Timber Towers Research Articles

Spatial Effectiveness in High-Rise Timber Towers: A Global Perspective

Spatial Effectiveness in High-Rise Timber Towers: A Global Perspective

The effect of wind on historical timber towers analyzed by plastic limit analysis in the focus of a collapse

Climate change severely impacts the architectural heritage. Old buildings may have survived many large storms and heavy snows in the past, but extremes have increased recently. Meanwhile, the condition of historical structures gradually degrades even if they have had regular maintenance.Church towers are strongly affected: they are subject to increased wind compared to the other parts of the building. They are in a high location and gain less attention because of their out-of-the-way position.On 17th September 2017, a massive storm in the Banat region, Romania, caused several church towers to collapse: the towers of Toager, Remetea Mare, Donceni and Ghilad fell down to pieces that day. The collapse of the tower of Dumbrava was one of the buildings involved, this study aims to clarify whether the poor condition of the building, or the flaw of the original design was the main reason for the failure in this village.The structural analysis of such historical timber structures can be problematic as the weak joints of the structure limit the load-bearing capacitance in an exceptionally low level if the traditional elastic analysis is used. The present paper points out that the plastic limit analysis can give a more realistic breaking load level for the high order statically indeterminate carpenter roofs.

Finland's wood-frame multi-storey construction innovation system: Analysing motors of creative destruction

Wood-frame multi-storey construction (WMC) is enjoying a period of increasing popularity in the public domain, with ‘timber towers’ and ‘wooden skyscrapers’ being labelled as potential game changers. Yet, whilst WMC is growing in some European cities, it still remains a curiosity. The emergence of WMC is the result of decades of science, technology and innovation policy and entrepreneurial experimentation. The aim of this paper is to analyse the emergence and evolution of the Finnish WMC from a technological innovation system perspective; paying attention to niche creation and regime destabilisation functions and motors of creative destruction. We analyse two distinct periods of activity in WMC innovation. Both were stimulated by government interventions looking to encourage value-added activity for the forestry sector in light of external pressures. Our analysis of WMC innovation systems functions highlights the importance of creative destruction in the science and technology push motor of innovation, especially where niche WMC technologies are competing against the incumbent concrete frame construction system.

Seismic behaviour of a traditional timber structure: shaking table tests, energy dissipation mechanism and damage assessment model

Traditional timber structures are well known as an efficient aseismic structure. In order to clearly understand the reasons for the good performance of the Chinese traditional timber structures during earthquakes, the energy dissipation mechanism of a Chinese traditional timber structure was studied by shaking table tests in this paper. A model at a 1:6 geometric scale was manufactured with the same fabrication methods to the prototype, a Chinese timber tower built in 1834. The model was subjected to 4 different horizontal waves with increasing intensity. The damage patterns, dynamic characteristics, and dynamic responses were obtained. The energy dissipation mechanism of the traditional timber structure was analysed based on the principle of energy balance. A new damage assessment model based on energy dissipation was also proposed and the results showed a good agreement with that given by an existing model.

Medieval Timber Motte Towers

TIMBER TOWERS, raised at castles and on mottes, have not been subject to the kind of extensive research coverage given to masonry examples. This article examines the evidence for medieval timber motte towers in Britain. Their shape and dimensions are discussed and their durability. The use of timber is explored in terms of its contribution to the tangible and intangible qualities of towers and fortifications. The article concludes with an examination of Hen Domen in Wales, and demonstrates that a broader approach to understanding these features can provide insights on medieval expressions of lordship and authority.

Concrete apartment tower in Los Angeles reimagined in mass timber

This study explores the seismic performance advantages and disadvantages of mass timber construction over reinforced concrete construction for high-rise buildings in high seismic regions. In a side-by-side comparison of a 20-story reinforced concrete tower and a corresponding mass timber tower, the timber tower is demonstrated to have roughly half the mass and twice the flexibility of the reinforced concrete tower. Building code minimum for acceleration and maximum for drift govern the lateral design of the theoretical mass timber tower, whereas code minimum acceleration and strength govern the reinforced concrete tower. The study demonstrates that mass timber provides a viable alternative to reinforced concrete construction in high seismic regions.

Super Tall Timber: design research for the next generation of natural structure

This research project aspires to make truly tall timber buildings a reality. Through a combination of theoretical design and physical testing this research demonstrates the viability of timber buildings at much greater heights than has previously been possible. By pushing the limits of theoretical designs into the realms of the supertall, sometimes beyond that which is feasible using current materials and construction technologies, this research also sets out the requirements for the next generation of engineered plant-based materials.The research is a collaboration between academics, practising architects and practising structural engineers. The approach is research through design, and design through research. Timber towers are designed well beyond existing heights, and analysed to understand how they stand up and which areas are most critical for further research. By bringing highly regarded architectural and structural designers together with the research capabilities of a leading university, this project creates a precedent-setting model for interdisciplinary engagement within and between the design and research communities. By coupling exemplary design in timber with a university’s research capacity, the project represents a real opportunity for transformational change in the design of tall timber buildings. Essential details and connections are determined and ‘unknowns’ with respect to material and structural performance are identified. A programme of testing to investigate these unknowns and validate the design approaches is carried out at the university. Outcomes of the test programme and new insights are fed back into the design process.The results show that tall timber towers are feasible, with substantial but surmountable questions outstanding. By providing thought provoking yet credible solutions for the design of tall timber buildings and exceeding current limits, the project can inspire the design community to think beyond the status quo and embrace the possibilities offered by timber construction.

