Timber Frame Structures Research Articles

Effect of lintel on horizontal load-carrying capacity in post-beam structure

This study is aimed to evaluate whether lintel has structural effect because it has not been categorized as a structural member. This study experimentally evaluated the horizontal load-carrying capacity of post-beam timber frame structures with bi-linear model and energy dissipation mechanism. To evaluate the effect on horizontal performance of lintel which has been widely used as wall frame in Korean traditional post-beam structure, two frames were tested in different types. One had no lintel and the other one had lintel at the height of 800 mm, respectively. Cyclic loading tests were conducted for each frame according to the standard loading protocol. Frame which had lintel showed slightly higher stiffness. And it showed noticeably significant energy dissipation performance after yield point of the joint. And that leads to the conclusion that lintel has structural effect and it should be considered as an important factor when evaluating horizontal performance of the structure after yield point of the joint.

Gravity and Wind Load Path Analysis of a Light-Frame and a Traditional Timber Frame Building

The objective of this study was to compare structural load path and system behavior of a light-frame (LF) and a timber frame (TF) structure. This load path analysis is part of a broader research effort that compares LF to TF residential structures. Structural analysis software was used to create a model of each structure. The TF structure was composed of large-dimension timbers and structural insulated panels (SIPs). An equivalent LF structure was designed for comparison, following the guidelines of the International Residential Code. Results show that TF outperforms LF in resisting uplift, as well as in story drift. TF also provides load paths that are more resistant to the introduction of large openings and the loss of a central post. Observed axial loads in TF posts show smaller ranges compared with LF studs.

Static and Thermohygrometric Analysis of a New Typology of Timber Framed Structure in Dolomites

In this paper a study is presented about timber frames structures in Dolomites area. A wood timber frame construction system spans across a very long period in time and across a broad geographical area. The construction elements have guaranteed longevity to structures located in very different areas, under a geographical, climatic and seismic point of view. In most frames cases, it is the masonry that constitutes the filling. This construction system in Europe has been used both for dwelling and work buildings. Timber frames solutions have been chosen according to local traditions, historical and economical context. This construction procedure is widespread present in the area of the Dolomites; in particular in the valleys nearby Cortina DAmpezzo, where environment conditions are particularly severe: traditional constructions used to combine the dwelling part with the barn. These buildings are nowadays, in a lot of cases, abandoned and there is no sign of interest as for a new use of them due to many changes, such as the disappearing of grazing and agriculture activities, the consequences of modern living on environment. Aim of this paper is to present a new kind of building (designed for housing), entirely wood framed (static function), filled with masonry (environmental comfort) and preserving the features of traditional buildings: proportions of the housing and of the frames, visible frame structure. The environmental comfort is provided by interior masonry filled frames. The paper presents the thermohygrometric analysis of the walls, the structural verifications of the main elements constituting the frame and the connections between them. Finally, attention is drawn to the aspect of durability indicating the proposed protective measures.

THERMAL PERFORMANCE OF THREE DIFFERENT STRAWBALE BUILDINGS AT THE KERKENES ECO-CENTER

By and large, straw is not considered to be a building material, yet in comparison with traditional materials, building with straw bales is definitely more energy-efficient, eco-friendly, and low-cost; qualities that are desirable in sustainable buildings. This paper presents information on three different straw bales buildings at the Kerkenes Eco-Center, which is located in the village of Sahmuratli in central Anatolia, Turkey. The first of these was constructed with load-bearing straw bale walls; the second with straw bales as infill in a timber-frame structure; while the third utilized straw bales in combination with Autoclave Aerated Concrete (AAC) blocks. This last was a hybrid wall construction that has been tried for the first time to take advantage of the thermal-insulation property of straw combined with the humidity-regulating property of mud plaster inside and the weather-resistance property of AAC outside. These three buildings are being monitored for their temperature and humidity variances with the help of data loggers; this data is also presented herein.

