Tumer R.,GZA GeoEnvironmental Inc. |
Grynkewicz F.,FGG Consulting LLC FGG
Geotechnical and Structural Engineering Congress 2016 - Proceedings of the Joint Geotechnical and Structural Engineering Congress 2016 | Year: 2016
In 2012, the Novartis Institute for Biomedical Research embarked on a 600 million expansion of its Cambridge, Massachusetts Campus with the addition of a 550,000 square foot complex which includes multiple levels of underground space. To excavate to the maximum depth in excess of 45 feet, the contractor faced several logistical challenges presented by the congested, urban location. These challenges included the shear size of the excavation, which occupied an entire city block, the presence of very soft clay deposits, the close proximity to adjacent buildings and varying structural systems and slab elevations. A support of excavation (SOE) system was designed which consists of a combination of deep soil mix wall and steel sheet piling to support a total excavation area of about 3.2 acres (138,500 sq ft). Since the use of tiebacks was limited due to the site location, the SOE was mostly supported by internal bracing; with single strut lengths reaching 240 feet. Finite element models were developed to account for soil non-linearity, SOE stiffness, and varying depths of excavation. With strut loads up to 1,200 kips, an instrumentation system provided real time data acquisition of the loads in the bracing and deflections of the SOE. The monitoring data were comparable to the stresses and deformations predicted by finite element model. © ASCE.
Heterogeneous redox conditions, arsenic mobility, and groundwater flow in a fractured-rock aquifer near a waste repository site in New Hampshire, USA [Conditions redox hétérogènes, mobilité de l'arsenic et écoulement souterrain dans un aquifère de roches fracturées près d'un site de décharge du New Hampshire, USA]
Harte P.T.,U.S. Geological Survey |
Ayotte J.D.,U.S. Geological Survey |
Revesz K.M.,U.S. Geological Survey |
Belaval M.,U.S. Environmental Protection Agency |
And 2 more authors.
Hydrogeology Journal | Year: 2012
Anthropogenic sources of carbon from landfill or waste leachate can promote reductive dissolution of in situ arsenic (As) and enhance the mobility of As in groundwater. Groundwater from residential-supply wells in a fractured crystalline-rock aquifer adjacent to a Superfund site in Raymond, New Hampshire, USA, showed evidence of locally enhanced As mobilization in relatively reducing (mixed oxic-anoxic to anoxic) conditions as determined by redox classification and other lines of evidence. Redox classification was determined from geochemical indicators based on threshold concentrations of dissolved oxygen (DO), nitrate (NO3 -), iron (Fe2+), manganese (Mn2+), and sulfate (SO4 2-). Redox conditions were evaluated also based on methane (CH4), excess nitrogen gas (N2) from denitrification, the oxidation state of dissolved As speciation (As(III) and As(V)), and several stable isotope ratios. Samples from the residential-supply wells primarily exhibit mixed redox conditions, as most have long open boreholes (typically 50-100 m) that receive water from multiple discrete fractures with contrasting groundwater chemistry and redox conditions. The methods employed in this study can be used at other sites to gauge redox conditions and the potential for As mobilization in complex fractured crystalline-rock aquifers where multiple lines of evidence are likely needed to understand As occurrence, mobility, and transport. © 2012 Springer-Verlag (outside the USA).
Lutenegger A.J.,University of Massachusetts Amherst |
Khalili J.,GZA GeoEnvironmental Inc.
Geotechnical Special Publication | Year: 2015
Results of axial tension (uplift) tests on driven open-end pipe piles and H-Piles with difference surface coatings are presented. Piles included plain steel, galvanized steel and piles coated with Slickcoat, a silicone epoxy surface coating. Open-end pipe piles with outside diameters of 2.875 in. and 4.5 in. and H-piles consisting of standard steel W6x9 sections were evaluated. Piles were installed using a simple gravity drop hammer. Uplift tests were conducted at four sites consisting of both clay and sand to evaluate the influence of surface coating on the short-term behavior and long-term behavior. Short-term tests were performed seven to ten days after driving; long-term tests were performed on the same piles 200 to 400 days after driving. Axial tension tests were performed to failure for each pile. A comparison of the installation driving records is presented which shows a similarity in driving resistance for the different surface coatings. Load tests are also presented and show that the Slickcoat coated piles gave a substantial decrease in shaft resistance for both short-term and long-term behavior as compared with plain or galvanized piles.
Brown C.,University of Massachusetts Amherst |
Meeks R.,University of Michigan |
Ghile Y.,Stanford University |
Hunu K.,GZA GeoEnvironmental Inc.
