Search

Due to the lack of essential understanding of asphalt foaming behavior, engineering problems such as mix design failure and unstable performance of foamed asphalt cold recycling mixtures are prone to occur. This paper develops a novel asphalt foaming performance testing system and proposes new indicators to evaluate the effectiveness of asphalt foaming. The 3D spatial coordinates of different points on the foamed asphalt surface and the height of the foamed asphalt corresponding to these coordinates can be continuously monitored by binocular ranging equipment. By analyzing these dynamic parameters, the application effect of binocular ranging technology, the expansion characteristics and dynamic evolution rules of foamed asphalt in the spatial domain are analyzed. Results showed that by a combined use of the designed binocular ranging system and new evaluation indicators, the foaming ability and post-foaming stability of asphalt can be accurately assessed by comprehensively reflecting the expansion characteristics of foamed asphalt. To achieve a more efficient mix design of foamed asphalt cold recycling mixture, the correlation between asphalt foaming indicators and the road performance of the mixture could be an important focus of the next stage. [ABSTRACT FROM AUTHOR]

The presence of convex corners will affect the earth pressure calculation, but there is a paucity of studies on calculating the ground pressure of convex corners in excavation engineering. To address this issue, equilateral convex corners are divided into two types according to the relative relationship between the side length size of equilateral convex corners and the excavation depth, and their respective earth pressure calculation model is established. The microelement static equilibrium equation is set by the horizontal layer analysis method, and then the equations for calculating active earth pressure strength, active earth pressure, and active earth pressure acting points on the equilateral convex corners are derived. The example analysis and comparative Plaxis three-dimensional (3D) finite-element verification show that the friction angle in the soil is an important factor in distinguishing between two kinds of equilateral convex corners, and the active earth pressure strength, the active earth pressure, and the acting point will be affected by the side length and rotation angle, where the influence of the side length on the active earth pressure strength is relatively small. The active earth pressure may show a variety of different variation laws affected by soil parameters. The acting point will move in both directions of the plane with the change of side length and rotation angle. The theoretical calculations of active earth pressure agree with the results of three-dimensional simulations, which may explain the rationality and practicality of the theoretical method in this paper. [ABSTRACT FROM AUTHOR]

This paper reports on a controlled experiment carried out to investigate the differences between novices and experts during the review of papers for engineering journals. A total of 17 young faculty members with PhD degrees were given instruction on the peer review process, and then had to review a short paper, for which the actual reviews were available. The quality of the reviews was assessed using criteria developed by editors of medical journals. The evidence obtained from this study helps to identify the critical areas in which reviewers fail to perform a good review, and then to develop strategies to overcome such limitations. [ABSTRACT FROM AUTHOR]

The traditional approach to formulating building codes often is slow and labor-intensive, and may struggle to keep pace with the rapid evolution of technology and domain findings. Overcoming such challenges necessitates a methodology that streamlines the modernization of codal provisions. This paper proposes a machine learning (ML) approach to append a variety of codal provisions, including those of empirical, statistical, and theoretical natures. In this approach, a codal provision (i.e., equation) is analyzed to trace its properties (e.g., engineering intuition and causal logic). Then a ML model is tailored to preserve the same properties and satisfy a collection of similarity and performance measures until declared equivalent to the provision at hand. The resulting ML model harnesses the predictive capabilities of ML while arriving at predictions similar to the codal provision used to train the ML model, and hence it becomes possible to use in lieu of the codal expression. This approach was examined successfully for seven structural engineering phenomena contained within various building codes, including those in North America and Australia. The findings suggest that the proposed approach could lay the groundwork for implementing ML in the development of future building codes. [ABSTRACT FROM AUTHOR]

Forum papers are thought-provoking opinion pieces or essays founded in fact, sometimes containing speculation, on a civil engineering topic of general interest and relevance to the readership of the journal. The views expressed in this Forum article do not necessarily reflect the views of ASCE or the Editorial Board of the journal. [ABSTRACT FROM AUTHOR]

Presents information on architectural and engineering education at Carnegie Mellon University in Pittsburgh, Pennsylvania. Educational programs in architecture; Information on graduate program in computational design; Educational programs in civil and environmental engineering.

The article offers tips on how to write an award-winning paper about engineering. According to the article, a prerequisite to writing a good paper is an in-depth understanding of the subject. This understanding should be beyond words and deep into concepts. To do this, one must have first-hand experience on the research that you are conducting.

