Application of an in-situ soil sampler for assessing subsurface biogeochemical dynamics in a diesel-contaminated coastal site during soil flushing operations

Kwon, Man Jae,O'Loughlin, Edward J.,Ham, Baknoon,Hwang, Yunho,Shim, Moojoon,Lee, Soonjae Elsevier 2018 Journal of environmental management Vol.206 No.-

<P><B>Abstract</B></P> <P>Subsurface biogeochemistry and contaminant dynamics during the remediation of diesel-contamination by in-situ soil flushing were investigated at a site located in a coastal region. An in-situ sampler containing diesel-contaminated soils separated into two size fractions (<0.063- and <2-mm) was utilized in two monitoring wells: DH1 (located close to the injection and extraction wells for in-situ soil flushing) and DH2 (located beyond sheet piles placed to block the transport of leaked diesel). Total petroleum hydrocarbon (TPH) concentrations and biogeochemical properties were monitored both in soil and groundwater for six months. A shift occurred in the groundwater type from Ca-HCO<SUB>3</SUB> to Na-Cl due to seawater intrusion during intense pumping, while the concentrations of Ni, Cu, Co, V, Cr, and Se increased substantially following surfactant (TWEEN 80) injection. The in-situ sampler with fine particles was more sensitive to variations in conditions during the remedial soil flushing process. In both wells, soil TPH concentrations in the <0.063-mm fraction were much higher than those in the <2-mm fraction. Increases in soil TPH in DH1 were consistent with the expected outcomes following well pumping and surfactant injection used to enhance TPH extraction. However, the number of diesel-degrading microorganisms decreased after surfactant injection. 16S-rRNA gene-based analysis also showed that the community composition and diversity depended on both particle size and diesel contamination. The multidisciplinary approach to the contaminated site assessments showed that soil flushing with surfactant enhanced diesel extraction, but negatively impacted in-situ diesel biodegradation as well as groundwater quality. The results also suggest that the in-situ sampler can be an effective monitoring tool for subsurface biogeochemistry as well as contaminant dynamics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> In-situ samplers well reflected biogeochemical dynamics during in-situ soil flushing. </LI> <LI> In-situ samplers with fine particles showed contaminant dynamics much sensitively. </LI> <LI> Soil particle sizes and TPH concentrations impact community diversity and composition. </LI> <LI> Soil-flushing negatively impacted diesel biodegradation as well as groundwater quality. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Vertical and torsional soil reactions for radially inhomogeneous soil layer

El Naggar, M. Hesham Techno-Press 2000 Structural Engineering and Mechanics, An Int'l Jou Vol.10 No.4

The response of an embedded body to dynamic loads is greatly influenced by the reactions of the soil to the motion of the body. The properties of the soil surrounding embedded bodies (e.g., piles) may be different than those of the far-field for a variety of reasons. It may be weakened or strengthened according to the method of installation of piles, or altered due to applying one of the soil strengthening technique (e.g., electrokinetic treatment of soil, El Naggar et al. 1998). In all these cases, the shear strength of the soils and its shear modulus vary gradually in the radial direction, resulting in a radially inhomogeneous soil layer. This paper describes an analysis to compute vertical and torsional dynamic soil reactions of a radially inhomogeneous soil layer with a circular hole. These soil reactions could then be used to model the soil resistance in the analysis of the pile vibration under dynamic loads. The soil layer is considered to have a piecewise, radial variation for the complex shear modulus. The model is developed for soil layers improved using the electrokinetic technique but can be used for other situations where the soil properties vary gradually in the radial direction (strengthened or weakened). The soil reactions (impedance functions) are evaluated over a wide range of parameters and compared with those obtained from other solutions. A parametric study was performed to examine the effect of different soil improvement parameters on vertical and torsional impedance functions of the soil. The effect of the increase in the shear modulus and the width of the improved zone is investigated.

