Full-scale Construction Research Articles

파이롯 규모 SI 공정 시험 설비에서의 헬륨 가열 장치 설계

In this study, researchers performed preliminary design and numerical analysis for a pilot-scale helium heating system in- tended to support full-scale construction for a sulfur-iodine (SI) cycle. The helium heat exchanger used a liquefied petroleum gas (LPG) combustor. Exhaust gas velocity at the heat exchanger outlet was approximately 40 m/s based on computational thermal and flow analysis. The maximum gas temperature was reached with six baffles in the design; lower gas temperatures were observed with four baffles. The amount of heat transfer was also higher with six baffles. Installation of additional baffles may reduce fuel costs because of the reduced LPG exhausted to the heat exchanger. However, additional baffles may also increase the pressure dif- ference between the exchanger's inlet and outlet. Therefore, it is important to find the optimum number of baffles. Structural analy- sis, followed by thermal and flow analysis, indicated a 3.86 mm thermal expansion at the middle of the shell and tube type heat exchanger when both ends were supported. Structural analysis conditions included a helium flow rate of 3.729 mol/s and a helium outlet temperature of 910°C. An exhaust gas temperature of 1300°C and an exhaust gas rate of 52 g/s were confirmed to achieve the helium outlet temperature of 910°C with an exchanger inlet temperature of 135°C in an LPG-fueled helium heating system.

Model Test of a 1:8-Scale Floating Wind Turbine Offshore in the Gulf of Maine1

A new floating wind turbine platform design called VolturnUS developed by the University of Maine uses innovations in materials, construction, and deployment technologies such as a concrete semisubmersible hull and a composite tower to reduce the costs of offshore wind. These novel characteristics require research and development prior to full-scale construction. This paper presents a unique offshore model testing effort aimed at derisking full-scale commercial projects by providing scaled global motion data, allowing for testing of materials representative of the full-scale system, and demonstrating full-scale construction and deployment methods. A 1:8-scale model of a 6 MW semisubmersible floating wind turbine was deployed offshore Castine, ME, in June 2013. The model includes a fully operational commercial 20 kW wind turbine and was the first grid-connected offshore wind turbine in the U.S. The testing effort includes careful selection of the offshore test site, the commercial wind turbine that produces the correct aerodynamic thrust given the wind conditions at the test site, scaling methods, model design, and construction. A suitable test site was identified that produced scaled design load cases (DLCs) prescribed by the American Bureau of Shipping (ABS) Guide for Building and Classing Floating Offshore Wind Turbines. A turbine with a small rotor diameter was selected because it produces the correct thrust load given the wind conditions at the test site. Some representative data from the test are provided in this paper. Model test data are compared directly to full-scale design predictions made using coupled aeroelastic/hydrodynamic software. Scaled VolturnUS performance data during DLCs show excellent agreement with full-scale predictive models. Model test data are also compared directly without scaling against a numerical representation of the 1:8-scale physical model for the purposes of numerical code validation. The numerical model results compare favorably with data collected from the physical model.

