Soils and Foundations最新文献_第5页

Levee vulnerability assessment using an integrated unsaturated transient seepage model, sensitivity analysis, and fragility curves 综合非饱和暂态渗流模型、敏感性分析和易损性曲线的堤坝易损性评价

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-07-23 DOI: 10.1016/j.sandf.2025.101658

E. Ajorlou, M. Ghayoomi

The accelerated changes in climate resulting in more frequent and disruptive floods necessitate broader perspectives of levee vulnerability assessment. This paper aims to advance levee vulnerability curves using global sensitivity analysis to identify critical inputs for developing multi-variable fragilities. This analysis is efficient and effective for skewed data such as extreme precipitation. The study categorizes inputs into geometry, precipitation, and soil characteristics, generating 30,000 scenarios for analysis. A transient unsaturated seepage analysis is conducted to examine different failure modes such as piping, erosion, and overflow, as well as erosion initiation and enlargement time and locations for each scenario. Results show that, in addition to the initial upstream water level and precipitation characteristics, soil properties—such as gravel and clay content, along with water retention parameters—are crucial for developing fragility curves across different soil types. Additionally, comparing fragility curves for historical data and future precipitation projections highlights the importance of integrating these projections into levee risk analysis for the next 30 years. As a practical implication, these fragility curves are applied to calculate failure probabilities for a levee case study. This research would support the integration of levee vulnerability assessments with social factors and stakeholder perspectives which also increases the applicability of fragility functions in flood risk mitigation.

气候的加速变化导致更频繁和破坏性的洪水，需要更广泛的视角来评估堤坝的脆弱性。本文旨在利用全局敏感性分析来推进堤防脆弱性曲线，以识别发展多变量脆弱性的关键输入。这种分析对于极端降水等偏斜数据是高效有效的。该研究将输入分类为几何形状、降水和土壤特征，生成了3万个场景供分析。通过暂态非饱和渗流分析，考察了管道、侵蚀和溢流等不同的破坏模式，以及每种情况下侵蚀的发生和扩大时间和位置。结果表明，除了初始上游水位和降水特征外，土壤性质（如砾石和粘土含量）以及保水参数对不同土壤类型的脆弱性曲线的形成至关重要。此外，比较历史数据和未来降水预测的脆弱性曲线，强调了将这些预测整合到未来30年堤坝风险分析中的重要性。作为实际应用，将这些脆性曲线应用于堤防的破坏概率计算。本研究将支持堤防脆弱性评价与社会因素和利益相关者的观点相结合，提高脆弱性函数在洪水风险缓解中的适用性。

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引用次数: 0

Direct shear testing of frozen soil-structure interface under high normal stress and frozen-thawing conditions 高正应力和冻融条件下冻土-结构界面的直剪试验

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-07-21 DOI: 10.1016/j.sandf.2025.101660

Bo Wang , Zhi-qiang Liu , Yu Bao

By using an improved DRS-1 high pressure direct shear test system, a series direct shear tests have been carried out under high normal stress and frozen-thawing conditions. Basic shear mechanical characteristics of the interface between the frozen soil and structure are summarized. Effects of normal stress and thawing temperature on the peak shear stress and the initial shear modulus are discussed. The results show that patterns of shear stress-displacement curve will transform gradually from strain softening to strain hardening as the thawing temperature increases. The peak shear strength of frozen soil-structure interface increases significantly with the increase of the normal stress, but decreases with the thawing temperature increases. High normal stress results in larger effective stress in the soil and hinders movement of soil particles on the interface. Increasing of the thawing temperature reduces the adfreezing force on the frozen soil-structure interface.