As inelastic design for wind is embraced by the engineering community, there is an increasing demand for computational tools that enable the investigation of the nonlinear behavior of wind-excited structures and subsequent development of performance criteria. To address this need, a probabilistic collapse assessment framework for steel structures is proposed in this paper. The framework is based on the integration of a high-fidelity fiber-based nonlinear structural modeling environment with a wind-tunnel-informed stochastic wind load model to perform nonlinear time history analysis. General uncertainty is propagated using a stratified sampling scheme enabling the efficient estimation of reliabilities associated with rare events. The adopted models for simulating high-fidelity nonlinear structural behavior were found, in general, to be adequate for capturing phenomena, including progressive yielding, buckling, and low-cycle fatigue, that are essential for wind induced collapse analysis. In particular, the adopted fatigue model was found to be capable of predicting damage and potential fiber/section fracture associated with non–fully reversing stress-strain cycles that are characteristic of wind loading. Through illustration on a 45-story archetype steel building, critical discussions on the types of observed collapse mechanisms, the difference between along-wind and across-wind nonlinear behavior, reliabilities associated with first yield, and collapse are presented. A probabilistic description of the residual and peak story drifts is also provided through development of fragility functions. [ABSTRACT FROM AUTHOR]

The article presents a list of papers related to hydraulic engineering including "Design of hydraulically efficient power-law channels with freeboard," "Estimating transition probabilities in Markov chain-based deterioration models for management of wastewater systems" and "Postprocessing the hybrid method for addressing uncertainty in risk assessments."

Reports that the American Society of Civil Engineers (ASCE) and the Structural Engineering Institute (SEI) are looking for nominations for the 2006 ASCE and SEI Awards. Objective of the ASCE and SEI Honors and Awards Programs; ASCE awards based on meritorious papers; SEI awards.

Geopolymers have been long recognized as the next-generation building material due to environmental reasons. However, geopolymers are inherently brittle and usually require high-temperature curing. This paper was intended to develop a ductile engineered geopolymer composite (EGC) under ambient curing conditions. Two types of metakaolin powder with different particle sizes were applied as the solid precursor. The tensile, compressive, and flexural behaviors of EGC with different mix designs were investigated. It was concluded that the combinational application of coarse and fine metakaolin is conducive to the tensile and compressive behaviors of EGC materials. As the alkali concentrations increased from 6 to 14 mol/L , the tensile and compressive strength of EGC increased, whereas the tensile ductility of EGC decreased gradually. Also, the SiO2/Na2O molar ratio had negligible influence on the tensile behavior of EGC, whereas the compressive strength decreased with the increase of SiO2/Na2O molar ratios. A numerical model to predict the flexural behavior of EGC was also proposed, and the accuracy was verified with experimental results. [ABSTRACT FROM AUTHOR]

In the era of automation and artificial intelligence, some problems in the petroleum industry can be efficiently solved by machine-learning models based on big data. Previous researchers have addressed truly precise methods to evaluate reserves from accessible well-test data, although enormous time, effort, and cost were required. However, due to the lack of sufficient conventional material balance (CMB) test data for a large number of wells in the Su Dong (SD) gas field, only 12 wells (0.99%) were generally suitable for previous methods. We substituted the fully built-up reservoir pressures used in CMB with those converted from shut-in casing-pressure data. Suffering from data noise caused by pressure fluctuation, only 22.91% of the plots were linear. The nonlinear plots were enhanced into linear plots by denoising and smoothening according to engineering knowledge. Machine-learning models were developed to perform the enhancement automatically, which constructed an adaptive and feasible workflow. The model improved the percentage of applicable wells to 68.16% (824 out of 1,209) and achieved considerable precision for reserve evaluation. The proposed method is much more suitable than CMB in gas fields featuring unstable production status and provides feasible reserve evaluation. This paper presents an exemplary demonstration of the combination of petroleum engineering and machine learning. [ABSTRACT FROM AUTHOR]

The article presents a list of articles related to hydraulic engineering published in several journals, including "Dissolution of Wollastonite in a Packed Bed Contactor," by G. S. Anand and A. Sriram, "Salt River Project Canal Automation Pilot Project: Simulation Tests," by E. Bautista, A. J. Clemmens and R. J. Strand, "Treatment of Acid Rock Drainage in a Meromictic Mine Pit Lake," by T. S. R. Fisher and G. A. Lawrence, "Modeling Steel-Frame Buildings in Three Dimensions: Panel Zone and Plastic Hinge Beam Elements," by S. Krishnan and J. F. Hall, and "Optimal Reservoir Operations for Irrigation Using a Three Spatial Scales Approaches," by F. Mannocchi and F. Todisco.

Lists several research articles on hydraulic engineering. "Oxygen sag models for multiorder BOD reactions," by D.D. Adrian and E.M. Roider; "Impacts of physical and chemical heterogeneities on aquifer remediation design," by A. Aksoy and T.B. Culver; "Evaluation of a system for residential treatment and reuse of wastewater," by R.W. Babcock Jr. and D.A. McNair; "Effects of ENSO and PDO on water supply in the Columbia River Basin," by S.B. Barton and J.A. Ramirez.

