Soils and Foundations最新文献_第5页

Laboratory experiments on small-scale freezing sampling method for sand 砂土小尺度冻结取样方法的室内试验研究

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-09-01 DOI: 10.1016/j.sandf.2025.101657

Pei-Chen Hsieh , Takashi Kiyota , Toshihiko Katagiri , Masataka Shiga , Manabu Takemasa , Ryohei Kobayashi

The need to collect high-quality undisturbed samples to accurately determine in-situ liquefaction resistance of sandy soils in laboratory tests is widely recognized. Decades ago, the freezing sampling method was developed to minimize sample disturbance by pre-freezing the ground. However, due to the large scale and high cost of the work, this method is rarely used in common geotechnical surveys. To address this issue, a small-scale freezing sampling method has recently been developed. It reduces the sampling time and amount of required coolant, and can be applied to conventional borehole surveys. On the other hand, the quality of the samples collected by this new method has not been properly assessed. In this study, therefore, the appropriate conditions for inserting the freezing tube with the help of a cylindrical sand column were discussed, and the small-scale freezing sampling method was successfully implemented in a calibration chamber, whereby hollow cylindrical frozen samples with an outer diameter of 100 mm were collected within approximately 40 min and using only about 70 kg of liquid nitrogen. The focus of the quality assessments of the collected frozen samples was placed on the density and shear wave velocity measurements. The results showed that the changes in the small strain shear moduli were −0.5 % between the stages before and after the sampling, suggesting that the implementation of small-scale freezing sampling can be expected to improve the accuracy of in-situ liquefaction resistance estimates and, in turn, the accuracy of liquefaction assessments.

在实验室测试中，需要收集高质量的原状样品来准确地测定沙土的原位液化阻力，这一点已得到广泛认识。几十年前，冻结取样法是通过对地面进行预冻结来减少取样扰动而发展起来的。但由于工程规模大、成本高，在普通岩土工程勘察中很少采用该方法。为了解决这一问题，最近开发了一种小规模冷冻取样方法。它减少了采样时间和所需冷却剂的量，可以应用于常规的井眼测量。另一方面，用这种新方法采集的样品的质量还没有得到适当的评价。因此，本研究探讨了利用圆柱形砂柱插入冷冻管的适宜条件，并在校准室中成功实施了小规模冷冻取样方法，在大约40分钟内收集了外径为100 mm的空心圆柱形冷冻样品，仅使用了约70 kg的液氮。冰冻样品的质量评价重点放在密度和横波速度的测量上。结果表明，取样前后的小应变剪切模量变化幅度为- 0.5%，表明实施小规模冻结取样有望提高现场液化阻力估算的准确性，进而提高液化评估的准确性。

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引用次数: 0

Study on the hydraulic characteristics of natural levees by field surveys: Case study of the Kokai River, Japan 自然堤防水力特性的野外调查研究——以日本Kokai河为例

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-09-01 DOI: 10.1016/j.sandf.2025.101679

Wenyue Zhang , Mai Tabuchi , Tomotaka Yoshikawa , Akihiro Takahashi

As compensation for the limited experimental data from the borehole logs, geological knowledge is expected to contribute to better risk assessment of the river levee system. Although natural levees have long been recognized as related to the underseepage risk of river levees, limited quantitative knowledge of hydraulic characteristics is available. Field surveys are conducted at a site along the Kokai River in Japan to reveal the hydraulic characteristics of natural levee sediments. Sounding tests allow us to capture laminar structures in the natural levee sediments. Through in-situ seepage tests, it is found that the silty materials in the natural levee sediments have hydraulic conductivity in the order of around E-06 m/s. Based on the results from the field surveys, numerical spatial hydraulic conductivity models of natural levees are built by applying geostatistical methods, including indicator Kriging and indicator simulations. The methodology in this study shows a possibility of quantifying geological knowledge, which finally contributes to the quantitative risk assessment against underseepage and internal erosion.