주거빈곤층의 주택개보수서비스 이용 경험

본 연구는 주거환경이 열악한 취약계층의 삶의 현실과 주택개보수서비스 이용 경험을 탐색하는데 목적이 있다. 이를 위해 서비스를 이용한 9명의 연구 참여자에게 심층 면접을 실시하였다. 연구 결과, 이들은 열악한 주거 환경 속에서 심리적 사회적으로 위축되는 한편, 비염과 알레르기 등의 건강상의 문제, 잠재된 위험에 대한 불안감 등을 안고 살고 있었다. 그러나 빈곤한 생활로 인하여 주택개보수에는 신경을 쓸 수 없는 형편이었으며, 집주인이나 세입자 모두 집에 대한 애착이 적어 주거개선에 무관심하여 주거의 열악함이 관리 되지 못하였다. 이러한 상황에서 담당 공무원 등의 연계로 주택개보수서비스를 이용할 수 있게 되었고, 이로 인해 서비스 수혜에 대한 고마움이 매우 컸다. 주택개보수서비스 이후, 외관상으로 깔끔해진 집과 수리 이후의 안정감, 사회관계의 회복, 따뜻한 겨울나기에 대한 기대 등 긍정적인 변화를 경험하였다. 그러나 이처럼 '고마운 서비스'임에도 불구하고, 주택개보수서비스는 '제한적인 서비스'로서의 한계 또한 갖고 있었다. 주로 외관상의 시급한 문제에 치중한 공사였고, 이는 제한된 공사비로 인한 경우가 많았다. 또한 현 주거의 문제는 개보수 뿐 아니라, 제도적으로 뒷받침되어야 하는 상황들도 많이 있어 근본적인 문제해결을 위해서는 제도 및 정책적 변화도 수반되어야 함을 알 수 있었다. 이와 같은 연구결과를 바탕으로 결론에서는 주택개보수서비스와 관련된 정책적 제언을 제시하였다. This study aims to explore the realities of life and the utilizing experience of housing improvement service among the vulnerable living in the indecent house. For this purpose of this study, we conducted in-depth interview with nine interviewees. As the result of this study, we figured out that the vulnerable living in the poor house had experienced psychological withdrawals, restricted of social activities, health problems, and feelings of insecurity. However, they could not afford to improve their houses because they were living below or near the poverty line. Local government provided the housing improvement service to cope with this problem. The people received this service gave positive reviews. Since their residential environment was improved, they felt easiness, strengthened social relationships, and expected a warm winter. Despite of 'thankful service', the housing improvement service had some limitations. Because of the limited budgets, full-scale construction services were unfeasible. Also we figured out it is necessary to make a change in housing policies for the people living in the poor houses. In the conclusion, we discussed and proposed the policies and practical suggestions.

Laboratory Evaluation and Field Construction of Roller-Compacted Concrete for Testing under Accelerated Loading

The Louisiana Department of Transportation and Development has seen a rapid decline of low-volume roadway serviceability in recent years as a result of oil and gas exploration within the Fayetteville Shale Play near Shreveport, Louisiana. Similar results are expected on the low-volume roadway network within the Tuscaloosa Shale Play, north of Baton Rouge, Louisiana, as exploration expands. The objectives of this research were to determine appropriate proportions of roller-compacted concrete mixture for the construction of accelerated loading test lanes and to document field construction activities. Concrete samples were produced with four cement contents to determine the effect of moisture and density; the samples were tested for compressive strength at 7 and 28 days of age. The field testing included nuclear density testing, thickness measurements, and field-prepared compressive strength specimens. A walking profiler was used to determine the international roughness index (IRI). All laboratory-produced mixtures exceeded a compressive strength of 4,000 pounds per square inch (psi). When the desired surface characteristics and density were considered, 450 lb/yd3 was chosen as the minimum cementitious content for the construction of the test lanes. The field construction results showed that the speed of construction affected the density, the IRI, and the surface characteristics. An increased speed of construction yielded a rougher surface texture (an increased IRI between 360 and 620 in./mi) and slightly lower densities. The compressive strengths were still adequate and exceeded 4,500 psi at 28 days old. On the basis of the field results, IRI values in the 100- to 130-in./mi range and compressive strengths exceeding 5,000 psi may be expected in a full-scale roadway construction effort.

Prediction of residual life based on the results of diagnosis of full-scale constructions and continuous monitoring of their technical condition

The article examines the prediction of the residual life on the results of diagnosis of full-scale constructions with continuous monitoring of their technical condition.

