bluuebunny/crossref_metadata_2025 huggingface dataset:
STUDY ON DAMAGE DETECTION OF SQUARE PYRAMID SPACE GRID STRUCTURE CONSIDERING INITIAL RANDOM DEFECTS
Authors: Limei Zhang , Shoujun Du , Meng Fan
Published: March 2020

Because of different types of load, material properties deviation and construction errors, structures have initial defects inevitably. Therefore structural damages emerge easily and have strong randomness. At the same time, the ideal design model often has difference with structure in service. To most structures, the initial testing dates cannot be obtained, while this initial model is very important to structural damage detection. So the ideal model needs to revise. In this paper, elastic modulus, Poisson ratio and link section area are given as initial random defects and these defects obey normal distribution which can be constructed by Monte Carlo probabilistic design method. Firstly, the sensitivity parameters to structural response will be received by PDS technology from Ansys. Next, the square pyramid space grid models with random defects were obtained. Finally, given link element damage, using the method combined curvature mode difference with wavelet transform, the link element damage can be determined. Through analysis, the effects about the initial defects to damage detection will be obtained.
STRUCTURAL DAMAGE DETECTION BY MULTI-SCALE CROSS-SAMPLE ENTROPY
Authors: Liang Jui-Chang , Wang Ming-Jing , Lin Tzu-Kang
Published: March 2020

This study proposes a structural health monitoring (SHM) system based on multi-scale entropy (MSE) and multi-scale cross-sample entropy (MSCE). By measuring the ambient vibration signal from a structure, the damage condition can be rapidly evaluated via a MSE analysis. The damage location can then be detected by analyzing the signals of different floors under the same damage condition via a MSCE analysis. Moreover, a damage index is proposed to efficiently quantify the SHM process. A numerical simulation of a four-story steel structure is used to verify that the damage location and condition can be detected by the proposed SHM algorithm, and the location can be efficiently quantified by the damage index. Based on the results, the damage condition can be correctly assessed, and accuracy rates of 60% and 86% for the damage location can be achieved using the MSCE and damage index methods, respectively.
EARLY WARNING AND FAILURE DETECTION IN BRIDGE USING WIRELESS VIBRATION SENSOR
Authors: Fardheny A. F. , Suprobo P. , Faimun
Published: March 2020

Infrastructure of transportation has become an important aspect in Indonesia. Indonesia needs to maintain this infrastructure. The bridge is one of the important infrastructure need proper maintenance. Indonesia has over 89,000 bridges with a total length of 1,050 km. In order to maintain all the bridges, an integrated structural health monitoring system (SHMS) needs to be built. The aim of this system is to provide early warning for degradation of bridge. Hence, Kutai Kartanegara bridge failure will never repeat. The aim of this research is to detect failure in a bridge and provide adequate warning using wireless vibration sensor. Vibrations information of a bridge is main purpose of this study which enables to determine health of a bridge. A device has been built for this task from accelerometer sensors. Vibration from an accelerometer has been used to find out bridge behavior. Research of this has been done in the laboratory and field. Finite element methods and propose spectral finite element methods have been applied in this research. The finding shows that the vibration information of a bridge has a lot of important information, such as spectral type of vibrations, frequencies, damping and mode shape of structures. Several conditions in laboratory and field have been analyzed. This study shows that vibration information can be used for early warning of bridge health and failure or damage in bridge.
THE ITALIAN LEGISLATION ON PROJECT VALIDATION
Authors: Gottfried Arie , Devito Antonio C. , Piantanida Paolo
Published: March 2020

Italy, first in Europe, introduced mandatory validation in building public works: the first years experienced some issues leading to a general updating of the national legislation, differentiating the project verification from the project validation. The former is a formal stage of the construction process committed to the Public Authority (through the Overall Procedure manager), the latter can usefully be performed by an external authority and involves systematic project examination and contractual documentation monitoring. The research critically approaches the modifications in the last decades on public work legislation, from the aged Merloni Act to the current Presidential Decree no. 207/2010. The paper focuses on the improvements on public building in design stage because of the mandatory validation. It also describes how some weak points have been solved and those that are still present in the Italian legislation. Particular attention is given to construction works below a certain threshold of amount.
BASE ISOLATION FOR SEISMIC RETROFITTING OF DAMAGED BUILDINGS
Authors: Mezzi Marco , Petrella Paolo
Published: March 2020

The paper deals with the retrofitting of r/c buildings damaged by the earthquake adopting the base-isolation. The case of one building is analyzed in detail. The seismic vulnerability of the building in the original configuration is assessed. A classification of the possible conventional works concerning repair, retrofit, seismic enhancement is carried out dealing with the structural effectiveness, impact, control in application and lifetime, related indirect works, cost. The main result is a tentative classification of the issues related to the insertion of a base-isolation system below an existing building aimed at its seismic enhancement, avoiding or relied strongly limiting other works in the building elevation. The retrofitting strategies, the enhancement levels, the application solutions are critically revised statement under the experience of the real cases faced with, also paying attention to the cost-effectiveness ratios.
TRIAL CONSTRUCTION FOR SEISMIC RETROFIT BY CFT BRACE ON AN ISOLATED ISLAND
Authors: Nakahara Hiroyuki , Ashida Yukiko
Published: March 2020