采用改进型DRS-1型高压直剪试验系统，在高正应力和冻融条件下进行了一系列直剪试验。总结了冻土与结构界面的基本剪切力学特性。讨论了正应力和解冻温度对峰值剪切应力和初始剪切模量的影响。结果表明：随着解冻温度的升高，剪切应力-位移曲线模式由应变软化逐渐转变为应变硬化；冻土-结构界面峰值抗剪强度随正应力的增大而显著增大，但随解冻温度的升高而减小。高的法向应力导致土体有效应力增大，阻碍了土体颗粒在界面上的运动。解冻温度的升高降低了冻土-结构界面的冻融力。

引用次数: 0

Experimental analysis of reinforcement methods for stone column foundations 石柱基础加固方法试验分析

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-07-18 DOI: 10.1016/j.sandf.2025.101661

Lihua Li , Jinlin Li , Zhiqi Zhan , Yilin Gui , Juqiang Liu

Geosynthetic-reinforced stone columns can significantly improve weak foundations. While previous studies have focused on the individual effects of vertical or horizontal reinforcement, the combined influence of both on stone column foundation performance remains poorly understood. Through physical model tests, this study investigated the effects of various reinforcement methods on the bearing capacity and deformation characteristics of stone column foundations, with a particular focus on the combined reinforcement in enhancing their performance, addressing this research gap. This study encompasses different enhancement lengths, horizontal reinforcement spacings, and combinations of reinforcement methods. Experimental results demonstrate that geosynthetics significantly limit radial deformation and improve the bearing capacity of stone column foundations. Notably, the bearing capacity increases with reduced reinforcement spacing and extended enhancement length. Among all the reinforcement types tested in this study, the full-length (L) vertical reinforcement demonstrated the most significant impact. Additionally, the study examines stress transfer and lateral stress distribution within the stone columns, revealing that as the load increases, the stress ratio at the stone column base and lateral stress rises, with lateral stress peaking at a depth of 2.5D from the surface. This behaviour aligns with the deformation patterns observed in the model tests.

土工合成增强石柱可以显著改善软弱地基。虽然以前的研究主要集中在垂直或水平加固的单个影响上，但两者对石柱基础性能的综合影响仍然知之甚少。通过物理模型试验，研究了各种加固方法对石柱基础承载力和变形特性的影响，重点研究了组合加固对石柱基础承载力和变形特性的影响，弥补了这方面的研究空白。本研究包括不同的加固长度，水平加固间距和加固方法的组合。试验结果表明，土工合成材料能有效地限制石柱基础的径向变形，提高地基承载力。随着加固间距的减小和加固长度的延长，其承载能力有所提高。在本研究测试的所有加固类型中，全长(L)垂直加固的影响最为显著。此外，研究还考察了石柱内部的应力传递和侧应力分布，发现随着荷载的增加，石柱基部应力与侧应力的比值增大，侧应力在距地表2.5D深度处达到峰值。这种行为与模型试验中观察到的变形模式一致。

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引用次数: 0

Seismic response of embankment dams: Shear beam analysis vs field observations 路堤坝的地震反应：剪力梁分析与现场观测

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-07-15 DOI: 10.1016/j.sandf.2025.101654

Krishna Santhosh , Tadahiro Kishida , George Mylonakis

Embankment dams are critical elements of infrastructure and perform as a system by integrating various components such as foundation, core, shell, filter and spillway. To analyze their entire response, it is important to properly identify the dynamic characteristics of the overall system based on observations. This paper explores the dynamic response of dams using an analytical shear beam analysis under plane-strain conditions, considering the variation of shear modulus and cross-sectional area with height. The governing differential equation is first solved analytically using Bessel functions, and dynamic response parameters are derived for different natural modes. Transfer functions are then derived from the bedrock to the crest for different variations of shear modulus and levels of material damping. Using these analytical results, the study assesses the applicability of the shear beam analysis to 23 embankment dams in Japan, utilizing decades of recorded acceleration time histories to identify their dynamic response and shear wave profiles with height.

