This paper reports on ongoing work toward implementing a predictive control approach for buildings systems for ventilation, lighting, and shading. The main objective of this method is the optimized control of multiple devices toward usage of passive cooling and natural lighting. In this way, control options (various opening positions of windows, shades, etc.) are generated and computationally assessed using a combination of option space navigation via genetic algorithms and numeric simulation.

Simulationsgestütztes Konzept zur Regelung und Steuerung von Lüftungs-, Beleuchtungs- und Verschattungseinrichtungen.
Im vorliegenden Artikel wird über laufende Arbeiten zur Entwicklung eines prädiktiven Konzepts zur Regelung und Steuerung von Lüftungs-, Beleuchtungs- und Verschattungssystemen in Gebäuden berichtet. Dabei geht es im Wesentlichen um die Optimierung der Regelung und Steuerung von Einrichtungen zur verstärkten Nutzung von passiver Kühlung und natürlicher Beleuchtung. Auf diese Weise werden Optionen zur Regelung und Steuerung (z. B. unterschiedliche Öffnungspositionen für Fenster und Sonnenschutz, usw.) erzeugt und digital beurteilt, wobei eine Kombination aus Optionsraum-Navigation (anhand genetischer Algorithmen) und numerischer Simulation zur Anwendung kommt.

In many geotechnical problems, the presence of water and air in the voids of a soil skeleton has an influence on the behaviour of the soil. Effects such as time-dependent deformations, temporary reduction in the shear strength of the soil or even liquefaction of loosely layered sands can occur. To account for these effects in a geotechnical analysis, the soil has to be considered as a multiphase material with interaction between the single phases. A simple dynamic approach for the numerical modelling of a fully saturated soil with the finite element method using an explicit time integration rule is presented here. The governing equations describing the soil as a two-phase material are implemented within the framework of a user subroutine working as a constitutive model in the analysis. Simple problems considering different boundary conditions, static and dynamic loading conditions and non-linear material behaviour are investigated to verify the implemented approach. The results are compared with analytical solutions and with solutions obtained by the finite element method using an implicit equation solver. Compared with implicit integration methods, the approach presented has the advantage that - for dynamic analyses especially. An explicit integration method is often computationally more efficient for the analysis of large models with relatively short dynamic response times and for the analysis of extremely discontinuous processes such as dynamic pile driving.

Einfacher dynamischer Ansatz zur numerischen Modellierung des Bodens als 2-Phasen-Material.
Bei vielen geotechnischen Fragestellungen wird das Bodenverhalten durch das Porenwasser und die Porenluft beeinflusst. Effekte, wie zeitabhängige Verformungen, eine temporäre Reduktion der Scherfestigkeit oder sogar eine Verflüssigung von locker gelagerten Sanden können die Folge sein. Um diese Effekte in einer geotechnischen Berechnung zu berücksichtigen, muss der Boden als Mehrphasengemisch mit einer Interaktion der einzelnen Phasen untereinander betrachtet werden. Es wird ein einfacher dynamischer Ansatz zur numerischen Modellierung von wassergesättigten Böden mittels der Finite-Elemente-Methode unter Verwendung einer expliziten Zeitintegration vorgestellt. Die den Boden als 2-Phasengemisch beschreibenden Gleichungen werden auf Basis einer User-Routine für Stoffmodelle implementiert. An einfachen Beispielen wird der Ansatz für verschiedene Randbedingungen, statische und dynamische Belastung sowie für nicht-lineares Materialverhalten untersucht. Das Ergebnis wird mit analytischen Lösungen oder Ergebnissen verglichen, welche mit einem impliziten Gleichungslöser berechnet wurden. Im Vergleich zur impliziten Formulierung besitzt der vorgestellte Ansatz den Vorteil, dass eine explizite Formulierung für dynamische Berechnungen häufig effizienter hinsichtlich der Rechenzeit ist, insbesondere für große Finite-Elemente-Modelle mit kurzen Simulationsdauern und Berechnungen mit extrem diskontinuierlichen Prozessen, wie beispielsweise bei der Rammung von Pfählen.