The authors have been developing a seismic retrofitting method using concrete-filled steel tubular (CFT) members as a diagonal brace. The features of the method are easy set-up and low-cost because we made the enforcing devices lightweight and a simple connecting method to the existing structures. This method provides many advantages for the buildings located at the places where are difficult to transport heavy materials and equipment. An experimental construction for the seismic retrofit was conducted at the 2-story RC building on an isolated island in Japan. The construction was succeeded by only three persons in two days without heavy equipment. This paper is consisted of the reports of the constructing process and the loading test of the connecting part of the method. The trial construction includes a new detail of the connection. Two specimens were made and tested to estimate the lateral load carrying capacity of the connection.
FREE VIBRATION OF LINEARLY TAPERED TIMOSHENKO BEAM USING CONSISTENT SHAPE FUNCTIONS
Authors: Trinh Huong Thanh , Dinh Kien Nguyen , Hibino T. , Gan Buntara S.
Published: March 2020

Tapered Beam elements are of great importance in a wide range of structural applications because of their optimized distribution of strength and weight compared with the uniform ones. Vibration analysis of beams with variable properties has been receiving great interest from engineers and researchers for a long time. This paper presents the way in which new shape functions are constructed and used for analyzing free vibration of Timoshenko beams with linear variation in height or width and various boundary conditions. Fundamental frequencies from the present work are compared with those obtained by different formulation and approaches. The shape functions in the paper are derived for a solid rectangular beam with linearly taper changing in its sectional dimensions. With the aid of the consistently derived shape functions in the finite element calculation, the solution to vibration problems with the least number of elements can be evaluated with high accuracy. A detailed example is presented and compared with a reference work to illustrate the accuracy and computational efficiency for vibration analysis of linearly tapered Timoshenko beams.
HUMAN SENSORY EVALUATION OF VIBRATIONS INSIDE TALL BUILDINGS
Authors: Suzuki Chihiro , Ishikawa Takashige
Published: March 2020

Long-period vibrations felt by residents or workers in tall buildings due to wind or earthquake are a frequent problem. Considering the fact that vibration by wind or earthquake is dynamic, we investigated a wide range of random vibration, including long-period vibration. We focused on sensory evaluation and investigated the relationship between perception or psychological quantity (magnitude of anxiety or discomfort) and random vibration. In this study, we performed experiments using actual vibrations in detached houses for original waveforms. The results show the possibility of estimation using the predominant frequency in a fast Fourier transform analysis and maximum acceleration for perception and psychological evaluation. Random vibration is hardly perceived compared with sinusoidal vibration, and anxiety or discomfort is hardly felt. We determined a range in which subjects perceive random vibration but do not feel anxiety or discomfort.
SEISMIC BEHAVIOR OF ANCHORAGE IN DIVERSE LIQUID STORAGE STEEL TANKS BY ADDED-MASS METHOD
Authors: Kildashti Kamyar , Mirzadeh Neda
Published: March 2020

Deformation of liquid storage tanks and the interaction between fluid and structure result in a variety of possible failure mechanisms during earthquakes. Among all failure modes, base-anchor failure is this paper’s focus. Three cylindrical steel tanks with different H/D were selected to investigate dynamic loadings on the tank seismic responses. The added-mass method was used in the finite element modeling of the steel tanks and fluid, and numerical analyses were performed. The added-mass method results were compared to conventional method outcomes using two or more lumped-mass and equivalent springs for tank-liquid simulation (Housner method). It was found that the added-mass method results in greater forces on the anchors in comparison to the lumped-mass method.
SEISMIC ASSESSMENT OF NON-DUCTILE REINFORCED CONCRETE C-SHAPED WALLS
Authors: Hoult Ryan D. , Goldsworthy Helen M. , Lumantarna Elisa
Published: March 2020

Buildings that rely on reinforced concrete walls and cores as their primary lateral loading system are prevalent in much of Australia’s building stock. Capacity design principles do not have to be adhered to in most low-to-moderate seismic regions, such as Australia. Consequentially, the level of detailing typically provided in accordance with the current and past concrete material standards, AS 3600 and AS 1480, is regarded as non-ductile from the seismic design point of view. These non-ductile reinforced concrete elements have been known to perform poorly when subjected to large lateral loads, as observed in the Christchurch earthquake in 2011. This paper presents an investigation into the seismic performance of C-shaped reinforced concrete walls acting as a core of a Mid-Rise building using current and past building codes in Australia. The displacement capacity of the building was calculated using a displacement-based assessment. A shear capacity model, which is a function of the curvature ductility of the walls, was also considered in the assessment. The results indicate that the older building is likely to fail in shear in the event of a 1000-year return period earthquake event. The building designed to current standards is vulnerable to a non-ductile failure from premature fracturing of the longitudinal reinforcing steel bars.
INFLUENCE OF ADDED VISCOUS DAMPERS ON THE PROBABILISTIC SEISMIC PERFORMANCE EVALUATION OF RC FRAMES
Authors: Landi Luca , Vorabbi Cristina , Diotallevi Pier Paolo
Published: March 2020