作为钻孔测井实验数据有限的补偿，地质知识有望有助于更好地对河流堤防系统进行风险评估。虽然自然堤防长期以来被认为与河流堤防的下渗风险有关，但水力特性的定量知识有限。为了揭示天然堤防沉积物的水力特性，在日本Kokai河沿岸进行了实地调查。探空试验使我们能够捕捉到天然堤防沉积物中的层流结构。通过现场渗流试验发现，天然堤防沉积物中的粉质材料具有E-06 m/s左右的水力导率。在野外调查结果的基础上，应用地质统计学方法，包括指标克里格法和指标模拟法，建立了天然堤坝的空间水力导率数值模型。本研究的方法显示了量化地质知识的可能性，最终有助于定量评估地下渗透和内部侵蚀的风险。

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引用次数: 0

Experimental and numerical simulation for shear failure mechanism of silty clay–structure interface 粉质粘土-结构界面剪切破坏机理的实验与数值模拟

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-09-01 DOI: 10.1016/j.sandf.2025.101683

Boxin Wang , Zihao Wang , Wen Zhang , Jingjing Pan , Jiaqi Liu , Qing Wang

The shear phenomenon between soil and foundation structure is common in foundation engineering. The change in the water content of stratum affects the shear behavior of soil and structure inevitably, especially in the region of cohesive soil with complex hydro-physical properties. In this paper, the silty clay in the Songnen Plain was used as a case study to reveal the shear failure mechanism of silty clay–structure interface under different water contents from multiple scales. First, the macroscopic mechanical characteristics were investigated by direct shear test and particle-image-velocimetry technology. To further explore the mesoscopic evolution law, this study proposed a novel FDM-DMDEM (Finite Difference Method–Determining Meso-parameter Discrete Element Method). This method enables direct calculation and assignment of meso-parameters required for the numerical model based on unsaturated soil theory, completely circumventing the laborious and subjective inverse calibration process inherent in conventional DEM. In this study, a 3D numerical model was established by using this coupling method and a parametric analysis was carried out. The results demonstrated that the meso-structure failure of silty clay within a certain range from the interface produced plastic deformation to form shear bands. Failure has two forms, namely, shear failure inside the shear band and shear failure outside the shear band. The increase in water content weakened the bonding force between particles, so that developing shear stress outside the shear band was difficult, resulting in typical shear failure inside the shear band. These findings could provide certain design references for the construction of foundation engineering in the Songnen Plain area.

土与基础结构之间的剪切现象是基础工程中常见的现象。地层含水率的变化不可避免地影响着土体和结构的剪切性能，特别是在水物性复杂的粘性土区域。本文以松嫩平原粉质粘土为例，从多尺度上揭示了不同含水量下粉质粘土-结构界面剪切破坏机理。首先，采用直剪试验和颗粒图像测速技术对其宏观力学特性进行了研究。为了进一步探索细观演化规律，本研究提出了一种新的FDM-DMDEM（有限差分法-确定细观参数离散元法）。该方法可以直接计算和分配基于非饱和土理论的数值模型所需的细观参数，完全避免了传统DEM固有的费力和主观的反校准过程。本文采用该耦合方法建立了三维数值模型，并进行了参数化分析。结果表明：粉质粘土在一定范围内的细观结构破坏，从界面开始产生塑性变形，形成剪切带；破坏有剪切带内剪切破坏和剪切带外剪切破坏两种形式。含水量的增加削弱了颗粒间的结合力，使剪切带外产生剪切应力变得困难，导致剪切带内出现典型的剪切破坏。研究结果可为松嫩平原地区基础工程的施工提供一定的设计参考。

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引用次数: 0

In-situ investigation on installation mechanisms of pre-bored grouted planted piles in deep and thick sand layers 深厚砂层中预钻孔灌注桩安装机理的现场研究

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-08-29 DOI: 10.1016/j.sandf.2025.101678

Jingwei Zhang , Zhencai Luo , Yunlong Liu , Bowen Zheng , Zhenguo Hou , Jin Kong

Due to merits of low noise and vibration, the pre-bored planted method has been widely used in engineering practice to assist the installation of the prestressed high-strength concrete (PHC) piles in area where deep and thick sand layers are commonly encountered. However, the research on the influence mechanism of pile driving methods in hard soil layers mainly focuses on the static pressing method and the hammering method, while the penetration characteristics under pre-bored assistance remains unclear. Therefore, a full-scale field test was conducted to investigate the installation effects. The penetration mechanisms of the piles with pre-bored assistance in areas with a deep and thick sand layer was discussed. Besides, an analytical method was proposed to predict the energy (hammer blow counts) necessary to drive pile to design depth. The results showed that the pre-bored grouted planted method significantly reduced the energy required for pile driving, compared to both the hammering method and the pre-bored planted method. This was because pre-drilling reduced displaced soil volume and relieved lateral stress. The pile load transfer mechanism was optimized by pre-drilling, which effectively leveraged the high compressive strength of the deep and thick sand layers. Meanwhile, the shaft friction within the grouted depth was significantly enhanced by the permeation, cementation and reinforcement effects of the concrete slurry, thereby improving the pile bearing capacity. Furthermore, the analytical method proposed based on the cavity expansion theory was capable of predicting the energy required for pile driving, which could guide the selection of pile driving equipment with minimum energy consumption and prevent pile damage caused by excessive hammering.