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2013
The influence of climate and the role of water security on economic growth are topics of growing interest. Few studies have investigated the potential role that climate hazards, which water security addresses, and their cumulative effects have on the growth prospects for a country. Owing to the relatively stationary spatial patterns of global climate, certain regions and countries are more prone to climate hazards and climate variability than others. For example, El Nino/Southern Oscillation patterns result in greater hydroclimatic variability in much of the tropics than that experienced at higher latitudes. In this study, we use a precipitation index that preserves the spatial and temporal variability of precipitation and differentiates between precipitation maxima (e.g. floods) and minima (e.g. droughts). The index is a more precise instrument for hydroclimate hazards than that used in any previous studies. A fixed effects, for year and country, regression model was developed to test the influence of climate variables on measures of economic growth and activity. The results indicate that precipitation extremes (i.e. floods and droughts) are the dominant climate influences on economic growth and that the effects are significant and negative. The drought index was found to be associated with a highly significant negative influence on gross domestic product (GDP) growth, while the flood index was associated with a negative influence on GDP growth and lagged effects on growth. The flood indexwas also found to have a negative effect on industrial value added in contemporary and lagged regressions. Temperature was found to have little significant effect. These results have important implications for economic projections of climate change impacts. Perhaps more important, the results make clear that hydroclimatic hazards have measurable negative impacts, and thus lack ofwater security is an impediment to growth. In addition, adaptation strategies should recognize the importance of managing hazards given the identification of precipitation extremes as the key climate influence on historical GDP growth. © 2013 The Author(s) Published by the Royal Society. All rights reserved.
Sejkora P.,GZA GeoEnvironmental Inc. |
Kirisits M.J.,University of Texas at Austin |
Barrett M.,University of Texas at Austin
Journal of the American Water Resources Association | Year: 2011
Animals, such as birds, are a source of fecal indicator bacteria and pathogens in the environment. Our objective was to determine whether a colony of cliff swallows nesting underneath a bridge would yield a measurable increase in fecal indicator bacteria (specifically Escherichia coli) in the underlying creek. When the swallows were absent, dry-weather concentrations of E. coli upstream and downstream of the bridge (in Austin, Texas) were below the Texas contact recreation criteria. When the swallows were present, dry-weather geometric-mean E. coli concentrations increased significantly from upstream (43 most probable number [MPN]/100ml) to downstream (106MPN/100ml) of the bridge. One exceedance and one near-exceedance of the Texas single-sample contact recreation criterion were observed during the swallows' nesting phase. When the swallows were present, the downstream E. coli geometric-mean concentration in storm events (875MPN/100ml) was significantly higher than the upstream concentration (356MPN/100ml), suggesting that runoff flushes swallow feces from the ground into the creek. Although the loading of E. coli from cliff swallows nesting under bridges can be significant (e.g., dry-weather loading of 3.1×108MPN/day/nest), the zoonotic potential of the cliff swallow must be examined to determine the risk to human health from contact recreation in waters contaminated with cliff swallow feces. © 2011 American Water Resources Association.
Bowman D.C.,GZA GeoEnvironmental Inc. |
Bowman D.C.,University of North Carolina at Chapel Hill |
Wilcock W.S.D.,University of Washington
Antarctic Science | Year: 2014
An ocean bottom seismometer (OBS) network was deployed for 1 month at Deception Island volcano, Antarctica, in early 2005. Although only two volcano-tectonic and three long-period events were observed, the three OBSs located > 2 km apart inside the caldera detected over 3900 events that could not be attributed to known volcanic or hydrothermal sources. These events are found on one instrument at a time and occur in three types. Type 1 events resemble impulsive signals from biological organisms while type 2 and type 3 events resemble long-period seismicity. The largest number of events was observed in a region of volcanic resurgence and hydrothermal venting. All three types occur together suggesting a common cause and they show evidence for a diurnal distribution. The events are most likely to be due to aquatic animals striking the sensors, but a geological source is also possible. In the first case, these signals indicate the presence of a biological community confined to the caldera. In the second case, they imply widespread hydrothermal activity in Port Foster. Future OBS experiments should bury the seismometers, include a hydrophone, deploy instruments side-by-side, or include a video camera to distinguish between biological and geological events. © Antarctic Science Ltd 2013.
Page M.J.,GZA GeoEnvironmental Inc. |
Fiscaletti D.D.,GZA GeoEnvironmental Inc.
Ports 2013: Success Through Diversification - Proceedings of the 13th Triennial International Conference | Year: 2013
In the 1940's, Pier No. 1 was constructed at the U. S. Naval Construction Battalion Center Davisville, (NCBC) in North Kingstown, Rhode Island. Located in the Advanced Base Depot at the NCBC, the pier provided an intermodal link for the transport of materials and supplies to Navy bases worldwide. Pier No.1, a 1,200ft long by 250ft wide, timber pile-supported pier, was utilized by Navy cargo vessels from its construction during World War II through the Vietnam War. Today, the NCBC forms a part of the Quonset Business Park and the Advanced Base Depot has been transformed into the Port of Davisville. The Port of Davisville primarily services car carriers. The vessels of today are significantly larger than the vessels of the World War II era for which the pier was originally designed. Improvements have been made and the existing tire and pile fender system is functioning; but, its ability to absorb berthing energy is limited and it requires regular maintenance. To reduce maintenance costs, reduce berthing impacts and extend the life of Pier No. 1, QDC pursued an upgrade of the existing fender system. This paper presents the basis of design and descriptions of the design and construction process for a new, innovative fender system for Pier No. 1. © 2013 American Society of Civil Engineers.
