Pub Date : 2025-08-01Epub Date: 2025-07-25DOI: 10.1016/j.sandf.2025.101663
Adam Jabłonowski , Adam Krasiński , Piotr Kanty
The article describes the results of laboratory tests of reinforced concrete pile sections instrumented with several measurement systems. Compression tests were carried out on three 300-mm-by-1.2-m cylindrical pile elements, reinforced with an IPE140 steel profiles. The elements were equipped with vibrating wire sensors for measuring strains and stresses in concrete, and two elements had additional fibre optic cables installed for measuring strains. During the tests, external measurements were also made for axial force and longitudinal deformations of the elements. The aim of the research was to compare the measured values of all the internal and external systems and to evaluate the reliability of internal systems. The analysis of the measurement results showed generally good reliability of strain measurements using local vibrating wire sensors and extensometers and especially fibre optic sensors. Measurements of stresses in concrete using an internal vibrating wire sensor were unfortunately much less reliable. The reasons for the reduced reliability of the stress measurements are discussed and a correction coefficient is proposed. The conclusions state that the research and its results are valuable and useful for measuring and monitoring of foundation piles and columns purposes.
本文介绍了用几种测量系统对钢筋混凝土桩截面进行室内测试的结果。压缩试验在三个300 mm × 1.2 m圆柱桩单元上进行，用IPE140钢型材加固。这些元件配备了振动线传感器，用于测量混凝土中的应变和应力，其中两个元件安装了额外的光纤电缆，用于测量应变。在试验过程中，还对构件的轴向力和纵向变形进行了外部测量。研究的目的是比较所有内部和外部系统的测量值，并评估内部系统的可靠性。对测量结果的分析表明，采用局部振动线传感器和伸缩仪，特别是光纤传感器进行应变测量，总体上具有较好的可靠性。不幸的是，使用内部振动线传感器测量混凝土应力的可靠性要低得多。讨论了应力测量可靠性降低的原因，并提出了修正系数。结论表明，本文的研究成果对桩基和桩柱的测量和监测具有一定的参考价值和实用价值。
{"title":"Laboratory tests of measurement systems in pile shafts","authors":"Adam Jabłonowski , Adam Krasiński , Piotr Kanty","doi":"10.1016/j.sandf.2025.101663","DOIUrl":"10.1016/j.sandf.2025.101663","url":null,"abstract":"<div><div>The article describes the results of laboratory tests of reinforced concrete pile sections instrumented with several measurement systems. Compression tests were carried out on three 300-mm-by-1.2-m cylindrical pile elements, reinforced with an IPE140 steel profiles. The elements were equipped with vibrating wire sensors for measuring strains and stresses in concrete, and two elements had additional fibre optic cables installed for measuring strains. During the tests, external measurements were also made for axial force and longitudinal deformations of the elements. The aim of the research was to compare the measured values of all the internal and external systems and to evaluate the reliability of internal systems. The analysis of the measurement results showed generally good reliability of strain measurements using local vibrating wire sensors and extensometers and especially fibre optic sensors. Measurements of stresses in concrete using an internal vibrating wire sensor were unfortunately much less reliable. The reasons for the reduced reliability of the stress measurements are discussed and a correction coefficient is proposed. The conclusions state that the research and its results are valuable and useful for measuring and monitoring of foundation piles and columns purposes.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101663"},"PeriodicalIF":3.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711538","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}
Pub Date : 2025-08-01Epub Date: 2025-07-14DOI: 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.