预钻孔灌注法由于具有低噪声、低振动的优点，在工程实践中广泛应用于深厚砂层地区的预应力高强混凝土桩的辅助安装。然而，硬土层中打桩方式影响机理的研究主要集中在静压法和锤击法，预钻辅助下的沉贯特性尚不清楚。因此，进行了全尺寸的现场试验来研究安装效果。探讨了预钻辅助桩在深厚砂层地区的侵彻机理。此外，提出了一种预测打入桩至设计深度所需能量（锤击次数）的分析方法。结果表明，与锤击法和预钻孔灌注法相比，预钻孔灌注法明显降低了打桩所需的能量。这是因为预钻减少了位移土体积，减轻了侧向应力。通过预钻优化桩基荷载传递机制，有效利用深、厚砂层的高抗压强度。同时，在灌浆深度内，混凝土浆体的渗透、胶结和加固作用显著增强了桩身摩擦力，从而提高了桩身承载力。此外，基于空腔扩展理论提出的分析方法能够预测打桩所需的能量，可以指导选择能耗最小的打桩设备，防止过度锤击造成桩的损坏。

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引用次数: 0

An experimental and theoretical research on shield screw conveyor discharging efficiency in moderately weathered mudstone strata and its influence on clogging 中等风化泥岩地层中盾构螺旋输送机卸料效率及其对堵塞影响的实验与理论研究

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-08-26 DOI: 10.1016/j.sandf.2025.101675

Bin Zhuo, Yong Fang, Liupan Dou, Xuedan Liu, Muyuan Zhu, Xiongyu Hu

When an earth pressure balance shield machine is tunneling in cohesive soils, a poorly effective soil conditioning scheme often leads to clogging in the cutterhead and the screw conveyor, which reduces tunneling efficiency and may even cause the shield machine to stop tunneling. Different from the conventional test method that use artificial clay soil, this study relies on the field shield engineering in mudstone strata and conducts soil conditioning tests using the field soil as the basic material. Using a shield soil migration model test, the whole process of clogging in a screw conveyor is reproduced, and the pattern of migration change of soil in the screw conveyor is obtained. The screw conveyor torque decreases with the increase of foam injection rate. When the slump of soil reaches 15 cm, the torque tends to be stable. Based on this, this study innovatively establishes a theoretical calculation model that can quantitatively describe the relationship between the soil discharge and the pressure gradient. Experimental verification shows that this model can not only quantitatively describe the variation laws of the soil discharge and the pressure gradient, but also qualitatively reveal the influence mechanism of the soil chamber pressure and soil fluidity on the discharge efficiency. Finally, using the Ziyang line of the Chengdu rail transit as a field test, it is found that under the recommended soil conditioning scheme, the clogging problem in the shield cutterhead and screw conveyor is greatly reduced and the efficiency of shield tunneling is significantly improved.

土压平衡盾构机在粘性土中掘进时，如果土壤调理方案效果不佳，往往会导致刀盘和螺旋输送机堵塞，降低掘进效率，甚至可能导致盾构机停止掘进。与常规使用人工粘土的试验方法不同，本研究依托泥岩地层的现场盾构工程，以现场土为基本材料进行土壤调理试验。通过盾构土迁移模型试验，再现了螺旋输送机内土体堵塞的全过程，得到了土体在螺旋输送机内的迁移变化规律。螺旋输送机扭矩随泡沫注入量的增加而减小。当土体坍落度达到15 cm时，扭矩趋于稳定。在此基础上，本研究创新性地建立了定量描述土流量与压力梯度关系的理论计算模型。实验验证表明，该模型不仅可以定量描述土流量和压力梯度的变化规律，而且可以定性地揭示土室压力和土壤流动性对泄放效率的影响机理。最后，以成都轨道交通紫阳线为现场试验，发现在推荐的土壤调节方案下，盾构刀盘和螺旋输送机的堵塞问题大大减少，盾构掘进效率显著提高。

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引用次数: 0

Seismic bearing capacity of strip footing above cavities in rock masses 岩体空腔上方条形基础抗震承载力研究

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-08-26 DOI: 10.1016/j.sandf.2025.101681