Impact of Herbicide Oxadiazon on Microbial Activity and Nitrogen Dynamics in Soil Environment

Rahman, Md. Mokhlesur,Song, Kyung-Sik,Rhee, In-Koo,Kim, Jang-Eok The Korean Society for Applied Biological Chemistr 2005 Journal of Applied Biological Chemistry (J. Appl. Vol.48 No.4

Influence of herbicide oxadiazon on soil microbial activity and nitrogen dynamics was evaluated. Soil samples were treated with oxadiazon at field and tenfold field rates and incubated. Organic amendment was added as an additional substrate for soil microorganisms. Tenfold field rate oxadiazon stimulated substrate-induced respiration (SIR) and dehydrogenase activity (DHA) in amended soil as compared to unamended soil and control treatment. Soil urease activity was not affected by oxadiazon treatment. In both amended and unamended soils, treatment of the herbicide at higher rate had not significant influence on $NH_4$-N and $NO_3$-N concentrations. Higher dose of oxadiazon was degraded in both soils, but dissipation rate in amended soil was higher than unamended soil, with half-lives ($t_{1/2}$) of 23.1 and 138.6 days, respectively. Recommended field rate did not affect microbial activity and nitrogen dynamics in soil ecosystem. Results showed influence of oxadiazon on cycling processes of nitrogen in soil was not significant however its effect on microbial activity was a tendency depending on addition of organic amendment to soil.

저변형률하 불포화 이암풍화토의 동적거동

허경한,정충선,배중선,Huh,Kyung-Han,Chung,Choong-Sun,Bae,Joong-Seon 한국방재학회 2004 한국방재학회논문집 Vol.4 No.2

본 연구는 정적은 물론 동적 거동에 관한 연구가 거의 없는 포항지역의 이암풍화토에 대하여 저변형률하에서의 동적 거동 파악을 위하여 수행되었다. 동적 거동에 영향을 미치는 요소들로는 간극비, 포화도 그리고 구속압 등 3가지의 변수를 설정하였다. 그 중 간극비와 포화도를 달리하여 공시체를 제작하고 구속압을 단계적으로 증가시켜가며 저변형률하에서의 전단탄성계수와 감쇠비의 거동을 고찰하였다. 이러한 저변형률하에서의 시험을 실시하기 위해 공진주 시험장치를 사용하였으며, 시험에서 얻어진 결과값들을 이용하여 이암풍화토의 동적 거동을 분석하였다. 연구결과에 의하면 저변형률하에서 이암풍화토의 최적포화도가 <TEX>$32{\sim}37%$</TEX> 나타났다. 이는 주광물의 비율과 형상뿐만 아니라 세립분의 함유량 차이로 인하여 화강풍화토보다 크게 나타났다. The interest in the dynamic properties of soils has increased strongly because of earthquake, heavy traffic, and foundations undergo high amplitude of vibrations. Most of soils in Korean peninsula are composed of granite soils, especially the decomposed mudstone soils are widely spread in Pohang areas, Kyong-buk province. Therefore, it is very important to investigate the dynamic properties of these types of soils. The most important soil parameters under dynamic loadings are shear modulus and material dampings. Furthermore, few definitive data exist that can evaluate the behavior of unsaturated decomposed mudstone soils under dynamic loading conditions. The investigations described in this paper is designed to identify the shear modulus and damping ratio due to a surface tension for the unsaturated decomposed mudstone soils under low and high strain amplitude. For this purpose, the resonant column test and the cyclic triaxial test were performed. Test results and data have shown that the optimum saturated degree of decomposed mudstone soils under low and strain amplitude is <TEX>$32{\sim}37%$</TEX> which is higher than that of decomposed granite due to the amount of fine particles as well as the type and proportion of chief rock-forming minerals.

