Wood Columns Research Articles

Carbon Sequestration in Lumber Columns: Facilitating the Reuse of Lumber Waste for Prefabrication through Computational Design and Augmented Fabrication

Industrial prefabrication brings benefits such as higher productivity and reduced waste production. However, waste, cut-offs, and failures cannot be prevented even in a prefabrication setting. Yet, most processes for utilizing scrap materials promote downgrading. This research presents a construction framework to facilitate the reuse and salvaging of lumber waste from a lumber construction company using a computational design (CD) and augmented reality (AR) setup. Specifically, we explore the design of columns based on an inventory of scrap materials and propose a high level of automation (LoA) prefabrication for reusing lumber waste for structural parts. The design and AR framework support the extension of the matching skillset through the integration of existing materials and the automation of creating an assembly plan for AR, improving the reusability of cut-off lumber blocks. It features a design tool for placing existing lumber scrap blocks and an integrated AR application for assembling these blocks into wood columns. The setup is demonstrated through column prototypes, resulting in six columns, each 10 feet high. The proposed methods extend the opportunities for designers to reuse lumber scraps for prefabrication and simplify assembly instructions for craftspeople, providing valuable tools to enable a resource-efficient workflow for lumber scrap.

Investigasi Visual Kelayakan Bangunan Publik di Desa Jamblang

Many functional old buildings and geological condition in Indonesia are prone to disasters, hence, the investigation is needed whether those buildings are still feasible to use. Periodic inspection is one of the methods to review the buildings by standard provisions. In this study, a survey was carried out based on Permen PU No. 16/RTM/2010 and Rapid Visual Screening (FEMA P-154). Both methods were used a special form that investigates the building visually. The purpose of the study was to investigate the existing building by reviewing the damage level of building components from the structural, architectural, mechanical, and electrical aspects, as well as to seismic hazards. Based on the Minister of Public Works Regulation Number 16/RTM/2010, the results show that there are several weathered wood columns and beams, cracked walls, and many piping and electrical that are no longer functioning. Based on Rapid Visual Screening (FEMA P-154), the final value of form level 2 is 0,2 which is similar with the SMin value, which indicating that the condition of the meeting building in Jamblang Village is categorized as prone to seismic hazards, therefore, the structure strengthening is required.

ANALISIS FAKTOR PENYEBAB MASYARAKAT LAMA MEMBANGUN RUMAH BERBENTUK PERSEGI PANJANG DAN KESESUAIANNYA TERHADAP PRINSIP RUMAH TAHAN GEMPA

As an earthquake prone area, building earthquake-resistant houses is a basic necessity for Bengkulu Province residents. The simple symmetrical house plan provides better structure to withstand earthquakes. Batu Kuning is a village located in Ulu Manna District, South Bengkulu Regency, Bengkulu Province. This village is a village that was affected by the earthquake in 2000 and 2007, as well as other earthquakes, although the impact was not as big as the two earthquakes. In the event of the earthquake, several houses were not heavily damaged or destroyed so they are still inhabited today. Observations made by the author found a tendency for the shape of the house to be simple, symmetrical and tend to be rectangular. The research method was carried out by distributing questionnaires to respondents with a total of 26 samples. The results of the questionnaire were processed and analyzed using the SPSS Version 26 program, which included data validity and reliability tests. The results obtained showed 26.72% in strength and resilience factors, 25.63% in economic and cost factors, 25.63% in construction factors, and 22.02% in customs and environmental factors. The dominant factor is the construction factor, with an indicator that the construction of a rectangular house is easier to work on. The suitability level of old people's houses with the principle of earthquake-resistant houses shows that 73.08% uses a continuous river stone foundation with a depth of more than 45 cm. 92.31% of the old community house structure in Batu Kuning Village, Ulu Manna Subdistrict, using wooden columns and beams. The use of lightweight (zinc) roofs is in accordance with the principles of building earthquake-resistant houses.

Material deterioration detection of wooden columns at the Nanyang Fuya Museum using a combination of macroscopic visual inspection and moisture content testing,

Wooden columns, as an important load-bearing wooden component of traditional wooden structures, determine the safety of an entire building. With the increase in material deterioration, the overall health and life of ancient buildings is affected. In this study, the deterioration of wooden columns of ancient buildings in the central axis of the Nanyang Fuya Museum was detected through a combination of macroscopic visual inspection and moisture content testing. The result was that the deterioration degrees and MCs of wooden columns located in the south direction, with good ventilation effect or with oil paint protection were lower than those of wooden columns located in the north direction, with poor ventilation effect or without oil paint protection. The deterioration degree increased with the increase of MC. The results of this research provide the basis for the analysis of the causes and risks of material deterioration.