{"title":"Behaviour of a sandy silt gold tailings under drained simple shear loading in a torsional shear hollow cylinder apparatus","authors":"Riccardo Fanni , David Reid , Andy Fourie","doi":"10.1016/j.sandf.2025.101635","DOIUrl":"10.1016/j.sandf.2025.101635","url":null,"abstract":"<div><div>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 (<em>K<sub>0</sub></em>) 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.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101635"},"PeriodicalIF":3.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144614046","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}
Pub Date : 2025-08-01Epub Date: 2025-07-23DOI: 10.1016/j.sandf.2025.101664
Makbule Ilgac , Adda Athanasopoulos-Zekkos , Chukwuebuka Chukwuemeka Nweke , Olga-Joan Ktenidou , Kyle Peterson , Robert E. Kayen
Investigating the seismic response of earth embankment dams is crucial for assessing the safety of existing dams and guiding new design procedures. The dam fundamental frequency (f0) is a critical parameter in the dynamic response of dams and can be evaluated using seismic recordings through Horizontal-to-Vertical Spectral Ratio (HVSR) and Standard Spectral Ratio (SSR) methods. This study focuses on assessing the vibration characteristics of Briones Dam, a 78 m-tall earth embankment dam located in the Bay Area in Northern California. First, earthquake-based Horizontal-to-Vertical Spectral Ratio (eHVSR) was estimated by dividing the horizontal records by the vertical components, and the SSR was determined by comparing crest recordings with those from the abutment. Additionally, a field test program was conducted to collect ambient noise measurements at Briones Dam, allowing for the calculation of microtremor-based HVSR. The fundamental frequency was estimated using three empirical methods: mHVSR (0.7–1 Hz), eHVSR (0.9–1.1 Hz), and SSR (1.2 Hz). The median fundamental frequency of the dam is estimated to be approximately 1 Hz at the center of the dam crest. The slight variations among these three methods suggest the need for further investigations that consider the geological and geotechnical conditions of the dam.
{"title":"Embankment vibration characteristics using ground motion records and ambient noise measurements, Briones Dam, California","authors":"Makbule Ilgac , Adda Athanasopoulos-Zekkos , Chukwuebuka Chukwuemeka Nweke , Olga-Joan Ktenidou , Kyle Peterson , Robert E. Kayen","doi":"10.1016/j.sandf.2025.101664","DOIUrl":"10.1016/j.sandf.2025.101664","url":null,"abstract":"<div><div>Investigating the seismic response of earth embankment dams is crucial for assessing the safety of existing dams and guiding new design procedures. The dam fundamental frequency (<em>f<sub>0</sub></em>) is a critical parameter in the dynamic response of dams and can be evaluated using seismic recordings through Horizontal-to-Vertical Spectral Ratio (HVSR) and Standard Spectral Ratio (SSR) methods. This study focuses on assessing the vibration characteristics of Briones Dam, a <em>78 m-tall</em> earth embankment dam located in the Bay Area in Northern California. First, earthquake-based Horizontal-to-Vertical Spectral Ratio (eHVSR) was estimated by dividing the horizontal records by the vertical components, and the SSR was determined by comparing crest recordings with those from the abutment. Additionally, a field test program was conducted to collect ambient noise measurements at Briones Dam, allowing for the calculation of microtremor-based HVSR. The fundamental frequency was estimated using three empirical methods: mHVSR (<em>0.7</em>–<em>1 Hz</em>), eHVSR (<em>0.9</em>–<em>1.1 Hz</em>), and SSR (<em>1.2 Hz</em>). The median fundamental frequency of the dam is estimated to be approximately <em>1 Hz</em> at the center of the dam crest. The slight variations among these three methods suggest the need for further investigations that consider the geological and geotechnical conditions of the dam.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101664"},"PeriodicalIF":3.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144694927","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}
Pub Date : 2025-08-01Epub Date: 2025-07-21DOI: 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.
{"title":"Direct shear testing of frozen soil-structure interface under high normal stress and frozen-thawing conditions","authors":"Bo Wang , Zhi-qiang Liu , Yu Bao","doi":"10.1016/j.sandf.2025.101660","DOIUrl":"10.1016/j.sandf.2025.101660","url":null,"abstract":"<div><div>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.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101660"},"PeriodicalIF":3.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144679368","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}
Pub Date : 2025-08-01Epub Date: 2025-07-03DOI: 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.
