RECONSTRUCTION OF BRIDGE SUPERSTRUCTURES FROM AIRBORNE LASER SCANNING POINT CLOUDS

The paper deals with the 3D reconstruction of bridges from Airborne Laser Scanning point clouds and cadastral footprints. The generated realistic 3D objects can be used to enhance city models. While other studies have focused on bridge decks to fill gaps in digital elevation models, this paper focuses on the decomposition of superstructures into construction elements such as pylons, cables and arches. For this purpose, the bridge type is classified, and a combination of model-based and data-based methods is used that are built on the detection of arcs, catenaries, and line segments in the point clouds. The described techniques were successfully applied to create 3D models of the Rhine bridges in the German state of North Rhine-Westphalia.

Implementation and Testing of Short Span Footbridge System Made of UHPC

This paper presents the results of testing and the first application of a newly developed innovative system of the bridge superstructures made of UHPC material. Being designed for footbridges it is called short span footbridge system - SSFS. This system was developed for a wide range of uses mainly as footbridges for pedestrians and cyclists and without waterproofing or surfacing. Prestressed prefabricated elements work as single-span beams with a span of up to 20 meters. Thanks to the optimization of the geometry design and the advantageous use of the mechanical properties of the UHPC material in combination with the prestressing, it was possible to achieve a very small construction height. These subtle and light load-bearing components tend to move away from traditional concrete structures, their span-to-depth ratios are closer to steel beams, but the needs for corrosion protection are eliminated using UHPC, which is inherently very durable and therefore almost maintenance-free. SSFS elements can be manufactured with a variable width of up to approx. 3.2 m, but they can be connected transversely and therefore the width of the structure is not limited. The first part of the paper is devoted to the development of the system and real applications of the first few footbridges made of UHPC material and other possibilities of this technology for future applications. The second part of the paper mentions the design and experimental verification of anchoring devices that are used to manipulate small-span footbridges made of UHPC.

fib Bulletin 99. Conceptual Design of Precast Concrete Bridge Superstructures

The purpose of this document is to present preliminary design procedures for bridge superstructures that are made partially or completely of precast concrete. This document deals with continuous and simply supported superstructures, used in integral or nonintegral bridges. The document is intended for engineers with limited experience who will find it an instructive detailed guide to carry out conceptual design of superstructures of these types. Additionally, it is intended for experienced engineers who are interested in learning how different countries solve similar conceptual design problems. Finally, it is intended to enrich the knowledge of precasters everywhere, to be able to enhance their own designs with ideas and methods from many different countries.

Effect of Skew Angle on Bridge Superstructures

In this paper, the effect of skew angle on reinforced concrete skew bridge decks is presented by using the grillage analogy. The actual deck system of the bridge is represented by an equivalent grillage of longitudinal and transverse beams. A span 26m of simply supported bridge deck is taken as the case study to obtain the values of the bending moment' s distribution versus span length for the one type of skewness and the results are compared against the moments of the right deck span of the bridge. The analysis results were based (BS5400) dead and live loads using Structural Analysis program (SAP2000). The analysis provided useful information about the variation of moments and shear forces with respect to change in skewness. It is concluded that in skew bridge deck, the bending moment is decreased, but torsional moments and shear forces are increased by increasing the skew angle. It is noticed that the maximum bending moment at skew angle 55o, by 76% in comparison with zero skew angle. On the other hand the maximum torsional moment increases for the same skew angle (55o) more than five times than with zero skew angles.

Strength and Stiffness Behavior of Earthquake Resistant Pedestrian LVL Timber Bridge

A bridge is a structure which is used to connect two areas separate by obstacles. The environmental damage caused a number of reductions in the production of timber, and by that, the LVL timber which is a high quality processed or engineered timber is chosen. This research determined the design of the timber bridge structure for pedestrian with simple beam type and earthquake resistant. The load in this bridge is referring to the SNI 1725:2016 and SNI 2833:2008, the design of the girder and the connection is referring to SNI 7973:2013, and the deflection is referring to the LFRD for Highway Bridge Superstructures. The timber bridge is designed to have a span of 10 metres long and 3 metres wide. The modeling and designing of the wooden bridge are using an application called SAP2000 based on finite element analysis. Result obtained from this research indicated that the longitudinal dimension of the girder is 360 mm x 630 mm and the cross sectional dimension is 180 mm x 270 mm. The number of bolts and lock screws needed on the connection among the longitudinal girders are 40 pieces, between the longitudinal girders and the cross sectional girders is three pieces, and between the railing and the slab are two pieces. Based on the stiffness review, the results showed that the bridge deflection that occurred was lower than the permit deflection