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41.
Jack C. Parker Ungtae Kim Alyson Fortune Steffen Griepke James P. Galligan Amber Bonarrigo 《Ground Water Monitoring & Remediation》2017,37(1):51-66
The objective of in situ thermal treatment is typically to reduce the contaminant mass or average soil concentration below a specified value. Evaluation of whether the objective has been met is usually made by averaging soil concentrations from a limited number of soil samples. Results from several field sites indicate large performance uncertainty using this approach, even when the number of samples is large. We propose a method to estimate average soil concentration by fitting a log normal probability model to thermal mass recovery data. A statistical approach is presented for making termination decisions from mass recovery data, soil sample data, or both for an entire treatment volume or for subregions that explicitly considers estimation uncertainty which is coupled to a stochastic optimization algorithm to identify monitoring strategies to meet objectives with minimum expected cost. Early termination of heating in regions that reach cleanup targets sooner enables operating costs to be reduced while ensuring a high likelihood of meeting remediation objectives. Results for an example problem demonstrate that significant performance improvement and cost reductions can be achieved using this approach. 相似文献
42.
The study is focused on the specific features of ice regime in Amur lower reaches and the structure of ice surface in branches of different size and dynamic state. The main features of ice stratigraphy in different parts of the river have been identified, and ice cover characteristics have been found to show considerable heterogeneity across the channel. Quantitative data on the concentration of terrigenous material in the ice and its distribution within the ice mass have been collected. The amount of terrigenous material was estimated in the ice in Amur lower reaches, from where it is largely exported into the Sea of Okhotsk during spring ice drift. 相似文献
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A note on the consolidation settlement of a rigid circular foundation on a poroelastic halfspace 下载免费PDF全文
This paper uses Biot's poroelasticity approach to examine the consolidation behaviour of a rigid foundation with a frictionless base in contact with a poroelastic halfspace. The mathematical development of the mixed boundary value problem involves a set of dual integral equations in the Laplace transform domain which cannot be conveniently solved by employing conventional procedures. In this paper, a numerical solution is developed using a scheme where the contact normal stress is approximated by a discretized equivalent. The influence of limiting drainage boundary conditions at the entire surface of the halfspace on the degree of consolidation of the rigid circular foundation is investigated. The results obtained in this study are compared with the corresponding results given in the literature. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Pile foundations that support transmission towers or offshore structures are dominantly subjected to cyclic lateral load induced by wind and waves. For a successful design, it is crucial to investigate the effect of cyclic lateral loads on the pile behavior that is loaded laterally. Although the p–y curve method is generally utilized to design the cyclic laterally loaded pile foundations, the effect of cyclic lateral loads on the pile has not been properly implemented with the p–y curve. This reflects a lack of consideration of the overall stiffness change in soil–pile interaction. To address this, a series of model pile tests were conducted in this study on a preinstalled aluminum flexible pile under various sandy soil conditions. The test results were used to investigate the effect of cyclic lateral loads on the p–y behavior. The cyclic p–y curve, which properly takes into account this effect, was developed as a hyperbolic function. Pseudo-static analysis was also conducted with the proposed cyclic p–y curve, which showed that it was able to properly simulate cyclic laterally loaded pile behavior in sandy soil. 相似文献
47.
Juhyun Kim 《Marine Georesources & Geotechnology》2018,36(5):579-588
Classification of fine-grained soils is typically conducted using plasticity charts. The typically used plasticity chart proposed by Casagrande was questioned by Polidori proposing different classification criterion in separating clayey and silty soils. Using natural clayey and silty soils sampled from four different coastal sites in Korea, applicability of both Casagrande’s and Polidori’s plasticity charts was evaluated. Classification results of Korean natural soils based on the Casagrande’s and Polidori’s plasticity charts did not match well with those based on the soils’ behavior reported in the previous publication. The disagreement in classification of Korean natural fine-grained soils may result from disregard of considerable silt fraction effect on plastic and liquid limits for Polidori’s chart. Consequently, revised proposal of Polidori’s plasticity chart was tentatively made for further classification of fine-grained soils suitable for Korean natural soils by accounting the effect of silt fraction on soil classification. 相似文献
48.
Submarine groundwater discharge revealed by aerial thermal infrared imagery: a case study on Jeju Island,Korea 下载免费PDF全文
Eunhee Lee Ki‐mook Kang Sung Pil Hyun Kil‐Yong Lee Heesung Yoon Seung Hee Kim Yongcheol Kim Zhen Xu Duk‐jin Kim Dong‐Chan Koh Kyoochul Ha 《水文研究》2016,30(19):3494-3506
Submarine groundwater discharge (SGD) is a global phenomenon that carries large volumes of groundwater and dissolved chemical species such as nutrient, metals, and organic compounds to coastal zones. We report the influence of SGD on the coastal waters of Jeju Island, Korea, using high‐resolution aerial thermal infrared (TIR) mapping techniques and field investigations. An aircraft‐based system was implemented using a cost‐effective TIR camera for aerial TIR mapping. Ground‐based calibrations and system integration with GPS/IMU (global positioning system/inertial measurement unit) were performed for the aerial systems. The aerial surveys showed distinct low‐temperature signatures of SGD along the coasts of Jeju Island, revealing large groundwater inputs from the coastal aquifers to the ocean. Multiple aerial surveys over a range of seasons and tidal stages revealed that SGD rates dynamically affect the sea surface temperature (SST) of the coastal zone. The in‐situ measurements supported that SGD has a substantial influence on the coastal water chemistry as well as SST. Our observations highlight the extent to which aerial‐based TIR mapping can serve as a powerful tool for studying SGD and other coastal processes. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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Md. Sharwar Murshed Sangil Kim Jeong-Soo Park 《Stochastic Environmental Research and Risk Assessment (SERRA)》2011,25(7):897-911
The beta-κ distribution is a distinct case of the generalized beta distribution of the second kind. In previous studies, beta-p and beta-κ distributions have played important roles in representing extreme events, and thus, the present paper uses the
beta-κ distribution. Further, this paper uses the method of moments and the method of L-moments to estimate the parameters
from the beta-κ distribution, and to demonstrate the performance of the proposed model, the paper presents a simulation study
using three estimation methods (including the maximum likelihood estimation method) and beta-κ and non beta-κ samples. In
addition, this paper evaluates the performance of the beta-κ distribution by employing two widely used extreme value distributions
(i.e., the GEV and Gumbel distributions) and two sets of actual data on extreme events. 相似文献