface may be able to mitigate structural distress from live load and/or thermal effects for IAB approach slabs in Illinois. In addition, lateral restraint from the abutment can be partially released by introducing new details that allow the approach slab to expand and contract with less restriction. This "breathing room" in the transverse direction is expected to reduce the potential risk of cracking due to thermal loads.
■590 ▼aSchool code: 0090.
■650 4▼aEngineering
■650 4▼aComputer engineering
■653 ▼aIntegral abutment bridges
■653 ▼aApproach slab
■653 ▼aStructural analysis
■653 ▼aConcrete cracking
■653 ▼aTruck loads
■653 ▼aThermal analysis
■653 ▼aMachine learning
■690 ▼a0543
■690 ▼a0537
■690 ▼a0464
■690 ▼a0800
■71020▼aUniversity of Illinois at Urbana-Champaign▼bCivil & Environmental Eng.
■7730 ▼tDissertations Abstracts International▼g86-11B.
■790 ▼a0090
■791 ▼aPh.D.
■792 ▼a2023
■793 ▼aEnglish
■85640▼uhttp://www.riss.kr/pdu/ddodLink.do?id=T17365843▼nKERIS▼z이 자료의 원문은 한국교육학술정보원에서 제공합니다.
