Research
in Civil and
Environmental Engineering
Research Centers and Facilities
- Center for Civil Engineering Earthquake Research (CCEER)
- Center for Advanced Technology in Bridges and Infrastructure (CATBI)
- Western Regional Superpave Center
- Center for Advanced Transportation Education and Research (CATER)
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Earthquake & Structural | Geotechnical | Pavements/Materials | Transportation | Environmental
Structural and Earthquake Engineering Research
Contact: Prof. Ian Buckle
The graduate program in Structural and Earthquake Engineering emphasizes the behavior of reinforced, prestressed, and steel structures under gravity and extreme loads such as earthquakes. The CEE Department hosts a state-of-the-art UNR NEES research laboratory. The Laboratory is equipped with three identical, biaxial, 50-ton shake tables, capable of being relocated on the Laboratory's tie-down strong floor. These tables are 4.25 m (14 ft) square and may carry up to a 445 kN (50-ton) payload at 1g acceleration. They may carry higher loads at lower accelerations, provided bearing capacities are not exceeded. Other peak performance characteristics include 1000 mm/sec (40 in/sec) velocity and +300 mm (+12 inches) stroke.
Three banks of blowdown accumulators are used to achieve this performance. Maximum velocity in continuous operation is 625 mm/sec (25 in/sec). The Laboratory also has seven MTS servo-controlled actuators ranging in size from 245 kN @ +75 mm stroke (55 kips @ + 3 in stroke) to 3.1 MN @ +600 mm stroke (700 kips @ + 24 in stroke). These actuators are used for large-scale experiments on structural components that are unsuitable for shake table execution and are mounted directly on the strong floor.
Three high-speed, data acquisition systems from National Instruments, Pacific Instruments and OPTIM Electronics are used for table-mounted and floor-mounted experiments. Total channel capacity is 250-channels, Data is currently archived on a data storage server and backed-up on CD-ROM. An SGI Origin 2200 Server with a library of simulation codes is available for data processing and numerical simulation studies.
The Laboratory was completed in 1992 and expanded to increase the area of the strong floor by 50% in 1999. The 780 m2 (8400 sq ft) precisely leveled strong floor, is a 4-cell box girder with tie-down holes in the upper slab at 600 mm (24-inch) centers. It weighs about 22 MN (5000 kips). To accommodate future needs of unknown shape and form, the facility is modular in design. Reaction buttresses are assembled from 85 kN (19- kip) concrete blocks, which are stressed together, and to the floor, in customized configurations. In like manner, the three shake tables are relocatable into different configurations according to the demand of present and future needs. Hydraulic pumps are located in a separate pump-house connected to the Laboratory through large diameter hardlines. Pumping capacity (continuous rating) is 1566 l/min (415 gpm). Blowdown accumulators lift this rate to 9084 l/min (2400 gpm) on demand, for short periods of time.
Center for Civil Engineering Earthquake Research
The mission of the Center for Civil Engineering Earthquake Research (CCEER), housed in the Department of Civil and Environmental Engineering of the College of Engineering, is to provide an organizational structure for conducting earthquake engineering research and develop and conduct short courses and seminars for the benefit of the earthquake engineering community and public alike. The Center publishes the results of its research in a series of technical reports. Principal research laboratories under the umbrella of the Center include the Advanced Geotechnical Engineering Laboratory and the Large-Scale Structures Laboratory, which is a member of the NSF-funded Network for Earthquake Engineering Simulation (NEES) and a NEES Equipment Site.
Center for Advanced Technology in Bridges and Infrastructure (CATBI)
The mission of CATBI is to foster broad mechanism and infrastructure for research, development, adoption, and widespread field implementation of advanced technologies and materials in bridges and other civil infrastructure systems. CATBI accomplishes its mission by conducting and directing research and holding periodic meetings of different stakeholders that include researchers, technology industries, public officials, practicing engineers, and construction industries. The current research projects in the Center are funded by the National Science Foundation, the Federal Highway Administration, the California Department of Transportation, and the Washington Department of Transportation.