This paper deals with the parameters which influence the probability of reaching the near collapse limit state of RC frame structures equipped with nonlinear fluid viscous dampers. The study can be divided into two steps. The first aims to assess how the median and the dispersion of seismic demand can vary in the RC frame structures with and without dampers, considering a wide set of ground motions. The second step evaluates the expression in closed form, given by 2000 SAC/FEMA method, to assess the annual probability of failure of RC structures. This probability has been estimated considering a wide set of ground motions and different methods to approximate the hazard curve. The evaluations have been made on the basis of the results of a large number of nonlinear dynamic analyses; in particular, 180 nonlinear dynamic analyses have been made for the case studies with and without dampers. In conclusion, it has been noticed that the probabilistic assessment depends on the number of records considered and that the simplified formula provided by the 2000 SAC-FEMA method is strongly sensitive to the variation of the hazard curve and the dispersion.
THE EFFECTS ON SHAPE-MODELING OF CONCRETE GRAVITY DAMS IN EARTHQUAKE RESPONSE ANALYSES
Authors: Nishiuchi Tatsuo
Published: March 2020

To clarify the effects of seismic response of concrete gravity dams under large earthquake, finite element method (FEM) analyses were carried out. In analyses, the height of dam and material properties of concrete and basement rock are same. The 2-dimensional (2D) and the 3-dimensional (3D) FEM model were made and used in earthquake response analyses. The contraction joints between dam block are concerned in 3D non-linear FEM analysis. In the case of same height of dam, the numerical results of damage states and placements in dam are different between 2D FEM model and 3D FEM model, due to the effect of difference in vibration mode of dam. In the 2D FEM model, the damage of top in cross-section becomes remarkable. In the 3D FEM model, the damage of attachment between dam body and basement rock at high-elevation becomes remarkable. The damage of 3D FEM model is smaller than that of 2D FEM model for the same acceleration level of earthquake. The influence of seismic response on contraction joints of 3D non-linear FEM dam model is smaller, which is as same as that of 3D linear FEM dam model. From the above results, the 2D FEM model gives a conservative assessment compared to the 3D FEM model.
A DEMOUNTABLE PRECAST REINFORCED CONCRETE BUILDING SYSTEM OF MULTI-STORY BUILDINGS
Authors: Witzany Jiri , Zigler Radek , Cejka Tomas , Polak Ales
Published: March 2020

The demountable precast reinforced concrete building system consists of bar and thin-walled units allowing designing hybrid integrated systems of multi-storey buildings. The system’s characteristic property are demountable, self-rectifiable and dry joints enabling assembly without wet processes and, in case of need, the disassembly and relocation of the structure. The system applies special mounting, the joint of prestressed hollow core floor units and the load-bearing structure by steel pins additionally embedded in the hollow cores. The article presents the results of experimental research into the major parts and joints of the load-bearing system and the verification of the load-bearing system’s prototype exposed to static load tests with an example of the load-bearing system’s assembly and disassembly.
AN EXHAUSTIVE SURVEY FOR RENOVATING FACILITIES IN DENSELY BUILT-UP WOODEN HOUSE AREAS
Authors: Takiyama Noriko , Hara Kohei , Sanuki Ryo , Matsumoto Masumi , Gondo Tomoyuki , Aoki Shigeru
Published: March 2020

We report the progress of our research on buildings and their surroundings for disaster prevention in Chuo-3, Ota City, one of the areas in Tokyo, Japan that is Densely Built-up Wooden House Areas in Tokyo, Japan. We conducted an exhaustive survey of 383 buildings and roads in the northwest area of Chuo-3. The buildings and their surroundings were considered. Next, we conducted microtremor measurements on the ground in the area. The major findings of the investigation are summarized as follows. (a) Over 80% of the buildings are detached houses, and some have billboard architectures. Slate and pantile are used as the roofing material for all the buildings. (b) The buildings are densely packed. Some adjoin the frontal road with a separation of 2 m or less. (c) According to the mictotremor measurement of the ground, the H/V spectrum changed gradually from the west to the east.
DYNAMIC TESTING OF SOIL-STEEL COMPOSITE RAILWAY BRIDGE
Authors: Beben Damian
Published: March 2020

