scholarly journals Safety Identifying of Integral Abutment Bridges under Seismic and Thermal Loads

2014 ◽  
Vol 2014 ◽  
pp. 1-12
Author(s):  
Narges Easazadeh Far ◽  
Majid Barghian
Keyword(s):  
Maintenance Cost ◽  
Seismic Load ◽  
Seismic Loads ◽  
Integral Abutment ◽  
Bridge Design ◽  
Safety Level ◽  
Integral Abutment Bridges ◽  
Load Combination ◽  
Abutment Bridges ◽  
Aashto Lrfd

Integral abutment bridges (IABs) have many advantages over conventional bridges in terms of strength and maintenance cost. Due to the integrity of these structures uniform thermal and seismic loads are known important ones on the structure performance. Although all bridge design codes consider temperature and earthquake loads separately in their load combinations for conventional bridges, the thermal load is an “always on” load and, during the occurrence of an earthquake, these two important loads act on bridge simultaneously. Evaluating the safety level of IABs under combination of these loads becomes important. In this paper, the safety of IABs—designed by AASHTO LRFD bridge design code—under combination of thermal and seismic loads is studied. To fulfill this aim, first the target reliability indexes under seismic load have been calculated. Then, these analyses for the same bridge under combination of thermal and seismic loads have been repeated and the obtained reliability indexes are compared with target indexes. It is shown that, for an IAB designed by AASHTO LRFD, the indexes have been reduced under combined effects. So, the target level of safety during its design life is not provided and the code’s load combination should be changed.

Pseudo-static Test on Mechanic Behavior of Pile with Pre-Hole filled by Foam in IABs

2019 ◽  
Author(s):  
Junqing Xue ◽  
Yibiao Lin ◽  
Ruihuan Fu ◽  
Bruno Briseghella ◽  
Fuyun Huang ◽  
...  
Keyword(s):  
Energy Dissipation ◽  
Seismic Performance ◽  
Damping Ratio ◽  
Seismic Load ◽  
Longitudinal Deformation ◽  
Integral Abutment ◽  
Integral Abutment Bridges ◽  
Concrete Piles ◽  
Abutment Bridges ◽  
Damping Material

<p>Comparing with the conventional jointed bridges, integral abutment bridges (IABs) have not the typical durability problems of expansion joints and bearings and could have better seismic performance due to the high redundancy and integrity. The concrete piles supporting the abutments are often considered as the most vulnerable component in IABs under longitudinal deformation of superstructure caused by temperature variation and seismic load. The pre‐hole method could be adopted to absorb the longitudinal deformation transferred from superstructure to the piles. Therefore, how to improve the energy dissipation of concrete piles to reduce the influence of seismic load is the key issue in IABs. In this paper, a technology based on piles with pre‐holes filled by damping material (called pre‐hole isolation pile) is proposed to improve the seismic response of IABs. The piles supporting the abutments of one real integral abutment bridge were chosen as case study. Pseudo‐static tests of two model piles with the scaled factor of 1/12.5 considering soil‐pile interaction (SPI) were performed. Foam was chosen as damping material. It could be found that compared with conventional piles, the hysteresis curve and the equivalent viscous damping ratio of pre‐hole isolation pile considering SPI was fuller and larger. According to the obtained results, the pre‐hole filled with foam technology could improve the energy dissipation of the concrete piles in integral abutment bridges and their seismic performance.</p>

Concrete Crack Control of Pile-to-Pilecap Connection in Integral Abutment Bridges under Cyclic Bridge Movement

2013 ◽  
Vol 753-755 ◽  
pp. 462-466 ◽  
Author(s):  
Woo Seok Kim ◽  
Jae Ha Lee ◽  
Chan Jeoung
Keyword(s):  
Seismic Loads ◽  
Finite Element Analyses ◽  
Integral Abutment ◽  
Integral Abutment Bridges ◽  
Crack Control ◽  
Concrete Crack ◽  
Abutment Bridges ◽  
And Performance ◽  
Simultaneous Translation ◽  
Spiral Type

Steel pile-concrete abutment connection in integral abutment bridges is vulnerable to cyclic bridge movement as well as seismic loads. Although this connection may determine the bridge strength and performance against the above loads, previous researches have merely focused on this connection. This study has investigated crack patterns using finite element analyses. The bridge movements were classified into three cases: (1) translation only; (2) rotation only; and (3) simultaneous translation and rotation. The identified cracks were diagonally occurred from the steel pile. PennDOT DM-4 reinforcement detail was hardly effective in controlling crack growing. This study also investigated spiral type reinforcement for the connection, and this type of reinforcement detail significantly improved the crack control capacity in integral abutment bridges.

