Experimental Investigation of Prestressing Strand Bond on Behavior of Concrete Members

Gajdošová

2016

KEM

The approach slab is in the terms of structural behaviour an area element with interaction with a subsoil, where one of its edge is connected thru the hinge on the abutment of the bridge. In a simplified structural schemes it is possible to model this slab element with a hinged connection to the abutment and the subsoil interaction is represented by a spring area under the approach slab. More difficult approach of modelling the reinforced concrete slab and the subsoil interaction is by 3D soil elements with the properties of soil embankment. In both cases of those linear approaches exists few imperfections, which does not represent the real behaviour. Load from the traffic acts on the slab cyclic. Therefore special problems occur in modelling of those transition areas. By crossing vehicles and its acting in time, continuous consolidation of the soil under the approach slab is being in progress. It can possibly cause creation of the void and consequently loss of a contact between the slab and subsoil. The paper deals with modelling of the reinforced concrete approach slab and the soil interaction with a nonlinear soil element, and also response of the slab on the cyclic load. All these effects can cause changes in structural scheme, and therefore changes in a strain of the slab member. The model is trying to describe the subsoil consolidation in time. In a connection with that fact, the fatigue failures of the approach slab are examined too.

“…This type of elements can be also linear or nonlinear. Differences between linear models with a various soil stiffness were explained in more detail in the previous work [3]. In Fig.…”

Section: Possible Structural Models Of the Approach Slabmentioning

confidence: 92%

Nonlinear Response of Approach Slab on Cyclic Loading

Gajdošová

2016

KEM

“…2. Comparison of the subsoil models in numerical calculations was presented in previous work [2], which dealt with the differences according to the bending moment calculations. For the analysis, the single-parametric Winkler model, double-parametric Winkler-Pasternak model and linear-elastic model of 3D soil elements were chosen.…”

Section: Structural Scheme Of the Approach Slabmentioning

confidence: 99%

Parametrical Study of the Shear Resistance of the Approach Slabs

2018

SSP

The transition zone of the road bridges is located right behind the abutment. Function of this structure is to ease the vehicle transition from the bridge on the rigid support to the embankment with much smaller stiffness. The main function of the approach slab is, as a part of the transition zone, helping the backfill to overcome different stiffness of the bridge foundations and embankment. The paper deals with shear resistance of the slabs for different lengths and widths. Parametrical study was performed according to Eurocode loading model 1 (Uniformed distributed load and Tandem system). Each of the analysed slabs was loaded with sets of different TS positions and location of the loading lanes. Envelopes of the shear forces of the approach slabs were analysed for each type of the slab. After that shear resistance of the slab with or without the shear reinforcement was calculated. The slab was divided into areas with same shear reinforcement distribution. The analysis is the part of the engineering tool for the bridge designers. According to length and width of the slab, the engineer can easily choose the shear reinforcement diameter and its distribution. The tool also provides the construction details of the shear reinforcement. There will be also the option for the reinforcement design of the slab, with hints for the structural scheme and calculation method.

“…Not only selection of the structural scheme, but also selection of the computational model of the elastic support is very important. This was closely analysed in a paper on modelling of transition areas [2]. The paper compared various computational models with different soil stiffness, as well as structural models, where the resulted bending moments were observed.…”

Section: Selection Of Computational Model and Structural Schemementioning

confidence: 99%

Design of Approach Slab of Road Bridges

2016

SSP

This paper deals with the design and assessment of approach slabs of the transition zones of road bridges. The main goal of this article is to evaluate design criteria of this reinforced concrete member with attention to the requirements according to European standards. Up to these days, used procedure for the design of the approach slabs of the bridge construction in Slovakia is based on previous Czechoslovak CSN 73 6244 standard introduced 1981. The reason for using this standard nowadays is mainly because of its simple form as an engineering tool for the design of the geometrical dimension and also the reinforcement of the approach slab. Design procedures used for the analysis are taking into account the simplest and also the most conservative structural schemes, it is the slab with a hinge support in the place of the abutment and the second simple support on the other side substituting the gravel subsoil. This scheme should represent possible consolidation of the embankment under the slab. For more precise description of the behaviour, models with elastic support are used. Using these models, the approach slabs will be analysed for the ultimate limit state. The analysis of the results for various geometrical dimensions could serve as a template for similar design tool, to which bridge designers are used to.