This paper presents the results from a prediction event, organized by the University of Western Australia (UWA) and the National Geotechnical Centrifuge Facility (NGCF), and performed as part of the International Symposium on Frontiers in Offshore Geotechnics to assess uncertainty in predicting the monotonic and cyclic lateral response of conductors. Geotechnical professionals from around the world were invited to predict the response of a model conductor (a flexible pile) subjected to a series of loading sequences in a centrifuge. A normally consolidated fine-grained soil was used in the tests, which was characterized by soil elements and in-flight T-bar penetrometer testing. While some participants provided accurate predictions, the mean response was an overestimate of the monotonic and cyclic load at the pile head, which was significant for large and very small displacements. An analysis of the submissions is presented to quantify the variability of the predictions received, assess the consequences of each design, and relay the uncertainty associated with engineering judgment in design. [ABSTRACT FROM AUTHOR]

Although there have been several studies about using recycled aggregates to construct recycled aggregate base (RAB) layers, there is a lack of information about the effects of gradation of recycled concrete aggregate (RCA) materials on the performance of such layers. There is also limited information available regarding the use of RCA and recycled asphalt pavement (RAP) materials together in RAB layers. In this study, three test cells were constructed with RAB layers using two different RCA materials with different gradations and a blend of RCA and RAP materials, and another cell was constructed with a natural aggregate base layer. Physical characteristics of the base layer aggregates were determined, and resilient modulus (MR) tests were performed. A series of falling weight deflectometer (FWD) tests were performed in the field, and changes in air and soil temperatures over time were monitored. This paper contains detailed information about the evaluation of the engineering properties of recycled aggregates and the preliminary performance of the constructed RAB layers. [ABSTRACT FROM AUTHOR]

The article presents information on several articles related to hydraulics submitted to the journal. Some of the articles are: "Nonlinear Modeling of El Nino/Southern Oscillation Index," by J.H. Ahn, and H. S. Kim; "Predicting Evaporation From Bare Soil and the Crop Coefficient for the Initial Period Using Common Soils Information," by R.G. Allen, W.O. Pruitt, D. Raes, M. Smith, and L.S. Pereira; "Estimating the Removal of Anthropogenic Organic Chemicals From Raw Drinking Water by Coagulation-Flocculation," by B.D. Ballard, and A.A MacKay.

This paper presents the findings from a study of the breakdown of project success criteria. An exploration of the evolution of studies on the success of engineering projects over decades was the basis for a project success definition proposal. Using a comprehensive literature review of success criteria for engineering projects, a list of 133 different success criteria was identified. Those criteria were analyzed to develop an integrated framework of project success criteria, describing its hierarchical decomposition. Such a breakdown structure could serve as a starting point when setting project success criteria for a specific project, because the importance of criteria will be context dependent. Practitioners or stakeholders could discuss and tailor it based on specific features of engineering projects or specific needs and interests. Generally, criteria have evolved from simple work-related factors to focusing more on the complex benefits of the projects. Such an evolving success definition has implications for further studies of project success and might contribute toward a long-term vision in which all projects will be delivered successfully. [ABSTRACT FROM AUTHOR]

A list of research papers and reports about engineering is presented. They include "Irregular Breaking Wave Transmission Over Submerged Porous Breakwater," "Scattering and Trapping of Wave Energy by a Submerged Truncated Paraboloidal Shoal" and "Effect of Upward Seepage on Scour and Flow Downstream of an Apron due to Submerged Jets."

Presents several papers concerning hydraulic engineering. "On modeling acoustic waves in saturated poroelastic media," by B. Albers and K. Wilmanski; "Least-cost design of water distribution networks under demand uncertainty," by A. Babayan, Z. Kapelan, D. Savic and G. Walters; "Inactivation of baccillus spores by ultraviolet or gamma radiation," by E.R. Blatchley III, A. Meeusen, A.I. Aronson and L. Brewster.

A list of articles related to energy engineering is presented, including "Dispersion Modeling of Leachates From Thermal Power," by G. Singh and colleagues, "Evaluation of Membrane Processes for Reducing Total Dissolved Solid Diagnosed to the Truckee River," by E. R. Mortensen and colleagues, and "In-Place Stabilization of Pond Ash Deposits by Hydrated Lime Columns," by S. K. Chand and C. Subbarao.

Presents a list of recommended articles on cold region engineering published in 2003. "Goodbye, Hazen; Hello, Kozeny-Carman," by W.D. Carrier III, published in the "Journal of Geotechnology and Geoenvironmental Engineering"; "Thermal Post-buckling of Uniform Columns on Elastic Foundation--An Intuitive Solution," by G.V. Rao and K.K. Raju, published in the "Journal of Engineering Mechanism"; "Soil Water Content Monitoring Using Electromagnetic Induction," by R.C. Reddy and B.R. Scanlon, published in the "Journal of Geotechnology and Geoenvironmental Engineering."

