Logistics planning is a critical part of developing supply chain for modular integrated construction (MiC) projects in Hong Kong where high-rise, high density and hilly landscape is the norm. It is important to minimize the total logistics and to guarantee timely delivery of modules, especially for several MiC projects being constructed during the same period. Nevertheless, there is a significant lack of studies on logistics planning, optimization and visualization for MiC projects. The aim of this paper is to establish an integrated MiC logistics planning and visualization platform, which is grounded on the integration of building information modeling (BIM), geographical information system (GIS) and vehicle routing problem (VRP) algorithm. The framework is then presented and evaluated using a case study to identify optimal logistics scenario of trailer routes to meet the installation time window of MiC projects in Hong Kong. The paper finds that the proposed platform has the ability to make optimized logistics scenario for MiC projects, and to visualize the logistics scenario in a 3-dimentional interactive environment. Future study will focus on adopting flexible control strategies and including more decision-making criteria of logistics planning in MiC projects such as road width limitation, travel speed and different module types
{"title":"Logistics Planning and Visualization of Modular Integrated Construction Projects Based on BIM-GIS Integration and Vehicle Routing Algorithm","authors":"Sanyuan Niu, Yezhou Yang, W. Pan","doi":"10.29173/MOCS141","DOIUrl":"https://doi.org/10.29173/MOCS141","url":null,"abstract":"Logistics planning is a critical part of developing supply chain for modular integrated construction (MiC) projects in Hong Kong where high-rise, high density and hilly landscape is the norm. It is important to minimize the total logistics and to guarantee timely delivery of modules, especially for several MiC projects being constructed during the same period. Nevertheless, there is a significant lack of studies on logistics planning, optimization and visualization for MiC projects. The aim of this paper is to establish an integrated MiC logistics planning and visualization platform, which is grounded on the integration of building information modeling (BIM), geographical information system (GIS) and vehicle routing problem (VRP) algorithm. The framework is then presented and evaluated using a case study to identify optimal logistics scenario of trailer routes to meet the installation time window of MiC projects in Hong Kong. The paper finds that the proposed platform has the ability to make optimized logistics scenario for MiC projects, and to visualize the logistics scenario in a 3-dimentional interactive environment. Future study will focus on adopting flexible control strategies and including more decision-making criteria of logistics planning in MiC projects such as road width limitation, travel speed and different module types","PeriodicalId":422911,"journal":{"name":"Modular and Offsite Construction (MOC) Summit Proceedings","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124531536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the mass timber industry taking off in 2015 in Oregon, when DR Johnson Lumber in Riddle, OR started producing CLT panels, government officials were eager to support it for its promise of economic development in rural communities and also had hopes of addressing the state’s affordable housing crisis using mass timber modular construction. While mass timber modular housing has had some success in Europe, the different construction standards and building culture in the United States make it more challenging. With few areas in Oregon in which housing is likely to be built over six stories tall or in large-scale developments, it did not seem possible that mass timber could solve the affordable housing crisis where it cannot compete in cost with standard light wood-frame construction. However, it did seem feasible that mass timber panels, which are so well-suited to customizable pre-fabrication through digital manufacturing, might be successful in an alternative building type for modular construction: classrooms. In successful models of mass timber modular classrooms in Austria and Germany, schools were built in much shorter timeframes and for 25% less cost than steel or concrete construction. The authors are now working with a modular building manufacturer in Oregon, Modern Building Systems (MBS), that produces custom-designed modular light wood-frame classrooms. While mass timber classrooms cannot compete in price with light wood-frame, particularly in single-story applications, they could be competitive for two story (or taller) schools, which are usually built using steel braced-frame and concrete block. Because MBS is 18 miles west of Freres Lumber, which is newly producing Mass Plywood Panels (MPP), and the MBS facility needs no modifications to use MPP instead of wood-frame, the authors are working with them to design an economically competitive mass timber module, with several potential clients interested in testing a prototype in 2019.