Guarente J.P.,GZA GeoEnvironmental Inc. |
Nourse C.B.,GZA GeoEnvironmental Inc.
Association of State Dam Safety Officials Annual Conference 2014, Dam Safety 2014 | Year: 2014
Man-made Lake Ladore was constructed in the mid-1800s as a "feeder" supply to the Delaware and Hudson Canal Company's coal transport canal. The Salvation Army acquired the property in 1967 and uses it as the centerpiece of a Retreat and Conference Center. HIGH hazard Ladore Dam impounds the Lake. The dam is a 330-foot long, 28-foot high hybrid structure made from connecting an original upstream earth and dry masonry structure to a downstream concrete gravity dam by ultimately filling the 50 feet between the two dams with soil. The original earth and dry stone masonry structure was constructed circa 1860. The concrete gravity dam, built circa 1907, is approximately 280 feet long and approximately 24 feet high. Fill between the dams was placed in the 1920s. Longstanding issues/major deficiencies at the dam include: • Spillway incapable of passing the SDF without overtopping. • Inadequate stability in sliding and overturning. • Hydraulic connections existed between the low-level outlet pipe and the surrounding embankment soils. • Significant uncontrolled seepage under the dam and through the upper portion of the sandstone foundation. • Significant surficial deterioration of the dam's concrete. • Discovery of an unknown pipe (likely a former pond drain) during low-level pipe replacement work., Initial recommendation was to keep the low-level outlet open at the downstream end/closed at the upstream end to mitigate severe seepage, soil loss and potential sliding failure. Overall design/construction objective was to address safety deficiencies in light of minimizing demolition/removal and replacement costs by maximizing the advantage of the existing mass of the "three dams." Solutions included: • A grouting program to fill seems in the fractured bedrock and deteriorated concrete/bedrock interface. • Tie-down anchors to improve stability. • A reinforced concrete structural facing, doweled into the downstream side of the dam and foundation bedrock. • Articulated block matting to mitigate erosion if overtopping occurred. • An innovative approach to grout the unknown pipe resulting in a stoppage of flow. Construction was executed in step-wise fashion over a period of 20 months. The over $2,000,000 invested on rehabilitation/remediation has resulted in a structure having a GOOD condition rating. Safe performance is expected under all loading including the SDF.
Hamper M.J.,GZA GeoEnvironmental Inc.
Shale Energy Engineering 2014: Technical Challenges, Environmental Issues, and Public Policy - Proceedings of the 2014 Shale Energy Engineering Conference | Year: 2014
The United States Environmental Protection Agency (US EPA) has issued a revised guidance manual on Spill Prevention, Control and Countermeasures (SPCC) plans in August 2013 for its Regional Inspectors. The manual also provides insights to the regulated community on achieving compliance with the largely performance-based SPCC regulations. The previous SPCC manual was published in November 2005. Since then, there have been revisions to the SPCC regulations in 2006, 2008, 2009 and 2011. These revisions have been incorporated into the 2013 SPCC guidance manual. The manual also includes expanded discussions of SPCC regulations that cover oil production and oil drilling and workover facilities. In addition to meeting the general SPCC requirements, the main components for oil drilling and workover facilities include positioning equipment to prevent discharges, providing catchment basins or diversion structures to intercept discharges of oil, and installing a blowout prevention assembly and well control system. For oil production facilities - in addition to the general SPCC requirements - there are requirements for bulk storage, flow-through process vessels, produced water containers, and transfer operations. Owner/operator self-certification of SPCC plans can be a cost-effective and flexible approach for the development of SPCC plans for facilities where the largest tank is either no greater than 18,900 L (5,000 gallons) (Tier I) or 37,800 L (10,000 gallons) (Tier II). © 2014 American Society of Civil Engineers.
Rodick M.A.,GZA GeoEnvironmental Inc. |
Nourse C.B.,GZA GeoEnvironmental Inc. |
Bjarngard A.B.,GZA GeoEnvironmental Inc.
Geotechnical Special Publication | Year: 2016
Deep ground freezing to a depth of about 135 feet, including an approximately 85-foot-Thick marine clay layer was utilized at an urban site in the northeast United States for temporary earth support during construction of below-grade structures. Since the freeze pipes were shut off in late 2002, up to approximately 9 feet of ground settlement has occurred, impacting site facilities including railroad tracks and underground utilities. After being retained in 2007, GZA GeoEnvironmental, Inc. (GZA) has utilized an observational method as a key component of study. Various geotechnical instruments have been used to monitor settlement rates up to approximately 1 inch per month. The observational method employed has allowed for a more enlightened remedial design process to occur, avoiding potentially wasteful emergency measures, and leading to a more sustainable rehabilitation of site facilities impacted by the settlement, including a deep 42-inch drain line.