In the course of replacing the existing Kugelstein Bridge over the Mur river the Austrian Federal Railways assigned FCP to conduct a comparative life-cycle cost analysis of different future design proposals. The following three bridge construction types were investigated:
The existing bridge is a double-track railway bridge with a length of 61.1 m and a total width of 11.6 m. The truss bridge built in 1966 is a single-span girder with an open deck. The bridge design of the new double-track Kugelstein Bridge is also intended to have a span length of approx. 60 m and a width of approx. 15 m.
The objective was to compare the various bridge types particularly with regard to the expected structural maintenance costs over the entire service life of 120 years.
Currently the third bridge is being built over the Bosporus. The bridge is part of a motorway bypass of Istanbul and predominantly serves as improved connection between the Asian part of Turkey with Europe.
The bridge is designed as a combined cable-stayed and suspension bridge. It will be the widest suspension bridge so far with 59 m deck width and the longest suspension bridge with rail system with 1408 m main span.
Currently the pylons with a height of approx. 330 m are being erected on both sides and the mounting of the main cables is imminent.
VCE installed a seismic monitoring system, which can record and evaluate earthquake events and the effects of strong wind events on the free-standing pylons, at both pylons. Both systems shall be extended with further construction progress and shall provide information on the state of construction of the suspension ropes and the deck. The design of this system also enables later integration into the permanent monitoring system for the measurement and analysis of the structure.
In the last two years the CC Asset Management & BRIMOS did intensive research in cooperation with our Czech partner office INFRAM in the scope of structural maintenance measures and their impact on the availability of road infrastructure.
By the end of 2014 the research project was positively concluded by the Austrian Research Promotion Agency (FFG) due to the achievement of the project objectives defined in the project proposal.
Contents of the project: Life Cycle Cost analyses for road infrastructure currently mainly focus on owner/operator related costs (economic agency costs). For upcoming Bridge Management Systems the incorporation of the overall impact on national economy gets an increasingly demanded issue (e.g. user-related time cost due to reduced availability or non-availability of infrastructure), as their monetary consequence is many times higher. Thus, added value is to be created by developing proper models – addressing mainly bridge structures – and by incorporating them into the existing decision processes for infrastructure maintenance.
Focus of the project: Increase in efficiency of traffic and use of infrastructure by means of information and communications systems
Subject of the present inspection was a dynamic special inspection of the bridge object A21.R1 according to RVS 13.03.11, which served for assessing the structural condition and the dynamic impacts of the traffic loads on the load-bearing capacity and operability.
The bridge object has been surveyed by VCE since 2000 (initial measurement) in the scope of structural monitoring.
The first follow-up inspection (2008) was carried out with regard to a basic future structural maintenance concept. The resulting maintenance measures and structural changes (2009- 2013) were also measured and evaluated by dynamic special inspections (2010 - 2014).
Due to the available long-term collection of data possible changes of the structural condition can be observed and evaluated and structural maintenance planning can be significantly supported.
Lamp poles must be regularly checked for damage and stability like all other structures. In addition to the obligatory visual inspection non-destructive measurement and test methods are preferentially applied. Apart from the bending test method, which involves the risk of damaging the pole, ultrasonic tests and dynamic methods were predominantly used.
VCE checks more than 5,000 steel lamp poles for the city of Vienna in the period from October 2014 to March 2015. They are distributed over the whole urban area. The check includes the visual inspection, BRIMOS® as method for stability determination and ultrasonic sound for wall thickness measurement.
VCE developed a tablet PC solution including software and database connection for quick and efficient handling of the test procedure:
All analysis results, photos, measurement data, etc. are automatically transferred to the database and the stability assessment result sheets are automatically generated for the report.
In March 2012 an abutment in Schönberg at the A13 Brenner motorway collapsed without any prior indication of such a failure. A lorry driver was killed in this serious incident.
On this occasion the Austrian motorway operator ASFINAG established an internal working committee under the leadership of the region SOUTH in order to check abutments with a similar design (construction before 1993 on the basis of a preceding assessment standard) in detail. Apart from static recalculations, surveys of the subsurface and specific structural grouted anchors for the increase in stability of individual objects, selected structures were tested for internal, non-visible damage.
VCE was invited to perform an extended structural assessment (special test) at two cantilever walls by means of vibration measurements. This special test is a method according to RVS 13.03.01 (Bulletin: Monitoring of Bridges and other Civil Engineering Structures), which is applied in terms of a pilot project at the abutment structures.
