Watertown, CT, United States
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Zhou K.,Bentley Systems Incorporated | Wu Z.Y.,Bentley Systems Incorporated
Engineering Structures | Year: 2017

Structural performance assessment is essential for maintaining the safety and functionality of in-service civil infrastructures. The field measurements that provide engineers with adequate useful information are required for effectively monitoring and evaluating structural performance. Moreover, strain/stress information generally shows powerful capacity for detecting the local structural property variations. Thus strain gauges are commonly used for monitoring and testing structural performance. Placing strain gauges is the key step towards a cost-effective monitoring or testing program. This paper presents a framework of strain gauge placement optimization to facilitate the practical applications of structural performance assessment. In this framework, two methods are developed and implemented to maximize the strain contributions to the structural performance assessment. The sensor placement solutions are optimized with genetic algorithm-based optimization tool, leading to a number of features that enrich the application flexibility. A systematic case study using an approach span of Verrazano Narrows Bridge in New York City is carried out to validate the framework. © 2017 Elsevier Ltd


News Article | May 24, 2017
Site: www.eurekalert.org

America's bridges received a grade of C+ on the 2017 Infrastructure Report Card, put out by the American Society of Civil Engineers (ASCE). Aging is a factor in this score -- almost four in 10 of the 614,387 bridges in the U.S. are 50 years or older, and the average age keeps climbing. But repair and rehabilitation are extremely costly -- the most recent estimate puts the nation's backlog of bridge rehabilitation needs at $123 billion. In 2013, the Delaware Department of Transportation decided to explore the effectiveness of a novel rapid replacement approach for a two-lane bridge just north of the C&D canal that was nearing the end of its useful service life. They collaborated with researchers at the University of Delaware on design and construction of a new bridge, which continues to be monitored via a custom-designed instrumentation system. The old bridge was replaced with what is known as a geosynthetic reinforced soil integrated bridge system (GRS-IBS). Developed and promoted by engineers at the Federal Highway Administration, this system lends itself to rapid and cost-effective construction. Christopher Meehan, the Bentley Systems Incorporated Chair of Civil Engineering at UD, explains that the novel design borrows from the field of retaining walls, where geosynthetic materials -- including textiles, grids, strips and nets-- are used to provide tensile reinforcement to soils, enhancing their overall strength and stability. "It turns out that concepts from these technologies can also be applied to bridges, saving money and reducing construction time," Meehan says. "The new bridge is basically a composite bridge structure that incorporates GRS abutments and prefabricated bridge superstructure elements. This approach eliminates the costly downtime associated with cast-in-place concrete, which can take a few weeks to a month to cure." For this project, the GRS abutments were constructed by laying locally available concrete masonry blocks in rows, filling behind them with gravel and covering the wall facing elements and backfill with a geosynthetic fabric. This process was repeated in layers to build each bridge abutment, and then a precast-concrete bridge superstructure was placed on top of the abutments. Next, some finish work was performed to bring the approach ways up to the grade of the bridge, and the entire bridge and roadway area was then paved. The resulting bridge superstructure spans approximately 37 feet, with a clear span over the inlet channel of a little more than 28 feet. The UD research team provided extensive technical support on the project, including designing and implementing a custom structural health monitoring system that comprises more than 150 sensors to continuously monitor the bridge's long-term performance. Meehan credits graduate students Majid Talebi, Tyler Poggiogalle, Dan Cacciola and Matthew Becker with making significant contributions to the design, construction and monitoring process. "The DelDOT journey to construct a GRS-IBS bridge actually began when Chris approached us with the idea to construct and monitor one of these innovative structures," says Barry Benton, chief bridge engineer at DelDOT and a 1992 graduate of UD in civil engineering. "From the very inception of the project, he worked closely with us to choose a location and assist in both the design and the monitoring plan. Since this was to be the first GRS-IBS bridge in Delaware, it was very important for us to understand how it would perform." DelDOT has since built another GRS-IBS bridge in Sussex County, which is performing well to date. Benton believes that this technology will yield the largest cost savings if an internal maintenance crew can be trained to do the work. "The beauty of the system is that it can be constructed quickly with small equipment, so it's a perfect fit for utilizing the talents of our own staff," he says. Meehan calls the GRS-IBS an accessible technology that can be built almost anywhere. "Geosynthetic reinforced soil structures are well-suited for construction all over the world, as geosynthetic materials are fairly light and can be easily imported," he says. "Beyond that point, various types of walls and bridge abutments can be constructed using locally sourced materials, with little need for cast-in-place concrete. The resulting structures are cost-effective and fairly forgiving with respect to settlement and lateral deflection, and they have been shown to perform relatively well in earthquakes."