A numerical method is developed for evaluating critical passive earth pressure coefficients Kp&ggr; for the case of an inclined rigid retaining wall resting against sloping cohesionless backfill. The methodology of the proposed investigation is based on the limit equilibrium approach with the assumption of a complete log spiral failure mechanism. The Kp&ggr; coefficients obtained from this study are compared with the existing theoretical and experimental results. The proposed Kp&ggr; values are on a par with the best upper bound solution given by Soubra and Macuh using the limit analysis method. Further, the results presented here compare fairly well with those given by Kerisel and Absi, which establishes the validity of the proposed research work. Efforts are taken to present the design tables for a wide variety of soil properties, soil-wall interface properties and geometrical properties of the wall and the backfill.

Ein einfacher Ansatz zur Bestimmung von Erdwiderstandsbeiwerten auf Basis der Methode des Grenzgleichwichts.
Eine numerische Methode zur Bestimmung des kritischen Erdwiderstandsbeiwerts Kp&ggr; wird entwickelt für den Fall einer geneigten, steifen Verbauwand vor geböschtem, kohäsionslosem Erdreich. Die Methodik der vorgeschlagenen Untersuchung basiert dabei auf dem Ansatz des Grenzgleichgewichts unter Annahme eines Versagensmechanismus mit logarithmischer Spiralform. Der mittels dieser Studie bestimmte Kp&ggr;-Beiwert wird mit vorhandenen theoretischen und experimentellen Ergebnissen verglichen. Es wird gezeigt, dass die vorgeschlagenen Werte für Kp&ggr; den Werten der besten Lösung unter Verwendung des Obere-Schranken-Theorems nach Soubra und Macuh entsprechen, welche mit Hilfe einer Grenzwertanalyse ermittelt wurde. Darüber hinaus stimmen die hier präsentierten Ergebnisse gut mit denen von Kerisel und Absi überein, was die Gültigkeit der vorgeschlagenen Vorgehensweise belegt. Bemessungstafeln für eine große Anzahl an Bodenparametern, Boden-Wand-Interface Parametern und geometrischen Parametern der Wand sowie des abzustützenden Erdreichs werden eingeführt.

The 4.2 km Eyholz tunnel is part of the autobahn A9 and is the essential element in the bypass of Visp in the canton Valais, Switzerland. The tunnel passes through geologically problematic and also tectonically highly stressed zones (Rhone-Simplon fault).
The excavation of the two two-lane bores is being performed conventionally, by blasting and also in loose material. The interesting structures include the underground junction caverns, where slip roads to join and leave the autobahn are included in the tunnel, resulting in cross-sections of up to 300m2 having to be excavated.
The overburden areas near the portals were excavated with tunnel excavators under the protection of elaborate jetted canopies. The two tunnel bores are being excavated in parallel and are connected with crosscuts every 270 m. As is typical for recent Swiss autobahn tunnels, a service duct is constructed under the carriageway. The inner lining of the main bores is progressing at the same time as the excavation and also the lining of the cavern with in-situ concrete. The first bore should open for traffic in 2013.
Der 4,2 km lange Autobahntunnel Eyholz ist Teil der Autobahn A9 und bildet das Kernstück der Umfahrung Visp im Kanton Wallis, CH. Der Tunnel befindet sich in geologisch schwierigen, und zusätzlich tektonisch stark beanspruchten Zonen (Rhone-Simplon Störung).
Die Ausbruchsarbeiten der beiden Doppelspurröhren werden konventionell, sowohl im Spreng- als auch im Lockermaterialvortrieb ausgeführt. Bautechnisch interessante Bauwerke sind unter anderem die unterirdischen Verzweigungskavernen. Hier wurden aus Platzgründen Ein- und Ausfahrtsspuren in den Tunnel verlegt, wodurch Ausbruchsquerschnitte bis 300m2 aufzufahren waren.
Die Überlagerungsbereiche der Portalstrecken wurden teilweise mit aufwändigen Jettschirmen gesichert und im Baggervortrieb ausgebrochen. Beide Tunnelröhren werden parallel ausgebrochen und sind alle 270 m mit Querschlägen miteinander verbunden. Typisch für die Schweizer Autobahnen in jüngerer Zeit ist ein, unter der Fahrbahn angeordneter Werkleitungskanal. Gleichzeitig zum Vortrieb laufen der Innenausbau der Hauptröhren sowie der Ausbau der Kavernen in Ortbeton. 2013 soll die erste Röhre ans Netz gehen.