Introduces a series of articles on hydraulic engineering featured in the February 2002 issue of the 'Journal of Hydraulic Engineering.'

A key underlying challenge in today's model-driven approach to engineering is how progress and level of effort are being measured and reported. Recent definitions such as level of development enable project teams to track completeness of information in building information modeling (BIM)-driven processes; yet, there are no established processes or metrics to reliably measure progress or track productivity of a model-driven engineering process as a function of the maturity of the model and/or the data that supports the engineering process. To address this gap in knowledge, this paper presents a discrete set of model maturity index (MMI) definitions to measure progress in engineering work, per modeling discipline. Using these MMI definitions, a model maturity risk index (Model MRI) toolkit was created to track maturity of an engineering process at the granularity of work breakdown structure locations. The MMI toolkit also reports risk in achieving certain MMI levels per modeling discipline. To benchmark maturity of the modeling work per project milestone or model review session and to establish workflows for tracking progress, an addendum to the modeling execution plan (ModelXP) is presented. New productivity and project controls metrics for tracking modeling work are also introduced. The developed definitions, toolkit, and addendum to ModelXP were validated through exhaustive surveys and charrette tests with project stakeholders involved in capital projects. The role of the MMI definitions and Model MRI toolkit in providing project controls insight and proactive management opportunities in real-world projects is discussed in detail. [ABSTRACT FROM AUTHOR]

This paper contains a summary of the developments and applications of the two-dimensional discontinuous deformation analysis (DDA2D) method regarding the modeling of rock-mass dynamics problems. Reviews on the control parameter value selections in DDA2D calculations and the developments and applications of the DDA2D regarding the analysis of rock slope failures, landslides, rockfall, some earthquake-related problems, and so forth, are performed. Research on the DDA2D for three basic rock-mass dynamics problems, such as block dynamic sliding, stress wave propagation, and dynamic fracturing, are specially stated. The modeling of rock blasting, a typical exact rock dynamics problem, is selected as a representative application example of the DDA method to be presented. Generally, the DDA2D has shown to be a powerful numerical method for the modeling of rock-mass dynamics. However, one should pay enough attention to the value selections of those important user-supplied control parameters, as well as to other important factors, such as block size and boundary conditions, for rock dynamics simulations, which have been specially addressed in the paper. [ABSTRACT FROM AUTHOR]

The condition assessment of existing buildings with special reference to the analysis of degradation level has been extensively and fruitfully applied in the field of maintenance and monitoring. This paper presents a methodology for detecting structural degradation of the building that can be implemented in a decision support system consisting in a platform connected with smart devices. The proposed procedure is suitable for calculating the degradation of the building through a set of key performance indices and an optimized analytic hierarchy process. In addition, the methodology is calibrated through the well-known Tuutti model to consider the damage evolution of reinforcements' corrosion. The results show that this calibration increases the accuracy of the assessment but reduces the robustness of the method. Moreover, an optimal calibration point is identified by exploiting the results of a set of case studies performed in Italy, Portugal, and Brazil. Finally, the method is compared with a similar approach for the degradation analysis developed in the University of Brasilia. [ABSTRACT FROM AUTHOR]

Ronald Hamburger The writers thank the discusser for his interest in the paper as well as his comments. However, as discussed in Suzuki and Lignos ([23]; [21]), in large-magnitude earthquakes that exhibit long-duration characteristics [Fig. Beam-column element model calibrated for predicting flexural response leading to global collapse of RC frame buildings. [Extracted from the article]

For this set of tests, the strain rate of the T-bar and centrifuge tests (calculated as the displacement normalized by the T-bar/pile diameter and divided by the time) were broadly comparable, as can be observed from Fig. Undrained shear strength against strain rate of simple shear, T-bar, and centrifuge tests. As noted in the original paper, the T-bar undrained shear strength gradient yielded a very similar value as the strength gradient calculated from the simple shear tests at a slow rate, despite the T-bars being performed at (considerably) higher strain rate than the slow simple shear tests. [Extracted from the article]

Drilling is a material removal process that introduces the plastic deformation and stresses around the hole. When large amounts of drilling stresses are added up, there will be deformation in the aerostructural assembly. This paper presents an aerostructural assembly deformation predicting method considering drilling-induced stresses around the riveting hole. Drilling-induced stresses are simulated with additional temperature fields. The assembly of the two riveted plates are considered to illustrate effects of drilling-induced stresses coupling and validate the proposed model. The simulation and experimental results show that one hole's drilling-induced stresses have negligible impact on the riveting deformation, while a lot of holes' drilling-induced stresses must be considered in assembling. When a lot of drillinginduced stresses are added up, there will be significant deformation in the aircraft's structure. The deformation predicting method outlined in this paper will enhance the understanding of the compliant components deformation resulting from the drilling stresses and help systematically improve the precision control efficiency in the civil aircraft industry. [ABSTRACT FROM AUTHOR]