The paper presents the results and conclusions of the field tests under service loads that were conducted on a soil-steel composite (SSC) railway bridge. Inductive gauges, extensometers and accelerometers were used to monitor displacements, strains and accelerations of this bridge, respectively. The maximum displacement and strain of the SSC bridge was –0.61×10-3 m and –54×10-6, respectively. The maximum SSC bridge and ballast accelerations were equal to 0.67 and 1.23 m/s2, respectively, and they did not exceed the Eurocode limit of 3.5 m/s2. On the basis of the measured displacements, a Discrete Fourier Transform (DFT) method was implemented to determine the frequencies of SSC bridge (dominant frequencies were 0.1 (or 0.2) and 1.2 Hz). The natural frequencies of the bridge were 0.25 and 1.3 Hz, and they corresponded to approximately two first dominant frequencies extracted from the forced vibration tests.
EXPERIMENTAL BREAKING OF A PRESTRESSED CONCRETE BRIDGE BEAM REINFORCED WITH BONDED FRP
Authors: Houel Adrien , Aubagnac Christophe , Germain Didier , Maherault Jean-Philippe
Published: March 2020

The Central and Eastern Territorial Directorate (DterCE) of Cerema in France has set up an experimental project about a prestressed concrete bridge beam recovered during the demolition of a bridge. Before testing, an accurate diagnosis of the beam has been achieved. Three series of tests were carried out in 2014: bending tests before reinforcement, after a first phase of reinforcement bonded composite materials, and finally after a second and final phase of reinforcement bonded composite materials. This final test was gradually led to a complete break of the beam. This experience on a PPCBB reinforced with FRP allows us to deliver some first lessons. The real break of the beam was held to a force of about 61 tons, corresponding to a bending at mid-span to about 20 cm. Thereafter, the effort has been decreasing. The complete shearing by delamination of the bonded composite reinforcements (which have thus accompanied the beam to maximum effort of loading), was held to a force of about 59 tons, corresponding to a bending to about 27 cm. The complete break in bending in a controlled section (cracking up in the upper table) was obtained for an imposed displacement of more than 40 cm.
BEHAVIOR OF STAINLESS STEEL LIPPED CHANNEL SECTIONS SUBJECTED TO ECCENTRIC COMPRESSION
Authors: Anwar-Us-Saadat Mohammad , Ahmed Shameem , Ashraf Mahmud
Published: March 2020

The design philosophy of stainless steel requires appropriate recognition of observed material nonlinearity and pronounced strain hardening. A rational method namely, the Continuous Strength Method (CSM) has recently been to incorporate these effects but, in its current form, CSM yields better results for stocky sections. Individual capacities (i.e., pure compression and pure bending) for all types of sections and cross-section resistance against combined loading (i.e. compression plus bending) for RHS and I-sections can be predicted using CSM. The current research numerically investigates the performance of stainless steel lipped channel (LC) sections subjected to compression and bending. Nonlinear finite element models are developed and validated using available experimental results, and are consequently used to generate additional results for a wide range of cross-sections through parametric studies. Current CSM guidelines are used to propose a new set of formulations for predicting the section resistance of lipped channel sections subjected to combined loading.
IMPROVING GRADUATES’ ATTRIBUTES THROUGH LABORATORY TEAMWORK
Authors: Ionescu Daniela , Petrolito Joe , Mainali Bandita , Al Abadi Haider
Published: March 2020

In today’s changing global environment engineering graduates are expected to have both technical and soft skills. Accordingly, La Trobe University has incorporated the soft skills of communication, teamwork, interpersonal skills and leadership into its Civil Engineering course. This paper describes the contribution of teamwork to the development of soft skills during laboratory classes in a number of subjects taught at the second, third and fourth years of study. The assessment for the practical component was designed to enhance teamwork and measure the students’ contribution during the laboratory/field sessions. The practical classes and teamwork requirements improved the students’ technical knowledge, and students became more aware of their own strengths and weaknesses. It also enhanced students’ communication skills and promoted the development of interpersonal skills and a responsible attitude.
HYGROTHERMAL DURABILITY OF ADHESIVELY BONDED FRP/STEEL JOINTS
Authors: Heshmati Mohsen , Haghani Reza , Al-Emrani Mohammad
Published: March 2020

The use of fiber reinforce polymer, FRP, bonding to strengthen and repair deteriorated steel structures is increasing owing to its unique advantages over traditional strengthening and repair techniques. However, the lack of knowledge regarding environmental durability of adhesively bonded FRP/steel joints still hinders the widespread application of this method in steel structures. A number of studies have reported significant degradation of mechanical properties of these joints in hot and wet environments. In addition to that, the mechanisms of failure have been observed empirically to change from cohesive failure in the adhesive to apparent interfacial failure with increasing amount of moisture. This study presents the results of an experimental and numerical investigation to predict the mechanical behavior of FRP/steel joints after hygrothermal aging. First, moisture diffusion kinetics and mechanical degradation of a two-part commercially available epoxy adhesive and Carbon FRP material were experimentally characterized over a wide range of temperature and humidity conditions. These parameters were then incorporated in a coupled 3D diffusion-mechanical finite element, FE, model. In addition, bonded double-lap shear joints of CFRP/steel were aged for up to a year and tested to failure. It is found that the presence of moisture for less than a critical period can increase the joint strength. However, prolonged exposure to the same moisture content degrades the load-carrying capacity of the joint.
EXPERIMENTAL STUDY ON SHEAR RESISTANCE EVALUATION OF PERFOBOND STRIP WITHOUT PENETRATING REBAR
Authors: Minh Hai Nguyen , Akinori Nakajima
Published: March 2020