No short description available.

Nominated for the Bernt Johansson Outstanding Paper Awards at Nordic Steel 2019
Most steel moment frames are designed so that the beams act as structural fuses during earthquake loading. This approach, while good for saving lives, has poor resilience because it is difficult to replace damaged beams in a building. A repairable steel moment-frame connection has been developed that may be attractive to engineers and building contractors. The connection has a fuse plate bolted to the beam bottom flange which experiences shear yielding during severe earthquakes, protecting both the column and the beam. After an earthquake, the fuse plates can be removed and replaced to unlock residual frame deformations and prepare the building for another event.
Full-scale experiments were conducted to validate the performance of this repairable connection. Two tests were performed with a W690 × 125 beam and W530 × 196 column. The tests demonstrated rotation capacities of at least 0.05 rad, which exceeds AISC requirements for special moment frames. The fuse plate was effective in preventing beam damage in each test, and the second test demonstrated that the connection could be repaired by replacing the fuse plate.

A reliability-based investigation into the ductility measures for reinforced concrete (RC) beams designed according to the current fib Model Code for Concrete Structures 2010 is presented in this paper. Based on the ductility ratio (= ratio of strain in tensile rebar to yield stress of steel), a limit state to ensure adequate ductility in RC beams is proposed. Results show that the ductility ratio generally follows a right-skewed distribution, and due to variability in the material properties and model error, there is high variability in the strain ductility. This high variability in the ductility ratio leads to a high probability of non-ductile behaviour for RC beam designs based on the code. This is more pronounced for normal-strength concrete and grade S500 steel. Based on a target probability taken from the literature, a modification to the allowable neutral axis depth advised by the code is proposed. The results presented in this paper indicate that more reliability-based studies of the safety factors provided by fib Model Code 2010 are needed in order to ensure adequate ductility in RC beams.

In Germany the stiffness and resistance of diaphragms used for stabilizing members are traditionally calculated according to the Schardt and Strehl approach. Compared with the approach of Bryan and Davies given in the ECCS Recommendations, it does not take into account the flexibility of the connections. This paper shows how to amend Schardt and Strehl’s approach to include this flexibility, leading to more realistic values of diaphragm stiffness. The article also introduces new procedures for the calculation of the resistance, adopted from European standards and recommendations. Finally, both a test and an example taken from the literature are recalculated for comparison.

In this article an attempt is made to simplify the application of EC 6 by a strict and clear division of the EC 6 into calculation, execution and materials. The calculation engineer does not, therefore, need to get involved with building materials specific parameters, which make it much more difficult to get a view over the variety of possible combinations. The introduction of classes in the characteristics that are relevant for building materials means that the structural engineer specifies suitable quantities necessary for his task, the builder/product manufacturer by suitable methods and choice of unit/mortar combinations achieves the required classes and, the product manufacturer, in particular, should be entitled to have the possibility of the individual specification, e. g. as part of general appraisal certificates.

The introduction of new vertical steel bolts is an easy, practical and common solution for retrofitting and strengthening slabs for punching. Although a common option where punching strengthening is concerned, few studies exist regarding how the bolt's anchorage dimensions and its embedment in the concrete slab affect the strengthening efficiency. This work presents an analytical approach that is able to predict the punching capacity of slabs strengthened with post-installed vertical steel bolts, taking into account the anchorage dimensions and positioning plus the material properties. This approach results from the combination of two physical models: one provided in the fib Model Code for Concrete Structures 2010 regarding the punching capacity estimation, and another that allows the deformation (crushing) of the concrete beneath the head of the anchorage to be taken into account. The predicted values are compared with experimental results, showing that the analytical approach is able to simulate correctly the anchorage behaviour and its influence regarding a slab's loadbearing capacity. A parametrical analysis is carried out in order to study the importance of different factors such as concrete compressive strength, longitudinal reinforcement ratio and steel bolt length, always accompanied by the effect of anchorage head size and embedment.