Due to the characteristics and the local conditions the following procedure was chosen for the two non-anchored supporting structures:
The Kocher Bridge near Untergröningen was built in 1953 as prestressed slab bridge with displacers and a length of 32.35 m. Due to problems with transverse prestressing the structure was reinforced with I-beams in cross direction.
Registered heavy-load transports with up to 410 tons pass the bridge once a week. A recalculation with the typical load diagram of the heavy-load transports did not provide a positive result. Therefore the bridge was equipped with a permanent monitoring system, which can determine changes in the structural condition as well as damage at an early stage.
An analysis of the measurement data over three months showed that the bridge is passed over by – frequently unregistered – heavy-load vehicles almost every night. Monitoring is to be continued up to the planned new construction in five years.
On 16 May heavy cable vibrations occurred at the stay cables of the Donaustadt Bridge. In the scope of a joint on-site inspection (Mr. Nöbauer / Wiener Linien, Mr. Furtner / VCE) the cable vibrations were monitored and the situation regarding the safety for the running underground railway operation was assessed.
The stay cables with the designations OW1 to OW5a were concerned, the stay cables OW1a and OW2 (corresponding to the 2nd and 3rd stay cable of the upstream structure) showed very strong vibrations. The cable vibrations observed were caused by the current weather conditions (rain, wind force, wind direction).
A follow-up BRIMOS® measurement of the affected cables OW1 to OW5a was carried out. Furthermore the lower and upper anchors of the cables OW1a and OW2 were visually inspected.
In a further step VCE will prepare a technical concept for the prevention of dangerous cable vibrations at the Donaustadt Bridge.
The condition of three reinforced concrete buildings in an industrial plant for the production of viscose rayons is determined and evaluated in order to plan their maintenance and further operation. The buildings are between 20 and 30 years old and partly exposed to considerable process-related stresses by water and chemical impacts.
The individual production lines consist of several buildings which have a very similar construction type but have been stressed to a different extent by the operation so far. In the course of the analysis load zones and condition matrixes are established. On this basis calculational, global and local life-time parameter studies are prepared as a basis for potential maintenance and rehabilitation measures in terms of a priority plan.
The present analysis can be seen as a preliminary stage of the future maintenance management system.
Between December 2013 and March 2014 Felbermayr carried out eight heavy transports starting from Rotterdam. For a new aluminium plant of Upper Austrian aluminium manufacturer AMAG in Ranshofen heavy components - produced by the mechanical engineering company Danieli - were transported. The route of transport led per ship from Rotterdam over the Rhine-Main-Danube Canal onwards to the Felbermayr heavy load harbour in Linz, followed by a concluding road transport to Ranshofen. The heavy components of about 200 tonnes were transported on 20-axle low loaders with a total transportation weight of up to 305 tonnes.
Two Bridges on the route (Object 307 and Object 305) had been monitored by VCE in the course of an accompanying monitoring program by means of periodic dynamic measurements with BRIMOS® Structural Health Monitoring during all heavy transports.
Due to static reasons one of the bridges had to be crossed in a so-called “backward motion”. This means that the low loader is pulled diagonally over the road using two towing vehicles in order to ensure a better weight distribution.
The Ogun River Bridge is part of a connecting road between the megacities of Lagos and Ibadan. The bridge spans the valley of the river Ogun on the north-eastern outskirts of Lagos by means of two parallel structures with a total length of 728.5 m each.
The 16-span prestressed concrete bridge was erected as first ILM bridge in Africa at the end of the 1970s. Every structure consists of a single-cell box girder and carries three lanes.
Both superstructures were severely damaged by fire. A road tanker was overthrown and approximately 30 tons of fuel were spilled and caught fire.
The construction company Julius Berger was commissioned with the general rehabilitation of the connecting road between Lagos and Ibadan. The companies BBV Systems GmbH and VCE carried out a BRIMOS inspection including an FE comparative calculation for the assessment of the bridge condition as a basis for maintenance or (partial) renewal.
Services of VCE: BRIMOS inspection of both superstructures, FE comparative calculation
The pedestrian bridge (also passed by vehicles of any kind by the local people) with a span of 80 metres was built as suspension bridge in 1983. The pylons and the deck consist of concrete. All 4 supporting cables are fully locked ropes with a diameter of 68 mm. The 104 suspending ropes and the 32 diagonal stabilizing ropes vary in their diameters between 16 and 22 mm.
The bridge is in a questionable condition. Some suspenders had to be exchanged already.