Environmental Engineering Research
Contact : Prof. Eric Marchand
Engineering Approaches for Prevention and Treatment of Acid Mine Drainage
Principal Investigator: Eric Marchand
Summary: Acid Mine Drainage (AMD) is a water quality problem throughout the world that lacks a clear, cost-effective solution. Much of the problem with AMD arises from the microbial mediation of metal releases from mine wastes, creating toxic metal and acid discharges. This project will investigate the role of enhanced heterotrophic microbial growth as an engineering control technique to lower the amount of arsenic released from arsenic bearing minerals at acid mine drainage (AMD) sites and control the arsenic speciation so it is not as mobile in the environment. This strategy will attempt to encourage the growth of microbes that do not produce acid in an effort to adjust the microbial ecology in a beneficial manner, thereby preventing AMD.
Evaluation of the Applicability of Centrate as a Nutrient Supplement to Irrigation Water
Principal Investigator: Eric Marchand
Summary: One effective and cheap mechanism that can prevent the degradation of water and air quality is to limit or reduce the discharge of pollutant streams from engineered processes into the environment. For example, centrate is an undesirable liquid byproduct of wastewater treatment that is high in nitrogen and phosphorus. The nutrients present in centrate offer a potential benefit of reusing the centrate by blending this waste stream with reuse water to lower the fertilizer demand of irrigation water. This project proposes to reduce waste streams from wastewater treatment and to benefit plants by investigating the chemical composition of centrate and then supplementing irrigation water with low concentrations of centrate.
Transport and Transformation of Natural and Synthetic Endocrine Disrupting Compounds
Principal Investigator: Edward Kolodziej
Summary: Any concentration of vertebrates (e.g. humans, cattle, fish, birds) produces a local accumulation of endocrine active steroid hormones that can enter receiving waters and potentially affect aquatic organisms if not properly controlled. Sources of steroid hormones include municipal wastewater effluent, agricultural operations such as confined animal feeding operations (CAFOs), or grazing livestock. These steroids include the endogenous steroids (steroids that are naturally produced) as well as exogenous compounds (man-made synthetics) such as pharmaceuticals or anabolic growth promoters such as trenbolone and melengestrol.
So why do these steroid hormones matter? Well, if you are a fish living in a receiving water with elevated concentrations of steroid hormones (or other endocrine disrupting compounds), you might find that your endocrine system has been "scrambled" a bit due to those contaminants. Does this sound like a positive or desirable outcome? Effects include feminization of male fish, the masculinization of female fish, intersex gondal tissue, and altered biochemistry and behavior along with many other effects. These effects do not cause death or cancer, but instead alter the fitness, behavior, and most importantly, the reproductive potential of affected organisms. Over generations, populations of aquatic organisms exposed to endocrine disrupting contaminants are smaller than populations of unaffected organisms due to reproductive disruption. Interestingly enough, this pattern of slow decline in population size despite no instances of acute or chronic toxicity is prevalent for many populations of aquatic organisms in today's environment. Could sublethal effects associated with endocrine disrupting contaminants be responsible for these declines?
My interest in endocrine disruption focuses upon identifying sources of steroid hormones and other endocrine disruptors, identifying their major transport and transformation pathways in the environment, and determining their persistence and degradation in the natural and engineered environment. Once we understand the sources of these compounds and their behavior in the environment, we can optimize our engineered systems to remove them and protect ecosystem health. Examples of optimizing engineered systems might include the quantification and manipulation of steroid hormone attenuation mechanisms in municipal wastewater treatment plants, engineered treatment wetlands, agricultural systems, and riparian buffer strips.