Measuring-up in timber: a critical perspective on mid- and high-rise timber building design

Architects, engineers and researchers alike often cite practical reasons for building with wood. Since the development of curved glulam beams and columns over a century ago, the widespread use of massive structural timber elements has allowed architects and engineers to design and build in wood with unprecedented speed and scale. Moreover, rising concerns of climate change and the carbon-dioxide emissions associated with construction encourage the use of wood as a viable alternative to steel and concrete, due to CO2 sequestration in trees.In mid- and high-rise buildings, the current shift from steel and concrete towards massive structural timber elements like glulam, laminated-veneer lumber (LVL) and cross-laminated timber (CLT) is evident in a number of recently completed timber buildings in Europe, ranging from seven to nine storeys. Several speculative design proposals have also been made for ‘timber towers’ of thirty, fortytwo and even sixty-five storeys, recognising that designing with massive structural timber elements in high-rise buildings is still in its infancy. This paper offers a new perspective on building with wood at this scale, beyond carbon sequestrationand construction.

Learning from Case Studies: Timber Tower of Gospić Cathedral and Traditional Timber Church

The conservation of historical timber structures requires both the knowledge of structural behavior of complete building and behavior of any single element in structure. Because of a poor communication between the institutions involved in the conservation and restoration of buildings and institutions that urgently require renovation of structures, renovation of historic buildings is often performed inappropriately due to engineering and architectural approach. Buildings are frequently subjected to inappropriate interventions, replacements of structural elements, or even worse, they are demolished. First case study in this paper is Cathedral from Gospic city which was subjected to inappropriate reconstruction in 1990s. Second case study is small traditionally constructed timber chapel in village Lijevi Stefanki which represents a valuable monument of rural cultural heritage.

Evaluation of Dynamic Behaviors and Damage Mechanism of Ancient Timber Architectures

An urgent is needed on the preservation of Chinese architectural heritages, since environmental and time impacts have been abating their structural resistance capability. It is of great importance in protecting and rehabilitating the ancient architectural culture of China to study the structural characteristics of ancient Chinese timber architectures. As a typical example of ancient timber architectures-Yingxian Wooden Pagoda in west of Shanxi Prince, the dynamic characteristics and damage mechanics of the tower are investigated experimentally and numerically by micro tremor measurements and means of finite-element-method (FEM). The micro tremor measurements are conducted on the tower (each floor) and the surrounding ground. From the micro tremor observation data, the predominant frequency of the surface ground and natural frequency, vibration mode and the damage distribution characteristics of the tower were evaluated. Based on the experimental studies, the tower is created by a delicate finite element model. And in order to simulate the mortise and tenon joint---bucket arches in the structure, which is a combination of a series of timber structures, a special beam-element group is developed. Numerical simulation of the seismic response of the tower shows that the second and third floors of the tower would be damaged more seriously than other floors for their severe stresses when acted by seismic loading. The present analysis of the tower shows the same phenomena. The results provide basis for repairing and reinforcing the ancient timber tower.

Structural Mechanism and Morphology of Timber Towers in Japan

abstractThe tower of Hohryuji, a typical traditional five-storied pagoda built approximately 1,300 years ago, plays an important role as a religious symbol, but it is also a great cultural asset for the harmony of its inventive high standard of traditional carpentry technology and its morphological beauty. There still exists over 300 of this kind of architecture in Japan today, and are considered as one of the typical Japanese beauty. The morphologies of our traditional timber towers are characterized by the tower's height, and the deep carvings formed by piling roofs projecting outward from its slender body in triples and quintuples. By using data from restoration reports and making models of the traditional timber towers, this paper will focus on their unique morphology and their structures, and investigate their relationship to interpret those special qualities.

The Roman Gask system tower at Shielhill South, Perthshire: excavations in 1973 and 1996

Reports on previously unpublished excavations of 1973 and subsequent investigations in 1996 which revealed a double ditched four post multi-period timber tower forming part of a group of four such towers at the southern end of the Flavian frontier.

A Napoleonic Fire Beacon on Moel y Gaer, Clwyd

This report describes the excavation of two timber towers sited at SJ21086905 on a hilltop in North Wales which commands an extensive view including the Dee Estuary. A brief 19th-century reference provides sufficient clues for their identification as a fire beacon established in 1814 and dismantled at the end of the war with Napoleon.