Timber roof structure for outdoor auditorium in Parque Paraiso, San Blas (Madrid)

p. 468-475A timber shell structure is designed to provide covering for an outdoor auditorium in Madrid (Spain). The covering comprises five independent overlapped marquees with similar shape but diverse dimensions. The surface geometry of each marquee is defined by a hyperbolic paraboloid, with its boundaries delimited by elliptical curves in horizontal projection. Structural section for the timber shell is a composite section with several staggered layers of straight sawn timber planks, arranged in two orthogonal directions following the straight skew lines of the hyperbolic paraboloid. Over them two continuous top layers are arranged which provides bracing for the structure and support for the waterproofing material. Each layer is laid over the previous one, bolted and glued with polyurethane adhesive. Special characteristics of the design analysis and detailed erection process are described. The designed solution provides lightweight roofing with a powerful and original image, short construction time and reasonable budget.Anton, A.; Meijide, AG.; Corbal, JJ. (2009). Timber roof structure for outdoor auditorium in Parque Paraiso, San Blas (Madrid). Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/653

Analysis of timber as sustainable material for construction

Comunicació presentada a IN-TECH 2014 International Conference on Innovative Technologies (Leiria, Portugal 10-13, september 2014).Facing the climate change scenario, professionals and technicians of civil engineering and architecture are searching for ecological solutions and construction methods that would allow for higher energy-efficiency and then reduce environmental impacts. Timber represents one of the best choices for energy-efficient construction, since it also functions as a material with good thermal transmittance properties if compared to other construction materials. This work analyses the possibilities and benefits that wood offers for the construction industry, in terms of sustainability. On the one hand, the sustainable forest management system contributes to ensure the quality and well-management in the exploitation of the forest in order to produce timber and other sub-products such as cork, paper and tree resins. In relation to this, the construction industry has an important role to increase the level of sustainable products by demanding certified timber. On the other hand, due to its Life Cycle Assessment (LCA), timber has the lower energy consumption compared to other building materials, as well as the CO2 stored and saved contributes to mitigate climate change. The LCA stages for the production of timber, the potential of saving carbon emissions and its comparison with other building products are presented. Concerning energy efficiency, once timber is implemented in a building taking part of the structure or as cladding material, it provides a high insulation decreasing the thermal transmittance of the walls, roofs, floors and windows. Its versatility as construction material also enables obtaining innovative solutions which can be implemented in buildings, as it is presented in this study. The optimum energy performance and low carbon emissions of timber make from this product a suitable and sustainable material to be highly considered for the construction industry

Multi–scale modelling of timber–frame structures under seismic loads

This paper introduces a versatile hysteretic constitutive law, developed for various joints with steel fasteners commonly used in timber structures (nails, screws, staples, 3D connectors of bracket type, punched plates). Compared to previous models available in literature, the proposed one improves numerical robustness and represents a step forward by taking into account the damaging process of joints with metal fasteners. Experimental tests carried out on joints are used for calibration purpose, and quasi–static and dynamic tests performed on shear walls allow validating the proposed Finite Element model. Finally, the development of a computationally efficient simplified FE model of timber–frame structures for shear walls is described, with emphasis on its validation and its use at the scale of a complete structure

Exchange Rates and the Competitiveness of the US Timber Sector in a Global Economy

This paper examines the competitiveness of the US timber industry under different exchange rate policies using a dynamic optimization model of global timber markets. We assume that exchange rates affect the cost structure of harvesting and managing forests and simulate the model for baseline conditions and four additional exchange rate policies. Two policies consider a strengthening United States dollar scenario and two policies examine weak South American currencies. Recently South America has increased its share of global timber production and is shipping increasing quantities of timber to the Unites States. The results indicate that US competitiveness in the forestry sector is sensitive both to strong US $policies and to the weak currency policies pursued by South American governments. A 20$ compared to all other currencies can reduce harvests by 4 7% in the United States over the next 50 years, while a similar reduction in currency values in South America can reduce U.S. production by around 0.4%. In dollar terms, each additional cubic meter of wood produced in South America due to currency policies can reduce producer surplus in the United States by $100.International Relations/Trade,

Economic development of a peripheral region: the case of Karelian timber industry

This paper focuses on current patterns of restructuring in Russian Karelia's timber industry, which constitutes the backbone of the regional economy. In particular, the paper investigates the relationship between an increased export orientation of this industry and a notable worsening of its output structure, combined with a lack of technological innovations. This situation results in a general instability of Karelian economy, which is increasingly dependent on fluctuations of international timber prices, as well as on exchange rate policy of the Russian government and central bank. This results in a decline in Karelian living standards, especially in remote rural settlements, which are crucially dependent on export of raw timber. Moreover, the current business climate in Russia strengthens Karelia's specialisation in export of raw timber and deters investment in higher-added-value timber-processing industries. The paper discusses this relationship and suggests that the Republic should start to stimulate the development of domestic-market-oriented timber-processing industries on account of an active inward investment promotion strategy.