Effect of soil pile structure interaction on dynamic characteristics of jacket type offshore platforms

Asgarian, Behrouz,Shokrgozar, Hamed Rahman,Shahcheraghi, Davoud,Ghasemzadeh, Hasan Techno-Press 2012 Coupled systems mechanics Vol.1 No.4

Dynamic response of Pile Supported Structures is highly depended on Soil Pile Structure Interaction. In this paper, by comparison of experimental and numerical dynamic responses of a prototype jacket offshore platform for both hinge based and pile supported boundary conditions, effect of soil-pile-structure interaction on dynamic characteristics of this platform is studied. Jacket and deck of a prototype platform is installed on a hinge-based case first and then platform is installed on eight skirt piles embedded on continuum monolayer sand. Dynamic characteristics of platform in term of natural frequencies, mode shapes and modal damping are compared for both cases. Effects of adding and removing vertical bracing members in top bay of jacket on dynamic characteristics of platform for both boundary conditions are also studied. Numerical simulation of responses for the studied platform is also performed for both mentioned cases using capability of ABAQUS and SACS software. The 3D model using ABAQUS software is created using solid elements for soil and beam elements for jacket, deck and pile members. Mohr-Coulomb failure criterion and pile-soil interface element are used for considering nonlinear pile soil structure interaction. Simplified modeling of soil-pile-structure interaction effect is also studied using SACS software. It is observed that dynamic characteristics of the system changes significantly due to soil-pile-structure interaction. Meanwhile, both of complex and simplified (ABAQUS and SACS, respectively) models can predict this effect accurately for such platforms subjected to dynamic loading in small range of deformation.

Effect of Decomposition on Nitrogen Dynamics in Soil Applied with Compost and Rye

Ko, Byong-Gu,Kim, Myung-Sook,Park, Seong-Jin,Yun, Sun-Gang,Oh, Taek-Keun,Lee, Chang Hoon 한국토양비료학회 2015 한국토양비료학회지 Vol.48 No.6

Soil organic matter (SOM) plays an important role in the continuous production and environmental conservation in arable soils. In particular, the decomposition of organic matter in soil might promote soil organic matter and fertility due to the mineralization of N. In this study, to evaluate the effect of organic matter amendment on the C mineralization and N dynamic, $CO_2-C$ flux, extractable N and $N_2O$ emission were determined using closed chamber for 4 weeks at 10, 15, $20^{\circ}C$ of incubation temperature after the mixture of $2Mgha^{-1}$ rice straw compost and rye in sandy loam and clay loam. Regardless of soil texture, decomposition rates of rice straw compost and rye at $10{\sim}20^{\circ}C$ of incubation temperature ranged from 0.9 to 3.8% and 8.8 to 20.3%, respectively. Rye application in soil increased $NH_4-N$ and $NO_3-N$ content as well as the $N_2O$ emission compared to the rice straw compost. After incubation for 4 weeks, total C content in two soils was higher in rice straw compost than in rye application. In conclusion, application of rice straw compost and rye to soil was able to improve the soil organic matter and fertility. However, organic matter including the recalcitrant compounds like rice straw compost would be effective on the management of soil organic matter and the reduction of greenhouse gases in soil.

평판재하시험, 흙강성측정기 및 동적콘관입시험기를 이용한 노상토의 탄성계수 비교

김규선 한국지반공학회 2015 한국지반공학회논문집 Vol.31 No.3

This paper describes the correlation and relationship between elastic moduli measured by three stiffness measurementmethods with different mechanical characteristics to evaluate the compaction characteristics of subgrade soils. The SoilStiffness Gauge (SSG) with very small strain (≈ 0.001%) ranges, static Plate Loading Test (PLT) with mid-level strain(≈ 0.01~0.1%) ranges, and Dynamic Cone Penetrometer (DCP) using penetration resistance were implemented tomeasure the elastic modulus. To use the elastic modulus measured by different measurement methods with a wide rangeof strain in practice, it is required to identify the correlation and relationship of measured values in advance. Thecomparison results of the measured elastic moduli (ESSG, EPLT, EDCP) using the three measurement methods for domesticand overseas subgrade soils under various conditions indicate that the evaluated elastic modulus relies on the types ofsoils and the level of stress condition. The correlation analysis of the measured elastic moduli except the data of cementtreated soils indicates that the static elastic modulus (EPLT) is evaluated as about 60 to 80% of the dynamic elasticmodulus (ESSG). Unusual soils such as cement treated soils are required to be corrected by the stress correction duringthe correlation analysis with typical soils, because these types of soils are sensitive to the stress condition when measuringthe static elastic modulus (EPLT) of soils. In addition, when considering the use of DCP data for the evaluation of theelastic modulus (EDCP), the measured data of the elastic modulus less than 200 MPa show more reliable correlation.