Experimental Study on the Axial Compression Performance of Glued Wood Hollow Cylinders Reinforced with BFRP

The present paper investigates the impact of basalt fiber reinforced polymer (BFRP) on the axial compression performance of glued wood hollow cylinders. This study aims to facilitate the application of BFRP in the field of structural reinforcement of glued wood hollow columns. Ten glued laminated wood hollow columns of the same size were designed and placed into five groups (ZC1 and ZRC2 to ZRC5), of which one group (ZC1), with a total of two pure wooden columns, was not arranged with BFRP, and the remaining two wooden columns in each group were arranged with BFRP at different distances. The destruction mode, ultimate load capacity, load–displacement curve, load–strain curve, and ultimate load capacity–total area of the BFRP paste curve of each specimen were obtained by conducting axial compression tests on five groups of wood columns reinforced with different basalt fiber cloths, which revealed the damage mechanism, the relationship between the ultimate load capacity and total area of BFRP paste, and pointed out the most effective area ratio. The test results show that the destruction mode of axially pressed, glued, laminated wood hollow columns is typical compression buckling damage, mainly manifested as follows: the wood at the middle or end of the specimen under pressure first buckles; then, with the increase in load, the specimen is crushed; at this time, the maximum ultimate bearing capacity of each specimen is in the range of 296.77~375.85 kN, the maximum longitudinal displacement is in the range of 2.77~3.38 mm, and longitudinal cracks appear at the end. It is worth noting that the growth rate of the ultimate bearing capacity varies with the increase in the total area of the BFRP paste. When the total area of the BFRP paste is less than a 3.2 × 105 mm2 range value, the growth rate of the ultimate bearing capacity is faster, and then, the growth rate gradually becomes slower. The optimum BFRP paste area ratio can be taken as k = 0.59. The ultimate bearing capacity after reinforcement increases from 11.06% to 26.65% compared with the pure wood column. According to GB50005-2017, “wood structure design standards” improve the hollow wood column bearing capacity calculation method and fit the BFRP reinforced hollow wood column’s ultimate bearing capacity calculation formula; the errors are within ±10%, which can provide a reference for the practical application of BFRP in the field of reinforcing glued wood hollow cylindrical structures.

Long-term creep behavior of timber columns: Experimental and numerical protocols

This work deals with an experimental and numerical approach to determining the differed behavior of compressed wood elements subjected to creep loading. An experimental protocol is associated with a mechanical model, whose purpose is to isolate the effects of creep from those of shrinkage-swelling, while allowing for a long duration test to be conducted. The experimental protocol is based on a compression creep test applied to five wooden columns disposed in a climatic room for one year. The numerical model is based on the use of a Kelvin-Voigt rheological model associated with a shrinkage-swelling element. An optimization study is proposed in order to interpolate the model parameters with respect to the experimental measurements. In the context of a linear viscoelastic behavior, the result of this interpolation allows to propose a model extrapolation for long times. Within the framework of the European code, Eurocode 5, this project aims to identify the long-term creep coefficient (kdef) adapted to compressed elements, in addition to evaluating the partial creep coefficients as a function of loading duration class.

Axial Compression Behaviors of Columns Fabricated from Bamboo Oriented Strand Boards

Due to the low specific strength of bamboo oriented strand boards compared with the commonly used wooden building materials, reasonable and novel cross-section designs of bamboo columns fabricated from bamboo oriented strand boards as structural members were investigated. An axial compression experiment was carried out on full-scale bamboo columns to characterize the ultimate behaviors under a concentric load. The ultimate bearing capacities of solid, hollow and five-core columns of the same height were not obviously different from each other. The columns with a larger slenderness ratio showed lower ultimate loads and higher axial deflections. The short columns experienced failure due to material crushing, and the long columns experienced a combination of material crushing and inelastic buckling. The empirical equations for predicting the ultimate bearing capacity for wooden columns showed applicability for bamboo columns. Non-linear finite element modeling analyses were carried out to validate the experimental results, and a satisfactory agreement was found in the failure modes and ultimate bearing capacity.

