Juang C.H.,Clemson University |
Juang C.H.,National Central University |
Wang L.,Clemson University |
Hsieh H.-S.,Trinity Consultants |
Atamturktur S.,Clemson University
Structural Safety | Year: 2014
In this paper, the authors present a methodology for the robust geotechnical design (RGD) of braced excavations in clayey soils. The maximum wall deflection induced by the excavation was chosen as the response of concern in the design and was computed using a finite element analysis model based upon the beam-on-elastic-foundation theory. The variation of the maximum wall deflection of a given design of a braced excavation due to uncertainty in the soil parameters and the surcharges was used as a measure of the design robustness. The robust design of the braced excavation system (including soil, wall, and support) was then formulated as a multi-objective optimization problem, in which the variation of the maximum wall deflection (a signal of the design robustness) and the cost were optimized with the strict safety constraints. Using a multi-objective genetic algorithm, the optimal designs were then determined, the results of which were presented as a Pareto Front that exhibited a trade-off relationship useful for design decision-making. Furthermore, the "knee point" concept, based upon the "gain-sacrifice" trade-off is used in the selection of the most-preferred design from the Pareto Front. Finally, a design example of a braced excavation system was used to illustrate the significance of this proposed methodology. © 2013 Elsevier Ltd.
News Article | October 31, 2016
Greenberg Traurig environmental attorneys Michael Cooke and Paul Seby participated in a panel on carbon dioxide and greenhouse gas issues and regulation during the Florida Section Air & Waste Management Association’s 52nd annual conference Oct. 26-27 at the Straz Center for the Performing Arts in Tampa. Cooke, of counsel at Greenberg Traurig’s Tampa office, moderated the panel and served as the conference’s technical committee co-chair. Seby, a shareholder at Greenberg Traurig’s Denver office, was a speaker on the panel. The panel discussed legal and policy issues associated with the regulation of carbon dioxide and other greenhouse gases. Presentations addressed ongoing litigation over the EPA’s “Clean Power Plan.’’ The plan set requirements for the reduction of carbon dioxide emissions from electric utility units but has been stayed by the U.S. Supreme Court pending the outcome of litigation. Cooke advises manufacturing companies, industrial facilities, natural gas pipelines companies, shipping terminals and electric utilities around the country on environmental issues, including air permitting, compliance and enforcement, and greenhouse gas matters. He served as director of FDEP’s Division of Air Resource Management from 2003 to 2006, managing the state’s air quality program. He also was general counsel for the Florida Public Service Commission. Seby advises public and private clients in the energy, mining, manufacturing and service industries on state and federal environmental regulations and policies. He has experience on a broad range of environmental legal issues, including air and water quality, recycling and waste disposal, and surface and ground water. He has represented clients in appearances before the U.S. Supreme Court, the U.S. Courts of Appeal and the Colorado Supreme Court. Others on the conference panel were Preston McLane, Environmental Administrator of the Florida Department of Environmental Protection’s Division of Air Resource Management; Howard Herzog of the Massachusetts Institute of Technology Energy Initiative; Shannon Bañaga, director of federal affairs for Tampa Electric Co.; and Katherine Katsourides of Trinity Consultants. Greenberg Traurig’s Environmental Practice assists clients with issues under the environmental and natural resource laws that affect their businesses. The firm’s environmental attorneys help secure permits and approvals; negotiate and close transactions; defend clients in enforcement actions; handle a broad range of environmental and toxic tort litigation; ensure the understanding and satisfaction of regulatory requirements; prepare for and respond to emergencies; craft approaches for legacy cleanup issues; and develop solutions for product regulation, market access, and environmental policy challenges. Greenberg Traurig, LLP is an international, multi-practice law firm with approximately 2,000 attorneys serving clients from 38 offices in the United States, Latin America, Europe, Asia, and the Middle East. The firm is No. 1 on the 2015 Law360 Most Charitable Firms list, second largest in the U.S. on the 2016 Law360 400, Top 20 on the 2015 Am Law Global 100, and among the 2015 BTI Brand Elite. More information at: http://www.gtlaw.com.