News Article | May 24, 2017
Site: phys.org

But repair and rehabilitation are extremely costly—the most recent estimate puts the nation's backlog of bridge rehabilitation needs at $123 billion. In 2013, the Delaware Department of Transportation decided to explore the effectiveness of a novel rapid replacement approach for a two-lane bridge just north of the C&D canal that was nearing the end of its useful service life. They collaborated with researchers at the University of Delaware on design and construction of a new bridge, which continues to be monitored via a custom-designed instrumentation system. The old bridge was replaced with what is known as a geosynthetic reinforced soil integrated bridge system (GRS-IBS). Developed and promoted by engineers at the Federal Highway Administration, this system lends itself to rapid and cost-effective construction. Christopher Meehan, the Bentley Systems Incorporated Chair of Civil Engineering at UD, explains that the novel design borrows from the field of retaining walls, where geosynthetic materials—including textiles, grids, strips and nets— are used to provide tensile reinforcement to soils, enhancing their overall strength and stability. "It turns out that concepts from these technologies can also be applied to bridges, saving money and reducing construction time," Meehan says. "The new bridge is basically a composite bridge structure that incorporates GRS abutments and prefabricated bridge superstructure elements. This approach eliminates the costly downtime associated with cast-in-place concrete, which can take a few weeks to a month to cure." For this project, the GRS abutments were constructed by laying locally available concrete masonry blocks in rows, filling behind them with gravel and covering the wall facing elements and backfill with a geosynthetic fabric. This process was repeated in layers to build each bridge abutment, and then a precast-concrete bridge superstructure was placed on top of the abutments. Next, some finish work was performed to bring the approach ways up to the grade of the bridge, and the entire bridge and roadway area was then paved. The resulting bridge superstructure spans approximately 37 feet, with a clear span over the inlet channel of a little more than 28 feet. The UD research team provided extensive technical support on the project, including designing and implementing a custom structural health monitoring system that comprises more than 150 sensors to continuously monitor the bridge's long-term performance. Meehan credits graduate students Majid Talebi, Tyler Poggiogalle, Dan Cacciola and Matthew Becker with making significant contributions to the design, construction and monitoring process. "The DelDOT journey to construct a GRS-IBS bridge actually began when Chris approached us with the idea to construct and monitor one of these innovative structures," says Barry Benton, chief bridge engineer at DelDOT and a 1992 graduate of UD in civil engineering. "From the very inception of the project, he worked closely with us to choose a location and assist in both the design and the monitoring plan. Since this was to be the first GRS-IBS bridge in Delaware, it was very important for us to understand how it would perform." DelDOT has since built another GRS-IBS bridge in Sussex County, which is performing well to date. Benton believes that this technology will yield the largest cost savings if an internal maintenance crew can be trained to do the work. "The beauty of the system is that it can be constructed quickly with small equipment, so it's a perfect fit for utilizing the talents of our own staff," he says. Meehan calls the GRS-IBS an accessible technology that can be built almost anywhere. "Geosynthetic reinforced soil structures are well-suited for construction all over the world, as geosynthetic materials are fairly light and can be easily imported," he says. "Beyond that point, various types of walls and bridge abutments can be constructed using locally sourced materials, with little need for cast-in-place concrete. The resulting structures are cost-effective and fairly forgiving with respect to settlement and lateral deflection, and they have been shown to perform relatively well in earthquakes." Explore further: Spotlight on robotic system for bridge inspection


Wu Z.Y.,Bentley Systems Incorporated | Behandish M.,University of Connecticut
14th Water Distribution Systems Analysis Conference 2012, WDSA 2012 | Year: 2012