In steel-concrete hybrid members and structures, to ensure required stress transmission between the steel and the concrete members, shear connectors are generally arranged between the two. A perfobond strip is widely used as the shear connector in various hybrid structures, and when applying the perfobond strip it is important to confirm its shear resistance. In this study, the shear resistance of the perfobond strip without the penetrating rebar is investigated experimentally by employing a simple push-out specimen. As a result, a design formula is proposed for evaluating the shear resistance of the perfobond strip, taking into account the dimensions of concrete block and the thickness of the perfobond plate, as well as the perforation diameter, and the concrete compressive strength.
EXPERIMENTAL STUDY ON FLEXURAL BEHAVIOR OF STEEL-CONCRETE COMPOSITE BEAM COMPRISING PRECAST COMPOSITE SLABS
Authors: Hou Hetao , Feng Mingyuan , Geng Lu , Chen Lei , Liu Haining
Published: March 2020

Four-point bending tests including twelve specimens were carried out to investigate the flexural rigidity, failure mode and ultimate capacity of the steel-concrete composite beam with a composite floor slab comprising 30 mm thick precast prestressed concrete panels and T-shaped concrete ribs (PPCRP). The test parameters included support length of PPCRP, thickness of the composite floor slab, longitudinal compressive reinforcement ratio, degree of the shear connection and the direction of T-shaped concrete rib. Strain distribution along the depth of mid-span section was obtained by strain gauges. Based on the moment-deflection curves of specimens, it was showed that flexural behavior of precast composite floor slab was similar to that of concrete floor slab cast in-situ during the elastic stage. Two failure phenomena were observed: i) Interface bond slip between the precast panel and the cast in-situ layer; ii) Diagonal shear crushing in one shear span. Compared with the floor slab cast in-situ, a slight decline in the ultimate flexural capacity was observed for the composite beam with composite floor slab. Analyses about the effects of all parameters on composite beams’ rigidity and ductility were presented.
PERCEIVED RISKS, OBLIGATIONS, AND UNCERTAINTIES: ANTECEDENTS OF UNPAID CONTRACTORS’ INTENTION TO SUSPEND WORKS AGAINST NON-PAYMENT
Authors: Lee Chia-Kuang , Yiu Tak-Wing , Cheung Sai-On
Published: March 2020

Non-payment issues have plagued the Malaysian construction industry for decades. To remedy non-payment, unpaid contractors can choose to mediate, adjudicate, arbitrate, or suspend works contractually. In spite of this convenience, previous studies have shown that the contractors in Malaysia do not favor this right in remedying non-payment, and similarly there is almost no case law to further illustrate the adversities in exercising this right. Previous study revealed that suspension of work was less favored. Until today, there is no study to explain the underlying reasons for this disinclination. Since there are no direct cases that deal with the proposition, the discussion of the issues in this paper is by way of indirect cases which are related to the problems that may arise when contractor suspends works. By using available case laws and reference to two Malaysian standard forms of contract such as CIDB 2000 and PAM 2006, this study postulates that possible perceived risks, obligations, and uncertainties are the antecedents of contractors’ intention to suspend works against non-payment. Accordingly, the findings shed a light to the practitioners about the do’s and don'ts in suspension of work. Optimistically, it offers premises for elevating these inhibitors, and thus increases the adoption of this clause with future interventions.
DEVELOPMENT OF CONCRETE SHEAR STRENGTH FOR SHEAR LUGS IN UNCONFINED GROUT POCKETS
Authors: Khan Pradip K. , Harter Phillip J.
Published: March 2020

The base plate anchorage system for major equipment supports is often designed with a combination of shear lugs and anchor bolts to resist equipment support reactions. Shear lugs are designed to transmit the design shear forces from the support base plates to the foundation concrete. The shear lugs are commonly placed inside a pre-formed grout pocket that is eventually filled with non-shrink high strength grout. The pre-formed grout pockets are sometimes left open to a free edge of concrete on one or more sides for ease of equipment installation and alignment before they are filled with grout. Where the equipment loads are applied in the direction of the free edge, the absence of adequate confinement makes it difficult to develop sufficient breakout strength in shear. This paper addresses a few practical issues that an engineer may face while designing non-confined grout pockets encasing equipment anchorage. It will also demonstrate different ways of improving the concrete breakout strength due to shear by means of providing reinforcements across the anticipated failure planes following the recommendations from different US codes and standards.
REVIEW OF CONSTRUCTION DISPUTE RESOLUTION PRACTICES IN THE MIDDLE EAST: CAUSES AND METHODS
Authors: Barakat Boushra , Awwad Rita , Menassa Carol
Published: March 2020