随着2015年俄勒冈州大规模木材产业的起飞，当DR Johnson Lumber in Riddle, OR开始生产CLT板时，政府官员渴望支持它，因为它承诺在农村社区发展经济，也希望通过大规模木材模块化建筑来解决该州的经济适用房危机。虽然大量木材模块化住宅在欧洲取得了一些成功，但美国不同的建筑标准和建筑文化使其更具挑战性。由于俄勒冈州很少有地区可能建造超过六层楼的房屋或进行大规模开发，因此大规模木材似乎不太可能解决经济适用房危机，因为它无法与标准的轻型木结构建筑在成本上竞争。然而，通过数字制造非常适合定制预制的大量木板似乎是可行的，它们可能在模块化建筑的另一种建筑类型中取得成功:教室。在奥地利和德国成功的大规模木材模块化教室模型中，学校在更短的时间内建成，比钢结构或混凝土结构的成本低25%。作者现在正在与俄勒冈州的模块化建筑制造商现代建筑系统公司(MBS)合作，该公司生产定制设计的模块化轻型木结构教室。虽然大型木材教室在价格上无法与轻型木结构教室竞争，特别是在单层建筑中，但它们对于两层(或更高)的学校来说可能具有竞争力，这些学校通常使用钢支撑框架和混凝土块建造。由于MBS位于Freres Lumber以西18英里处，该公司正在新生产大型胶合板(MPP)，而且MBS工厂不需要修改就可以使用MPP代替木框架，因此作者正在与他们合作设计一种具有经济竞争力的大型木材模块，有几个潜在客户有兴趣在2019年测试原型。
{"title":"Mass Timber Modular Construction: Developments in Oregon","authors":"J. Sheine, M. Donofrio, M. Gershfeld","doi":"10.29173/MOCS97","DOIUrl":"https://doi.org/10.29173/MOCS97","url":null,"abstract":"With the mass timber industry taking off in 2015 in Oregon, when DR Johnson Lumber in Riddle, OR started producing CLT panels, government officials were eager to support it for its promise of economic development in rural communities and also had hopes of addressing the state’s affordable housing crisis using mass timber modular construction. While mass timber modular housing has had some success in Europe, the different construction standards and building culture in the United States make it more challenging. With few areas in Oregon in which housing is likely to be built over six stories tall or in large-scale developments, it did not seem possible that mass timber could solve the affordable housing crisis where it cannot compete in cost with standard light wood-frame construction. However, it did seem feasible that mass timber panels, which are so well-suited to customizable pre-fabrication through digital manufacturing, might be successful in an alternative building type for modular construction: classrooms. In successful models of mass timber modular classrooms in Austria and Germany, schools were built in much shorter timeframes and for 25% less cost than steel or concrete construction. The authors are now working with a modular building manufacturer in Oregon, Modern Building Systems (MBS), that produces custom-designed modular light wood-frame classrooms. While mass timber classrooms cannot compete in price with light wood-frame, particularly in single-story applications, they could be competitive for two story (or taller) schools, which are usually built using steel braced-frame and concrete block. Because MBS is 18 miles west of Freres Lumber, which is newly producing Mass Plywood Panels (MPP), and the MBS facility needs no modifications to use MPP instead of wood-frame, the authors are working with them to design an economically competitive mass timber module, with several potential clients interested in testing a prototype in 2019.","PeriodicalId":422911,"journal":{"name":"Modular and Offsite Construction (MOC) Summit Proceedings","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127027576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Canada, off-site construction is still the exception rather than the norm when it comes to wood construction. In Europe’s Alpine Region or Scandinavian countries, off-site construction is standard when it comes to wood construction. This paper will focus on the reasons why Canada’s wood construction industry will shift from mainly on-site to mainly off-site construction over the next 10 to 15 years. In countries with relatively demanding requirements on energy efficiency and air tightness, off-site construction has been dominating the market for more than 20 years. British Columbia adopted the BC Energy Step Code in 2017, a roadmap defining the energy efficiency of buildings over the coming years leading up to 2032, when all new construction will be required to be Net Zero ready. It is expected that the National Building Code of Canada will also encourage higher energy performance levels in the near future. Consequently, thermally better-performing envelopes will have to be produced and rigorous air tightness levels will have to be achieved for the sustainability goals given by the province. Envelope assemblies will get thicker, bulkier and heavier to meet these requirements. In this regard, a market shift to a greater amount of off-site construction is likely to be experienced to meet these targets in a controlled environment. This study is exploring the direct and indirect connections between sustainability and energy efficiency requirements given by codes to technical and cost-efficient solutions offered by industry.