Scientifically based biodiversity management in timber concessions: contribution to conservation and sustainable use of biodiversity

During the past 25 years, forest laws in Central African countries have undergone major changes. Management plans were made mandatory: nearly 19 million hectares of timber concessions (38% of total granted concessions) were subject to a management plan in 2013 and the dynamics is currently underway. The management plan is based on a set of technical and scientific studies, including statistical surveys (management inventories) covering the whole concession and taking into account all timber species, large mammals and the main non timber forest products. These inventories allow, at concession level, to characterize ecosystems and to assess the forest conservation values, through floristic and faunal biodiversity indicators and by taking into account threats to the forest ecosystems, especially anthropogenic ones. Such management inventories are used especially for planning and forecasting harvests, while minimising environmental impacts on the forest structure and functioning, and retaining regeneration capacities of the timber species and the forest ecosystems. The knowledge gained on specific and ecosystemic biodiversity helps to define management rules to ensure the sustainability of different timber species' populations, noticeably the exploited ones. It is also used to design areas within the concessions were exploitation will not take place due to conservation interest (most biodiversity-rich areas, protection of rare or endangered species...). Such so-called “conservation series” therefore complement the protected areas network. Well-managed forest concessions can help conserve the regional forest ecosystems and maintain essential functions that they provide. However, management plans were up to now designed at the concession scale. Data acquired in forest concessions also significantly contribute to improve knowledge of the forest ecosystems and their functioning at the regional level. Using this data, the CoForChange Project (http://www.coforchange.eu) issued a map of the forest ecosystems developed in the "Sangha River Interval" region. This project suggested that those forest ecosystems could react differently to disturbance, and could need an adaptation of management methods to each ecosystem. Based on forest inventories, other initiatives are underway to map the forest types and the biomass stock at the scale of Central Africa, and might be of particular interest for policy decisions on forest ecosystems. (Texte intégral

How to use a nondestructive evaluation of timber structures

A variety of NDE techniques can be employed by an inspector in order to determine the condition of an timber structure. Advances are needed to improve the effectiveness of predicting timber properties and overall structural capacity from various NDE methods. The goal of this paper is to describe a combination of techniques that will provide a more effective prediction of timber structure condition and capacit

Timber load-bearing structure of a sports hall

Obsahem diplomové práce je návrh a posouzení dřevěné nosné konstrukce sportovního objektu s kruhovým půdorysem, tzn. ve tvaru kopule. Konstrukce je navržena jako: geodetická a žebrová kopule. Obě jsou z lepeného lamelového dřeva s podružnými prvky z rostlého dřeva.The diploma thesis covers a design and an assesment of a timber bearing structure of sports hall. The plan of the hall is round, i.e. the object is shaped as a dome. The structure is designed in two ways: geodesic and ribbed dome. Both options are made of glued laminated timber and structural timber.

Bolts connection technique of bamboo in construction work

The construction industry is increasingly developing and growing rapidly with more advanced technologies. The world timber demand is increasing at a rapid rate but the timber supply is however depleting. It has been found through research that bamboo can suitably replace timber and other materials in constructions. This study was conducted to investigate the structural strength of bamboo connections involving only spliced joint and compared with control samples strength of bamboo which were not connected. Bending test was conducted on four types of bamboo connection structures which werehalf-lapped splice joint using 3 bolts, half-lapped splice joint using 2 bolts, side plate splice joint, sleeves and insert joint and control sample bamboo. Every connection had six samples to determine the structural strength of the bamboo connection. From the tests conducted, the maximum load that can be borne by the bamboo structure and the bending ofthe bamboo structure will be obtained. Data were compared with the theoretical calculation based on the study of Janssen's. The connection structure that can bear maximum load was sleeves and inserts which was 5.997 kN. The control samples bamboo maximum load was 4.504 kN. Meanwhile, half-lapped splice joint using 3 bolts and 2 bolts were 4.789 kN and 4.04 kN. Structural connections that carriedthe lowest load was side plate splice joint which was only 2.659 kN.Compared with the bending moment of Janssen’s theory, all the connections did not exceed the maximum allowable bending moment. This showed that the study was in accordance with the standards approved by Janssen's theory. The study found that the structure of connections that can be used in the construction work was sleeves and inserts

Study on China's timber resource shortage and import structure:natural forest protection program outlook,1998 to 2008

The state of China's ecological environment has improved to some extent since the Chinese government initiated the Natural Forest Protection Program (NFPP) in 1998. The logging prohibition and limitation policies adopted by the NFPP, however, have reduced domestic timber supply. Together with the thriving economy, decreasing domestic timer supply continues to widen the gap between supply and demand. Importation is considered to be the primary solution to this issue, making China the world's largest timber importer. China's major timber suppliers are Russia, Malaysia, Papua New Guinea, New Zealand, and Gabon, among which Russia accounts for more than 61 percent of China's total timber imports. The relatively cheaper conifers imported from Russia account for more than 60 percent of all imported timber, with volumes continually increasing because of the rapid pace at which China has been implementing its infrastructure projects. In addition, as living standards continue to improve, requirements for home decor and furniture also grow, further increasing the demand for tropical to temperate timber. In the long term, imports will remain the main solution to the insufficient domestic timber supply in China.NFPP; timber resource shortage; timber import structure