In-plane shear behaviour of traditional timber walls

The reconstruction of Downtown Lisbon after the 1755 earthquake was based on a novel constructive system of masonry buildings with an internal three-dimensional timber-framed structure named “gaiola pombalina”. This internal structure aimed at improving the global stability of masonry buildings, enhancing their capacity to dissipate energy under seismic loadings. But this structural system is not only typical of Portugal, but constitutes part of the built heritage of various countries. This paper aims at getting experimental insight on the mechanical behaviour of timber-framed walls subjected to in-plane loading, as only scarce information is available in literature, in order to assess their effective performance to seismic actions. To do this, the experimental results of cyclic tests carried out on traditional timber-framed walls with distinct typologies will be analysed, namely (1) unreinforced timber-framed walls without infill; (2) timber-framed walls without infill with Glass Fibre-Reinforced Polymer sheets (GFRP) placed at the connections; (3) timber-framed walls with brick masonry infill.

Timber Engineering Notebook No. 5: Timber frame structures – platform frame construction (part 3)

Timber Engineering Notebook No. 5: Timber frame structures – platform frame construction (part 3)

Timber Engineering Notebook No. 4: Timber frame structures – platform frame construction (part 2)

Timber Engineering Notebook No. 4: Timber frame structures – platform frame construction (part 2)

Timber Engineering Notebook No. 3: Timber frame structures – platform frame construction (part 1)

Timber Engineering Notebook No. 3: Timber frame structures – platform frame construction (part 1)

Design Integrated Parametric Modeling Methodology for Han-ok

Han-ok, the traditional Korean house, has the timber frame structure which is common in East Asia. Because the timber frame structure requires a vast amount of hand-cutting woodwork, prefabrication based on computer aided manufacturing (CAM) should be applied to reduce the construction cost of Han-ok. In order to implement them successfully, it is necessary to manage the building information in an organized system based on data handling technology, such as building information modeling (BIM) and parametric modeling. Three-dimensional, object-based parametric modeling technology not only enhances the construction process but also associates well with design study, especially when applying it to Han-ok. By applying the principle of Kan, the Korean traditional concept of a bay, this paper suggests a parametric modeling methodology that reduces modeling tasks and increases the efficiency of design study.

Business Process Reengineering in The Construction Of Precast Timber Frame Buildings

This study deals with the issue of optimising the work processes of a company building precast timber frame structures, primarily intended for the long-term stay of people, such as: family houses, kindergartens, hotels etc. The issue is considered within the framework of the business process reengineering of the company. At the end a proposal is given for the optimal organizational structure of the company. The basis of the study is found in the importance of precast building in the contemporary way of life. The increasing demands of energy and ecology, the need to reduce the stress of those involved in the construction process, the pace of building etc., are only some of the reasons which favour the construction of precast, timber frame buildings. In this context, we are referring exclusively to construction using precast elements (panel construction) with the maximum degree of readiness, which at the same time enables quick and good quality construction. However, the high level of readiness of the panels is also linked to an increase in the risks of production (the occurrence of faults and their consequences) which necessarily requires detailed analysis of the organizational system of the company. This study attempts to direct consideration towards the optimal organizational structure of a company dealing with constructing precast timber frame buildings, which on the one hand ensures production of the quality required, and on the other finds an optimal solution to the question of the organization of production, social relationships within the company, worker satisfaction etc. In the end this should result in optimization (increase) of profits.

Surface rupture of the Greendale Fault during the Darfield (Canterbury) earthquake, New Zealand

The Mw 7.1 Darfield (Canterbury) earthquake of 4 September 2010 (NZST) was the first earthquake in New Zealand to produce ground-surface fault rupture since the 1987 Edgecumbe earthquake. Surface rupture of the previously unrecognised Greendale Fault during the Darfield earthquake extends for at least 29.5 km and comprises an en echelon series of east-west striking, left-stepping traces. Displacement is predominantly dextral strike-slip, averaging ~2.5 m, with maxima of ~5 m along the central part of the rupture. Maximum vertical displacement is ~1.5 m, but generally < 0.75 m. The south side of the fault has been uplifted relative to the north for ~80% of the rupture length, except at the eastern end where the north side is up. The zone of surface rupture deformation ranges in width from ~30 to 300 m, and comprises discrete shears, localised bulges and, primarily, horizontal dextral flexure. At least a dozen buildings were affected by surface rupture, but none collapsed, largely because most of the buildings were relatively flexible and robust timber-framed structures and because deformation was distributed over tens to hundreds of metres width. Many linear features, such as roads, fences, power lines, and irrigation ditches were offset or deformed by fault rupture, providing markers for accurate determinations of displacement.