Trace Contaminants Removal in Algal Bioreactors for Biofuels Production
Principal Investigator: Edward Kolodziej
Summary: The available climate evidence seems to unequivocally suggest that we need to move beyond fossil carbon based energy production and we need to do so immediately. What will replace petroleum and coal based energy without adverse effects on the global economy? Algal biofuels are one potential element of the diverse and sustainable energy portfolio of the future, especially if the algae can be grown on low quality recycled carbon and nutrient sources such as treated municipal wastewater. This concept is the basis of the OMEGA biofuels system which utilizes conventionally treated municipal wastewater as the feedstock for algal bioreactors that also can produce biofuels. Working with Dr. Jonathan Trent (NASA), we are exploring the range of water quality improvements these algal bioreactors are capable of and the mechanisms responsible for contaminant reduction. Most studies to date suggest that algal biofuels production alone is not cost effective or energetically favorable. However, if the algal bioreactors also provide ancillary benefits such as wastewater treatment, these symbiotic systems may become economically viable options for fossil carbon replacement. Our goal is to evaluate this possibility, essentially by treating the algal bioreactors as a tertiary wastewater treatment system that incidentally produces carbon neutral biofuels. Sustainable treatment of municipal wastewater with algae is actually a very old concept, extensively investigated by another famous UC Berkeley researcher Dr. William Oswald as early as the 1950s. He may have been farther ahead of his time than he knew. Or maybe his work just proves the point that there are no new ideas, only ideas whose time has finally arrived.
Water Characterization and Sediment Transport Analysis of the Upper Walker River
Principal Investigator: Keith Dennett
Summary: Walker Lake in western Nevada is a desert terminal lake that is some of the little remaining habitat for endangered Lahontan Cutthroat trout. The Walker Lake Basin also is one of Nevada’s most productive agricultural areas, creating conflict between environmental and agricultural uses of the limited water resources of the Walker River. This project attempts to characterize sediment and dissolved salt fluxes through the Walker River basin, as one of the main mechanisms of habitat degradation in Walker Lake is the increasing lake salinity, driven by salts entering the lake via Walker River.
Laboratory experiments in conjunction with field sampling indicate that the West Walker River has approximately twice the dissolved salts when compared to the East Walker River. A comparison between the historical data for the United States Geological Survey (USGS) site at Wabuska, Nevada and CWR #3 in this project indicated that the transport of total dissolved solids (TDS) dropped by approximately 82% corresponding to an 82% reduction in salt flux when compared with historical data gathered in 1995. The observed statistical correlations between analytes studied and flow and the difference in water quality between the east and west forks of the Walker River, indicated a potential for controlling the mass of dissolved salts on the combined Walker River, and an increase in water quality, through flow regulation on the east and west forks of the Walker River.
Geotechnical Engineering Research
The Geotechnical faculty are active in several research programs. The specific research projects in geotechnical engineering vary widely from year to year, but the principal research areas are indicated by the interests of the individual professors as listed in their bio and personal webpage.
Pavements/Materials Engineering Research
Western Regional Superpave Center
The Western Regional Superpave Center (WRSC) in the department of Civil and Environmental Engineering is one of five centers established by the Federal Highway Administration to promote the implementation of superpave technology for asphalt pavements. The WRSC conducts national and regional research into pavement materials, design, performance, and rehabilitation. The research activities of WRSC are funded by federal and state agencies and private industry. The WRSC research activities are conducted by full-time researchers and graduate students at both the Master and Doctoral levels
Evaluation of Construction Techniques for Longitudinal Joints in HMA Pavements
Hot mixed asphalt (HMA) pavements are normally constructed with multiple passes of the paver. Typically, one lane is laid-down with each pass. Consequently, a longitudinal construction joint is formed between the constructed lanes. A low density at the longitudinal joint would result in water penetrating into the HMA layer and damaging the HMA mix and the supporting layers. The water damage usually causes premature failure of the flexible pavement. One way to avoid such failures is to construct a dense longitudinal joint that would prevent the intrusion of water. The overall objective of this research was to establish the needed knowledge base for the development and implementation of a longitudinal joint specification for the Nevada Department of Transportation (NDOT). A field-testing program was carried out to evaluate the effectiveness of the various joint geometries and compaction techniques in increasing the joint density and providing improved performance.