No short description available.

This paper is concerned with a numerical simulation model (ekate) specifically designed for shield tunnelling in fully and partially saturated soils based upon the Finite Element Method (FEM). The model considers all relevant components - the soil, the lining, the tail void grouting, the hydraulic jacks and different types of face support - involved in shield tunnelling. The surrounding soft soil is formulated as a three-phase material, consisting of the soil skeleton, pore water and air. This model allows for the simulation of consolidation processes in partially saturated soils as well as of flow of compressed air often used as temporary face support during repair interventions at the cutting wheel. Despite the complexity connected with the relatively high degree of realism of the simulation model, only little effort is required from the user to establish a realistic 3D model for shield tunnelling. To this end an automatic model generator has been developed which allows for a user friendly generation of the discretized model including all components involved and to investigate variants with a minimum effort for the user. The model allows for realistic predictions of settlements and also provides information on deformations and stresses in the ground, the lining and the TBM, respectively. In addition to its use as a prognosis tool in the design process, in particular for tunnelling projects in sensitive urban areas, the model also may be used to assist the driving and steering process in mechanized tunnelling. The paper provides an overview over the main components of the model, the automatic model generator and the tri-phasic representation of the soil. A simulation of a compressed air intervention of a shield tunnel in soft soil demonstrates the applicability of the model.

Various methods are suggested in the available codes to design roof detailing in cold formed screwed-down roof systems made of cold-formed purlins covered with metal sheeting. The evaluation of the global anchorage force of the roof and the local forces in fasteners is pursued aiming at designing support detailing and purlin-sheeting connection, respectively. Two factors, “R” and “r”, are here employed to synthetically describe the stabilization forces that are required at the supports and along the span. It is shown that these two factors are implicitly provided by some codes for steel structures, but they can be even directly calculated by a simplified finite element model of the whole roof system, here presented. A comparison with the other available approaches is carried out, revealing that the proposed model is an extremely useful tool both for the design and the verification of the structural elements. The described procedure for calculation is shown to be extremely general and easily adaptable to new roof systems, with structural details even not foreseen in the actual codes. For example it can be used to solve the lack of Eurocode 3, Part 1-3, Chapter 10, because, as opposed to the assumption of Eurocode, elastic lateral support can here be envisaged, instead of full lateral support.

When it comes to the general design of laterally loaded piles in offshore environments, bedding resistance is usually modelled by the p-y method recommended in the offshore guidelines (OGL). Several investigations presented in the literature indicate that the head displacements of large-diameter monopiles are underestimated for extreme loads but overestimated for small operational loads. An extensive evaluation of the OGL method is presented here using three-dimensional numerical simulations. The evaluation has shown that the OGL method is not applicable for the design of large-diameter piles. Moreover, modified p-y formulations presented in the literature accounting for the effect of the pile diameter are also not generally suitable for piles with arbitrary dimensions and load levels. Therefore, the derivation of a new p-y approach is presented in detail. The new approach consists of “basic p-y curves” that are valid for a pile of infinite length exhibiting a constant horizontal deflection. In an iterative scheme, these basic curves are adapted depending on the pile deflection line and the pile length to account for a more realistic bedding resistance along the pile shaft. A comprehensive parametric study with 250 pile-soil systems reveals that the new p-y approach is able to predict the horizontal loadbearing behaviour as well as the local pile-soil interaction quite realistically.