Tomosynthesis Feasibility Study for Visualization of Interiors of Wood Columns Surrounded with Walls

The need for non-destructive testing and evaluation of Korean traditional wooden buildings is increasing because of their widespread deterioration. Among all types of deterioration, termite damage in wooden columns is the most difficult to detect with the naked eye because it starts inside the wood, and the initial deterioration is small. X-ray computed tomography (CT) is the best technology to investigate the inner state of wood that has less damage, but applying it to wooden columns between walls is challenging. Therefore, the feasibility of tomosynthesis, which is a method to reconstruct a coronal section of a subject with a few X-ray projections from a limited angle of rotation, was studied as an alternative to CT. Pine (P. densiflora) with three artificial holes was prepared as a specimen to evaluate the quality of reconstructed tomosynthesis images according to the different number of projections. The quality of the tomosynthesis images in the in-focus plane was evaluated using the contrast-to-noise ratios, while a vertical resolution between the images was assessed by determining the artificial spread function. The quality of the tomosynthesis image in the in-focus plane increased as the number of projections increased and then remained constant as the number of projections reached 21 or over. In the case of vertical resolution, there was no significant difference when 21 projections or more were used to reconstruct the images. A distinct difference between coronal section images was found when the distance was more than 10 mm from one plane to another plane.

Study on Seismic Performance of Wooden Column in Ancient Buildings under Secondary Loading

In order to provide some scientific references for the restoration of ancient timber buildings, the wooden column was subjected to a secondary load through the quasi-static test. The seismic performance parameters of wooden column such as the damage of the wooden column, P-Δ hysteretic curve, P-Δ skeleton curve and stiffness degradation were analyzed. The test results showed that the wooden column could still maintain the lateral resistance capacity after the secondary load under the action of low reversed cyclic load. The hysteretic curve of the wooden column had a certain degree of a pinch effect, which indicated that the semi-rigid characteristic of the wooden column was reserved after the secondary loading. The lateral stiffness of the wooden column after the secondary load decreases with the increased of the lateral displacement. The lateral stiffness decreases with the increase of displacement. It showed that the wooden column still had good seismic behavior after secondary load.

Life Prediction Model of Wooden Structure Based on Artificial Intelligence Algorithm

The ancient wooden structure in China is a precious architectural cultural heritage in history, which has high cultural and artistic value. However, due to the influence of its own material structure and the long-term preservation and maintenance process, due to long-term loads, earthquakes, fires, man-made damage, etc., ancient buildings have suffered more or less damage, which may cause sudden failure of the structure, which seriously affects the safety of the building structure. Therefore, the research on the prediction of the life of ancient wooden structures has guiding significance for sustainable development. This paper studies the life prediction of ancient buildings and introduces artificial intelligence algorithms. By comparing the old and new of the ancient building with the damage of the various structures of the ancient building, and using a variety of methods to find a more accurate method to predict the life of the ancient building, through various aspects of research and comparison, we have discovered the variation of wooden columns and beams. The coefficients are 22.97% and 22.54%, which affect the service life of wooden members. The residual strength ratios of the compressive design strength and flexural design strength of the new material and the old material are 60.42% and 26.67%, respectively.

Experimental study on mechanical properties of column foot of ancient timber structures – Take the drum-shaped plinth as an example

The column foot is a typical structural feature of ancient buildings in China. The sliding rotation of the joint is related to the overall structural safety of the ancient wooden structure. In order to study the mechanical properties of column foot under horizontal force, based on the investigation of column foot forms and referring to the engineering practice of Qing Dynasty, the 1:3.2 scale models of three typical column foundation forms, i.e. Floating, Guan-jiao, and Tao-ding, were made, and the static and quasi-static loading tests were carried out. The horizontal static loading is carried out under the vertical force, and the parameters such as the angle change of the axis, the horizontal displacement load curve, the lateral stiffness and the failure mode are obtained. The results show that: during the loading process, there is no slippage of the wooden column, and the failure mode of the column foot is the overturning failure of the wooden column; The angle formed by the axis of the timber column accounts for more than 25% of the overall lateral displacement, which should not be ignored in the mechanical analysis. The hysteretic curve, skeleton curve, stiffness degradation rate and energy dissipation capacity of different column foot is obtained in the quasi-static test of horizontal low cycle repeated loading. The results show that the shape of the hysteretic loops of the column foot presents an inverse Z shape, and the area of the hysteretic loops increases with the increase of the horizontal displacement; The results show that the energy dissipation capacity of the flat Floating is better than that of the other two forms, and that of Guan-jiao is the second; The results show that Tao-ding has the strongest lateral stiffness, while Floating is slightly weaker.

Tower transformed to protect the past

Clifford's Tower has graced York's skyline for nearly 800 years, and has now been reopened by English Heritage as a fully restored, technology-enhanced ruin. This current project was to preserve and protect the ruins, particularly vulnerable parts like the upper Tower walls, and provide a more valuable public resource. The solution was an innovative free-standing timber deck from which steel walkways were suspended at mid-floor height. The deck protects the very top of the walls without placing any strain on them. The weight of the deck - and the 150 people that can be on it at any one time - is carried by the four wooden columns. These are made of Glulam - wood laminate glued together under heat and pressure to provide an incredibly strong, and environmentally beneficial, alternative to steel.