The construction industry in the Middle East region is witnessing a continuous growth and is attracting international contractors and investors to its large-scale projects. However, this growth is accompanied by an inevitable increase in claims and disputes consequently leading to significant delays and additional costs. The purpose of this research is to identify the most common causes of disputes in the Middle East (ME) region, and shed the light on the most frequently used dispute resolution methods. It then goes further to briefly discuss the applicability of alternative dispute resolution methods in this region and compare the findings to the perspective of experts in the field. Findings show that disputes are mainly due to the lack of construction management expertise, as well as other contractual, cultural and legal factors. As for the most commonly used dispute resolution methods, they are identified to be negotiation, litigation and arbitration. This paper provides contractors, owners and professionals in the ME region and foreign countries with invaluable insights into construction claims’ types and dispute resolution systems in the ME region.
EMERGENCY EVACUATION SIMULATION VISUALIZED BY MOBILE MAPPING SYSTEM
Authors: Tsujihara Osamu , Ito Hideyuki , Okamoto Terumasa
Published: March 2020

Recently, studies on evacuation simulations have drawn up scenarios of evacuation under various situations. In this study, a system is proposed to show the results of evacuation simulations for disasters such as tsunamis and fires, with maps and serial images taken by MMS (Mobile Mapping System). The all-around view camera, angle meter, and GPS (Global Positioning System) antenna are mounted on a moving object, such as a car, in MMS. The serially-taken images can be related to GIS (Geographic Information System). Users can not only virtually experience the evacuation but also find the dangerous places by observing the 360-degree surrounding image.
COST CALCULATION IN PREFABRICATED TIMBER CONSTRUCTION: PROCESS ANALYSIS ON SITE AND APPLICABILITY FOR FUTURE PROJECTS
Authors: Koppelhuber Joerg , Schlagbauer Dieter , Heck Detlef
Published: March 2020

Advancements of recently developed timber products such as cross laminated timber (CLT) and its increasing application in construction demand economical standardization and unification. Therefore cost calculation of solid wood building systems need to be established. Following the systematic analysis of operation procedures, a research project was carried to gain accurate data on effort and performance values for future cost calculations. The absence of specific literature on cost calculations of timber buildings leads to evaluations based on in-house knowledge without cross company references. So a data acquisition on labor costs and machinery expenses on site is required to obtain primary data and input parameters in the cost calculations. Because of the high grade of prefabrication of timber structures, labor costs are the leading influence parameters. The methodology according to the technique of REFA and the specific circumstances of the timber installation process were implemented into the analysis to generate an appropriate system for the examination of these new building systems. To create a feasible and applicable database of values performance factors and activity values have been examined on site, interpreted and edited for future cost calculation of cross laminated timber assembly works. This survey on site contributes another module in the lack of knowledge to optimize the construction management within the construction process of large scale timber buildings.
EXPERIMENT ON THE SLACK IN LIFELINES USED FOR ROOF WORK
Authors: Takahashi Hiroki , Hino Yasumichi , Ohdo Katsutoshi
Published: March 2020

Falls are the most common type of accident on construction sites in Japan. Preventing falls from roofs necessitates the installation of scaffolds around houses, but this regulation failed to ease the difficulty experienced by construction workers as they erected scaffolds in a disaster area during the Great East Japan Earthquake. The challenge stemmed primarily from debris around the site. The threat to scaffold safety was unacceptable given that the time spent on scaffold installation and dismantling was longer than that typically spent on roof work. When installing scaffolds around a house was problematic, the construction workers used lifelines and safety belts when working on roofs. Nevertheless, the advantages of this approach are limited by the absence of specific criteria that regulate the use of these safety devices. When a worker falls from a roof, the fixed end of a lifeline usually holds up the worker, thereby preventing crashes to the ground. The problem is that the standards for measuring or evaluating the appropriate amount of slack in lifelines are unclear. We therefore examined existing criteria by testing a full-scale roof device and using parameters such as lifeline slack in the experiment. The torso load during a prevented fall is absorbed by the adopted lanyard and lifeline. The lanyard’s hook hits roof eaves, thus increasing torso load. This result underscores the importance of providing a small lifeline slack.
BUILDING INFORMATION MODELING AND OPERATING of RFID TECHNOLOGY TO IMPROVE OCCUPATIONAL SAFETY IN CONSTRUCTION INDUSTRY
Authors: Kelm Agnes , Helmus Manfred , Meins-Becker Anica
Published: March 2020