The design of the bridge does not conform to the available plan documents and the static calculation to a great extent.
As a basis for future maintenance VCE was commissioned with the measurement of all cable forces by means of the Brimos technology.
Services of VCE: Measurement of all cable forces
The town of Zwettl is relieved from through traffic by the construction of a bypass. The latter forms a half ring around the town and is mostly built as a 3-lane road. In this process existing connections (highways B 38, B 36 and L 71) are crossed and integrated. The 11.7 km long local bypass is composed of three maintenance sections
and is to be constructed in the scope of a PPP project in the next few years and to be operated for 25 years (2018-2043). VCE prepared the maintenance and operation concept for the whole contract section in form of action and cost planning as well as optimization in the scope of the tendering procedure. Apart from 185,000 m² of road surface (asphalt construction method) 21 bridges and approx. 1.5 km of noise barriers were included.
Itemization of the services accomplished by VCE:
Planning of the structural maintenance of roads:
Planning of structural maintenance of civil engineering structures:
Planning of operation:
A new cable-stayed bridge was built over the Albert Canal in Belgium. The stay cables were supplied and installed by Mekano 4. The longest stay cables had to be equipped with dampers in order to prevent dangerous cable vibrations.
VCE supported Mekano 4 in the development and design of a new hydraulic damper. Furthermore, the cable force and the damping behaviour of all stay cables were measured and analyzed. The effectiveness of the vibration dampers was checked by free vibration decay tests at the stay cables.
The bridge was additionally equipped with a permanent monitoring system consisting of a meteorological station, accelerometers for selected stay cables and deformation sensors for the monitoring of the damper function. All measurement data are made available to the client via the BRIMOS® Web-User-Interface.
Services:
The new cable-stayed bridge over the Mississippi in St. Louis, Missouri, will be the longest cable-stayed bridge in the US with a main span of 460 metres upon completion at the beginning of 2014. The bridge deck is a composite concrete-steel structure. The stay cables with 31-73 strand bundles are up to 244 metres long.
In order to avoid dangerous cable vibrations, the owner stipulated a minimum requirement of 1% critical damping for cable vibration damping. This is a very high requirement compared to international standards and guidelines (cf. SETRA 0.5% critical damping). Therefore all stay cables were equipped with frictional dampers by the cable supplier VSL. The function of the dampers had to be verified by independent experts by means of measurements and vibration tests. The respective inspections were carried out at three stay cables by VCE in December 2013. The measurements were performed with uninstalled dampers, installed inactive dampers and with installed active dampers at all cables. All tests were repeated three times. The measurements showed that the damping of the stay cables could be increased from 0.2% internal damping to a minimum of 1.5% total damping for the longest stay cables and 2% total damping for the shortest cables by the dampers.
In the course of the installation of a Structural Health Monitoring System the structures of the “Halic Metro Crossing” were measured and analyzed by means of BRIMOS®-Wireless. The initial measurements comprised the two foreshore bridges, the cable-stayed bridge, the pylons, the swing bridge as well as the stay cables themselves – all in all more than 300 measuring points.
Bridge lengths:
During the completion of the installation works in December 2013 a snap back test as well as a measurement for the assessment of the resonance vibrations during the start and an emergency stop of the turning procedure of the swing bridge were carried out.
Services: Preparation of a concept for the initial measurements, performance of the measurements, analysis, report
Ausgangslage war eine rechnerische Tragsicherheits-bewertung der stählernen Dachkonstruktion unseres Büros im Jahr 2011. Diese Nachrechnung nach dem wesentlich strikteren Eurocode zeigte erwartungsgemäß in einigen Fällen eine Überschreitung der zulässigen Grenzwerte. Die Situation wurde damals unter der Anwendung probabilistischer Ansätze als akzeptabel eingestuft.
Um diese Annahmen zu bestätigen wird, die tatsächliche Belastung des Tragwerks durch Wind und Schnee mittels eines permanenten Monitoring-Systems ermittelt.
Die gesamte Überwachung dauert 3 Jahre, um für die Beurteilung repräsentative Jahresgänge einerseits und eine ausreichende Anzahl an Extremereignissen andererseits erfassen zu können.
Zur Kalibrierung der Lebensdauerprognose wird duch die Messanlage das reale Tragverhalten über die 3 Jahre dokumentiert.
Der aktuelle Jahresbericht bezieht sich auf einen Beobachtungszeitraum von 16 Monaten und beinhaltet die Auswertung des gemessenen Tragwiderstands über die Zeit unter dem Einfluss wechselnder meteorologischer Einwirkungen bzw. unter Starkwindereignissen.