Twenty Years of Improvement in the Seismic Performance of Masonry Veneer Construction

A lot of clay has flowed through the kilns since the 1989 Newcastle earthquake. Several significant changes have occurred to make masonry veneer construction safer and stronger over this period, both in the methods of construction of the veneer and the understanding of the behaviour of the veneer panels. These changes have lead to the conclusion that masonry veneer construction can be reliably considered to provide some bracing resistance to a light timber-framed structure, even if only to resist its own inertial loads. Recent research undertaken at BRANZ has investigated the behaviour of full-scale brick veneer single- and two-storey buildings under slow static and dynamic cyclic loading. This paper describes the developments that have occurred since 1989 and this recent research that has provided the new confidence in the seismic performance of clay brick veneer.

Super-light concrete with pearl-chains

The paper presents a new technology invented by the author by means of which it is possible to create very light concrete structures. The new super-light structures are resource-saving in terms of consumption of raw materials and energy for production and transport, and the cost is often less than half that of similar structures in concrete and steel. They are heat-insulating, fire-resistant and they open up the possibility for large spans and the creation of advanced shapes. Fields of application include roofs, shells, beams, columns, walls, façades, offshore structures, tunnels and structures with large spans for bridges, factories, warehouses, shopping centres, car parks, assembly and sports halls and so on. The new structures are new applications for well-understood components, so it is not necessary to prove that they are possible. However, the paper presents tests that were made to illustrate the applicability and to reveal any potential hidden problems. Continuing research will aim to reduce the weight and thereby the resource consumption further. In addition, the paper introduces pearl-chain reinforcement, which is a new principle for creating compression and tension zones. A small number of simple mass-produced prefabricated components are used to establish compression and tension zones for optimised or advanced shapes in super-light structures. Furthermore, the principle provides new options for prestressing light aggregate concrete structures in general. Pearl-chain reinforcement is self-supporting. It is visible and open for inspection before being cast into a structure, and it can support moulds for the structure, reducing the need for scaffolding. Stable meshes of pearl-chain reinforcement are advantageous for both large-scale structures, such as bridges, girders, shells and domes, and for small-scale applications, such as façade elements, crash barriers and secondary structures. One special small-scale application of the principle is in frame building, where super-light frames with pearl-chain-reinforced components have some of the same advantages as timber-frame structures with regard to stability, heat insulation, economy and simple erection processes, but without the disadvantages of fire and rot.

ガラス繊維強化ナイロン樹脂を用いた合理化軸組工法（第2報）

ガラス繊維強化ナイロン樹脂を挿入型のプレートとして用いるドリフトピン接合を考案し，前報においてドリフトピン1本によるせん断性能を調べた。今回は種々の軸組接合部について引抜およびせん断耐力試験を行い，強度性能をプレカット接合部および金物接合部と比較検討した。柱-土台接合部の引抜許容耐力は15.3 kNで，山形プレートによる金物接合部よりも高くなったが，初期剛性は低くなった。梁-梁接合部のせん断許容耐力は20.7 kNであり，腰掛け蟻接合したプレカット接合部より低かったが，最大荷重，初期剛性，降伏耐力および終局耐力はこれより高くなった。柱-梁接合部のせん断試験では，プレートの破損による脆性的な破壊が生じたため許容耐力は28.1 kNとなり，かたぎ大入れほぞ差し接合したプレカット接合部より低くなったが，初期剛性，降伏耐力および終局耐力はこれより高くなった。

Multi-Storey Timber and Mixed Timber–RC/Steel Construction in USA

Multi-storey timber-frame construction is used in North America for both residential and commercial structures. Timber is the predominant structural material used in residential construction throughout the USA. Reinforced concrete and steel assemblies mixed into timber-frame structures provide added performance for fire protection and earthquake resistance. This paper reviews the development of multi-storey timber-frame construction in the USA and the use of timber-frame mixed with concrete and steel elements.