堤防大坝是基础设施的重要组成部分，它将基础、核心、壳、过滤器和溢洪道等各种组成部分集成为一个系统。为了分析它们的整个响应，重要的是要根据观察正确地识别整个系统的动态特性。考虑剪切模量和截面积随高度的变化，采用剪力梁解析法研究了平面应变条件下大坝的动力响应。首先利用贝塞尔函数解析求解控制微分方程，推导出不同自然模态下的动力响应参数。然后导出了基岩到波峰的传递函数，用于不同剪切模量和材料阻尼水平的变化。利用这些分析结果，该研究评估了剪切梁分析对日本23个堤防大坝的适用性，利用数十年记录的加速度时程来识别它们的动力响应和剪切波随高度的分布。

引用次数: 0

Reliability based seismic slope failure assessment of a high concrete face rockfill dam close to an active fault zone 靠近活动断裂带的高面板堆石坝地震边坡破坏可靠度评估

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-07-15 DOI: 10.1016/j.sandf.2025.101653

Ugur Safak Cavus , Murat Kilit

This study assesses the earthquake-induced failure risks of the upstream and downstream slopes of a concrete face dam (CFRD), which is under the influence of a nearby active fault, using the reliability-based analysis method. For this purpose, peak ground accelerations (PGAs) that may occur at the dam site were calculated probabilistically and their contribution to the sliding risks of dam slopes was determined in accordance with the conditional probability theorem. Upstream and downstream slopes of CFRDs are usually conventionally designed as 1.3–1.5H:1V and 1.3–1.6H:1V, respectively throughout the world. Such slope design is considered sufficient for almost every case. The findings of this study are fully applicable and very important for the structural design of all concrete-faced rockfill dams (CFRDs) worldwide. Since, the slope design of CFRDs is similar and usually traditionally (1.3–1.5H; 1V for upstream slope and 1.4–1.6H:1V for downstream slope). However, this study proves that only conventional upstream slope design (1.3–1.5H:1V) can be safe for even very high peak ground accelerations (PGAs) occurring due to a nearby active fault, but contrary to expectations, downstream slope of CFRDs cannot be sufficiently safe and maintain its slope sliding safety when PGAs reach high levels. When the critical PGA level is exceeded, the downstream slope carries the risk of losing its stability with high probability, as emphasized in this study. Therefore, this study provides a new design strategy and extremely important information for dam design engineers which is to design a rather flatter downstream slope such as 1 vertical to 1.8–2.0 horizontal or, instead, to design a downstream rockfill berm supporting conventional design if CFRDs are to be built in high seismic hazard potential areas or close to active faults. Suggested such type of designs will be economical and sufficiently safe.

采用基于可靠度的分析方法，对受附近活动断层影响的混凝土面板坝上下游边坡地震破坏风险进行了评估。为此，根据条件概率定理，对坝址可能出现的峰值地加速度（pga）进行了概率计算，并确定了它们对坝坡滑动风险的贡献。在世界范围内，cfrd的上、下游坡度通常分别设计为1.3 ~ 1.5 h:1V和1.3 ~ 1.6 h:1V。这种坡度设计被认为对几乎所有情况都是足够的。研究结果对世界范围内混凝土面板堆石坝的结构设计具有一定的参考价值。由于cfrd的坡度设计相似，通常采用传统的(1.3-1.5H；上游坡1V，下游坡1.4-1.6H:1V)。然而，本研究证明，对于附近活动断层产生的峰值地加速度（pga），只有传统的上游边坡设计（1.3-1.5H:1V）才能保证安全，而与预期相反，当峰值地加速度达到较高水平时，cfrd下游边坡不能足够安全并保持边坡滑动安全。当超过临界PGA水平时，下游边坡具有高概率失稳风险，这是本研究所强调的。因此，本研究为大坝设计工程师提供了一种新的设计策略和极其重要的信息，即设计一个相当平坦的下游斜坡，如1垂直到1.8-2.0水平，或者在地震高发区或靠近活动断层的地区建造cfrd，而不是设计一个支持常规设计的下游堆石护堤。建议这种设计既经济又足够安全。

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引用次数: 0

Behaviour of a sandy silt gold tailings under drained simple shear loading in a torsional shear hollow cylinder apparatus 砂质粉砂金尾矿在排水单剪荷载作用下的扭剪空心圆筒试验研究