Yao Xiao , Qiuyan Lin , Wenyue Fang , Rui Zhang

This paper employs an adaptive finite element limit analysis (AFELA) combined with nonlinear programming (NLP) to investigate the seismic bearing capacity of strip footings overlying cavities in rock masses that obey the generalized Hoek–Brown (GHB) failure criterion. The feasible arc interior point algorithm (FAIPA) is utilized to solve the optimization models, and a novel imprecise step search algorithm is introduced to improve the NLP convergence. Based on the self-developed AFELA procedure, the bearing capacity reduction factor R of strip footing on a rock mass has been calculated, with the results presented in tables and charts. Parametric analysis reveals that a footing centered above a cavity does not exhibit the lowest capacity, likely due to a beneficial arching effect. Failure modes associated with varying parameters are also discussed, and the results show that increasing the horizontal seismic coefficient reduces the extent of the failure zone.

本文采用自适应有限元极限分析（AFELA）和非线性规划（NLP）相结合的方法，研究了岩体中服从广义Hoek-Brown （GHB）破坏准则的覆空条形基础的抗震承载力。采用可行弧内点算法（FAIPA）求解优化模型，并引入一种新的不精确步进搜索算法来提高NLP的收敛性。基于自行开发的AFELA程序，计算了岩体条形基础的承载力折减系数R，并以表格形式给出了计算结果。参数分析表明，以空腔为中心的基础并没有表现出最低的承载力，这可能是由于有益的拱效应。结果表明，水平地震系数的增大减小了破坏区范围。

引用次数: 0

Experimental and numerical study on helical piles in aeolian sand: bearing behavior and design methods 风沙中螺旋桩的试验与数值研究：承载性能与设计方法

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-08-22 DOI: 10.1016/j.sandf.2025.101680

Yongping Li , Songzhao Qu , Jing Bai , Dongming Yang , Sangtian Hu , Lefu Di , Ruiyuan Han , Yijin Wu , Yuan Xiang , Dapeng Wang , Yi Zhang , Yonghua Guo , Zhe Zhang

In aeolian sand, the mechanical behavior of helical anchors involves complex performance evolution mechanisms that are not yet fully understood. This study employs a multi-scale integrated approach combining field tests, numerical simulations, and machine learning to systematically investigate the evolution laws of the bearing behavior of helical anchors. The results indicate: (1) The critical embedment depth threshold for helical anchors in aeolian sand is H = 5D; beyond this threshold, the load direction effect can be neglected. (2) Multi-plate helical anchors exhibit significant geometrically nonlinear superposition behavior. Dense spacing (S/D < 4) produces notable stress superposition effects (η = 1.15–1.32), whereas wide spacing (S/D ≥ 4) results in independent bearing units (η = 0.97–1.03). (3) The XGBoost machine learning model identifies the internal friction angle, anchor plate diameter, and embedment depth ratio as the most influential features affecting bearing capacity. Based on these control parameters, predictive equations for the bearing capacity coefficient N_q and soil lateral friction coefficient K_u were developed, with predictions showing excellent agreement with experimental data. This provides engineers with a reliable analytical framework for performance-based design. The study not only deepens the understanding of the behavioral mechanisms of helical piles in aeolian sand but also offers practical solutions for geotechnical engineering practice.

在风沙中，螺旋锚的力学行为涉及复杂的性能演化机制，目前尚未完全了解。本研究采用现场试验、数值模拟和机器学习相结合的多尺度综合方法，系统研究螺旋锚杆承载行为的演化规律。结果表明：(1)螺旋锚在风沙中的临界嵌入深度阈值为H = 5D；超过这个阈值，载荷方向效应可以忽略不计。(2)多板螺旋锚具有显著的几何非线性叠加行为。密间距（S/D < 4）产生显著的应力叠加效应（η = 1.15 ~ 1.32），宽间距（S/D≥4）产生独立的承载单元（η = 0.97 ~ 1.03）。(3) XGBoost机器学习模型识别出内摩擦角、锚板直径和嵌入深度比是影响承载力的最重要特征。基于这些控制参数，建立了承载力系数Nq和土侧摩擦系数Ku的预测方程，预测结果与试验数据吻合良好。这为工程师提供了基于性能的设计的可靠分析框架。该研究不仅加深了对风沙中螺旋桩行为机理的认识，而且为岩土工程实践提供了切实可行的解决方案。

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引用次数: 0

Liquefaction response of reclaimed soils from effective stress analysis 基于有效应力分析的复垦土液化响应

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-08-22 DOI: 10.1016/j.sandf.2025.101677