Algorithm for developing a computational model of a wooden multi-storey building

Introduction. The idea of building wooden multi-storey buildings in Russia is becoming more and more relevant every year. The emergence of new technologies makes this area of construction promising. The purpose of the article is to illustrate the stages of design, which will contribute to the successful development of projects of multi-storey buildings, where wood is used as the main material of load-bearing structures. As a confirmation of the correctness of these algorithms, the results are demonstrated.
 
 Materials and methods. For a general representation of the stages of construction of this type of objects, an algorithm for their design is given, which allows to streamline the process of selecting structural elements, to focus on the key points of the design process, which ultimately facilitates the complexity of designing this kind of structures. The use of wooden components made of CLT, LVL and glued wooden columns is proposed as bearing elements. Calculations of structures were carried out taking into account the software package in compliance with the current regulatory documentation.
 
 Results. After analyzing the key aspects according to the developed algorithm, it is necessary to proceed to solving the main issue of the development of the building’s load-bearing system. The creation of the model in question was carried out using three-dimensional design software products, followed by calculations by Autodesk Robot Structural. With the help of the calculation program, the results of bending and internal stresses were obtained. Based on the results of calculations of the load-bearing structural elements, a comparative analysis of the load-bearing characteristics in various types of structural systems was performed.
 
 Conclusions. Thanks to the competent study of key issues at the initial stages of design, it is possible to achieve a balanced model of a multi-storey wooden building, which is successfully implemented by builders.

Example Analysis of Digital Wireless Mapping Applied to Construction Engineering Measurement

This paper provides an in-depth study and analysis of the measurement of construction projects using digital wireless mapping and illustrates it using examples. Static measurements determine the relative positions between ground points with high accuracy using a baseline vector network composed of simultaneous observations by multiple receivers, using the correlation of errors in space and time. Technology-based on this error correlation, then the distance observation error or coordinate observation error measured by the base station is sent to the mobile station through the data chain to correct the station star distance observation or coordinate value of the mobile station, improving the operational accuracy and efficiency of the mobile station. The measurement avoids the tedious measurement organization work and long-time data collection and postcomputation work of static measurement, and the coordinates of the mobile station can be obtained in real-time. To verify whether the accuracy of the 3D model built by the 3D reconstruction method integrating UAV and camera (air ground) images can meet the accuracy requirements for the installation deviation detection of the assembled building components, the 3D reconstruction of the physical objects was completed by this method. The accuracy of the 3D model built by this method was evaluated by comparing the measurement coordinates of 25 prearranged checkpoints in the 3D model with those of the total station. The test results show that the maximum point accuracy of the 3D model is 2.305 mm, and the average medium error is 2.147 mm, which can meet the accuracy requirements of the installation deviation detection of the assembled building components. The detection of installation deviation of wooden columns was completed by measuring the 3D model, and it was verified that the method is intuitive, fast, accurate, and batch completion of the deviation detection of axis position, elevation, small labour, batch detection of components, and contactless mapping compared with the traditional detection methods.

Application of multi-camera digital image correlation in the stability study of the long timber column with the circular cross-section under axial compression

Displacement meter synthesis (DMS), as a traditional method, is widely used to capture the local deformation of a specimen. However, for axis-symmetrical circular columns, the axial compression instability cannot be accurately evaluated using the DMS method due to the uncertain bending direction. To address this problem, a 360° full-surface digital image correlation (DIC) system composed of eight cameras is proposed to capture the full-field deformation information of the column surfaces under axial compression. The objective of this study was to experimentally validate the efficiency of the proposed novel measurement in tracking the full-filled compressive deformation of a long wooden column with the circular cross-section. The test results showed that the columns experience instable failure. The multi-camera DIC system can completely reconstruct the three-dimensional shape of the circular column and obtain the whole process deformation state at any position on the surface of the timber column. The DIC method also can capture the uncertain lateral deformation direction and obtain the data of lateral deflection at the mid-span of timber columns. The multi-camera DIC provides an intuitive and comprehensive new test method for the test and analysis of the stability of axisymmetric long timber columns.