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-07-14 DOI: 10.1016/j.sandf.2025.101635

Riccardo Fanni , David Reid , Andy Fourie

Experimental results are presented in this technical paper to investigate the mechanisms of plane strain consolidation and drained shearing typical of below slope conditions. Five torsional shear hollow cylinder tests were conducted on a sandy silt gold tailings, where consolidation was performed under at-rest (K₀) conditions, and by applying a horizontal shear stress, while maintaining plane strain conditions. The tests were carried out under drained simple shear conditions (strain controlled) on tailings specimens prepared in loose and dense states and along a constant shear stress drained stress path (stress controlled) on a loose specimen, using an automated computer-controlled testing procedure. The evolution of static stresses in the loose and dense specimens during principal stress rotation, while maintaining plane strain conditions, were examined. These tests provide valuable insights into the behavior of tailings under plane strain conditions, contributing to the calibration of numerical models for slope analysis and more broadly for plane strain problems.

本文给出了典型坡下条件下平面应变固结和排水剪切机理的试验结果。对某砂质粉砂金尾矿进行了5次扭剪空心筒试验，分别在静止（K0）条件下、施加水平剪应力时、保持平面应变条件下进行固结。试验采用计算机自动控制的试验程序，在松散和致密状态下制备的尾矿试样在排水简单剪切条件下（应变控制）进行试验，在松散试样上沿恒定剪切应力排水应力路径（应力控制）进行试验。在保持平面应变条件下，研究了松散和致密试样在主应力旋转过程中静应力的演变。这些试验对尾矿在平面应变条件下的行为提供了有价值的见解，有助于校准边坡分析的数值模型，更广泛地用于平面应变问题。

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引用次数: 0

Shaping force-transfer arch to retain subsurface cavity in coarse sandy ground 粗砂地基中成形传力拱保留地下空腔

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-07-14 DOI: 10.1016/j.sandf.2025.101652

Daichi Yokoyama , Masahide Otsubo , Reiko Kuwano

Ground cave-ins, which are the collapse and discontinuous subsidence of the ground surface, are thought to be caused by the expansion and upward movement of subsurface cavities due to fluctuations in the groundwater table or earthquakes. Compared to cohesive clays or plastic silts, cohesionless sands are more vulnerable to cavity formation and subsequent ground cave-ins. With recent technology, such as ground-penetrating radar, geometrical information on cavities, e.g., location and shape, can be detected. In practice, the soil cover thickness-to-cavity width ratio (

H / B

) is often used for risk assessments of cave-ins. However, it is questionable whether

H / B

alone is sufficient for these risk assessments since the mechanical responses, such as the resistance of the remaining soil above the cavity, are not considered. For this reason, the aim of the present contribution is to understand the mechanism underlying the subsurface cavity stability by considering the force transfer around the cavity. Suction measurement, cavity retention, and needle penetration model tests were conducted using various coarse granular materials. The results revealed that suction is essential to preventing cavities from collapsing, and that suction is higher for smaller particles, particles with lower degrees of saturation, and particles with angular shapes and smoother surfaces. In addition to

H / B

, the mechanical interlock from angularity or roughness contributes to cavity stability. Laboratory needle penetration tests revealed the existence of a force-transfer arch between the sound and weakened zones around a cavity, which is related to the cavity stability. Furthermore, the position of the arch is affected not only by

H / B

, but also by the particle characteristics (e.g., friction angle) and cavity roof shape. Therefore, considering the material type and the shape of the cavity roof, along with

H / B

, will lead to enhanced assessments of the cave-in potential of subsurface cavities.