Meteorosensitive architecture: Biomimetic building skins based on materially embedded and hygroscopically enabled responsiveness

In this paper, the authors present research into autonomously responsive architectural systems that adapt to environmental changes using hygroscopic material properties. Instead of using superimposed layers of singular purpose mechanisms–for sensing, actuation, control and power–in the form of high-tech electronic equipment as is emblematic for current approaches to climate responsiveness in architecture, the presented research follows an integrative, no-tech strategy that can be considered to follow biological rather than mechanical principles. In nature plants employ different systems to respond to environmental changes. One particularly promising way is hygroscopic actuation, as it allows for metabolically independent movement and thus provides an interesting model for autonomous, passive and materially embedded responsiveness. The paper presents a comprehensive overview of the parameters, variables and syntactic elements that enable the development of such meteorosensitive architectural systems based on the biomimetic transfer of the hygroscopic actuation of plant cones. It provides a summary of five years of research by the authors on architectural systems which utilize the hygroscopic qualities of wooden veneer as a naturally produced constituent within weather responsive composite systems, which is presented through an extensive analysis of research samples, prototypes at various scales, and two comprehensive case studies of full scale constructions.

Discussion of “Multivariate distribution for undrained shear strengths under various test procedures”

Care needs to be exercised when examining the empirical correlations for undrained shear strength proposed by Ching and Phoon (2013) because the manuscript does not adequately define the overconsolidation ratio (OCR), and the data in Table 2 that were used to develop the empirical correlations include values of OCR, as small as 1.1, 2.2, and 3.3 and as large as 50, 60, and 80. A clear distinction needs to be made among (i) OCR = p ′ / vo ′ , where for a natural soil deposit sublayer p ′ is the preconsolidation pressure and vo ′ is preconstruction effective vertical pressure; (ii) OCR = p ′ / vc ′ , where vc ′ is a consolidation pressure in the recompression range of a natural soil deposit sublayer with a preconsolidation pressure p ′ ; and (iii) OCR = vm ′ / vc ′ , where vm ′ , for a soil sublayer in the field or in the laboratory, is the maximum effective vertical pressure after loading and primary consolidation, and vc ′ is a consolidation pressure after unloading and primary rebound. In addition, the data in Table 2 include natural soil deposits as well as specimens reconstituted in the laboratory. In geotechnical engineering, there is a separate body of empirical literature on undrained shear strength of soft clay and silt deposits with values of p ′ / vo ′ typically less than 3 and rarely greater than 6 (Terzaghi et al. 1996, Arts. 20.1 to 20.7), and on undrained shear strength of stiff clays and shales (Terzaghi et al. 1996, Art. 20.8). This discussion only concerns soft clay and silt deposits because for these soils exists an adequate body of laboratory andfield undrained shear strengthdata as a functionof composition (e.g., expressed in termsof plasticity index, Ip), mode of shear (e.g., field vane (FV), direct simple shear (DSS), triaxial compression and extension (TC and TE, respectively), unconfined compression (UC), and mobilized in full scale construction), and rateof shearor time to failure (e.g., FVandUC fast, and field construction much slower).

Применение метода конечных элементов при расчете на малоцикловую усталость элементов конструкции неподвижной опоры трубопроводов для участков надземной прокладки нефтепровода «Заполярье — НПС „Пур-Пе“»

The present article studies the order of performing low-cycle fatigue strength calculation of the elements of the full-scale specimen construction of the fixed support DN 1000 of the above-ground oil pipeline “Zapolyarye — Purpe” during rig-testing. The calculation is performed with the aim of optimizing the quantity of testing and, accordingly, cost cutting for expensive experiments. The order of performing the calculation consists of two stages. At the first stage the calculation is performed by the finite element method of the full-scale specimen construction’s stressed-deformed state in the calculation complex ANSYS. Thearticle describes the main creation stages of the finite element calculation model for the full-scale specimen in ANSYS. The calculation model is developed in accordance with a three-dimensional model of the full-scale specimen, adapted for rig-testing by cyclic loads. The article provides the description of the full-scale specimen construction of the support and loading modes in rig-testing. Cyclic loads are accepted as calculation ones, which influence the support for the 50 years of the oil pipeline operation and simulate the composite impact in the process of the loads’ operation connected to the changes in the pumping pressure, operational bending moment. They also simulate preloading in the case of sagging of the neighboring free support. For the determination of the unobservable for the diagnostic devices defects impact on the reliability of the fixed support and welding joints of the fixed support with the oil pipeline by analogy with the full-scale specimen, artificial defects were embedded in the calculation model. The defects were performed in the form of cuts of the definite form, located in a special way in the spool and welding joints. At the second stage of calculation for low-cycle fatigue strength, the evaluation of the cyclic strength of the full-scale specimen construction’s elements of the fixed support was performed in accordance with the requirements of Russian State Standard GOST R 52857.6—2007 on the basis of the overall and local stress condition, received according to the results of the calculation in ANSYS. In accordance with the results of the conducted work the conclusion was drawn about fulfilling the standard requirements for the low-cycle fatigue strength of the developed full-scale specimen of the support. Therefore, the application of the modern approaches to the numerical modeling of the fixed support construction operation allowed minimizing the quantity of full-scale tests of the specimen with the cyclic load, escaping the excessive conservatism in evaluation of the cyclic strength and developing of the optimal for the metal intensity construction.