Design System for HMA Containing a High Percentage of RAP Material
Reclaimed asphalt pavement (RAP) is generated by cold milling, heating/softening and removal of the existing aged asphalt pavement, full depth removal, or plant waste hot mix asphalt (HMA) materials. The interest in the use of RAP has increased dramatically since the recent price increases in crude oil and energy in general. Therefore the use of RAP materials in HMA can be highly beneficial from both the economical and long-term performance aspects if the appropriate testing and analysis procedures are used to design the final mixtures. The overall objective of this research effort is to develop testing and analysis procedures that can be effectively used to evaluate RAP materials and optimize the performance of HMA mixtures containing RAP materials. The research effort will cover the various aspects of the design process starting with the evaluation of the RAP materials (binders and mixtures) through the mix design process and the performance evaluation of the final HMA mixture containing RAP materials.
Warm Mix Asphalts
Asphalt pavements make up 95% of the paved roads in the US. The production and construction of asphalt mixtures are conducted at extremely elevated temperatures which consumes a significant amount of fuel and generates high dust and emissions. Typical asphalt mixtures are produced by heating the aggregates and asphalt binders at 325oF and laying the mix down on the road at 300oF. This process is known as the Hot Mix Asphalt (HMA). The Pavements/Materials Program in the Department of Civil and Environmental Engineering is a member of a national group that is working to develop a technology by which asphalt mixtures can be produced and constructed at lower temperatures. This process is called Warm Mix Asphalt (WMA). The WMA technology is expected to reduce the production temperature to around 250oF and the construction temperature to around 200oF. These reductions in temperatures are expected to reduce CO2, CO, and NOX emissions by some 35%, reduce dust generation by 90%, and reduce fuel usage by around 35%. The overall objective of this research effort is to gain an understanding of the effects of commercially available warm mix additives on the performance of the asphalt binder and mixture and mixture workability. This understanding will allow for optimization of mixture design and construction practices for application of warm mix technology to the field. Optimized practices will be applied in field trials and evaluated/refined through monitoring of pavement performance. Overall the work of the Pavements/Materials Program is expected to generate positive impacts on highway workers safety, the economy, and the environment.
Impact of Hydrated Lime on Performance of Asphalt Mixtures
The purpose of this project is to quantify expected increases in pavement life from adding lime to asphalt, based on extensive laboratory testing of multiple lime-asphalt mixtures. This project differs from previous studies in several respects. First, because lime is used in asphalt primarily for antistripping benefits, previous studies rarely quantify lime’s other performance benefits. Second, because testing is typically performed on only the asphalt mix being considered for a project, and only as necessary to satisfy specifications, typical studies do not capture the full range of failure modes and environmental stresses. Furthermore, once specifications are met, test results are rarely translated into pavement performance characteristics. This project, by contrast, will evaluate five asphalt mixtures with the most widely accepted laboratory tests for the following modes of pavement failure: moisture damage, fatigue cracking, permanent deformation, thermal cracking, and oxidative aging.
Transportation Engineering Research
The Center for Advanced Transportation Education and Research (CATER) was established in 2010. The theme is development of efficient, sustainable, and environmentally friendly transportation systems. The vision is to become a focal research and education center in the desert southwest region (primarily covering Nevada, California, Utah, Arizona, and New Mexico) that emphasizes interdisciplinary collaboration in applied transportation research. The mission is to develop operationally efficient, economically sustainable, and environmentally friendly transportation systems for the state of Nevada, the desert southwest region, and the United States; Educate the next-generation of transportation professionals equipped with advanced technical skills and strong professional motivations.