신한옥형 공공건축물 보급 및 확산을 위한 법 제도적 정책 제언

Purpose: From 2009, Ministry of Land, Infrastructure and Transport is conducting study to introduce the concept of “New Han-Ok style”, which has a high degree of freedom and utilization than basic Han-Ok and Transformed Han-ok, and to extend it to public buildings. As a result of the study, 4 New Han-Ok public buildings were constructed from 2015 to the present, but their evaluation and recognition are still limited. Therefore, this study intends to find out the policy alternatives necessary for the spread of New Han-ok style public buildings through the activation policies and related projects in the traditional Han-Ok. Method: Currently in Korean law, “Han-Ok” means a traditional building, whose main structure of which consists of wooden columns, beams and Korean style roof frames. But there are no exact regulations on the New Han-Ok and Han-Ok Architectural style in the same law. And also the central and local governments are providing support projects limited to traditional Han-Ok for real life and residence purposes, so it is difficult to support modern Han-Ok that is unsuitable for legal conditions. Result: As a result, it is effective to use public buildings that are more accessible than individual residential Han-Ok to revitalize Han-Ok, and the state needs to establish policies to promote Han-Ok culture centered on public buildings. In addition, further studies related to Policy on the standardization of the Han-Ok industry and the easy dissemination of Han-Ok technology are needed for spread and expand interest to Han-Ok.

Beyond Bauhaus: Modernism in Britain, 1933–1966

Beyond Bauhaus: Modernism in Britain, 1933–1966

Effects of dowels on the mechanical properties of wooden composite beams in ancient timber structures

In order to provide more accurate suggestions for the restoration of ancient timber buildings, five types of specimens were designed for static loading tests. The tree species used for the specimens was larch. The wooden composite beams were composed of purlins, tie plates, and fangs. The study analyzed the effects of the number and position of dowels on the mechanical behaviors of wooden composite beams in ancient timber buildings. The bending moment, slippage, strain of the wooden composite beams under the deflection of the beam allowed according to code, and the ultimate bearing capacity of the wooden column composite beams under failure conditions were examined. The test results showed that the dowels could improve the bending capacity of the wooden composite beams. The even distribution of the dowels was beneficial in reducing the sliding effect of the wooden composite beams. Under the amount of deflection allowed by the code, the mid-span section strain along the height of the wooden composite beam approximately conformed to the plane section assumption. The wooden composite beam still had bending capacity after each member failed. The results of this study illustrated that dowels improved the overall mechanical properties of the wooden composite beams.

Seismic behaviour evaluation of CLT horizontal diaphragms on hybrid buildings with reinforced concrete shear walls

In the last years in a worldwide level, the number of CLT buildings in height has been increased. In seismic countries, the design of these buildings is limited because there are still discussions about parameters of wood seismic design such as the modification factor of structural response and the allowed story drift. In this context, a hybrid building shaped by a gravity slab system (CLT) and wood columns combined with a seismic-resistant system of reinforced concrete cores, allow the use of wood in high buildings with fewer restrictions than CLT buildings.Each floor of the hybrid building explained before is composed by a horizontal diaphragm, shaped by CLT panels and connections that provide flexibility to the system. Due to the horizontal diaphragm role in the transfer of seismic loads to the vertical elements, the traditional design expects the diaphragm to behave inside the elastic range. Therefore, the study of the behaviour in a hybrid configuration is taking relevance.A group of four hybrid buildings with different configurations was submitted to three types of analysis (nonlinear static, spectral modal, time-history), which demonstrate an oscillating seismic behaviour among semi-rigid and flexible. Also, the connections of the models submitted to the time-history analysis were not in the inelastic range, which was justified by the correct choice of the design model. Finally, it was concluded that the correct diaphragm classification is very important because it was demonstrated that increasing the flexibility of the diaphragm increased their demand and decreased the demand on the walls.

The Thermal Performance of Chinese Vernacular Skywell Dwellings

The aim of this research was to investigate the thermal performance of Chinese vernacular skywell dwellings. This was done by the analysis of on-site measurements of the environmental performance and computer simulation of solar conditions of eight vernacular skywell dwellings in three villages in southeastern China—Xidi, Zhifeng, and Yuyuan. Through the discussion of several heat inputs and outputs, it can be concluded that evaporative cooling had a substantial influence on the temperature in the skywells of dwellings in Xidi and Zhifeng villages. In addition to the buffering of temperature by thermal mass, evaporative cooling was found to further reduce the fluctuation in temperature inside the skywell and is likely to have been the main reason that the mean dry bulb temperatures inside the skywells in these villages were lower than the mean external dry bulb temperatures. Moreover, the construction materials of Chinese vernacular dwellings (skywell wall, floor material, wooden column, and panels) are likely to be hygroscopic.