This paper presents a real-time pump scheduling (RTPS) methodology and the case study of a large water distribution system. The method employs the artificial neural network (ANN) based on graphics processing unit (GPU), a meta-model or surrogate solver for evaluating the hydraulic responses of pump scheduling solutions. A genetic algorithm (GA) is used to search for nearoptimal pump operation policy (POP) subject to water supply service requirements. The resulting POP is applied to the system operation for a predefined period or so-called rolling-forward time step that is much less than a typical operation cycle (e.g. 24 hours). A rolling-forward time step is determined such that the surrogate model is capable of predicting sufficiently accurate hydraulic responses for the purpose of GA solution evaluations. At the end of each rolling forward step, new boundary conditions, e.g. tank levels obtained from the field monitoring system, are used as the initial conditions for the next GA+ANN optimization process. This RTPS methodology has been successfully applied to identify the tank operation range for real-time operation and minimize the pumping energy cost of a large demand monitoring zone (DMZ) in the UK. The results indicate that significant saving in energy costs can be achieved in comparison with the current operation policies. Copyright © (2012) by Engineers Australia.


Wu Z.Y.,Bentley Systems Incorporated | Khaliefa M.,University of Connecticut
World Environmental and Water Resources Congress 2012: Crossing Boundaries, Proceedings of the 2012 Congress | Year: 2012

Cloud computing is quickly becoming an innovative model for delivering IT infrastructure, applications and data management. It shifts the emphasis from static, stand-alone applications to dynamic, shared environments, dynamically allocated among various tasks and accessed via a network. In this paper, we investigate the use of cloud computing for high performance optimization of water distribution systems. The paper covers the general survey of leading commercial cloud computing services, high performance computing (HPC) cloud differentiators and demonstration of the improved HPC cloud implementation. With necessary background information on cloud computing, a prototype of the high performance computing (HPC) cloud is proposed and developed for water system optimization. The prototyped HPC cloud is constructed by using many-core machines that form the cloud platform for running parallel applications. Finally, as an example of cloud-based water distribution optimization, a pump scheduler has been deployed onto the HPC cloud with web-based user interface, through which a user could submit, execute and retrieve optimization analysis jobs. © ASCE 2012.


Wu Z.Y.,Bentley Systems Incorporated | Behandish M.,University of Connecticut
14th Water Distribution Systems Analysis Conference 2012, WDSA 2012 | Year: 2012

This paper presents the comparison of two different approaches for solving the computationally intensive problem of near-optimal pump scheduling for large water distribution systems. The optimization problem is formulated to minimize the pump operation cost subject to water supply service requirements. The first method, utilizes the hydraulic model integrated with a parallel genetic algorithm (GA), which can run on either a many-core machine or a cluster of many-core machines. The second method, on the other hand, uses a GPU-Accelerated artificial neural network (ANN) meta-model to surrogate the hydraulic model in GA optimization. The study shows that the GPU-based ANN is capable of rapidly predicting the energy rates with adequate accuracy and robustness, as well as the tank levels which can be used for online optimization on a rolling-forward basis. GA+ANN is capable of reducing the optimization run time from several hours to a few minutes, thus enables real-time or online pump scheduling for large water distribution systems. Copyright © (2012) by Engineers Australia.


Giustolisi O.,University of Bari | Walski T.M.,Bentley Systems Incorporated
Journal of Water Resources Planning and Management | Year: 2012

Solving water distribution network hydraulics depends to a greatextent on demand representation in the related simulation models. The classical approach of simulation models for water distribution networks (WDNs) is described as demand-driven. The demands are fixed a priori in the model as an assumption or from field observations. Recentlya more realist approach to predict the hydraulic system behavior, described as head/pressure-driven, better accounts for the fact that thedemands depend in some ways on head status of the network. Thus, thispaper presents a comprehensive view of demands in the enhanced WDN simulation models, including considerations of humanbased, volume-based,uncontrolled orifice-based, and leakage-based demands as distinct types of network outflows. The paper proposes and discusses the representation of each type of demand in a comprehensive framework that is consistent with the hydraulic principles and the specific working condition. © 2012 American Society of Civil Engineers.


