Experimental and Numerical Investigations of Flat Approach Slab–Soil Interaction in Jointless Bridge

In jointless bridges, a grade flat approach slab (GFAS) with the same elevation as the pavement can transfer the girder’s longitudinal deformation to the backfill. However, any cracks and settlement of the pavement usually occur at the end of the GFAS. To address this shortcoming, the buried flat ap...

Full description

Saved in:
Bibliographic Details
Main Authors: Yufeng Tang, Bruno Briseghella, Junqing Xue, Camillo Nuti, Fuyun Huang
Format: Article
Language:English
Published: MDPI AG 2024-12-01
Series:Applied Sciences
Subjects:
Online Access:https://www.mdpi.com/2076-3417/14/24/11726
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1850050968431886336
author Yufeng Tang
Bruno Briseghella
Junqing Xue
Camillo Nuti
Fuyun Huang
author_facet Yufeng Tang
Bruno Briseghella
Junqing Xue
Camillo Nuti
Fuyun Huang
author_sort Yufeng Tang
collection DOAJ
description In jointless bridges, a grade flat approach slab (GFAS) with the same elevation as the pavement can transfer the girder’s longitudinal deformation to the backfill. However, any cracks and settlement of the pavement usually occur at the end of the GFAS. To address this shortcoming, the buried flat approach slab (BFAS) horizontally embedded at a depth in the backfill was proposed. The complicated flat approach slab–soil interaction (FASSI) of the BFAS has not been systemically investigated. To address this gap, the influence of the FASSI on the mechanical performance of the approach slab and the backfill deformation was investigated in this research to understand the mechanism of the FASSI in absorbing one part of the girder’s longitudinal deformation and transferring the rest to the soil. Experimental tests on the FASSI with different embedded depths under longitudinal displacements were conducted. Numerical parametric analyses were carried out by considering the embedded depths and slab lengths as the parameters based on a finite element model verified using the test results. The results show that load–displacement curves of the FASSI comprise three stages: the elastic stage (approach slab’s displacement was absorbed by sand), the elastoplastic stage (sand deformation was observed), and the failure stage (overall shear failure of the sand was found). The longitudinal displacement transfer mode and vertical deformation distribution mode of the sand were affected by the embedded depth and slab length. With an increase in the embedded depth or a decrease in the slab length, the sand deformation decreases, which is beneficial for avoiding pavement crack risks and improving the pavement evenness. Finally, a simplified calculation formula that can be used to predict the load–displacement curves of the FASSI was proposed. This research provides the theoretical basis for the design and construction of the flat approach slab in jointless bridges.
format Article
id doaj-art-c0209b001b3d494bb7aa4b7d0975871d
institution DOAJ
issn 2076-3417
language English
publishDate 2024-12-01
publisher MDPI AG
record_format Article
series Applied Sciences
spelling doaj-art-c0209b001b3d494bb7aa4b7d0975871d2025-08-20T02:53:18ZengMDPI AGApplied Sciences2076-34172024-12-0114241172610.3390/app142411726Experimental and Numerical Investigations of Flat Approach Slab–Soil Interaction in Jointless BridgeYufeng Tang0Bruno Briseghella1Junqing Xue2Camillo Nuti3Fuyun Huang4College of Civil Engineering, Fuzhou University, Fuzhou 350108, ChinaCollege of Civil Engineering, Fuzhou University, Fuzhou 350108, ChinaCollege of Civil Engineering, Fuzhou University, Fuzhou 350108, ChinaCollege of Civil Engineering, Fuzhou University, Fuzhou 350108, ChinaCollege of Civil Engineering, Fuzhou University, Fuzhou 350108, ChinaIn jointless bridges, a grade flat approach slab (GFAS) with the same elevation as the pavement can transfer the girder’s longitudinal deformation to the backfill. However, any cracks and settlement of the pavement usually occur at the end of the GFAS. To address this shortcoming, the buried flat approach slab (BFAS) horizontally embedded at a depth in the backfill was proposed. The complicated flat approach slab–soil interaction (FASSI) of the BFAS has not been systemically investigated. To address this gap, the influence of the FASSI on the mechanical performance of the approach slab and the backfill deformation was investigated in this research to understand the mechanism of the FASSI in absorbing one part of the girder’s longitudinal deformation and transferring the rest to the soil. Experimental tests on the FASSI with different embedded depths under longitudinal displacements were conducted. Numerical parametric analyses were carried out by considering the embedded depths and slab lengths as the parameters based on a finite element model verified using the test results. The results show that load–displacement curves of the FASSI comprise three stages: the elastic stage (approach slab’s displacement was absorbed by sand), the elastoplastic stage (sand deformation was observed), and the failure stage (overall shear failure of the sand was found). The longitudinal displacement transfer mode and vertical deformation distribution mode of the sand were affected by the embedded depth and slab length. With an increase in the embedded depth or a decrease in the slab length, the sand deformation decreases, which is beneficial for avoiding pavement crack risks and improving the pavement evenness. Finally, a simplified calculation formula that can be used to predict the load–displacement curves of the FASSI was proposed. This research provides the theoretical basis for the design and construction of the flat approach slab in jointless bridges.https://www.mdpi.com/2076-3417/14/24/11726jointless bridgesflat approach slabapproach slab–soil interactionload–displacement curvesand deformationsimplified calculation formula
spellingShingle Yufeng Tang
Bruno Briseghella
Junqing Xue
Camillo Nuti
Fuyun Huang
Experimental and Numerical Investigations of Flat Approach Slab–Soil Interaction in Jointless Bridge
Applied Sciences
jointless bridges
flat approach slab
approach slab–soil interaction
load–displacement curve
sand deformation
simplified calculation formula
title Experimental and Numerical Investigations of Flat Approach Slab–Soil Interaction in Jointless Bridge
title_full Experimental and Numerical Investigations of Flat Approach Slab–Soil Interaction in Jointless Bridge
title_fullStr Experimental and Numerical Investigations of Flat Approach Slab–Soil Interaction in Jointless Bridge
title_full_unstemmed Experimental and Numerical Investigations of Flat Approach Slab–Soil Interaction in Jointless Bridge
title_short Experimental and Numerical Investigations of Flat Approach Slab–Soil Interaction in Jointless Bridge
title_sort experimental and numerical investigations of flat approach slab soil interaction in jointless bridge
topic jointless bridges
flat approach slab
approach slab–soil interaction
load–displacement curve
sand deformation
simplified calculation formula
url https://www.mdpi.com/2076-3417/14/24/11726
work_keys_str_mv AT yufengtang experimentalandnumericalinvestigationsofflatapproachslabsoilinteractioninjointlessbridge
AT brunobriseghella experimentalandnumericalinvestigationsofflatapproachslabsoilinteractioninjointlessbridge
AT junqingxue experimentalandnumericalinvestigationsofflatapproachslabsoilinteractioninjointlessbridge
AT camillonuti experimentalandnumericalinvestigationsofflatapproachslabsoilinteractioninjointlessbridge
AT fuyunhuang experimentalandnumericalinvestigationsofflatapproachslabsoilinteractioninjointlessbridge