Ein neuer statischer p-y-Ansatz für Pfähle beliebiger Abmessungen in Sand.
Für die Bemessung horizontal belasteter Offshore-Pfähle wird der Bettungswiderstand üblicherweise durch die in den Offshore-Richtlinien (OGL) empfohlene p-y-Methode ermittelt. Verschiedene Untersuchungen aus der Literatur zeigen, dass die Verformungen von Monopiles mit großen Durchmessern für Extremlasten durch die OGL-Methode unterschätzt, für geringe Betriebslasten dagegen überschätzt werden. Der vorliegende Artikel beinhaltet eine umfassende Bewertung der p-y-Methode basierend auf dreidimensionalen numerischen Simulationen. Als Ergebnis ist festzustellen, dass die OGL-Methode zur Bemessung von Pfählen großer Durchmesser nicht geeignet erscheint. Auch modifizierte p-y-Ansätze zur Berücksichtigung des Einflusses des Pfahldurchmessers sind nicht generell anwendbar für Pfähle beliebiger Abmessungen und Belastungen. Diesbezüglich soll die Ermittlung eines neuen p-y-Ansatzes dargestellt werden. Der neue Ansatz basiert auf sogenannten “p-y-Basiskurven”, welche Gültigkeit für einen unendlich langen Pfahl mit einer über die Länge konstanten horizontalen Verschiebung aufweisen. In einem iterativen Vorgehen werden diese Basiskurven zur Erreichung eines realistischen Verlaufs der Bettungswiderstände in Abhängigkeit der Pfahlbiegelinie und -länge angepasst. Eine umfassende Parameterstudie mit 250 Pfahl-Bodensystemen zeigt, dass der neue p-y-Ansatz geeignet ist, sowohl das globale Tragverhalten als auch die lokalen Pfahl-Boden-Interaktionen realistisch zu prognostizieren.

Hygrothermal models allow designers to evaluate the hygrothermal performance of building envelopes. However, hygrothermal modeling needs the input of the external climate loading, a moisture reference year, to evaluate moisture damage risk of building envelope. In this paper, a new procedure is proposed for selecting moisture reference years. A metric, called Climatic Index, combining wind-driven rain load and potential evaporation is developed in this study. Climatic Indices over 30 years are determined for a wall envelope located in Zurich, Switzerland. The hygrothermal performance of the wall envelope and its moisture damage risk are simulated and evaluated using a hygrothermal risk indicator, called the RHT Index. A clear correlation between Climatic Index and RHT Index is found for the specific moisture damage considered, mold growth. The selection procedure combines a first selection of three years around the 10 % level criterion based on the Climatic Index, followed by a careful comparison of different years based on RHT Index and a final selection of the year with the largest RHT Index as moisture reference year. The combination of Climatic Index and RHT Index allows for the selection of moisture reference years with known level of damage risk.

Ein neues Verfahren zur Auswahl von Feuchte-Referenzjahren für hygrothermische Simulationen.
Hygrothermische Modelle ermöglichen es Planern, die hygrothermischen Eigenschaften der Gebäudehülle zu bewerten. Zur Bewertung des Risikos von Feuchteschäden sind für die hygrothermische Modellierung Daten zur äußeren klimatischen Belastung erforderlich, und zwar in Form eines Feuchte-Referenzjahres. Der vorliegende Beitrag schlägt ein neues Verfahren zur Auswahl von Feuchte-Referenzjahren vor. In der Studie wird eine Maßzahl namens “Klimatischer Index” entwickelt, die windbasierte Regenlast und potenzielle Verdunstung kombiniert. Klimatische Indexwerte für 30 Jahre werden für eine Außenwand in Zürich (Schweiz) bestimmt. Das hygrothermische Verhalten der Außenwand sowie ihr Risiko von Feuchteschäden werden simuliert und bewertet anhand eines hygrothermischen Risikoindikators, genannt RHT-Index. Für die hier speziell betrachtete Art von Feuchteschäden, den Schimmelbefall, wird ein eindeutiger Zusammenhang zwischen Klimatischem Index und RHT-Index ermittelt. Das Verfahren umfasst eine erste Auswahl von drei Jahren basierend auf einem 10%-Kriterium und dem Klimatischen Index, dem dann ein sorgfältiger Vergleich verschiedener Jahre auf Grundlage des RHT-Index folgt und schließlich die Auswahl jenes Jahres mit dem höchsten RHT-Index als Feuchte-Referenzjahr. Die Kombination von Klimatischem Index und RHT-Index ermöglicht die Auswahl von Feuchte-Referenzjahren mit bekanntem Schadensrisiko.