Despite a slight decrease of the number of accidents at work on German construction sites in recent years, prevention activities should be strengthened and started explicitly in addition. In particular, a large number of accidents on construction sites are carried out by the collision of different trades and the absence or not wearing appropriate PPE for workers of adjacent trades. An important potential is seen in the optimization of the safety and health by making available pre-defined information about safety and health throughout the life cycle of buildings. Using this information, preventive measures can be taken faster, more effective, safer and preventive. The method of Building Information Modelling (BIM) forms the basis for a comprehensive building information model or building data model. From the perspective of the applicant the method of BIM in conjunction with the Auto-ID-based tracking of actual process data, however, provides additional data to planning data among other OSH-related processes. This data can be used for the further phases of the life cycle of buildings, which are in the building phase, the use phase and rebuilding phase and the decommissioning phase considerable potential, especially for the optimization of occupational safety and health. The primary objective of this research project is to identify, define and standardize health and safety information and provide them for preventive measures with the BIM method.
RATIONAL SOLUTIONS FOR THE MODERNIZATION OF APARTMENT HOUSES
Authors: Miniotaite Ruta
Published: March 2020

In the article the problems of the modernization (renovation) of dwelling-houses are discussed according juridical, social, ecological, technical-technological and economical aspects. When the decision to renovate the dwelling-house is made, first the juridical problems have to be solved. These problems involve planning of investment project, social problems of individual flat dwellers and the infringement of their rights. In many cases the modernization of dwelling-house is suspended because of the improper solution of juridical and social questions. Other renovation problems are: unqualified house energy audit making, technically unsound heating insulation and architecture of house facade decisions, and final approximation all decisions. The house energy audit is performed before modernization, the theoretical heat transfer coefficient and resistance of external walls are calculated and heat transfer coefficient according the standard STR 2.05.01:2013 “Design of the Energy Performance of Buildings” is noted. Designing a technical project for the multi-apartment house modernization, it is necessary to make a precise evaluation of heat loss before and after the modernization, to calculate the modernization workload and the expected decrease of heat consumption. Performing the modernization works constant and qualified supervision must be performed. Actually home-owners do not have any economic benefit because of the rising heat selling prices. But after the modernization the living conditions are improved, heat energy is saved state-wide, and environmental pollution is reduced.
AN ARTIFICIAL NEURAL NETWORK MODEL FOR PREDICTING FATIGUE OF CONSTRUCTION WORKERS IN HUMID ENVIRONMENTS
Authors: Yi Wen , Chan Albert P. C.
Published: March 2020

Climate change is experienced in many countries located in tropical/ subtropical regions with generally hot/humid condition. Heat illness, particularly heat stroke, has caused a substantial increase in morbidity and mortality during heat waves. Thus, the high incidence of heat stroke is a pressing concern in the construction industry. Construction workers, being exposed to such unpleasant working environment, are at a higher risk of heat stress while undertaking physically demanding tasks. This paper aims to establish a model for predicting fatigue of construction workers in hot weather. During the period of summer months in 2010 and 2011, we conducted 39 field measurements on six construction sites in Hong Kong and collected a series of meteorological, personal, and work-related parameters. A total of 550 synchronized datasets were measured to establish the model. Artificial neural networks (ANNs), a type of artificial intelligence technology which implements more complex data-analysis features into existing applications, was applied to forecast the fatigue of construction workers. Performance measures including mean absolute percentage error (MAPE), R2, and root-mean-square deviation (RMSE) confirm that the established model is a good fitting with high accuracy. The ANN-based model presents a reliable and scientific forecast physical condition of workers which may enhance the occupational health and safety (OHS) in the construction industry.
INVOCATION OF A STEP-IN CLAUSE IN PRISON PPPs: SUSTAINABILITY OR MANAGEMENT VAGARY?
Authors: Khatleli Nthatisi
Published: March 2020

The extension of the PPP procurement method to custodial services was met with a lot of resistance and disapproval from some quarters within and without the government circles in South Africa. The model utilized in the two facilities currently in operation is design, construct, finance, operate and maintain. The recent invocation of a “step-in” clause in one of the facility was regarded as a vindication that private operators are contextually unsuitable to manage the correctional facilities in South Africa. This research interrogated the monitoring mechanisms set up to oversee the running of the facility and the operational management pitfalls that necessitated this intervention. Through interviews with the private operators, consultants, government officials and the PPP Unit, proper insight was garnered about what could have gone wrong. It was demonstrated that private management is not foolproof against the challenges of managing a facility housing dangerous convicts. Because of the operational challenges encountered by private operators there was a strong advocation for an adaptation of the PPP model where there is a hybrid in management, since South Africa initially entered into PPP arrangements due to lack of finance not due to ineffective management acumen. The study is instructive to future correctional services facilities and inspirational to other jurisdictions where the arrangement is currently mooted.
AN ASSESSMENT OF THE EVOLUTION OF HOUSING POLICY FRAMEWORK
Authors: Aigbavboa Clinton
Published: March 2020

Globally, housing policies have been used as an attempt to try and address housing problems, particularly in respect to the low-income earners, with the view of helping them access better housing. The evolution of housing policy in developing countries has been studied and identified in different ways, however, this paper present a robust theoretical background of the developments in housing policy framework. The data used in this paper were derived from secondary sources only; through a detailed review of related literature on the subject to meet the research objectives. The study is an in-depth literature exploration of the theoretical perspective of the housing studies framework. The literature reviewed found that the theory of housing had its origin in the Paleolithic period when homo-sapiens began to use natural materials like stone, wood, leaves, animal skin and other similar items to create shelter from elements of weather. It was also found that there are various theoretical perspective frameworks that have been used in the study of housing, such as political, social, developmental, institutional, and radical perspectives amongst others. This study provides a robust theoretical framework used in housing study.
INFLUENCE OF TEMPERATURE ON LABOR PRODUCTIVITY IN SHUTTERING WORKS
Authors: Hofstadler Christian
Published: March 2020