{"title":"Consequences of the BC Energy Step Code on Offsite Construction","authors":"Guido Wimmers, A. Conroy","doi":"10.29173/MOCS126","DOIUrl":"https://doi.org/10.29173/MOCS126","url":null,"abstract":"In Canada, off-site construction is still the exception rather than the norm when it comes to wood construction. In Europe’s Alpine Region or Scandinavian countries, off-site construction is standard when it comes to wood construction. This paper will focus on the reasons why Canada’s wood construction industry will shift from mainly on-site to mainly off-site construction over the next 10 to 15 years. In countries with relatively demanding requirements on energy efficiency and air tightness, off-site construction has been dominating the market for more than 20 years. British Columbia adopted the BC Energy Step Code in 2017, a roadmap defining the energy efficiency of buildings over the coming years leading up to 2032, when all new construction will be required to be Net Zero ready. It is expected that the National Building Code of Canada will also encourage higher energy performance levels in the near future. Consequently, thermally better-performing envelopes will have to be produced and rigorous air tightness levels will have to be achieved for the sustainability goals given by the province. Envelope assemblies will get thicker, bulkier and heavier to meet these requirements. In this regard, a market shift to a greater amount of off-site construction is likely to be experienced to meet these targets in a controlled environment. This study is exploring the direct and indirect connections between sustainability and energy efficiency requirements given by codes to technical and cost-efficient solutions offered by industry.","PeriodicalId":422911,"journal":{"name":"Modular and Offsite Construction (MOC) Summit Proceedings","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126513255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Volume module systems in the refining and petrochemical industries are large, multi-level systems that are fabricated offsite and stacked onsite, with integral piping and wiring interconnections. This is a case study in a program management system that was introduced for a particular volume module system. Modular design and fabrication suffer from inherent shortcomings: it is neither cheap nor fast nor does it result in any meaningful increase in quality. Lessons learned reveal cheaper, faster and better methods that overcome the inherent shortcomings of modular design and construction. These lessons can inform current trends in modular design and fabrication in the USA and Canada.
{"title":"Case Study: Program Management of Volume Modules","authors":"Gregory F. Starzyk","doi":"10.29173/MOCS139","DOIUrl":"https://doi.org/10.29173/MOCS139","url":null,"abstract":"Volume module systems in the refining and petrochemical industries are large, multi-level systems that are fabricated offsite and stacked onsite, with integral piping and wiring interconnections. This is a case study in a program management system that was introduced for a particular volume module system. Modular design and fabrication suffer from inherent shortcomings: it is neither cheap nor fast nor does it result in any meaningful increase in quality. Lessons learned reveal cheaper, faster and better methods that overcome the inherent shortcomings of modular design and construction. These lessons can inform current trends in modular design and fabrication in the USA and Canada.","PeriodicalId":422911,"journal":{"name":"Modular and Offsite Construction (MOC) Summit Proceedings","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132572354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Construction manufacturing specifications play an important role in assessing quality requirements on a construction project. However, working with these specifications can be overly complicated and error prone to the large amount of regulations and codes that need to be considered and their inter-dependencies. In building information modelling (BIM), the model is a digital representation of a complex construction product and contains precise product information data. The data is currently embedded into the model as properties for parametric building objects that are exchangeable among project operators. Some effort has been previously done to enhance the BIM model to obtain construction-oriented data and linking information that is crucial to manufacturing and quality control and assurance with BIM modelling still remains a challenge. This study proposes an extension to the current BIM-based product-oriented ontology model to include manufacturing processes and inspection, and quality control specifications. By automatically identifying which specifications are applicable to certain products and to extract the requirements imposed, this approach can support and enable automatic decision making in quality inspection and control tasks, which solely depend on information and knowledge from construction specifications. This approach is tested and validated using a light-gauge steel frame wall under Canadian construction standards and regulations.