In this work, gene expression programming (GEP), as a new tool, has been used to predict the bond strength of fibre-reinforced polymer-to-concrete composite joints as the performance symbol of this structure. Some 238 datasets were collected from the literature, divided into 192 and 46 sets at random and then trained and tested respectively by means of GEP. The parameters width of prism, concrete cylinder compressive strength, width of fibre-reinforced polymer (FRP), thickness of FRP, modulus of elasticity of FRP and bond length were used as input parameters. Using these input parameters, the bond strength of FRP-to-concrete composite joints in different conditions was predicted in the GEP model. The training and testing results in the GEP model show that GEP is a powerful tool for predicting the bond strength values of the FRP-to-concrete composite joints in the range considered.

Concrete construction is becoming increasingly complex and the importance of producing structures that are both cost effective and durable in the long term has never been higher. Therefore, an understanding of concrete durability is considered fundamental to determine the service life of new or existing structures. However, at present a significant number of existing concrete structures and bridges have already been deteriorated by a chemo-mechanical process known as Delayed Ettringite Formation (DEF). This phenomenon causes expansion of the affected concrete, generally leading to cracking and a decrease of its mechanical properties. The disease or deterioration mechanism therefore induces serious problems regarding serviceability, sustainable operation and structural integrity, which makes it necessary to apply predictive models able to re-assess the mechanical state of the affected structures. In this way, chemo-mechanical modelling must be performed considering the influence of humidity, stiffness reduction and stress in the development of expansion.
The elaborated 3D model was applied to an existing viaduct affected by DEF. The displacements and stresses were computed based on the experimental data obtained from the in-situ measurements. The computed results highlight the relationship between the saturation degree and the expansion. Finally, comparisons between different calculations with and without considering the anisotropy of expansion and stiffness reduction are presented and discussed.

A new modified mix proportioning method for producing normal-strength concrete using recycled concrete aggregate, called the equivalent coarse aggregate mass (ECAM) method, is proposed in this paper. The basic concepts of the proposed method with calculations for mix design are presented by designing 14 mixes and testing 99 concrete samples (57 cubes and 42 cylinders). Experimental work was carried out in two phases. In the first phase, an experimental programme was conducted to verify the proposed mix design method by studying a single parameter - uniaxial compressive strength. Five different mixes with initial 0, 25, 50, 75 and 100 % replacement by mass were designed, cast and tested in this phase. It was concluded from the first phase that the proposed method can be adopted for designing the recycled concrete up to a nominal replacement ratio of 50 %. Accordingly, the second phase of experimental study was carried out to design three different grades of concrete strength using the proposed method to investigate the mechanical properties of the recycled concrete. Seven different mechanical properties - compressive strength, splitting tensile strength, modulus of elasticity, Schmidt hammer test, ultrasonic pulse velocity test, fresh density and hardened density - were investigated and are presented and discussed here.

This paper provides a detailed overview of the design and construction of a series of temporary pavilions based on the Tensairity® principle. The pavilions are currently used in the Superbike racing category (Ducati Superbike Team), for the Audi tron Sailing Series, the ISAF Sailing World Cup and for other temporary events (3KIT pavilion). The paper describes the Tensairity® principle, the architectural and structural design of the pavilions, the manufacturing of the components and the assembly of the Tensairity® roofs.

Cuauhtémoc Stadium, a first division football stadium in Puebla, México, with more than 51 000 seats, has recently been completely renovated. The brand-new façade has become an icon for the club and for the city. The façade is designed as a skin of single-layer ETFE foil in a combination of three different shades of blue and translucent white. The design and construction of the façade is the result of an international collaboration between local contractor DÜNN Lightweight Architecture, from Zapopan, Mexico, and LEICHT Structural engineering and specialists consulting GmbH, based in Munich, Germany. This paper will elaborate on the boundary conditions of the project and the technical decisions made for the construction of the façade.

