Approach Slabs

2014 ◽  
pp. 663-692
Keyword(s):  
Approach Slabs

Design and Performance of Jointless Bridges in Ontario: New Technical and Material Concepts

2000 ◽  
Vol 1696 (1) ◽  
pp. 109-121 ◽  
Author(s):  
Iqbal Husain ◽  
Dino Bagnariol
Keyword(s):  
Economic Benefits ◽  
Integral Abutment ◽  
Expansion Joints ◽  
Actual Performance ◽  
Approach Slabs ◽  
Approach Slab ◽  
Jointless Bridges ◽  
Integral Abutment Bridge ◽  
Existing Bridges ◽  
Deck Slab

It is well recognized that leaking expansion joints at the ends of bridge decks have led to the premature deterioration of bridge components. The elimination of these maintenance-prone joints not only yields immediate economic benefits but also improves the long-term durability of bridges. In Ontario, Canada, “jointless” bridges have been used for many years. Recently, the use of two main types of these bridges has increased dramatically. The first type is an “integral abutment” bridge that comprises an integral deck and abutment system supported on flexible piles. The approach slabs are also continuous with the deck slab. The flexible foundation allows the anticipated deck movements to take place at the end of the approach slab. Control joint details have been developed to allow movements at this location. The second type is a “semi-integral abutment” bridge that also allows expansion joints to be eliminated from the end of the bridge deck. The approach slabs are continuous with the deck slab, and the abutments are supported on rigid foundations (spread footings). The superstructure is not continuous with the abutments, and conventional bearings are used to allow horizontal movements between the deck and the abutments. A control joint is provided at the end of the approach slab that is detailed to slide in between the wing walls. Some of the design methods and construction details that are used in Ontario for integral and semi-integral abutment bridges are summarized. A review of the actual performance of existing bridges is also presented.

Design of Ribbed Concrete Approach Slab Based on Interaction with the Embankment

2005 ◽  
Vol 1936 (1) ◽  
pp. 181-191 ◽  
Author(s):  
X. M. Shi ◽  
C. S. Cai ◽  
George Voyiadjis ◽  
Zhongjie Zhang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Scientific Basis ◽  
Structural Performance ◽  
Element Analysis ◽  
Design Engineers ◽  
Approach Slabs ◽  
Approach Slab ◽  
Beam Design ◽  
Three Dimensional Finite Element

To alleviate the “bump” problem at bridge ends, a ribbed concrete approach slab (similar to slab-on-beam bridge decks) was proposed in place of the pile–column-supported approach span or flat slab system. The effect of given embankment settlement on the structural performance of a ribbed concrete approach slab with a span length of 60 ft and a width of 40 ft was investigated. The approach slab was modeled as a ribbed slab with a beam spacing of 32, 16, and 12 ft. A three-dimensional finite element analysis was conducted to model the interaction between the approach slab and the embankment soil. Finite element modeling techniques that simulate the separation of the slab and soil provide information on the effect of the embankment settlement on structural performance and beam design. The predicted internal forces provide design engineers with a scientific basis to design the approach slab properly, considering different levels of embankment settlements. Current AASHTO code specifications do not provide guidelines to design approach slabs considering the embankment settlement.

scholarly journals Dynamic modelling of bridge approach slabs under moving loads

2021 ◽  
Vol 33 (1) ◽  
pp. 30-36
Author(s):  
Ihsan Al-abboodi ◽  
Osamah Al-salih ◽  
Ammar Dakhil
Keyword(s):  
Dynamic Modelling ◽  
Moving Loads ◽  
Approach Slabs ◽  
Bridge Approach

Structural Performance of Bridge Approach Slabs under Given Embankment Settlement

2005 ◽  
Vol 10 (4) ◽  
pp. 482-489 ◽  
Author(s):  
C. S. Cai ◽  
X. M. Shi ◽  
G. Z. Voyiadjis ◽  
Z. J. Zhang
Keyword(s):  
Structural Performance ◽  
Approach Slabs ◽  
Bridge Approach

Reliability of Approach Slabs and Modelling of Transition Zones of Bridges

2016 ◽  
Vol 821 ◽  
pp. 741-746 ◽  
Author(s):  
Kamil Laco ◽  
Viktor Borzovič
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Structural Models ◽  
Reinforced Concrete Slab ◽  
Transition Zones ◽  
Approach Slabs ◽  
Approach Slab ◽  
Complex Models ◽  
The One ◽  
Civil Engineers

The approach slab is the structural member of transition zones, which compensates a different settlement of bridge abutment and a road embankment. The main reason of different settlement is the consolidation of soil under the slab and the abutment. The geometry of approach slab, its length and the thickness is defined on the basis of differential settlement of embankment and the abutment. The static behaviour of slab is defined as a slab on elastic soil. The reinforced concrete slab is supported with the line rigid support on the one edge, and the rest of slab area interacts with the soil. The civil engineers design the reinforcement in those slabs based on the simplified structural scheme, without considering the elastic area support. This scheme is the simple supported slab on the both ends. The paper is dealing with the comparing of different structural models of the reinforced concrete approach slabs. The complex models of transition zones with the brick elements of the soil and the interaction with the reinforced concrete slab with the soil embankment are compared with the simplified models used by civil engineers. The analysis was performed on the transition zone of highway bridge from Slovakia based on its geometry and the subsoil consistence. In the parametric study was compared 8 soil stiffness’s on 10 structural models.

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