Link-to-column connections in steel eccentrically braced frames must be capable of sustaining large cyclic forces and inelastic rotations. United States code provisions require that satisfactory performance of link-to-column connections be verified by testing under a prescribed loading protocol. However, there are few link-to-column connection details that have satisfied these testing criteria. This paper describes a pilot investigation of two promising link-to-column connection details, as follows: (1) the fillet welded connection, which uses fillet welds or a combination of fillet and groove welds between the link and the column flange; and (2) the supplemental web doubler connection, which reinforces the connection region using a pair of doubler plates in the first link web panel next to the column, parallel to but offset from the link web. These two details showed excellent performance in a series of eight tests. This paper describes these link-tocolumn connection details, summarizes the results of cyclic loading tests, and discusses design issues and approaches for these connections. [ABSTRACT FROM AUTHOR]

The article presents a list of research papers on topics related to hydraulic engineering published in the February 2006 issue of the "Journal of Hydraulic Engineering." The papers include "Effect of Media Grain Shape on Particle Capture During Filtration," by J. M. H. Barton and S. G. Buchberger, "Lime-Soda Softening Process Modifications for Enhanced NOM removal," by M. Bob and H. W. Walker, and "On the Fully Nonlinear Boussinesq-Type Equations for Waves and Currents Over Porous Beds," by Q. Chen.

Presents a list of research papers on cold regions engineering.

The most recent tendencies in pavement engineering design are directed to the return of the use of fundamental mechanical principles of engineering to predict design life through the concept of damage. Damage is associated with the relation between (1) the number of repetitions a material can resist until failure and (2) the predicted repetitions the designer is expecting during a period of time. Generally, mechanical responses as strains, stresses, and displacements are used to calculate the number of repetitions until a specific failure. In rigid pavements, there are analytical solutions that range from simple Westergaard's closed-form formulas to complex numerical solutions (as discrete-element methods and finite-element methods). This paper describes work done to develop an additional option in the middle: models calibrated to have the simplicity of the closed-form formulas and the accuracy of the finite-element methodology. Those models were then included in a graphical user interface, which will be used as the structural response engine in local mechanistic-empirical (M-E) design software. [ABSTRACT FROM AUTHOR]

Recently, formal approaches to interface management (IM) have been adopted in a number of large-scale engineering and construction (E&C) projects. However, understanding of the role and performance of IM practices in E&C projects is quite limited today. Given this circumstance, this paper attempts to understand the effectiveness of IM practices in E&C projects from the perspective of dealing with project complexity. To fulfill the objective, data on project complexity and IM practices were collected from 45 large-scale E&C projects and analyzed using quantitative analysis methods such as principal component analysis and linear regression. The data analysis revealed that current formal IM practices employed in E&C projects are effective for mitigating the adverse impact of project complexity originating from uncertainty in scope and communication and large numbers of stakeholders; however, they are not as effective for dealing with project complexity originating from large numbers of engineered items. These results provide insights into the direction of future advancement in IM techniques for large-scale E&C projects. [ABSTRACT FROM AUTHOR]

Gravity currents play an important role in many aspects of natural processes and engineering practice. This paper presents a systematic lock-exchange experimental study to investigate the influence of linearly stratified environments and ramp slope on the hydrodynamics of gravity currents. A high-speed camcorder and particle image velocimetry (PIV) are applied to analyze the macro- and microstructures of gravity currents. It is observed that the front velocity of the gravity currents increases first then decreases for both stratified and unstratified environments. However, the density contrast that drives the currents decreases more quickly in stratified environments as the currents descend the ramp, causing more intense deceleration of the front velocity, which indicates the damping of ambient stratification on gravity currents. Based on the thermal theory, a new set of analytical formulas is then developed to determine the front location and velocity at the deceleration stage by considering the ambient density variation at depth. Further downstream, the currents would separate from the ramp and then horizontally intrude into the ambience where the currents are neutrally buoyant if the relative stratification parameter S > 1. An improved equation taking into account of the ramp slope, ambient stratification, and inflow buoyancy flux is proposed to predict the separation depth where the horizontal intrusion happens. Furthermore, velocity profiles in the body part of gravity currents are well predicted by two equations with three fitted parameters obtained by using the present experimental data. The vorticity fields of the gravity currents are quantitatively investigated to show that the weaker stratified ambience can lead to a stronger vorticity field, in which the Kelvin-Helmholtz instabilities and turbulent billows at the interface significantly affect the entrainment and mixing. In comparison with the gravity currents in the unstratified ambiance, the turbulent mixing in the stratified environments is generally reduced. The presence of stratification can result in a more complicated motion and fluid structure of the gravity currents. [ABSTRACT FROM AUTHOR]