Riwaj Dhakal, Misko Cubrinovski

One-dimensional (1D) dynamic effective stress site response analysis (ESA) is performed for profiles at the port of Wellington, New Zealand (CentrePort), which contains reclamation fills comprised of gravel-sand-silt (G-S-S) mixtures and hydraulic fills. The first phase of the study realistically simulates three recent earthquake case histories while considering modelling uncertainties by using the PM4Sand and the Stress-Density constitutive models. The results illustrate possible mechanisms explaining the severity of liquefaction manifestation and soil ejecta characteristics observed in G-S-S fills through careful engineering interpretation of the response. Challenges for 1D ESA to explain complex manifestation patterns affected by two-dimensional variability in fill composition and response characteristics are illustrated for the hydraulic fills. In the second phase of analyses, ESA-based response measures are proposed to quantify the severity of the liquefaction response for a range of input seismic demands. The response characteristics show very small scatter despite using a range of different input ground motions and two soil constitutive models. Results illustrate the capability of ESA to capture details of the liquefaction response such as the similar threshold seismic intensity for liquefaction triggering of the loosely deposited fills, different maximum response of the sites reflecting the differences in the thicknesses of the fills, and the evolution of the response from triggering to maximum reflecting differences in depositional characteristics.

对新西兰惠灵顿港（CentrePort）的剖面进行了一维动态有效应力响应分析（ESA），该剖面包含由砾石-沙子-淤泥（G-S-S）混合物和水力填充物组成的填海填充物。研究的第一阶段在考虑PM4Sand和应力-密度本构模型建模不确定性的情况下，实际模拟了最近三次地震的历史。研究结果通过对G-S-S填充物响应的细致工程解释，阐明了解释液化表现的严重程度和土壤喷射特征的可能机制。对于水力充填体，1D ESA在解释受充填体组成和响应特性二维变化影响的复杂表现模式方面面临挑战。在分析的第二阶段，提出了基于esa的响应措施，以量化一系列输入地震需求下液化响应的严重程度。在不同的输入地震动范围和两种土本构模型下，响应特性的离散性很小。结果表明，ESA能够捕捉液化响应的细节，如松散沉积填筑体液化触发的阈值地震烈度相似，反映填筑体厚度差异的不同地点的最大响应，以及反映沉积特征差异的响应从触发到最大的演变过程。

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引用次数: 0

Seismic performance of an existing anchored quay wall in the Ravenna port (Italy) 拉文纳港（意大利）现有锚碇码头墙的抗震性能

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-08-22 DOI: 10.1016/j.sandf.2025.101676

Pierluigi Alesiani , Paolo Ruggeri , Viviene M.E. Fruzzetti , Giuseppe Scarpelli

Evaluating the seismic performance of retaining walls is a significant engineering challenge due to non-linear soil-structure interaction, site response effects and ground motion properties. State of the art methods, based on non-linear dynamic analysis, are nowadays able to give reliable results when the numerical modeling is carried out with careful evaluation of seismic signals and appropriate choice of constitutive relationship for soils. However, a similar analysis is mostly restricted to relevant infrastructures. For large part of the practical situations, the simplified seismic analysis still represents the most used tool for design and verification. The new generation of Eurocode in Europe has introduced some innovations on the use of simplified seismic analyses making them more rationale and site-specific. In this paper, a case study involving the seismic evaluation of an existing anchored sheet-pile quay wall in the Ravenna port is presented. A well-known geotechnical setting and the data from an extensive field and laboratory investigation available for the area, allowed to perform both simplified and non-linear dynamic seismic analyses. The simplified seismic analysis according to the pseudo-static method outlined in the new draft of Eurocode 8 (FprEN1998:2024 TC250 – part 1 and 5), has been carried out and compared with the seismic performance of the quay wall evaluated through a 2D FEM non-linear dynamic analysis. Also, the seismic displacements of the quay wall from 2D FEM non-linear dynamic analysis were compared with recently proposed Newmark-type simplified methods. Relevant aspects of the presented case study are the very deep location of the bedrock, which required a separate model for site response analysis and 2D FEM non-linear dynamic analysis of the structures and the significant length of the wall embedment, due to poor geotechnical properties of the ground, which resulted in a pronounced spatial variation with depth of the ground motion.

