Stochastic modelling and assessment of long-span precast prestressed concrete elements failing in shear

Vibration measurements have been correlated on five long-span floors in a two-storey shopping centre. The floors are used primarily as walking areas and have been considered satisfactory with respect to floor vibrations. Three of the floors are steel beam composite concrete deck construction, and two are precast, prestressed, concrete beam construction.Dynamic characteristics of the floors as determined by the heel impact test were compared with quiet occupancy criteria. Results suggest that quiet occupancy criteria can be increased by at least a factor of three for walking areas in shopping centres.Calculations of fundamental frequency and initial peak acceleration from heel impact for the five floors are also presented and the results compared with measured values.

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The Contribution of Screed to the Structural Behaviour of Precast Prestressed Concrete Elements

Structural Engineering, Mechanics and Computation ◽

10.1016/b978-008043948-8/50035-7 ◽

2001 ◽

pp. 351-358

Author(s):

H.D. Beushausen ◽

R.D. Kratz ◽

M.G. Alexander

Keyword(s):

Prestressed Concrete ◽

Structural Behaviour ◽

Concrete Elements ◽

Precast Prestressed Concrete

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Real condition experiment on a new bridge weigh-in-motion solution for the traffic assessment on road bridges

10.2749/ghent.2021.1242 ◽

2021 ◽

Author(s):

François-Baptiste Cartiaux ◽

Véronique Le Corvec ◽

Jorge Semiao ◽

Bernard Jacob ◽

Franziska Schmidt ◽

...

Keyword(s):

Prestressed Concrete ◽

Large Scale ◽

Bridge Deck ◽

Bridge Management ◽

Box Girders ◽

Long Span ◽

Traffic Loads ◽

Weigh In Motion ◽

Bridge Weigh In Motion ◽

Precast Prestressed Concrete

Weigh-in-Motion is currently the only way to precisely assess and monitor traffic loads on road bridges from real measurements. This assessment helps to detect potential overweight vehicles and to optimize the maintenance operations on the bridge thanks to an accurate knowledge of its real load conditions.An experiment, performed on a precast prestressed concrete beam girders bridge overcrossing a highway in France, is described. The Weigh-in-Motion (WIM) system uses the bridge deck as a large scale, part of the weighing device, and measures strain in critical parts of the structure.The system is able to get significantly accurate estimations of the gross weight of the vehicles on most types of bridges, including long span box girders, large composite decks or the multiple precast prestressed concrete beams considered in the study. However, the axle load estimation is still much less accurate and not presented here.The experiment started in February 2019 and is still going on, also proving the robustness of the solution for an operation over long durations, as a permanent part of the bridge management through its whole lifecycle. Thus, the WIM sensors used are relevant for the Structural Health Monitoring of the bridge deck as well.

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Precast Prestressed Concrete Truss-Girder for Roof Applications

Journal of Structures ◽

10.1155/2014/524156 ◽

2014 ◽

Vol 2014 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Peter Samir ◽

George Morcous

Keyword(s):

Cross Sections ◽

Prestressed Concrete ◽

Precast Concrete ◽

Maintenance Cost ◽

Element Analysis ◽

Long Span ◽

Structural Capacity ◽

Bridge Girder ◽

Steel Trusses ◽

Precast Prestressed Concrete

Steel trusses are the most popular system for supporting long-span roofs in commercial buildings, such as warehouses and aircraft hangars. There are several advantages of steel trusses, such as lightweight, ease of handling and erection, and geometric flexibility. However, they have some drawbacks, such as high material and maintenance cost, and low fire resistance. In this paper, a precast concrete truss is proposed as an alternative to steel trusses for spans up to 48 m (160 ft) without intermediate supports. The proposed design is easy to produce and has lower construction and maintenance costs than steel trusses. The truss consists of two segments that are formed using standard bridge girder forms with block-outs in the web which result in having diagonals and vertical members and reduces girder weight. The two segments are then connected using a wet joint and post-tensioned longitudinally to form a crowned truss. The proposed design optimizes the truss-girder member locations, cross-sections, and material use. A 9 m (30 ft) long truss specimen is constructed using self-consolidated concrete to investigate the constructability and structural capacity of the proposed design. A finite element analysis of the specimen is conducted to investigate stresses at truss diagonals, verticals, and connections. Testing results indicate the production and structural efficiency of the developed system.

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Probabilistic modelling of prestressed concrete roof girders

MATEC Web of Conferences ◽

10.1051/matecconf/202031000055 ◽

2020 ◽

Vol 310 ◽

pp. 00055

Author(s):

Drahomír Novák ◽

Lukáš Novák ◽

Ondřej Slowik

Keyword(s):

Nonlinear Model ◽

Prestressed Concrete ◽

Probabilistic Approach ◽

Experimental Studies ◽

Stochastic Modelling ◽

Sensitivity Analyses ◽

Concrete Girders ◽

Structural Resistance ◽

Prestressed Concrete Girders ◽

Precast Prestressed Concrete

The paper describes several parts of complex stochastic modelling of precast prestressed concrete girders failing in shear. Experimental studies have been performed on scaled elements as well as on full-scale girders. These tests serve as basis for developing the deterministic nonlinear model and subsequent probabilistic assessment of structural resistance. The combination of nonlinear finite element method and probabilistic analysis is a strong tool for the realistic modelling of structures, but it is extremely time consuming, especially when 3D nonlinear model with many input random parameters is analysed. Therefore, sensitivity analyses have been performed and a surrogate model has been developed. Safety formats are utilized and compared with fully probabilistic approach to determine design value of ultimate capacity of girders.

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