This paper addresses one of the costs of new bridges, i.e., the cost of doing the preliminary engineering (PE). This particular aspect of cost has largely been neglected because of the difficulty in obtaining appropriate data. Typically, PE costs are determined as a percentage of construction costs, disregarding other project-specific parameters. Bridge projects let by the North Carolina (NC) DOT between 2001 and 2009 were reviewed. From an analysis of these 461 projects, the writers developed statistical models linking variation in PE costs with distinctive project parameters. The primary contribution this paper makes to the body of knowledge is the finding that PE cost estimates for bridge projects are commonly and significantly underestimated. The writers found that bridge projects exhibited a mean PE cost ratio of 28%. This result is significantly greater than the percentage used in practice. An investigation of data sources related to bridge projects, a description of regression techniques applied to predict the PE cost of such projects, and an assessment of the predictive performance of models are addressed in this paper. New knowledge contributions include identification of key factors affecting the PE costs of bridges, illustration of how those key factors enabled us to predict PE costs of future projects, and discussion of the data collection problems that hindered model development. The writers' PE cost analyses and predictive modeling effort relate to infrastructure funding issues. All of the parties involved in infrastructure construction, from legislators to contractors, must understand costs and have confidence in the cost estimates developed to ensure efficient and effective funding of infrastructure projects. This paper on bridge PE costs addresses one component of infrastructure funding. [ABSTRACT FROM AUTHOR]

Maintaining project control demands construction project managers navigate the discrepancies between target and actual performance-a specific challenge for large-scale construction projects that generate large amounts of ever-changing data. Project managers often use visual representations of data to make better-informed decisions; however, current approaches often fail to manifest the multifaceted considerations that render a successful project. Better visual representation tools would streamline communication and improve project efficiency. Applying a variety of research methods ranging from literature reviews to simulation and usability tests, this investigation's six-step process developed four alternative visual representations prototypes for improved performance monitoring: Activity Icons, Map of Activities, Activity Wall, and Activity Gazer. This paper contributes to the body of knowledge by iteratively designing these four prototype visual representations in consultation with experienced project managers and by assessing industry's receptivity. This paper also lays the foundation for long-term expansion of research into the most successful of the developed visual representation prototypes: Activity Gazer. [ABSTRACT FROM AUTHOR]

The redundancy of a structure refers to the extent of degradation the structure can suffer without losing some specified elements of its functionality. However, because future structural degradation is unknown during design and analysis, it is evident that structural redundancy is related to robustness against uncertainty. This paper proposes a quantitative and widely applicable concept of strong redundancy and shows its relation to the info-gap robustness of the structure. In particular, one of this paper's propositions establishes general conditions in which the strong redundancy is equivalent to the robustness. This paper also defines a concept of weak redundancy and presents propositions that relate it to the strong redundancy and the robustness. Results are illustrated with several heuristic and engineering examples. [ABSTRACT FROM AUTHOR]

The solutions of transition curves presented in this paper are new geometric solutions that can be used in various tasks related to road designing. Their basic advantage is that they form groups of transition curves. This paper is concerned with transition curves with the classical curvature diagram and so-called general transition curves. These can be a valuable alternative for the traditional solutions (first transition curve-circular arc-second transition curve or first transition curve-second transition curve). As a result, they are particularly useful when it comes to solving road design-related tasks, e.g., location of siding within road junctions when there are land limitations or for grade-line setting out through assigned points of set elevations. As for the presented solutions of general transition curves, they add to the range of geometric tools that can be used for road designing in a site plan and a longitudinal profile. The solutions of general transition curves described are well-suited for special areas of road designing, such as forming a completely curvilinear road design. It is equivalent to the solutions presented in the literature called polynomial location. [ABSTRACT FROM AUTHOR]

What information can or cannot be exchanged between different systems? Since the dawn of the computer-aided design and engineering era, interoperability has been an issue. The exchangeable set of information between different systems has been loosely defined as the intersection of information. Yet, as information flow has directionality, a general definition of 'intersection' is inadequate to define an exchangeable set of information. This paper proposes a new directive set operation, semantic intersection, and discusses which information can or cannot be exchanged between different systems using the concept of semantic intersection. This opens up the possibility of predetermining or calculating the exchangeable set of information between two or more systems or the possibility of automated generation of a standard product model between different systems. This paper focuses on data exchange between systems, but the proposed theory is also applicable to data exchange between human beings. [ABSTRACT FROM AUTHOR]