The ITER magnet systems: progress on construction

Construction of the ITER magnet systems has been started at the end of 2007 following the signature of the first procurement arrangements (PA) for the toroidal field (TF) conductors. Six ITER members are involved in the share of the ITER magnet components and, to date, eighteen PA between the ITER Organization and six domestic agencies have been signed. Substantial progress towards full-scale construction has been achieved with the placement of the first large manufacturing contracts, the production of several tens of tons of advanced Nb3Sn and NbTi strand, and the set-up of large cabling and jacketing facilities. The detailed design of the coils and support structures has also been finalized. The qualification of the fabrication processes for the TF coils and poloidal field (PF) coils has been initiated. The detailed design of the central solenoid (CS) coils is being developed. The design of the correction coils (CCs) with their support structures has been finalized, as well as for the TF gravity supports and clamps of the PF coils. The manufacture of prototypes of the feeder lines and current leads has been started, while ITER is in charge of the procurement of the required magnet instrumentation. This paper provides a progress report on the ITER magnet construction as per December 2010.

Building components for an outpost on the Lunar soil by means of a novel 3D printing technology

3D-printing technologies are receiving an always increasing attention in architecture, due to their potential use for direct construction of buildings and other complex structures, also of considerable dimensions, with virtually any shape. Some of these technologies rely on an agglomeration process of inert materials, e.g. sand, through a special binding liquid and this capability is of interest for the space community for its potential application to space exploration. In fact, it opens the possibility for exploiting in-situ resources for the construction of buildings in harsh spatial environments. The paper presents the results of a study aimed at assessing the concept of 3D printing technology for building habitats on the Moon using lunar soil, also called regolith. A particular patented 3D-printing technology – D-shape – has been applied, which is, among the existing rapid prototyping systems, the closest to achieving full scale construction of buildings and the physical and chemical characteristics of lunar regolith and terrestrial regolith simulants have been assessed with respect to the working principles of such technology. A novel lunar regolith simulant has also been developed, which almost exactly reproduces the characteristics of the JSC-1A simulant produced in the US. Moreover, tests in air and in vacuum have been performed to demonstrate the occurrence of the reticulation reaction with the regolith simulant. The vacuum tests also showed that evaporation or freezing of the binding liquid can be prevented through a proper injection method. The general requirements of a Moon outpost have been specified, and a preliminary design of the habitat has been developed. Based on such design, a section of the outpost wall has been selected and manufactured at full scale using the D-shape printer and regolith simulant. Test pieces have also been manufactured and their mechanical properties have been assessed.

Na putu ka arhitekturi usmerenoj ka izvođenju - Istraživacki centar za arhitekturu i tektoniku (The research centre for architecture and tectonics) - integrisanje arhitektonskog obrazovanja sa istraživanjem putem projektovanja zajedno sa praksom usmerenom ka perspektivi

This article examines the development of the integrative and interdisciplinary approach to research by design in architecture pursued at the Research Centre for Architecture and Tectonics (RCAT). RCAT constitutes the primary research environment of the Institute of Architecture at the Oslo School of Architecture and Design and focuses on an extensive scope of research activities related to architecture and the built environment that are geared towards the development of a comprehensive approach to performance-oriented architecture. This involves specific ways of integrating architectural education and research, in particular research by design, to support the development of related knowledge, concepts, methods and frequently also the production of reliable empirical data, engaging real-life design problems and seeking interaction with practice. Advanced computational design underpins a lot of the research, as well as scaled and full-scale construction.