地面塌陷是指地表的塌陷和不连续的下沉，被认为是由于地下水位的波动或地震引起的地下空洞的扩张和向上运动造成的。与粘性粘土或塑性粉砂相比，无粘性砂更容易形成空洞和随后的地面塌陷。利用最近的技术，例如探地雷达，可以探测到空腔的几何信息，例如位置和形状。在实践中，土覆盖厚度-洞腔宽度比（H/B）常用于塌方风险评估。然而，单靠H/B是否足以进行这些风险评估是值得怀疑的，因为没有考虑机械反应，例如空腔上方剩余土壤的阻力。因此，本文的目的是通过考虑空腔周围的力传递来理解地下空腔稳定性的机制。采用不同的粗颗粒材料进行吸力测量、空腔保留和针刺模型试验。结果表明，吸力对防止空腔坍缩至关重要，并且对于较小的颗粒、饱和度较低的颗粒以及棱角形状和表面较光滑的颗粒，吸力更高。除了H/B外，来自角度或粗糙度的机械联锁有助于腔体稳定性。实验室针刺试验表明，在腔体周围的声区和弱区之间存在一个力传递拱，这与腔体的稳定性有关。此外，拱的位置不仅受H/B的影响，还受颗粒特性（如摩擦角）和空腔顶板形状的影响。因此，考虑空区顶板的材料类型和形状，并结合H/B，将有助于加强对地下空区塌陷潜力的评估。

{"title":"Shaping force-transfer arch to retain subsurface cavity in coarse sandy ground","authors":"Daichi Yokoyama , Masahide Otsubo , Reiko Kuwano","doi":"10.1016/j.sandf.2025.101652","DOIUrl":"10.1016/j.sandf.2025.101652","url":null,"abstract":"<div><div>Ground cave-ins, which are the collapse and discontinuous subsidence of the ground surface, are thought to be caused by the expansion and upward movement of subsurface cavities due to fluctuations in the groundwater table or earthquakes. Compared to cohesive clays or plastic silts, cohesionless sands are more vulnerable to cavity formation and subsequent ground cave-ins. With recent technology, such as ground-penetrating radar, geometrical information on cavities, <em>e.g.,</em> location and shape, can be detected. In practice, the soil cover thickness-to-cavity width ratio (<span><math><mrow><mi>H</mi><mo>/</mo><mi>B</mi></mrow></math></span>) is often used for risk assessments of cave-ins. However, it is questionable whether <span><math><mrow><mi>H</mi><mo>/</mo><mi>B</mi></mrow></math></span> alone is sufficient for these risk assessments since the mechanical responses, such as the resistance of the remaining soil above the cavity, are not considered. For this reason, the aim of the present contribution is to understand the mechanism underlying the subsurface cavity stability by considering the force transfer around the cavity. Suction measurement, cavity retention, and needle penetration model tests were conducted using various coarse granular materials. The results revealed that suction is essential to preventing cavities from collapsing, and that suction is higher for smaller particles, particles with lower degrees of saturation, and particles with angular shapes and smoother surfaces. In addition to <span><math><mrow><mi>H</mi><mo>/</mo><mi>B</mi></mrow></math></span>, the mechanical interlock from angularity or roughness contributes to cavity stability. Laboratory needle penetration tests revealed the existence of a force-transfer arch between the sound and weakened zones around a cavity, which is related to the cavity stability. Furthermore, the position of the arch is affected not only by <span><math><mrow><mi>H</mi><mo>/</mo><mi>B</mi></mrow></math></span>, but also by the particle characteristics (<em>e.g.,</em> friction angle) and cavity roof shape. Therefore, considering the material type and the shape of the cavity roof, along with <span><math><mrow><mi>H</mi><mo>/</mo><mi>B</mi></mrow></math></span>, will lead to enhanced assessments of the cave-in potential of subsurface cavities.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101652"},"PeriodicalIF":3.3,"publicationDate":"2025-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144614047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of high pressure on microbiologically induced calcium carbonate precipitation of methane hydrate-bearing sand layers 高压对含甲烷水合物砂层微生物诱导碳酸钙沉淀的影响

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-07-07 DOI: 10.1016/j.sandf.2025.101651