Construction simulation is the science of developing and experimenting with computer-based representations of construction systems to understand their underlying behavior. This branch of operations research applications in construction management has experienced significant academic growth over the past two decades. In this paper, the author summarizes his views on this topic as per his Peurifoy address, given in October 2008. The paper provides an overview of advancements in construction simulation theory as reported in literature. It then summarizes the key factors that contribute to successful deployment of simulation in the construction industry, and the key attributes of problems that make them more amenable for simulation modeling as opposed to other tools. The paper then provides an overview of long-term simulation initiatives leading to the next generation of computer modeling systems for construction, where simulation plays an integral role in a futuristic vision of automated project planning and control. [ABSTRACT FROM AUTHOR]

Construction and engineering practitioners have found it increasingly difficult to learn from their mistakes, particularly with regard to the prevention, identification and/or containment of design errors. Yet, design errors have been the root cause of numerous catastrophic accidents that have resulted in the death and injury of workers and members of the public. This paper examines and classifies the nature of error and design error causation in construction and engineering projects. A review of the normative literature revealed that design errors are caused by an array of factors that can work interdependently. A generic framework is developed that classifies design error according to people, the organization, and project is presented. The paper suggests that people, over and above organizational and project management strategies, have the greatest propensity to reduce errors through the process of situated learning and knowing. This is because the working environment provided by an organization and the processes used to deliver construction and engineering projects influence the nature and ability of people to undertake tasks. Consequently, there is no single but rather a multitude of strategies that need to be adopted in congruence to reduce design errors so that safety and project performance are ameliorated. [ABSTRACT FROM AUTHOR]

The design of formworks for holding fresh concrete possesses a difficult engineering challenge. Present standards assume fresh concrete to have a nonviscous fluid behavior when calculating the lateral pressure to which the formwork walls will be the subject. This paper describes a finite-element model to determine these pressures, taking into account the interaction between the fresh concrete and the formwork wall. The use of this numerical model shows that present standards may underestimate the lateral pressures that can be exerted particularly with respect to tall formworks. The paper also discusses the influence of different mechanical variables on the results returned by the proposed model. The proposed model may be of use to practicing engineers and of interest to researchers examining load distributions in formworks. [ABSTRACT FROM AUTHOR]

Recent developments in technology, such as building information models (BIMs), immersive displays, and mobile computing tools, have enabled changes in the means and locations of communication throughout the building architecture, engineering, construction, and operation (AECO) industry. This paper presents the findings from an exploratory study regarding the planning of physical media for effective communication in conjunction with the developments in BIM use. While literature shows that there has been noticeable impact of physical media on communication, there has been little evidence of consistent and thorough planning and evaluation of media for investment or project level planning. The exploratory study identifies media synchronicity theory as a starting point for identifying the media needs by task for more effective planning of communication, as well as potential considerations unique to the AECO industry. The paper concludes with studies which have begun for planning more specific applications for BIM and media within AECO. [ABSTRACT FROM AUTHOR]

Control of reference mark stability is essential for monitoring of deformations of engineering structures or displacements of points in geodetic networks. Some robust estimates, which are based on median application, can be used for such purposes. For example, some R-estimates can be applied to determine displacements of geodetic points thus to identify unstable reference marks. However, such simplest approach can sometimes fail. Thus, a more complex strategy for monitoring of geodetic point stability is elaborated and presented in this paper. The concept presented here concerns leveling networks and applies some R-estimate and also other median-based estimates, i.e., the median distance to the median and the average distance to the median. The method proposed in this paper is illustrated with some practical examples and is compared with the traditional method for geodetic point stability monitoring. [ABSTRACT FROM AUTHOR]