{"title":"Automatic Selection Tool of Quality Control Specifications for Off-site Construction Manufacturing Products: A BIM-based Ontology Model Approach","authors":"P. Martinez, Rafiq Ahmad, M. Al-Hussein","doi":"10.29173/MOCS87","DOIUrl":"https://doi.org/10.29173/MOCS87","url":null,"abstract":"Construction manufacturing specifications play an important role in assessing quality requirements on a construction project. However, working with these specifications can be overly complicated and error prone to the large amount of regulations and codes that need to be considered and their inter-dependencies. In building information modelling (BIM), the model is a digital representation of a complex construction product and contains precise product information data. The data is currently embedded into the model as properties for parametric building objects that are exchangeable among project operators. Some effort has been previously done to enhance the BIM model to obtain construction-oriented data and linking information that is crucial to manufacturing and quality control and assurance with BIM modelling still remains a challenge. This study proposes an extension to the current BIM-based product-oriented ontology model to include manufacturing processes and inspection, and quality control specifications. By automatically identifying which specifications are applicable to certain products and to extract the requirements imposed, this approach can support and enable automatic decision making in quality inspection and control tasks, which solely depend on information and knowledge from construction specifications. This approach is tested and validated using a light-gauge steel frame wall under Canadian construction standards and regulations.","PeriodicalId":422911,"journal":{"name":"Modular and Offsite Construction (MOC) Summit Proceedings","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130227958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Daneshvar, Jan Niederwestberg, C. Dickof, Jean-Philippe Letarte, Y. Chui
In the context of the global trend of designing sustainable structures, the attention towards high-rise timber buildings of 8 to 25 storeys has been increasing in recent years. Balloon construction technique using a relatively new heavy timber material, cross-laminated timber (CLT), has been shown to be promising for high-rise building applications, given its compatibility with off-site construction techniques and its desirable mechanical characteristics. To date, tall timber buildings using CLT have been built mainly in non-seismic or low-seismic locations around the world, whereas their application in high seismic regions has been limited to platform construction. More research on the behaviour of CLT structures during seismic events in terms of system behaviour as well as the behaviour of components, particularly connections, is required. The research presented in this paper seeks to initiate the process of seismic design of tall wood buildings using a balloon construction technique. Two buildings, one three-storey fictitious building and one to-be-constructed ten-storey building, both located on the west coast of Canada, were considered and designed based on the NBCC 2015 seismic provisions. The loads on the shear walls, which span over three storeys, were extracted in order to estimate realistic demands on lateral load resisting systems (LLRS) in the balloon construction. Different connections, including base shear connections, panel-to-panel shear connections, as well as high-capacity hold-downs, were designed accordingly. An experimental program was developed to investigate the behaviour of these connections, focusing on yielding and failure mechanisms in each connection category. This paper explains different phases of the experimental program and introduces connection details designed to achieve the research goals. The results of this study will contribute to the body of knowledge on seismic behaviour of prefabricated mass timber buildings, and will benefit engineers and practitioners using timber to design high-rise structures.
{"title":"Cross-Laminated Timber Shear Walls in Balloon Construction: Seismic Performance of Steel Connections","authors":"H. Daneshvar, Jan Niederwestberg, C. Dickof, Jean-Philippe Letarte, Y. Chui","doi":"10.29173/MOCS120","DOIUrl":"https://doi.org/10.29173/MOCS120","url":null,"abstract":"In the context of the global trend of designing sustainable structures, the attention towards high-rise timber buildings of 8 to 25 storeys has been increasing in recent years. Balloon construction technique using a relatively new heavy timber material, cross-laminated timber (CLT), has been shown to be promising for high-rise building applications, given its compatibility with off-site construction techniques and its desirable mechanical characteristics. To date, tall timber buildings using CLT have been built mainly in non-seismic or low-seismic locations around the world, whereas their application in high seismic regions has been limited to platform construction. More research on the behaviour of CLT structures during seismic events in terms of system behaviour as well as the behaviour of components, particularly connections, is required. The research presented in this paper seeks to initiate the process of seismic design of tall wood buildings using a balloon construction technique. Two buildings, one three-storey fictitious building and one to-be-constructed ten-storey building, both located on the west coast of Canada, were considered and designed based on the NBCC 2015 seismic provisions. The loads on the shear walls, which span over three storeys, were extracted in order to estimate realistic demands on lateral load resisting systems (LLRS) in the balloon construction. Different connections, including base shear