Schroeder A.J.,Trinity Consultants
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA | Year: 2012
A study of 1-hr NO2 concentrations predicted by AERMOD for a hypothetical source at four locations throughout the US with hourly varying background O3 concentrations was carried out. The sensitivity of the model-predicted concentrations to the tier used was presented based on distance from the source and evaluated on a 1-hr NO2 NAAQS design concentration basis. The case studies highlighted important sensitivities to be considered when implementing the three-tiered NO to NO2 conversion methodology to predict 1-hr NO2 concentrations using AERMOD. The Tier 1 assumption of full conversion would always result in the highest predictions of NO2 concentrations. However, there were some situations when the use of the Tier 2 methodology would lead to lower predictions of NO2 concentrations than Tier 3 methodologies. For a particular ambient O3 concentration, the Tier 3 methodologies would also yield a greater difference in NO2 and NOx concentrations for higher emission rate sources than for lower emission rate sources. This is an abstract of a paper presented at the 105th AWMA Annual Conference and Exhibition 2012 (San Antonio, TX 6/19-22/2012).
Darrat I.,Trinity Consultants
EM: Air and Waste Management Association's Magazine for Environmental Managers | Year: 2014
EPA will continue to conduct LDAR audits and seek enhanced LDAR requirements for facilities undergoing enforcement action. Facilities subject to LDAR requirements that have not been affected thus far should consider the lessons learned from the refining and chemical sectors that have already been affected.
Schroeder A.J.,Trinity Consultants
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA | Year: 2011
The stringency of EPA's recently issued 1-hr SO 2 and NO 2 NAAQS has led many dispersion modelers to need to consider ways to reduce conservatism in modeling analyses in all ways possible. Thus, a new focus on considering the use CALPUFF to predict near-field impacts in regulatory analyses may be needed. The differences in concentrations predicted using the regulatory versions of AERMOD and CALPUFF for a case study were studied using a hypothetical emission source in the mountainous region of central Mexico. The meteorological data used in each analysis was derived from three years of MM5 output run at 4 km resolution. The CALMET meteorological preprocessor was used to generate CALPUFF-compatible meteorological data from the full 4 km gridded MM5 data set. To generate an AERMOD-ready meteorological dataset valid for central Mexico, where few surface meteorological stations are present, surface and upper air data sets in a raw data format were produced from the MM5 data sets using a recently developed tool. The results highlight the importance of the consideration of terrain when selecting a representative meteorological data station for an AERMOD analysis. This is an abstract of a paper presented at the 104th AWMA Annual Conference and Exhibition 2011 (Orlando, FL 6/21-24/2011).
Schewe G.J.,Trinity Consultants
Air and Waste Management Association - Guideline on Air Quality Models 2013: The Path Forward | Year: 2013
One turbulence enhancing feature that is offered in the AERMOD Model is the option to allow the consideration of the effects of increased heating and mechanical effects from an urban area on pollutant dispersion under stable atmospheric conditions. The effect of this option is an attempt by AERMOD to account for the potential increased turbulence that is generated by an urban area. Urban heating can cause a weak convective-like boundary layer to form during the nighttime, whereas in rural areas a stable boundary layer is assumed in the turbulence calculations. AERMOD enhances the turbulence for nighttime urban conditions over that which is expected in the adjacent rural, stable boundary layer, and also defines an urban boundary layer height to account for limited mixing that may occur under these conditions. As stated in the AERMOD Implementation Guide,1 the magnitude of the urban heat island and the associated upward heat flux effect is driven by the urban to rural temperature difference that develops at night. Thus, the AERMOD Model formulation guide 2 uses the urban-rural temperature difference, △Tu.r, to determine the amount of enhancement. The methodology is based on an empirical relationship whereby the temperature difference was measured as a function of cities of various size based on populations ranging from about 1,000 to 2,000,000 persons. AERMOD uses population of an urban area as a surrogate for actual urban area to rural area temperature differences to define the magnitude of this differential heating effect. The question posed by this paper is whether this differential heating and associated nighttime enhanced turbulence can apply also to a large industrial facility and then to what degree this may affect the outcomes of the AERMOD model with and without the urban option. Large industrial facilities may be spread over hundreds of acres and may themselves be a source of sufficient heat generation and loss to cause a similar enhanced turbulence effect to that observed in urban areas. Large petroleum refineries are one example of such facilities. Thus, the enhanced turbulence due to the temperature differences between the industrial complex and nearby rural areas perhaps should be considered. Following the AERMOD guidance, however, this effect is generally ignored if the population density or land use of the area in and around the industrial facility does not meet EPA's criteria for classification as an urban area (regardless of the magnitude of the heat island effect that could be produced by the industrial complex). Obviously, population will not be the critical determinant of whether a facility should be considered urban or rural as no persons actually reside at the industrial site. This paper presents a comparison of the temperature differences between an industrial site and nearby rural areas and an urban area and rural areas to determine that the urban option applies. The paper then applies the urban option in the context of an AERMOD application to typical refinery emission sources at receptors located in flat and elevated terrain to determine modeled 1-hour SO2 concentrations in the form of the 1-hour National Ambient Air Quality Standard (NAAQS). For elevated stacks common to refineries, the urban option had little influence on modeled impacts in flat terrain. In an elevated terrain situation characteristic of the undulating terrain and rolling hills present in many areas of the Eastern United States (i.e., local relief of approximately 150 to 300 feet), applying the urban option caused a substantial decrease in modeled concentrations during nighttime conditions as compared to the equivalent concentrations predicted when using rural dispersion parameters. The effect of the urban option in elevated terrain is so substantial that applying this option can alter the conclusions of a 1-hour SO2 NAAQS modeling study as to whether an industrial facility does or does not cause or contribute to a modeled NAAQS exceedance.