Aerial Robotic Construction towards a New Field of Architectural Research

This paper takes a first step in characterizing a novel field of architectural research - aerial robotic construction (ARC) - where aerial robotics is used not only for construction, but as a guiding principle in the design and fabrication process. Featuring autonomous flying vehicles that lift small building elements and position them according to a precise digital blueprint, ARC offers a comprehensive new approach to architecture research and technology. Developed by the research groups of Gramazio & Kohler and Raffaello D'Andrea at ETH Zurich, ARC offers unique advantages over traditional approaches to building: it does not require scaffolding, it is easily scalable, and it offers digital integration and informational oversight across the entire design and building process. This paper considers 1) research parameters for the individual components of ARC (such as module design, connection methodologies, vehicle cooperation, and construction sequencing/synchronization), and 2) the architectural implications of integrating these discrete components into a systemic, unifying process at the earliest stages of design. Fidelity between the design concept and the full-scale construction is of particular concern.

Augmenting Architecture through Desktop Manufacturing

Personal desktop manufacturing, with its roots in hacker culture, is on the cusp of exploding into the main stream due to the advent of affordable personal 3D printers. This paper is an exploration of these advances in desktop manufacturing technology and their impact on our relationship with products and the built environment. The paper draws parallels to the personal computing and desktop publishing revolutions that offer clues to the future of personal desktop manufacturing. Four major themes have emerged from this exploration: Personal empowerment, remote printing and collaboration, full-scale digital construction, and, most intriguingly, architectural prosthetics. Based on an open-source philosophy and creative commons licensing, desktop manufacturing is redefining our relationship with large manufacturers and is beginning to convert us back from a consumerist culture into a creator one.

Early-Age Shrinkage of Ultra-High-Performance Concrete under Drying/Wetting Cycles and Submerged Conditions

Concrete is usually subjected to early-age variation in temperature, relative humidity (RH), wind, and other environmental loading that can alter its behavior. In this study, the early-age shrinkage behavior of ultra high-performance concrete (UHPC) is investigated under simulated field conditions. In this article, the effects of shrinkage mitigation methods, including a shrinkage-reducing admixture (SRA) and a super-absorbent polymer (SAP), were explored. The simulated field conditions included drying/wetting (DW) cycles and submerged (SM) conditions, and were compared to sealed and drying conditions under constant temperature and RH. The results in this article show the substantial influence of environmental conditions on the shrinkage behavior of UHPC. It was discovered that exposure to simulated field conditions dismisses the effectiveness of using SRA through a washing-out mechanism. Moreover, incorporating SRA and SAP simultaneously optimized their benefits and allowed for overcoming their deficiencies under various exposure conditions. The article concluded that adequate consideration of in-place conditions in testing protocols of UHPC should allow for gaining a better understanding of shrinkage mitigation mechanisms and developing suitable performance specifications before a wide implementation of UHPC in full-scale field construction.

Covering It All

Landfill covers that will permanently contain the residuals of chemical warfare agents and pesticides at the Rocky Mountain Arsenal Superfund site, in Colorado, were designed to perform many functions, including providing a barrier to water infiltration, soil and wind erosion, and intrusion by wildlife. Designed as alternatives to the types of covers normally used at hazardous waste sites, the covers had to be validated beyond a shadow of a doubt before full-scale construction could begin.