由于非线性土-结构相互作用、场地反应效应和地震动特性，评估挡土墙的抗震性能是一项重大的工程挑战。目前，基于非线性动力分析的方法，在对地震信号进行仔细评估和适当选择土的本构关系的情况下进行数值模拟，能够给出可靠的结果。然而，类似的分析主要局限于相关的基础设施。在大部分实际情况下，简化地震分析仍然是最常用的设计和验证工具。欧洲新一代的欧洲规范在简化地震分析的使用上引入了一些创新，使它们更加合理和具体。本文介绍了拉文纳港现有锚固板桩码头墙的地震评价实例。众所周知，该地区的地质技术背景和广泛的现场和实验室调查数据，允许进行简化和非线性动态地震分析。根据欧洲规范8新草案（FprEN1998:2024 TC250 - part 1和part 5）中概述的拟静力法进行了简化的地震分析，并与通过二维有限元非线性动力分析评估的码头墙抗震性能进行了比较。同时，将二维有限元非线性动力分析得到的码头墙体地震位移与近期提出的newmark型简化方法进行了比较。所提出的案例研究的相关方面是基岩的非常深的位置，这需要一个单独的模型进行现场响应分析和二维有限元非线性动力分析的结构和墙体嵌入的显著长度，由于地面的岩土性能差，导致地面运动的深度明显的空间变化。

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引用次数: 0

Bioremediation for seleno-oxyanions in tunnel-excavated muck using selenate-reducing bacterium Stutzerimonas stutzeri NT-I 利用硒还原菌Stutzerimonas stutzeri NT-I对隧道开挖淤泥中硒氧阴离子进行生物修复

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-08-12 DOI: 10.1016/j.sandf.2025.101659

Osamu Otsuka , Mitsuo Yamashita

Selenium is a rare metal found mainly in volcanic sediments; it is naturally distributed in Japan owing to its sulfide deposits. Selenium exists in soil as highly toxic and soluble seleno-oxyanions, namely, selenate and selenite. The Japanese government has established standards for soluble selenium concentrations in soil, achieved by water shielding or the addition of insolubilization agents. If the selenium (and/or other heavy metals) in tunnel-excavated muck exceeds the environmental standards, it should be treated similarly to contaminated soil. However, conventional treatments leave selenium residues in tunnel-excavated muck, preventing their reuse due to the risk of selenium re-elution. This study attempted to insolubilize soluble seleno-oxyanions in tunnel-excavated muck by adding the bacterium Stutzerimonas stutzeri NT-I, which reduces selenate to insoluble elemental selenium and then to volatile dimethyl diselenide. Selenate reduction tests were conducted by adding heavy metals, including As(III), As(V), Cd(II), Pb(II), and Fe(III), to examine the selenate reduction ability and growth of S. stutzeri NT-I in the presence of their ions. The results showed that the S. stutzeri NT-I reduced the selenate by 50 mg/L concentrations for all the tested contaminants. In naturally contaminated tunnel-excavated muck, heavy metal elements, nitrate, and nitrite contents were detected at levels of <50 mg/L, suggesting that they do not adversely affect the selenate reduction by S. stutzeri NT-I. The results indicate that selenium insolubilization using S. stutzeri NT-I can be applied to a wide range of tunnel-excavated muck.

硒是一种稀有金属，主要存在于火山沉积物中；由于其硫化物矿床，它在日本自然分布。硒在土壤中以高毒性和可溶性的硒氧离子存在，即硒酸盐和亚硒酸盐。日本政府已经建立了土壤中可溶性硒浓度的标准，通过水屏蔽或添加不溶剂来实现。如果隧道开挖淤泥中的硒（和/或其他重金属）超过环境标准，则应将其与受污染的土壤类似处理。然而，传统的处理方法将硒残留在隧道开挖的淤泥中，由于硒的再洗脱风险，使其无法再利用。本研究试图通过添加Stutzerimonas stutzeri NT-I细菌，使隧道开挖淤泥中的可溶性硒氧阴离子失溶，将硒酸盐还原为不溶性元素硒，然后转化为挥发性二甲基二硒化物。通过添加As（III）、As(V)、Cd（II）、Pb（II）和Fe（III）等重金属进行硒酸盐还原试验，考察S. stutzeri NT-I在其离子存在下的硒酸盐还原能力和生长情况。结果表明，S. stutzeri NT-I对所有被测污染物的硒酸盐浓度降低了50 mg/L。在自然污染的隧道开挖淤泥中，重金属元素、硝酸盐和亚硝酸盐含量在50 mg/L的水平下被检测到，这表明它们不会对S. stutzeri NT-I还原硒酸盐产生不利影响。结果表明，S. stutzeri NT-I对硒的不溶化作用可广泛应用于隧道开挖的淤泥中。

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引用次数: 0