Giustolisi O.,University of Bari | Berardi L.,University of Bari | Walski T.M.,Bentley Systems Incorporated
Journal of Hydroinformatics | Year: 2011

The Colebrook-White formulation of the friction factor is implicit and requires some iterations to be solved given a correct initial search value and a target accuracy. Some new explicit formulations to efficiently calculate the Colebrook-White friction factor are presented herein. The aim of this investigation is twofold: (i) to preserve the accuracy of estimates while (ii) reducing the computational burden (i.e. speed). On the one hand, the computational effectiveness is important when the intensive calculation of the friction factor (e.g. large-size water distribution networks (WDN) in optimization problems, flooding software, etc.) is required together with its derivative. On the other hand, the accuracy of the developing formula should be realistically chosen considering the remaining uncertainties surrounding the model where the friction factor is used. In the following, three strategies for friction factor mapping are proposed which were achieved by using the Evolutionary Polynomial Regression (EPR). The result is the encapsulation of some pieces of the friction factor implicit formulae within pseudo-polynomial structures. © IWA Publishing 2011.


Syed J.L.,Al Ain Distribution Company | Wu Z.Y.,Bentley Systems Incorporated
World Environmental and Water Resources Congress 2012: Crossing Boundaries, Proceedings of the 2012 Congress | Year: 2012

Water transmission main is subjected to hydraulic transients due to sudden pipe failure, valve closure or any other transient phenomenon. These hydraulic transients might cause adverse effect within the pumps, bursting of the transmission main and detachment of the pipe from the joint locations such as air valve or control valve. The negative transient pressures can cause water quality issues especially from intrusion of contaminants from at the air valves and loose joints. In order to avoid both unacceptable minimum and maximum transient pressures, surge protection is imperative for a water transmission main. It is a common practice to locate the surge vessel near the pumps in order to dampen the generated surge due to sudden pump failure. In this study, surge analysis results considering two different topology configurations (Option 1 & 2) with respect to different surge vessel locations are compared for a water transmission main connected to two pumps (each having a capacity of 14.5 l/s @ 110 m head ) in parallel. The transmission main is serving residential consumers which are located on 50 m higher elevation from the pump station at a distance of about 12.5 KM. For Option 1, it is considered that two surge vessels are placed on a 150 mm DI line, 2.5 m far at the downstream side of each pump. For Option 2, only one surge vessel is placed on a 300 mm transmission main originating just after the parallel connection of the 150 mm DI lines at the downstream of the two pumps. Transient analysis is undertaken for different vessel sizes of two configurations. The results obtained are compared for the Minimum Transient Pressures in the modelled pipeline. Although, comparative difference between the two configurations is not much but gives a clear indication that surge vessel location and sizes could play a vital role in controlling the transient pressures. It is also observed that the pre-charge pressure in the surge vessel is also very important for controlling the transient pressures and must be precisely determined with respect to the mechanism of the working of the selected surge vessel. © 2012 ASCE.


Grant
Agency: GTR | Branch: EPSRC | Program: | Phase: Research Grant | Award Amount: 72.25K | Year: 2011

The AEC (Architecture, Engineering and Construction) industry is a highly fragmented data intensive project-based industry depending on a large number of very different professions and firms, with strong data sharing requirement across lifecycle stages from concept design to demolition. The process of designing, re-purposing, constructing and operating a building involves not only the traditional disciplines (Structure, Mechanical & Electrical, etc.) but also many new professions in areas such as energy, environment, waste, and assisted living with large data sharing requirements. In this context, data management support for the project lifecycle tends to be fragmented with a lack of an overall (project wide) data management policy. Additionally, data sets relating to a particular project can often be stored in: (i) local computers of designers/architects - often with limited network connectivity, persistence and availability; (ii) independently managed, single company-owned archives - where access is dictated by a company specific policy or by a charging model; (iii) shared archives owned by a consortium, often in the context of a particular building project - based, at best, on access policy associated with the project. The CloudBIM proposal explores the feasibility and potential for utilizing Cloud capability to address data storage and processing needs of stakeholders in the AEC (Architecture, Engineering and Construction) sector, with a view of delivering a cloud platform for research. CloudBIM will involve close consultation and interaction with major participants in the area to assess stakeholders perceptions about outsourced, virtualized Cloud storage for supporting multi-site, multi-team collaborative projects. A prototype cloud platform (based on CometCloud - www.cometcloud.org) and associated governance model will be developed and made available to the AEC research community. The project will deliver several reports based on a number of people-based activities, involving BRE (Building Research Establishment) and MBEKTN (Modern Built Environment Knowledge Transfer Network), along with a prototype using real project case studies BIM (Building Information Model) data to be provided by Bentley. A key outcome will be to spur a wide range of research-oriented activities through a strategic roadmap aimed at the exploitation of the resulting CloudBIM platform.

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