In construction, total labor productivity is determined by the quality of effectively combining elementary production factors. For labor-intensive activities, one of the most important elementary factors is the people that the achievable labor productivity depends on. In respect of the circumstances under which they perform work, there are optimal weather conditions that meet the requirements for being capable of achieving normal output. To record the influence of temperature on labor consumption rates and labor productivity in formwork-related activities, an expert survey was conducted in Austria and Germany, which included a total of 35 respondents from construction contractors (from both construction trades and industry; survey period: August 2012 to April 2013). The average professional experience of respondents equaled 17 years (minimum experience: five years; maximum experience: 43 years). Filled-in questionnaires were analyzed using an exploratory data analysis. This paper outlines the statistical bases for Huber’s M-estimator method, which was successfully applied in this analysis. Box plots of the variables were used to graphically represent distributions. A box plot describes the position and spread of a distribution, and provides information with respect to any outliers or extremes. Initially, the optimal daily temperature for achieving the highest possible labor productivity was determined. Subsequent work steps involved the documentation of changes in labor productivity that occurs if temperatures deviate from their optimal range.
BUILDING SUSTAINABILITY ANALYSIS: ANALYTICAL HIERARCHY PROCESS TO ANALYZE COST, LEED CREDITS, AND CARBON NEUTRALITY
Authors: Doczy Ryan , AbdelRazig Yassir
Published: March 2020

For building owners, there are several factors that must be considered when considering whether or not a building has achieved its goals. One such problem building owners facing during a project’s design phase is the creation of a proper balance between reducing immediate costs and increasing the sustainability of a building. Due to the implications these decisions will have on buildings’ owners and occupants, owners need to have decision support tools to be able to assist them in determining how well a building will meet their goals and preferences. The model described by this paper utilizes the Analytical Hierarchy Process and Multiple Attribute Utility Theorem to compare a project’s competing alternatives in terms of their ability to meet the project’s LEED, carbon neutral/Net-Zero, and cost/benefit goals. Utilizing a combination of user preferences and data on an alternative’s anticipated costs and level of sustainability, a score will be generated that allows the user to determine how well the alternative comes to meeting the project’s overall goal. This process will be applied for a case study library building to determine the alternative that best meets the project’s overall goal. The model’s results and validity are discussed.
BIM ORIENTED EQUIPMENT CHOICE ON CONSTRUCTION SITE
Authors: Trani Marco , Bossi Benedetta , Cassano Manuele , Todaro Davide
Published: March 2020

Construction site needs a previous production design of each equipment working area in order to avoid possible criticalities that can affect productivity or safety during construction. The ongoing research is developing a method aimed to the integration of construction site design in a BIM design process. Construction site planning is a multiple step process one of which is the choice of the equipment to be used for construction works. In order to facilitate this choice, a design method, supported by a BIM equipment library and an advanced database, has been developed. In particular each equipment of the library has been characterized by a number of selected operational information. Their classification took into account different aspects of construction requirements such as productivity, sustainability, health and safety. Thanks to a BIM design approach the parameters that express operational information (e.g., weight and dimensions, capacity, etc.) are immediately available for site-designer’s tasks. He has in fact to match the information with site context and production requirements in order to assure the satisfaction of the above mentioned requirements. The database has been populated by a series of existing equipment supplied with their specific operational information. Moreover the database has been provided with a data-browser able to match itself equipment and site information, revealing a number of equipment suitable to site situation. The application of this method in real case studies confirmed a great decrease in site-design time and good matching of different type of information.
TOWARD EFFECTIVE AND EFFICIENT PROCESS IN PROJECT VALIDATION
Authors: Gottfried Arie , Piantanida Paolo
Published: March 2020

In Italy, following the introduction of European regulations and the updating of the national legislation on public works, the project verification and validation play a strategic rule in reducing problems and variation issues at each design phase and during the completion stage. We have the opportunity of a behind-the-scenes journey considering two early validation experiences in Italy and the phase following their tender of bidding. The first case study is the “Progetto Raddoppio” for the Politecnico di Torino, that is to say the project of extension works of the buildings for Departments and lecture halls in Turin Polytechnic: these works went to an end, and now we can evaluate pros and cons of that early validation experience on the works management and on the built product. The second case is the “Urban Center” commissioned by Comune di Torino, a large exhibition area coming from a deep renovation of the buildings formerly “Officine grandi riparazioni ferroviarie” (Railways Heavy Reparation Works). In this case, the works never begun, but the validation process was completed and some issues arisen.