Entity

Time filter

Source Type

Redwood City, CA, United States

Sarver E.,Virginia Polytechnic Institute and State University | Slabaugh R.,Arcadis | Strock C.,Virginia Polytechnic Institute and State University | Edwards M.,DPR Construction
Journal of the Electrochemical Society | Year: 2016

"Flow electrification" occurs whenever a fluid passes along a charged surface, creating an electrokinetic "streaming current" or "streaming potential' and is known to cause non-uniform corrosion (and other) problems in non-aqueous fluids. After observing unusual corrosion failures of copper in relatively low conductivity (≈150 μS/cm) potable water, a series of laboratory studies was conducted that verified flow electrification could also develop in aqueous systems and contribute to non-uniform corrosion. Relatively high direct streaming currents along pipelines were quantified in model systems with plastic dielectrics, which accelerated corrosion on the affected pipe section by up to 0.5 μA/cm2 (assuming uniform corrosion). Very rapid non-uniform pipe failures (i.e., full wall penetration in 7 months) occurred in a system without dielectrics simulating a potable water recirculation system. The effects of flow electrification were virtually eliminated by addition of low levels of zinc phosphate, an inhibitor used in approximate 25% of potable water distribution systems. Flow electrification was also observed in plastic pipe systems with brass connectors. © The Author(s) 2016. Published by ECS. Source


Korman T.M.,California Polytechnic State University, San Luis Obispo | Huey-King L.,DPR Construction
Practice Periodical on Structural Design and Construction | Year: 2014

The coordination of mechanical, electrical, plumbing, and fire protection systems involves locating equipment and routing heating, ventilating, and air-conditioning duct, water supply piping, sanitary drainage piping, and electrical conduit and raceway, as well as fire protection systems in a manner that satisfies many different types of constraint. The process has historically been a major challenge for the specialty contractors who fabricate and install these systems. Prior to the development of building information modeling (BIM) technology, the coordination of these building systems involved sequentially comparing and overlaying shop drawings to detect and eliminate spatial and functional interferences between the numerous systems. With BIM, which is able to provide a virtual construction solution where the design (three-dimensional), schedule (four-dimensional), cost (five-dimensional), and life cycle analysis (six-dimensional) can be interlinked, the process has been able to evolve, and the challenges of identifying and resolving physical interferences have been significantly reduced. However, many challenges still remain, and without adequate background and knowledge regarding the functionality of these systems, the likelihood that the results of the process will yield a poorly coordinated system is still high. Factors including systems performance, safety, and constructability must also be taken into account. Lack of knowledge and faulty assumptions often mislead personnel during the process to accepting results produced using BIM technology. This paper describes the development of a meaningful building systems coordination. Exercises for construction engineering and management students were designed in collaboration between academia and industry to enhance awareness and the knowledge required to produce a well-coordinated system. © 2014 American Society of Civil Engineers. Source


Uddin M.M.,East Tennessee State University | Khanzode A.R.,DPR Construction
Practice Periodical on Structural Design and Construction | Year: 2014

In today's architecture, engineering, and construction (AEC) industry, building information modeling (BIM) technologies and practices are making a significant difference in how building projects are delivered. BIM models and tools let stakeholders visualize, simulate, and analyze how a building might behave, perform, or appear - with more precision than ever before. BIM technology and practices are not only improving design and construction processes by delivering projects faster, more cost effectively, and more sustainably, but are also helping BIM professionals by expanding career possibilities within the field. This paper identifies key personnel in AEC industry who are taking advantage of BIM technologies and practices and explains how BIM has enhanced their career paths. The study found that new processes of BIM enhance the careers of existing professionals and create new career paths for young professionals. Until recently, positions like BIM engineer/BIM manager did not exist, but now they are key positions in many companies. BIM is also opening up positions for young engineers in nontraditional industries like manufacturing, energy, media and entertainment, healthcare companies, and facility management. © 2014 American Society of Civil Engineers. Source


Tang P.,Arizona State University | Chen G.,Arizona State University | Shen Z.,Arizona State University | Ganapathy R.,DPR Construction
Computer-Aided Civil and Infrastructure Engineering | Year: 2016

Changes of designs and construction plans often cause propagative design modifications, tedious construction coordination, cascading effects of errors, reworks, and delays in project management. Among various building elements, those having piece-wise linear geometries (i.e., connected straight line segments), such as connected straight sections of ducts in mechanical, electrical, and plumbing systems, frequently undergo spatial changes in response to the changes of their surroundings. On the other hand, the piece-wise linear geometries pose challenges to analyzing and controlling changes in construction and facility management. State-of-the-art 3D change detection algorithms often face ambiguities about which points belong to which objects when piece-wise linear object are spacked in small spaces. This article examines a spatial-context-based framework that uses spatial relationships between piece-wise linear building elements (ducts in this article) to enable fast and reliable association of 3D data with ducts in as-designed models for supporting reliable change analysis. Three case studies showed that this framework outperformed a conventional change detection method, and could handle large dislocations of piece-wise linear elements and occlusions. ©2015 Computer-Aided Civil and Infrastructure Engineering. Source


Maestas A.,DPR Construction | Parrish K.,Arizona State University
22nd Annual Conference of the International Group for Lean Construction: Understanding and Improving Project Based Production, IGLC 2014 | Year: 2014

In the past few decades, lean manufacturing principles have been adopted as standard business practices in an attempt to create a less wasteful, more productive, and increasingly sustainable workplace. In particular, companies in the construction industry have focused on this concept to improve quality, productivity, safety and general business. This experience has been variable: while many companies tout the benefits of lean construction, some companies stand out as the leaders in its application, though companies all employ the same lean principles. Research suggests those companies that are most successful implement lean business culture across all levels in the organization. This paper examines the commonalities between four books discussing lean culture and how the common principles from these books informed the cultural underpinnings of a particularly successful lean contractor, DPR Construction (DPR). Specifically, this paper explores the book The Toyota Way by Jeffery Liker, focusing on its four sections of lean management principles and the research and findings on successful business principles in the books Built to Last, Good to Great, and Great by Choice by Jim Collins. The authors compare these books and highlight how their principles support the culture at DPR, which exemplifies an effective lean business culture. Source

Discover hidden collaborations