Nonlinear dynamic analysis of soil nail walls considering different modeling approaches

Mahdi Bayat,Amir Homayoon Kosarieh,Mehran Javanmard 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.39 No.6

Soil nailing is one of the most common and important techniques to exchange conventional retaining systems for deep excavation. This approach contains a significant saving in cost and time of construction compared to conventional retaining systems. In this paper, an attempt has been made to evaluate the dynamical response of a deep vertical excavation on ground of 8 m height using soil nail wall. It has been tried to investigate the effects of different modeling approaches on the dynamic response of soil-nailed walls by considering the three behavioral methods; Mohr Coulomb (MC), hardening soil (HS) and hardening soil model with Small-Strain stiffness ensued from small strains (HSS). Nonlinear time history analysis has been implemented to compare the displacements under the sinus excitation with 0.5, 1, and 1.5 Hz with PGA= 0.3 g. Different points along the height of the wall are selected and considered. At the last part of this paper, incremental dynamic analysis (IDA) was implemented to the soil nail wall to consider the effect of the different earthquake records on the response of the wall. The IDA curve is also presented for the considered soil nail wall.

Lateral seismic response of building frames considering dynamic soil-structure interaction effects

S. Hamid RezaTabatabaiefar,Behzad Fatahi,Bijan Samali 국제구조공학회 2013 Structural Engineering and Mechanics, An Int'l Jou Vol.45 No.3

In this study, to have a better judgment on the structural performance, the effects of dynamic Soil-Structure Interaction (SSI) on seismic behaviour and lateral structural response of mid-rise moment resisting building frames are studied using Finite Difference Method. Three types of mid-rise structures,including 5, 10, and 15 storey buildings are selected in conjunction with three soil types with the shear wave velocities less than 600m/s, representing soil classes Ce, De and Ee, according to Australian Standard AS 1170.4. The above mentioned frames have been analysed under two different boundary conditions: (i) fixed-base (no soil-structure interaction), and (ii) flexible-base (considering soil-structure interaction). The results of the analyses in terms of structural lateral displacements and drifts for the above mentioned boundary conditions have been compared and discussed. It is concluded that the dynamic soil-structure interaction plays a considerable role in seismic behaviour of mid-rise building frames including substantial increase in the lateral deflections and inter-storey drifts and changing the performance level of the structures from life safe to near collapse or total collapse. Thus, considering soil-structure interaction effects in the seismic design of mid-rise moment resisting building frames, particularly when resting on soft soil deposit, is essential.

Effect of Decomposition on Nitrogen Dynamics in Soil Applied with Compost and Rye

Byong-Gu Ko,Myung-Sook Kim,Seong-Jin Park,Sun-Gang Yun,Taek-Keun Oh,Chang Hoon Lee 한국토양비료학회 2015 한국토양비료학회지 Vol.48 No.6

Soil organic matter (SOM) plays an important role in the continuous production and environmental conservation in arable soils. In particular, the decomposition of organic matter in soil might promote soil organic matter and fertility due to the mineralization of N. In this study, to evaluate the effect of organic matter amendment on the C mineralization and N dynamic, CO₂-C flux, extractable N and N₂O emission were determined using closed chamber for 4 weeks at 10, 15, 20°C of incubation temperature after the mixture of 2 Mg ha<SUP>-1</SUP> rice straw compost and rye in sandy loam and clay loam. Regardless of soil texture, decomposition rates of rice straw compost and rye at 10~20°C of incubation temperature ranged from 0.9 to 3.8% and 8.8 to 20.3%, respectively. Rye application in soil increased NH₄-N and NO₃-N content as well as the N₂O emission compared to the rice straw compost. After incubation for 4 weeks, total C content in two soils was higher in rice straw compost than in rye application. In conclusion, application of rice straw compost and rye to soil was able to improve the soil organic matter and fertility. However, organic matter including the recalcitrant compounds like rice straw compost would be effective on the management of soil organic matter and the reduction of greenhouse gases in soil.