connections, panel-to-panel shear connections, as well as high-capacity hold-downs, were designed accordingly. An experimental program was developed to investigate the behaviour of these connections, focusing on yielding and failure mechanisms in each connection category. This paper explains different phases of the experimental program and introduces connection details designed to achieve the research goals. The results of this study will contribute to the body of knowledge on seismic behaviour of prefabricated mass timber buildings, and will benefit engineers and practitioners using timber to design high-rise structures.","PeriodicalId":422911,"journal":{"name":"Modular and Offsite Construction (MOC) Summit Proceedings","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132676774","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jin Ouk Choi, J. O’Connor, Y. Kwak, Rajarshi Ghimire
Modularization is a well-known construction technique where sections of the job are moved from on-site to a fabrication shop. Previously, the researchers identified the 21 most influential Critical Success Factors (CSFs) for successful modularization and quantified the degree of each CSF’s accomplishment by conducting a survey with 19 subject matter experts, and a case study with three modular projects. Through this methodology, the findings relied on the experience of experts. However, still missing from the understanding of modularization CSFs is a validation of the current degree of each CSF’s accomplishment by examining actual modular projects using a sufficient number of samples. This paper presents a comparison of CSF accomplishment degree between 25 actual sample projects (project based) and the industry experts’ survey results (experience-based estimation). The study results indicate that the industry experts made a good estimation of the current occurrence degree of each CSF. The study did identify, however, three significantly overestimated CSFs and three underestimated CSFs. The three most overestimated CSFs are Owner-Furnished/Long Lead Equipment Specification, Cost Savings Recognition, and O&M Provisions. The three most underestimated CSFs are Contractor Experience, Management of Execution Risks, and Transport Delay Avoidance. This study will help the industry to 1) better understand modularization CSFs and their accomplishment statuses; 2) achieve higher modular project performance by accomplishing the CSFs
{"title":"Calibrating CII RT283’s Modularization Critical Success Factor Accomplishments","authors":"Jin Ouk Choi, J. O’Connor, Y. Kwak, Rajarshi Ghimire","doi":"10.29173/MOCS99","DOIUrl":"https://doi.org/10.29173/MOCS99","url":null,"abstract":"Modularization is a well-known construction technique where sections of the job are moved from on-site to a fabrication shop. Previously, the researchers identified the 21 most influential Critical Success Factors (CSFs) for successful modularization and quantified the degree of each CSF’s accomplishment by conducting a survey with 19 subject matter experts, and a case study with three modular projects. Through this methodology, the findings relied on the experience of experts. However, still missing from the understanding of modularization CSFs is a validation of the current degree of each CSF’s accomplishment by examining actual modular projects using a sufficient number of samples. This paper presents a comparison of CSF accomplishment degree between 25 actual sample projects (project based) and the industry experts’ survey results (experience-based estimation). The study results indicate that the industry experts made a good estimation of the current occurrence degree of each CSF. The study did identify, however, three significantly overestimated CSFs and three underestimated CSFs. The three most overestimated CSFs are Owner-Furnished/Long Lead Equipment Specification, Cost Savings Recognition, and O&M Provisions. The three most underestimated CSFs are Contractor Experience, Management of Execution Risks, and Transport Delay Avoidance. This study will help the industry to 1) better understand modularization CSFs and their accomplishment statuses; 2) achieve higher modular project performance by accomplishing the CSFs","PeriodicalId":422911,"journal":{"name":"Modular and Offsite Construction (MOC) Summit Proceedings","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116490111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Teodosio, K. Shanaka, K. S. K. Baduge, P. Mendis
The strong demand for houses has been hampered by a shortage of skilled labor in Australia, which can be potentially alleviated using prefabrication. Significant advancements in the design and construction of prefabricated houses have been observed; however, most substructure constructions still use traditional cast-in-place method that is labor intensive and weather-dependent. Prefabrication of footing systems is an advantageous solution since this require minimal manual labor and shorter construction period. The design of an innovative prefabricated footing needs to consider structural integrity and design assembly. One of the important structural issues for light-weight houses is cyclic differential ground movements affecting footing systems due to reactive soils. This shrink-swell movements are due to the decrease and increase in soil moisture, which can cause minor to severe damage depending on the presence of fines. Due to the issues on shortage of skilled labor and housing, and the costly impact of shrink-swell movements of reactive soils to footings, this study aims to develop a prefabricated footing based on optimized waffle raft. The developed system can easily be installed in stable to highly reactive sites, minimizing site disturbance, on-site assembly requirements and maximizing construction speed, quality and sustainability.