Hsieh P.-G.,Hwa Hsia University of Technology |
Ou C.-Y.,National Taiwan University of Science and Technology |
Shih C.,Trinity Consultants
Canadian Geotechnical Journal | Year: 2012
Previous studies have shown that installation of cross walls in deep excavations can reduce lateral wall deflection to a very small amount. To predict the lateral wall deflection for excavations with cross walls, it is necessary to perform a three-dimensional numerical analysis because the deflection behavior of the diaphragm wall with cross walls is by nature three dimensional. However for the analysis and design of excavations, two-dimensional plane strain analysis is mostly used in practice. For this reason, based on the deflection behavior of continuous beams and the superimposition principle, an equivalent beam model suitable for two-dimensional plane strain analysis was derived to predict lateral wall deflection for excavations with cross walls. Three excavation cases were employed to verify the proposed model. Case studies confirm the proposed equivalent beam model for excavations with cross walls installed from near the ground surface down to at least more than half the embedded depth of the diaphragm wall. For the case with a limited cross-wall depth, the proposed model yields a conservative predicted lateral wall deflection.
Yonley C.,Trinity Consultants |
Remsberg M.,Trinity Consultants
IEEE Transactions on Industry Applications | Year: 2015
As the rulemaking compliance dates come further into effect in 2015, U.S. cement plants will take final actions to upgrade compliance programs for the National Emission Standards for Portland Cement Manufacturing [also known as the Portland Cement Maximum Achievable Control Technology (PC MACT)]. For those facilities using alternative fuels and possibly raw materials, past practices will also require altering to address the non-hazardous secondary material (NHSM) and Commercial and Industrial Solid Waste Incineration (CISWI) rules. Meanwhile, there is continued work by the industry and the U.S. Environmental Protection Agency (EPA) to decipher and clarify final implementation steps of each rule and, in particular, to address the question of "what is a waste," which drives facility implementation strategies. The Portland cement industry has a long and proven track record in historically implementing the PC MACT rules and in using alternative fuels and raw materials (AFR) for a variety of environmentally and economically beneficial reasons. As the final compliance steps are put in place, there are continuing questions on how the new rules will be successfully implemented, while optimizing plant operations and continuing to grow the important AFR programs. Given that this suite of regulations will forever change the playing field on day-to-day operations, and the historic use of AFR in cement plants in the U.S., there will be critical compliance and financial risk implications on how to best manage final decisions. This paper reviews final approaches for cement plant operators to maximize opportunities and reduce unintentional risks posed by the new rules, by exploring the lessons learned on implementing PC MACT, CISWI, and NHSM rules based on the authors' work with the Portland Cement Association, individual facilities, and general industry/EPA discussions. © 1972-2012 IEEE.
Fillo J.F.,Trinity Consultants
Air and Waste Management Association - Climate Change Conference 2013: Impacts, Policy and Regulation | Year: 2014
The complexity of ESG and carbon reporting and disclosure continues to increase, with such disclosures often addressing corporate strategy, risk and opportunity management, and associated programs and initiatives: • Reporting and disclosure of GHG emissions has evolved from voluntary to mandatory in many parts of the world • Disclosure of ESG performance is becoming increasingly embedded in the fabric of statutory securities reporting for publicly traded companies • While sustainability reporting is largely voluntary, it is mandatory in selected countries and for targeted industry sectors • The bar is being raised on 'voluntary' reporting frameworks, driven by stakeholder interests, including those of shareholders, business partners and civil society While there is overlap between these myriad requirements, they all have their own unique attributes that must be addressed. Consistency in reporting between these different venues is critical to corporate sustainability, credibility and reputation.
Trinity Consultants | Date: 2014-11-07
Computer software for predicting injury to persons and damage to structures resulting from the detonation of explosives; Computer software for predicting injury to persons and damage to structures resulting from vapor cloud explosions.