Design of integral abutment bridges for combined thermal and seismic loads

2015 ◽  
Vol 9 (2) ◽  
pp. 415-430 ◽  
Author(s):  
Narges Easazadeh Far ◽  
Shervin Maleki ◽  
Majid Barghian
Keyword(s):  
Seismic Loads ◽  
Integral Abutment ◽  
Integral Abutment Bridges ◽  
Abutment Bridges

scholarly journals Influence of Construction Joint and Bridge Geometry on Integral Abutment Bridges

2021 ◽  
Vol 11 (11) ◽  
pp. 5031
Author(s):  
Wooseok Kim ◽  
Jeffrey A. Laman ◽  
Farzin Zareian ◽  
Geunhyung Min ◽  
Do Hyung Lee
Keyword(s):  
Prestressed Concrete ◽  
Extreme Temperature ◽  
Bending Moment ◽  
Design Guidelines ◽  
Time Dependent ◽  
Steel Bridge ◽  
Integral Abutment ◽  
Integral Abutment Bridges ◽  
Construction Joint ◽  
Abutment Bridges

Although integral abutment bridges (IABs) have become a preferred construction choice for short- to medium-length bridges, they still have unclear bridge design guidelines. As IABs are supported by nonlinear boundaries, bridge geometric parameters strongly affect IAB behavior and complicate predicting the bridge response for design and assessment purposes. This study demonstrates the effect of four dominant parameters: (1) girder material, (2) bridge length, (3) backfill height, and (4) construction joint below girder seats on the response of IABs to the rise and fall of AASHTO extreme temperature with time-dependent effects in concrete materials. The effect of factors influencing bridge response, such as (1) bridge construction timeline, (2) concrete thermal expansion coefficient, (3) backfill stiffness, and (4) pile-soil stiffness, are assumed to be constant. To compare girder material and bridge geometry influence, the study evaluates four critical superstructure and substructure response parameters: (1) girder axial force, (2) girder bending moment, (3) pile moment, and (4) pile head displacement. All IAB bridge response values were strongly related to the four considered parameters, while they were not always linearly proportional. Prestressed concrete (PSC) bridge response did not differ significantly from the steel bridge response. Forces and moments in the superstructure and the substructure induced by thermal movements and time-dependent loads were not negligible and should be considered in the design process.

Behaviour of H-piles supporting an integral abutment bridge

2014 ◽  
Vol 51 (7) ◽  
pp. 713-734 ◽  
Author(s):  
Shelley A. Huntley ◽  
Arun J. Valsangkar
Keyword(s):  
Axial Load ◽  
Integral Abutment ◽  
Integral Abutment Bridges ◽  
Expansion Joints ◽  
Thermal Bridge ◽  
Double Curvature ◽  
Abutment Bridges ◽  
Integral Abutments ◽  
Integral Abutment Bridge ◽  
Lateral Displacements

Integral abutment bridges accommodate thermal superstructure movements through flexible foundations rather than expansion joints. While these structures are a common alternative to conventional design, the literature on measured field stresses in piles supporting integral abutments appears to be quite limited. Therefore, field data from strain gauges installed on the abutment foundation piles of a 76 m long; two-span integral abutment bridge are the focus of this paper. Axial load, weak- and strong-axis bending moments of the foundation piles, as well as abutment movement and backfill response, are presented and discussed. Results indicate that the abutment foundation piles are bending in double curvature about the weak axis, as a result of thermal bridge movements, and bending also about the strong axis due to tilting of the abutments. A simple subgrade modulus approach is used to show its applicability in predicting behaviour under lateral loading. In the past, much emphasis has been placed on the lateral displacements of piles and less on variations of axial load. In this paper, a new hypothesis, which offers insight into the mechanisms behind the observed thermal variations in axial load, is proposed and assessed. The data from the field monitoring are also compared with the limited data reported in the literature.

Sign in / Sign up

Export Citation Format

Share Document