Personal exposure to inhalable cement dust among construction workers

A case study was carried out in 2006-2007 to assess the actual cement dust exposure among construction workers involved in a full-scale construction project and as a comparison among workers involved in various stages of cement and concrete production. Full-shift personal exposure measurements were performed for several job types. Inhalable dust and cement dust (based on analysis of elemental calcium) concentrations were determined. Inhalable dust exposures at the construction site ranged from 0.05 to 34 mg/m3, with a mean concentration of 1.0 mg/m3. For inhalable cement dust mean exposure was 0.3 mg/m3 (range 0.02-17 mg/m3). Reinforcement and pouring workers had the lowest average concentrations. Inhalable dust levels in the ready-mix and pre-cast concrete plants were, on average, below 0.5 mg/m3 for inhalable dust and below 0.2 mg/m3 for inhalable cement dust. Highest dust concentrations were measured in cement production, particularly during cleaning tasks (inhalable dust GM=55 mg/m3; inhalable cement dust GM=33 mg/m3) at which point the workers wore personal protective equipment. Elemental measurements showed highest but very variable cement percentages in the cement plant and very low percentages of cement during reinforcement work and pouring.

Methods for and fish responses to channel remeandering and large wood structure placement in the Shibetsu River Restoration Project in northern Japan

The Shibetsu River Restoration Project intends to reestablish a historic meander pattern by connecting a 3.5-km channelized reach with a series of oxbow lakes that were previously isolated by channel straightening. Prior to full-scale construction, a remeandering experiment (pilot) was conducted upstream of the project segment to assess the methods for and ecological responses to channel remeandering. Large wood (LW) structures were also installed in the experimental remeandering reach. The channel remeandering project with LW placement in a large lowland river is the first undertaken in Asia, and it has rarely been undertaken elsewhere. In this report, we present an overview of the Shibetsu River Restoration Project and the methods for and fish responses to channel remeandering and LW placement in the experiment.

Construction of Steel Pipe Sheet Piles with Newly Developed Joint System

H-joint in steel pipe sheet piles (SPSP) is introduced and developed, the joint is made by welding a cylindrical steel pile on either side of an H steel section, welding is continuous along their lengths therefore it is completely waterproof with high strength; the two connected piles are installed simultaneously hence short construction time is required. It is shown through full-scale field construction tests using 3 existing SPSP installation methods, that construction of H-joint SPSP is practical and have high construction accuracy of 1/250~1/1400. A segment joint for connecting two H-joint SPSP segments in the field is proposed and evaluated for bending strength. It was observed that (1) failure of the segment joint did not occur and that failure of the material was due to local buckling at the bending section of the pipe pile (2) Bending strength capacity of the continuous SPSP and SPSP with segment joint is nearly equal (3) Load on the main piles is transferred to H steel when development of plastic zone in main piles occurs and then transferred to the splice plate. A segment cutting test is conducted to show that cutting of temporary portions of H-joint SPSP segment is practical and easy.

3D Print as Corporeal Design Medium

Because it produces representational models, not full-scale architecture, 3D printing often supports the study of form, not architectural materials, structure and tectonics. This research asks how 3D printing can support material study and contribute to a process of design by making, similar to that achieved with mock-ups and other full-scale constructions. It clarifies the nature of design by making through an elaboration of key activities, and then shows how 3D printing can support each activity. The research includes a design experiment in which students used unique 3D printing techniques to enhance the experience of design by making. These techniques include 1) confronting a material foil, 2) embedding material placeholders in parametric models, 3) oscillating between representational and literal interpretations, and 4) using 3D prints as a corporeal medium. With these techniques, 3D printing offered a unique flavor of design by making, which can complement full-scale computer-aided manufacturing techniques.

Roadbed Degradation Mechanism under Ballastless Track and Its Countermeasures

Recently, ballastless tracks with cement grouted into ballast have been constructed on a full-scale construction operation. However, where roadbed constituents are of clay, roadbed soil outflow or even voids in the roadbed are likely to occur after heavy rainfall. In this study, the authors carried out tests with a full-scale ballastless track model laid on a saturated clayey roadbed. As a result, the defect mechanism of clayey roadbeds under ballastless tracks has been clarified. In addition, the authors have confirmed the improved effect of two countermeasures against roadbed failures by means of tests using the fullscale model.