{"title":"An Optimized Prefabricated Raft Footing System for Houses on Shrink-Swell Soils: Preliminary Results","authors":"B. Teodosio, K. Shanaka, K. S. K. Baduge, P. Mendis","doi":"10.29173/MOCS77","DOIUrl":"https://doi.org/10.29173/MOCS77","url":null,"abstract":"The strong demand for houses has been hampered by a shortage of skilled labor in Australia, which can be potentially alleviated using prefabrication. Significant advancements in the design and construction of prefabricated houses have been observed; however, most substructure constructions still use traditional cast-in-place method that is labor intensive and weather-dependent. Prefabrication of footing systems is an advantageous solution since this require minimal manual labor and shorter construction period. The design of an innovative prefabricated footing needs to consider structural integrity and design assembly. One of the important structural issues for light-weight houses is cyclic differential ground movements affecting footing systems due to reactive soils. This shrink-swell movements are due to the decrease and increase in soil moisture, which can cause minor to severe damage depending on the presence of fines. Due to the issues on shortage of skilled labor and housing, and the costly impact of shrink-swell movements of reactive soils to footings, this study aims to develop a prefabricated footing based on optimized waffle raft. The developed system can easily be installed in stable to highly reactive sites, minimizing site disturbance, on-site assembly requirements and maximizing construction speed, quality and sustainability.","PeriodicalId":422911,"journal":{"name":"Modular and Offsite Construction (MOC) Summit Proceedings","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129341483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents the direct displacement-based design (DDD) procedure, structural modelling method, and structural performance calibration for post-tensioned CLT shear wall structures (PT-CLTstrs). Numerical models of the post-tensioned (PT) CLT shear walls were developed and calibrated with the experimental results. Based on the developed shear wall models, parametric analysis were conducted to investigate the lateral performance influencing factors. Then, a DDD procedure was developed and demonstrated by the design examples of a set of 8-, 12-, and 16-storey PT-CLTStrs. The corresponding simplified structural models were developed, and then a series of pushover and time-history dynamic analysis were conducted to calibrate the calculated structural performance objectives with the design targets of the DDD procedure. Finally, the empirical cumulative distribution functions (CDFs) of the maximum inter-storey drift (MaxISDR) were constructed. It is found that when the width of the PT CLT shear walls increases from 1.8 m to 3.0 m, the base shear at the drift of 2.0 % increases by twice accordingly. When the diameter of the PT strand increases from 15.2 mm to 34.6 mm, the base shear at the drift of 2.0 % increases by up to five times. Additionally, the MaxISDR limitation of the PT-CLTStrs is recommended as 2.2 % under the collapse prevention (CP) hazard level. The study results can serve as guidelines for the development of engineering design methods for the PT-CLTStrs.
{"title":"Structural Design and Modelling Method for the Post-tensioned CLT Shear Wall Structures","authors":"Minjuan He, Xiaofeng Sun, Zheng Li","doi":"10.29173/MOCS80","DOIUrl":"https://doi.org/10.29173/MOCS80","url":null,"abstract":"This paper presents the direct displacement-based design (DDD) procedure, structural modelling method, and structural performance calibration for post-tensioned CLT shear wall structures (PT-CLTstrs). Numerical models of the post-tensioned (PT) CLT shear walls were developed and calibrated with the experimental results. Based on the developed shear wall models, parametric analysis were conducted to investigate the lateral performance influencing factors. Then, a DDD procedure was developed and demonstrated by the design examples of a set of 8-, 12-, and 16-storey PT-CLTStrs. The corresponding simplified structural models were developed, and then a series of pushover and time-history dynamic analysis were conducted to calibrate the calculated structural performance objectives with the design targets of the DDD procedure. Finally, the empirical cumulative distribution functions (CDFs) of the maximum inter-storey drift (MaxISDR) were constructed. It is found that when the width of the PT CLT shear walls increases from 1.8 m to 3.0 m, the base shear at the drift of 2.0 % increases by twice accordingly. When the diameter of the PT strand increases from 15.2 mm to 34.6 mm, the base shear at the drift of 2.0 % increases by up to five times. Additionally, the MaxISDR limitation of the PT-CLTStrs is recommended as 2.2 % under the collapse prevention (CP) hazard level. The study results can serve as guidelines for the development of engineering design methods for the PT-CLTStrs.","PeriodicalId":422911,"journal":{"name":"Modular and Offsite Construction (MOC) Summit Proceedings","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116749339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Aranda, A. Salenikovich, J. Daniel Dolan, P. Dechent