Architecture, engineering, and construction industry participants often find it pragmatic to implement a project-specific dispute resolution ladder (DRL) as a managerial tool to assist in the prompt resolution of claims and change orders (CCOs) that might arise during the project construction phase. This project-specific DRL consists of a single or multiple alternative dispute resolution (ADR) techniques that require capital expenditures to cover the expenses incurred by the owner’s/contractor’s employees and third-party neutrals. If a project-specific DRL is properly chosen, then the capital expenditures are outweighed by the expected benefits from the DRL implementation; namely, prompt resolution of the CCOs without incurring excessive cost overruns on an already financially stressed project budget, as well as avoiding the escalation of the claims to a dispute that requires long protracted litigation for final settlement. Typically, the decision as to which ADR techniques to include in the project-specific DRL is undertaken during the project planning phase prior to the actual occurrence of the CCOs. In this case, the project owner decide to invest in a DRL in exchange for the expected savings in the project. This decision regarding the project-specific DRL is usually done based on the experience of the project parties with the ADR techniques. However, such a decision needs to be guided by a financial tool that allows the project owner to evaluate alternative DRLs and choose the most economically feasible alternative based on the project and ADR characteristics. In this paper, a financial model is developed to evaluate DRL implementations in construction projects by drawing analogies from real option theory with exogenous competitive entry. More specifically, the occurrence of a given CCO will result in a reduction in the value of expected savings in the project due to DRL implementation. This is similar to the reduction in the gross value of a capital investment project in a commercial property due to competitive entry by another similar commercial property developer in the market. At the same time, the CCO resolution due to an effective DRL implementation will allow project owner to recover part of the losses in the expected savings in the project due to the DRL implementation. The model presented in this paper takes into account the characteristics of the various ADR techniques included in the project-specific DRL, and the characteristics of the CCOs occurring during the construction phase of the project. A case study of a real construction project is used to illustrate the practical implementation of the model. The results indicate that for this case project and from a financial point of view, the investment in the chosen project-specific DRL was not worthwhile because of the high uncertainty in the project, and the low effectiveness of the selected DRL. These conditions did not provide the owner with the anticipated advantage of the DRL implementation in reducing the value of the CCOs occurring in the project. At the same time the cost of the DRL implementation exceeded the actual savings attained in the project. [ABSTRACT FROM AUTHOR]

This paper proposes a modified origin-based partial linearization method for solving the logit-based stochastic user equilibrium traffic assignment problem formulated by a strictly convex minimization model in terms of origin-based link flows. As a feasible descent direction method, it first generates a feasible descent direction in terms of the origin-based link flows by Bell’s second logit-based stochastic network loading algorithm without path enumeration, and it proceeds to improve the descent direction according to the Fukushima’s strategy and the PARTAN technique which haven been successfully applied to accelerate convergence of the link-based Frank-Wolfe method for solving the deterministic user equilibrium traffic assignment problem. To tackle the numerical overflow or underflow issue of the exponential function calculation arising in the computerized logit-based stochastic network loading algorithms, this paper develops a scientific notation based engineering approach for large-scale problems. Two numerical examples are carried out to compare the proposed solution method with the conventional origin-based partial linearization method and the method of successive averages in computational time and accuracy of solution. [ABSTRACT FROM AUTHOR]

The paper provides a review of empirical modeling and its application within construction engineering and management. The scope of application and trends in use of this approach are first assessed, and the potential for its further development is identified. This is followed by an examination of the key components of empirical modeling, namely: the structure and operation of the model and the scheme used in its development. The paper then provides a rigorous methodology that must be followed to ensure the validity and value of the end model, covering the steps: strategizing; data collation and assessment; model development; model evaluation and final selection; final validation; and implementation. The methodology is designed to cater for all forms of empirical modeling including the procedurally more demanding development algorithms that have become available in recent years, such as simulated evolution. Overall, the paper is designed to provide researchers embarking on an empirical modeling study with an overview of when it is appropriate to use this approach, what type of system to adopt, and how to ensure development of a successful end product. [ABSTRACT FROM AUTHOR]

This paper suggests the methodology to follow when conducting discrete-event simulation (DES) studies in construction engineering and management research. Emphasis is made on the steps that, due to the uniqueness of the construction environment, are particularly important yet are not discussed extensively in the general DES literature. Guidelines are provided to determine what aspects of a DES study demand a rigorous application of the theory depending on the purpose of the study. The paper concludes with the importance of properly understanding the probabilistic concepts upon which DES relies and on coupling this understanding with engineering judgment as a key for successful use of DES in construction research. [ABSTRACT FROM AUTHOR]

The evolution of research in the area of construction engineering and management has moved toward the use of quantitative metrics and research methods for identifying and evaluating the impact of events or procedures on the construction process. While quantitative research methods can be very important for answering certain research questions, there are important reasons for adopting qualitative or mixed methodology studies to gain a better understanding of complex phenomena. This paper explores the use of observational studies and their potential use within the field of construction research. Observational studies can provide answers to “what” phenomena occurred, particularly when people are involved in a process, along with gaining insights into “why” the phenomena occurred. This paper discusses two types of observational studies, structured and unstructured, and provides a procedure for their implementation within construction research. To clearly demonstrate the methodology, a case study focused on the investigation of two different versions of an educational simulation application, the virtual construction simulator (VCS), is used to illustrate the benefits and challenges of implementing mixed methodology observational studies. The case study involved the video recording and analysis of interactions between student team members when using the VCS application for a construction sequencing task. The video recordings were analyzed, and important insights were identified, both qualitative and quantitative. Through content analysis, it was determined that the improvements made in a new version of the VCS application were beneficial, and the detailed observational studies identified insights into why the revisions in the application yielded improved results. This case study details the steps and considerations involved in planning an observational study, as well as the benefits and challenges that researchers may encounter when using observational research methodologies. [ABSTRACT FROM AUTHOR]