No short description available.

In the AiF-FOSTA research project P1020 [1], a new design model for welded joints was developed. In this context, a small scale test on flat tensile specimens was designed, with the help of which various influences on the strength and ductility of the welds were investigated. Furthermore, extensive tests were carried out on overlap joints, cruciform joints with double fillet welds as well as partially and fully penetrated butt joints. This was done to calibrate the weld construction factor &agr;w, which takes into account the influence of the type of joint on the load-bearing capacity. In the following article, after a short summary of the current state of research, the design model, and the results from the parameter studies on flat tensile tests are described in more detail in [2-4]. Subsequently, the test program on welded joints and the calibration of the weld construction factor &agr;w are presented. Finally, the results of the design model and the tests carried out are compared with test results from other research projects and the design model of prEN 1993-1-8 [5].

Software for calculating the internal forces, moments and deflections of sandwich elements with reinforced concrete facings has been developed as part of a research project at Technische Universität Kaiserslautern. Sandwich elements with stiff concrete facings are internally statically indeterminate. Cracking of the concrete facings leads to a redistribution of the internal forces and moments over the length and across the cross-section of the element. This redistribution must be considered in the structural design of such elements.
An existing program for calculating metal-faced sandwich elements was considerably extended by an iterative approach that allows the internal forces and moments to be calculated with the exact stiffness of the cracked facings. This iterative approach and the calculation algorithm behind the new software, called swe2+, are explained in this paper. A verification of the calculation results and a parametric study of a two-span sandwich element are also presented.

A new requirement of the BSH (Bundesamt für Seeschifffahrt und Hydrographie, the regulatory authority for offshore wind farms in Germany), is the assessment of the effect of cyclic loading on the capacity of foundations supporting offshore wind turbines. There are few practical design methods until now. This paper presents a new approach for assessing offshore piles subjected to cyclic axial loading, which combines two known methods, the approach for static loading as developed by the Imperial College of London (termed ICP approach) and a load-transfer-approach as incorporated in software “RATZ” for cyclic loading. Results using this method are compared against tests performed for the Health & Safety Executive (HSE) in Dunkirk and very good agreement is found.

Ein neuer Ansatz für die Bemessung axial-zyklisch belasteter Pfähle von Offshore-Konstruktionen.
Es ist eine Anforderung des BSH, dass die Wirkung zyklischer Belastung auf die Tragfähigkeit von Fundamenten von Offshore-Windenergieanlagen beurteilt wird. Bisher sind praktisch anwendbare Bemessungsmethoden selten. In diesem Beitrag wird ein neuer Ansatz vorgestellt, der zwei bekannte Methoden kombiniert, die ICP-Methode für die statische Belastung und ein Ansatz über Last-Verschiebungskurven für zyklische Belastung. Ergebnisse, die mit dieser Methode erzielt werden, werden mit Versuchen verglichen, die für die HSE in Dünkirchen durchgeführt wurden, und eine sehr gute Übereinstimmung wird festgestellt.

Most excavated material generated from tunnelling projects ends up being deposited on land. The EU funded project “DRAGON” aims to develop technologies to analyse and characterise this material so that the potentially usable fraction can be easily separated from non-usable material. Increasing use of this material by external industries will improve resource efficiency while reducing landfill quantities and disposal costs. One of the project goals is to assess the potential environmental benefits/costs of applying DRAGON technology to planned future EU tunnelling projects. A three stage approach has been adopted to meet this goal. Firstly, the potential for diverting material from landfill must be assessed. To account for the diversity of tunnelling projects, this will be based on an average of 54 recent tunnelling projects. Secondly, a life cycle assessment (LCA) model will be created to allow each of these tunnelling projects to be analysed and the potential benefits of using DRAGON technology will be compared against the ‘business as usual’ case. These results will then be averaged to give the expected environmental costs/benefits per t excavated material. Finally, these costs/benefits will be scaled up to account for the expected amount of material from future European tunnelling projects - expected to be around 800 m. t.