Shear walls are the major components of the lateral-force-resisting system (LFRS) in light-frame wood buildings. With the growing popularity of mid-rise prefabricated light-frame wood construction, engineers need basic design information on the shear walls to design and produce safe structures in case of high winds and earthquakes. The racking resistance of light-frame shear walls depends on many factors, including sheathing and hold-down devices and, most importantly, sheathing-to-framing fastenings. While the performance of nailed shear walls has been studied extensively, and design information is included in the design codes, there is little information on stapled shear walls, specifically in the US and Canada. The cost of staples is significantly less than that of equivalent nails; hence, the use of staples instead of nails would allow cost savings in mass production if they provide sufficient resistance and displacement capacity in the engineered shear walls. This paper presents the results of a pilot study which was focused on the comparison of the performance of nailed and stapled shear walls in laboratory tests under monotonic and cyclic loading in accordance with ASTM E564 and E2126, respectively. Several series of tests were performed on 2.4-m (8-ft) square shear walls with 11-mm (7/16-in) OSB sheathing with various hold-downs and various spacing of sheathing staples and nails on the perimeter of the sheathing panels (5-cm (2-in), 10-cm (4-in) and 15-cm (6-in)) and 19-mm and 10-mm edge distances. The staples were 16-gauge (50-mm (2-in) long with 11-mm (7/16-in) crown). The nails were 8d box steel wire nails (63-mm (2½-in) long with 2.87-mm (0.113-in) diameter). The test results revealed a similar performance of the nailed and stapled shear walls, and the need for careful detailing. Therefore, prefabrication of walls in the factory settings is preferable to the on-site construction to allow the production quality control.
{"title":"Characterisation of the Lateral Resistance of Stapled Shear Walls","authors":"R. Aranda, A. Salenikovich, J. Daniel Dolan, P. Dechent","doi":"10.29173/MOCS125","DOIUrl":"https://doi.org/10.29173/MOCS125","url":null,"abstract":"Shear walls are the major components of the lateral-force-resisting system (LFRS) in light-frame wood buildings. With the growing popularity of mid-rise prefabricated light-frame wood construction, engineers need basic design information on the shear walls to design and produce safe structures in case of high winds and earthquakes. The racking resistance of light-frame shear walls depends on many factors, including sheathing and hold-down devices and, most importantly, sheathing-to-framing fastenings. While the performance of nailed shear walls has been studied extensively, and design information is included in the design codes, there is little information on stapled shear walls, specifically in the US and Canada. The cost of staples is significantly less than that of equivalent nails; hence, the use of staples instead of nails would allow cost savings in mass production if they provide sufficient resistance and displacement capacity in the engineered shear walls. This paper presents the results of a pilot study which was focused on the comparison of the performance of nailed and stapled shear walls in laboratory tests under monotonic and cyclic loading in accordance with ASTM E564 and E2126, respectively. Several series of tests were performed on 2.4-m (8-ft) square shear walls with 11-mm (7/16-in) OSB sheathing with various hold-downs and various spacing of sheathing staples and nails on the perimeter of the sheathing panels (5-cm (2-in), 10-cm (4-in) and 15-cm (6-in)) and 19-mm and 10-mm edge distances. The staples were 16-gauge (50-mm (2-in) long with 11-mm (7/16-in) crown). The nails were 8d box steel wire nails (63-mm (2½-in) long with 2.87-mm (0.113-in) diameter). The test results revealed a similar performance of the nailed and stapled shear walls, and the need for careful detailing. Therefore, prefabrication of walls in the factory settings is preferable to the on-site construction to allow the production quality control.","PeriodicalId":422911,"journal":{"name":"Modular and Offsite Construction (MOC) Summit Proceedings","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122687387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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