Joyce Nakayenga , Toshiro Hata , Alexandra Clarà Saracho , Stuart Kenneth Haigh

Sporosarcina newyorkensis is an indigenous microbe found in sedimentary layers bearing methane hydrates in the oceans around Japan’s main islands. It can survive extremely cold temperatures and precipitate calcium carbonate (CaCO₃). This has led to interest in applying the microbe in microbiologically induced calcium carbonate precipitation (MICP) to improve the properties of the surrounding sand and to facilitate the exploration of methane hydrates. Using the injection method, a large-scale laboratory experiment was conducted in this study on sand columns with a diameter of 60 cm and a height of 70 cm to evaluate the MICP performance of S. newyorkensis under high overburden pressures of 3.5 and 20 MPa. The results indicated that S. newyorkensis can precipitate CaCO₃ at high overburden pressures and reduce the permeability of sand. The unconfined compressive strength and amount of precipitated CaCO₃ were seen to decrease with the distance from the injection well, but they remained sufficient to distances of up to 20 cm. S. newyorkensis was also found to increase the pH level, which would further promote CaCO₃ precipitation and, in turn, lower hydraulic conductivity and stabilize hydrate-bearing sand formations.

纽约孢子虫是一种在日本主要岛屿周围海洋中含有甲烷水合物的沉积层中发现的本土微生物。它可以在极冷的温度下生存，并沉淀碳酸钙（CaCO3）。这引起了人们对在微生物诱导碳酸钙沉淀（MICP）中应用微生物的兴趣，以改善周围砂的性质，并促进甲烷水合物的勘探。本研究采用注砂法，在直径为60 cm、高度为70 cm的砂柱上进行了大型室内试验，评价了3.5 MPa和20 MPa高覆盖层压力下，S. newyorkensis的MICP性能。结果表明，在高覆盖层压力下，newyorkensis可使CaCO3沉淀，降低砂体渗透率。无侧限抗压强度和CaCO3的析出量随着距注入井的距离而减小，但在距注入井20 cm处仍保持充足。研究还发现，S. newyorkensis增加了pH值，这将进一步促进CaCO3的沉淀，从而降低水力导电性，稳定含水合物的砂层。

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引用次数: 0

Suffusion behavior under fluctuated hydraulic gradient conditions focusing on amount and size of soil particles contained in drainage 波动水力梯度条件下的渗流行为主要关注排水中所含土壤颗粒的数量和大小

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-07-03 DOI: 10.1016/j.sandf.2025.101600

Taichi Ishimaru , Motoyuki Suzuki , Asahi Komori

Suffusion is the detachment and migration of fine particles through voids connected by the matrices of coarse particles. Although water storage structures are known to be affected by fluctuations in seepage flow, due to fluctuations in the water storage levels brought about by rainfall and agricultural activities, the suffusion behavior when the hydraulic gradient is fluctuated is unclear. In this study, one-dimensional downward water-passing experiments with suffusion were performed using a cylindrical column device, and the changes in the amounts of the discharged water and soil particles, as well as the turbidity of the drainage over time, were examined. The behavior of suffusion was investigated from two viewpoints: the quantitative changes in the amount of discharged drainage and the amount of discharged soil particles due to the progress of suffusion, and the qualitative changes in the particle size composition of the discharged soil particles. A unique feature of this study was the tracing of the changes in the particle size composition of the discharged soil particles from the relationship between the turbidity and the concentration of drainage during suffusion. As a result, it was found that not only the amount of soil particles discharged by suffusion, but also the particle size composition of the discharged soil particles changed under both constant and fluctuated hydraulic gradient conditions.