Base isolation of timber-framed buildings

This paper investigates the practicality of using base-isolation devices to protect lightweight buildings, such as timber-framed houses, against earthquakes.
 As the timber-framed buildings considered are designed to a lateral seismic force of 0.24W in Wellington (where W is building weight), it was considered that the appropriate isolation level should be significantly lower, say 0.1W, and lower still in Auckland where such buildings are designed for a lateral force of 0.12W. An analysis showed that houses which had a base-isolation yield set to yield at 0.1 W would have unacceptable deformations under the design wind load if the isolators were located beneath a timber floor, but may be satisfactory if located beneath a concrete slab. A large-scale test using isolators beneath pre-cast floor slabs showed the method used would work even if it was unduly expensive. However, an analysis indicated that there might be little protection for some building contents.
 A literature survey of alternative base-isolation solutions showed a wide range of innovative, but often impractical, concepts have been proposed. However, one concept showed promise for timber-framed structures. This used two layers of synthetic sheet beneath a concrete floor slab to provide a slip layer. The sheet materials recommended reputably gave a dynamic friction coefficient of 0.07. BRANZ measured the friction coefficient using large samples of both these and other sheet materials. It was concluded that the measured friction was too high for use for the planned buildings, although it may have application for low-rise heavy-brittle construction.
 Alternative base-isolation concepts are presented which will be useful to others interested in this topic.

A Semi-Elliptical, Timber-Framed Structure at Inveresk (The Most Northerly Amphitheatre in the Empire?)

Excavation carried out prior to the development of Park Lane Hospital, Musselburgh revealed the partial remains of a probable ring-groove house of first millennium B.C. date and a later sub-rectangular, post-built structure attached to a curving fence line. Although initially interpreted as a Roman granary, it now seems likely that the features were the partial remains of a timber amphitheatre associated with Roman Inveresk. Ditches and a number of negative features of unknown date and function were also recorded.

木質ラーメン構造による実大3層立体フレームの振動台実験

Full-scale tests were carried out to examine the seismic performance of three-story timber frame structure with moment resisting joints. Size of this frame is 5,460mm by 5,460mm wide and 8,580mm height, total weight was 163kN. Specification of damage points, i.e. repair point, was controllable with this method which is concentrated damage points to the joint parts. This structural frame was repaired after the shaking table tests, and examined the effect of these repairs. The experimental result showed not only high resistance to earthquake but also effect of repairs. About comparison of experiments and analysis, both Static and Dynamic analysis almost coincided with each experimental results.

軸組構法２階建木造住宅の振動台実験に基づく損傷同定手法の検討

In this study, based on the shaking table test of two-storied timber frame structure, we examined the validity of damage detection indices calculated by using response accelerations and strains, which were previously proposed for a unit frame. Applicability of the index f1, based on the negative slopes of bending moment, became poor for the two-storied timber frame structure compared to the previous test of unit frame. While the index f3, based on the discontinuity of strain energy, still can detect damage time and location of column accurately. Furthermore, a new index considering both f2, using the negative slopes of shear force, and f4, based on the discontinuity of kinetic energy, was proposed. The index accurately detects damage time when somewhere damaged in the whole structure.

Diagnosis and monitoring of timber buildings of cultural heritage

The aim of this paper is to present a methodology for the evaluation of historical timber frame structures, based on numerical modelling coupled with on site measurements. The underlying question which is raised in this research project is: how can we assess the current state of safety of a structure which has several centuries of existence, and is likely to undergo new loads for various reasons? The dynamic response of a timber frame bell tower to the swinging bell action has been measured at critical points, identified by a parametric study, and compared to a FE analysis of the system, using modified EC5 assumptions. The results have shown that the kinematics of horizontal displacements is correctly described by the numerical model, as well as the calculated amplitude of movements.