Gleichzeitig erfolgte anhand des angeführten, permanent überwachten Zeitraums (12/2011 – Ende 03/2013) eine ausführliche Analyse und Evaluierung der realen Wind- & Schneelasten gegenüber dem Windlastmodell bzw. dem Schneelastmodell des Eurocode.
Der Hunter Expressway (Bauphase 2010 bis 2013) ist eine etwa 40 km lange Autobahn an der australischen Westküste (Nähe Newcastle).
Kurz vor der Öffnung für den Verkehr wurde in vier Brücken (drei davon sind Twin-Bridges) des Hunter Expressway ein Structural Health Monitoring System eingebaut. Mittels Schlauchwaagensystem werden die Setzungen der Pfeiler überwacht, Ultraschallsensoren detektieren Längs- und Querverschiebungen.
Zusätzlich wird die Lufttemperatur entlang der Bauwerke, sowie der Flüssigkeitsstand im Ausgleichsbehälter des Schlauchwaagensystems erfasst.
Key-Features:
Leistungen: Erarbeitung eines Structural Health Monitoring Konzepts, Vorfertigung des Systems bei VCE, Installation des Systems vor Ort, Kalibrierung, Beratung für die Grenzwert-Definition, On-site operation & maintenance training
Dynamische Untersuchung der Tragsicherheit der Zwischendecke mit BRIMOS Structural Health Monitoring
Den Deckeneinsturz des Autobahntunnels Sasago in Japan, Anfang Dezember 2012, hat die ASFINAG zum Anlass genommen, um eine interne Arbeitsgruppe einzurichten sowie ein Pilotprojekt zur dynamischen Untersuchung an der Zwischendecke des Plabutschtunnels (Oströhre) ins Leben zu rufen.g
Dieses Pilotprojekt dient dazu, parallel zu konventionellen Tragwerksprüfungen, Ergebnisse aus dem Schwingungsverhalten der Zwischendecke zur Bewertung des Tragwerkszustandes heranzuziehen und Empfehlungen für die weitere Vorgehensweise abzugeben. Ziel ist es, die Tragsicherheit der Zwischendecke zu bewerten, die Versagensmöglichkeiten aufzuzeigen und geeignete Kontroll- bzw. Prüfmechanismen (visuell, mechanische oder dynamische) vorzuschlagen, um diese zu verhindern.
Zusätzlich wird ausgelotet, in welchem räumlichen Umfang diese Art der Sonderprüfung bei vergleichbarem Aufwand auf andere Tunnelabschnitte bzw. andere Tunnelobjekte übertragbar wäre.g
Die dynamische Untersuchung mit BRIMOS® (Messung & Rechnung) umfasste drei ausgewählte Deckenabschnitte in der Oströhre des Plabutschtunnels. Jeder der drei baugleichen Abschnitte hat eine Länge von ca. 12 m.
Beim Bürohochhaus “Gold Tower” mit 37 Stockwerken im Jumeirah-Lake-Towers District in Dubai bersten immer wieder einzelne Glasscheiben der Fassadenelemente. Insbesondere die äußeren Glasscheiben der Isolierverglasung sind betroffen.
Auf Wunsch des Eigentümers wurde neben der Untersuchung des Glases von VCE eine messtechnische Untersuchung und Beurteilung der Hochhausstruktur sowie der Curtain Wall und der Einspannung der Glasfassadenelemente in der Curtain Wall mit BRIMOS® durchgeführt.
Messung der Hängerkräfte in den Stiegenhäusern 5 und 7
Das Mariinski-Theater (russisch Мариинский театр) ist eines der bekanntesten Opern- und Balletthäuser der Welt. Das Gebäude liegt am Sankt Petersburger Theaterplatz. Viele wichtige russische Opern und Ballette wurden hier uraufgeführt. Das Theater wurde um einen 550 Million Dollar Neubau erweitert (Mariinski Theater II). Dieser wurde am 2. Mai 2013 in Anwesenheit des russischen Staatschefs Wladimir Putin eröffnet.
Im Theater gibt es zwei Stiegenhäuser, bei welchen die Stiegen von der Decke abgehängt sind – im ovalen Stiegenhaus mit 32 Hängern und im anderen Stiegenhaus mit 6 Hängern. Die Kräfte in sämtlichen Hängern waren 3 Tage vor der Eröffnung messtechnisch mittels BRIMOS® zu überprüfen.