渗透是细颗粒通过由粗颗粒基质连接的空隙脱离和迁移的过程。虽然已知蓄水结构会受到渗流波动的影响，但由于降雨和农业活动带来的蓄水水位波动，水力梯度波动时的渗流行为尚不清楚。在本研究中，采用圆柱柱装置进行了一维向下扩散进水实验，考察了排放的水和土壤颗粒量以及排水浊度随时间的变化。从渗流过程中排水量和排入土壤颗粒量的量变和排入土壤颗粒粒径组成的质变两个角度研究了渗流行为。本研究的一个独特之处在于，通过浸渍过程中浊度与排水浓度的关系，追踪了排放土壤颗粒粒径组成的变化。结果发现，在恒定和波动水力梯度条件下，不仅渗透排出的土粒量发生了变化，而且排放土粒的粒径组成也发生了变化。

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引用次数: 0

Integrated remediation through solidification and dewatering of contaminated soil from laboratory investigation to in-situ application 从实验室研究到现场应用的污染土壤固化脱水综合修复技术

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-07-03 DOI: 10.1016/j.sandf.2025.101602

Tingting Deng , Yongfeng Deng , Hang Liu , Fang Liu , Zhenshun Hong , Xueyu Geng

Solidification/stabilization of heavy metal contaminated soils often falls short of achieving the desired quality due to challenges in effectively controlling mixing uniformity. Optimization of mixing equipment and construction technology is a common way to improve mixing uniformity. However, optimizing mixing equipment has high cost, limited site applicability and limited effect on improving uniformity. To solve the problem, a combined solidification/stabilization - vacuum dewatering technique (SSVD) was proposed, which is to increase the water to binder ratio to make the binder and heavy metal contaminated soils mixed evenly and then immediately vacuum dewatering. Its efficiency was explored through both laboratory experiments and a pilot project. Because zinc is a well-known factor that decreases compressive strength and cementation speed, zinc contaminated soil was studied. The findings indicate that the vacuum dewatering successfully removes water from solidified soils during the initial 12 h of setting and hardening in the field, indicating the feasibility of more water incorporation to raise the mixing workability. Furthermore, it can enhance the microstructure to prevent the migration of pollutant, and extract the heavy metals from the solidified mass by the cation exchanges. After 28 days of curing, laboratory tests showed a 1.9-4.1 times’ increment in strength and a 1.7-17.8 times’ reduction in permeability after dewatering. In the field, these values increase by 1.8 times and decrease by 1.7 times, respectively. The Zn²⁺ observed diffusivity also decreases by 2.0 times after dewatering in the laboratory. Microstructure analysis reveals that the vacuum dewatering significantly reduces the porosity of the solidified matrix, thereby enhancing its integrity. The proposed technology holds potential for the application not only in the solidification/stabilization remediation but also in the soft ground improvement in term of the better workability and homogeneity, stronger densification and capsulation, and less pollutant retention and binder consumption.

由于难以有效控制混合均匀性，重金属污染土壤的固化稳定性往往达不到预期的质量。优化搅拌设备和施工工艺是提高搅拌均匀性的常用方法。但优化搅拌设备成本高，现场适用性有限，提高均匀性效果有限。为了解决这一问题，提出了一种固化/稳定-真空复合脱水技术（SSVD），即提高水胶比，使黏合剂与重金属污染土壤混合均匀，然后立即真空脱水。通过实验室实验和试点项目对其有效性进行了探讨。由于锌是众所周知的降低抗压强度和胶结速度的因素，因此对锌污染土壤进行了研究。研究结果表明，真空脱水在田间凝固硬化初始12 h内成功地去除了固化土中的水分，表明增加水分掺入以提高混合和易性是可行的。此外，它可以增强微观结构，防止污染物的迁移，并通过阳离子交换从凝固体中提取重金属。养护28 d后，室内试验表明，脱水后强度增加1.9 ~ 4.1倍，渗透率降低1.7 ~ 17.8倍。在野外，这些值分别增加1.8倍和减少1.7倍。在实验室脱水后，Zn2+的扩散率也下降了2.0倍。显微组织分析表明，真空脱水显著降低了固化基体的孔隙率，提高了固化基体的完整性。该技术具有较好的和易性和均匀性、较强的致密性和荚膜性、较少的污染物滞留和粘结剂消耗等优点，不仅在固化/稳定修复中具有应用潜力，而且在软土地基改善中也具有应用潜力。

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引用次数: 0