{"title":"Integrated remediation through solidification and dewatering of contaminated soil from laboratory investigation to in-situ application","authors":"Tingting Deng , Yongfeng Deng , Hang Liu , Fang Liu , Zhenshun Hong , Xueyu Geng","doi":"10.1016/j.sandf.2025.101602","DOIUrl":"10.1016/j.sandf.2025.101602","url":null,"abstract":"<div><div>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 Zn<sup>2+</sup> 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.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101602"},"PeriodicalIF":3.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549031","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}
Pub Date : 2025-08-01Epub Date: 2025-07-24DOI: 10.1016/j.sandf.2025.101662
Hongwei Ma , Guoqiang Ma , Weiqiang Zhang
The screw threads continuously distributed along the surface of the pile significantly modify its bearing mechanism, distinguishing it from traditional column piles. Currently, methods for calculating the uplift bearing capacity of screw piles remain underdeveloped. This study presents a calculation method for the uplift bearing capacity of screw piles based on the segmented displacement coordination iterative method, as well as a prediction method for the ultimate uplift bearing capacity using the intersection convergence method. The accuracy of these methods was validated through model and field tests. Using these theoretical calculation and prediction methods, the uplift bearing characteristics and influencing factors of screw piles were analyzed. The results demonstrated that the unique screw thread structure of screw piles significantly enhances their uplift bearing capacity compared to column piles. The P-s curve of screw piles exhibits a slow variation characteristic, and under ultimate bearing state, the shaft resistance is primarily provided by the deeper soil layers. The ultimate uplift bearing capacity of screw piles rises initially and declines as the screw pitch increases, reaching its maximum value when the screw pitch equals the second critical screw pitch. Furthermore, as the internal friction angle increases, screw piles outperform column piles more significantly in uplift capacity.
{"title":"Prediction method of screw pile bearing capacity under uplift load","authors":"Hongwei Ma , Guoqiang Ma , Weiqiang Zhang","doi":"10.1016/j.sandf.2025.101662","DOIUrl":"10.1016/j.sandf.2025.101662","url":null,"abstract":"<div><div>The screw threads continuously distributed along the surface of the pile significantly modify its bearing mechanism, distinguishing it from traditional column piles. Currently, methods for calculating the uplift bearing capacity of screw piles remain underdeveloped. This study presents a calculation method for the uplift bearing capacity of screw piles based on the segmented displacement coordination iterative method, as well as a prediction method for the ultimate uplift bearing capacity using the intersection convergence method. The accuracy of these methods was validated through model and field tests. Using these theoretical calculation and prediction methods, the uplift bearing characteristics and influencing factors of screw piles were analyzed. The results demonstrated that the unique screw thread structure of screw piles significantly enhances their uplift bearing capacity compared to column piles. The <em>P-s</em> curve of screw piles exhibits a slow variation characteristic, and under ultimate bearing state, the shaft resistance is primarily provided by the deeper soil layers. The ultimate uplift bearing capacity of screw piles rises initially and declines as the screw pitch increases, reaching its maximum value when the screw pitch equals the second critical screw pitch. Furthermore, as the internal friction angle increases, screw piles outperform column piles more significantly in uplift capacity.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101662"},"PeriodicalIF":3.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703985","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}
Loose sandy soil layers are prone to liquefaction under strong earthquakes, causing damage to civil engineering structures inside or upon the liquefied ground. According to the present Japanese design guideline on liquefaction countermeasures for river levees, the entire depth of the liquefiable subsoil below river embankments should be improved. However, this approach is not economical against deep liquefiable subsoil. To rationalize the design approach, this contribution investigated the performance of a floating-type cement treatment method, in which only the shallower part of the liquefiable subsoil is reinforced. A series of centrifuge shaking table model tests was conducted under a 50 environment. The depth of improvement (cement treatment) was varied systematically, and the effect of the sloping ground was examined. The experimental results revealed that the settlements of river embankments can be reduced linearly by increasing the depth of improvement. Moreover, the acceleration of embankments can be reduced drastically by the vibration-isolation effect between the cement-treated soil and the liquefiable soil. These effects contribute to the safe retention of the embankment shape even when the liquefied sloping ground causes lateral flows. Towards practical implementation, discussions on the effect of permeability on cement-treated soil were expanded. Furthermore, the stress acting on cement-treated soil during shaking was measured using an acrylic block to explain the occurrence of cracks in the soil.
{"title":"Centrifuge model tests on liquefaction-induced settlement of river embankments reinforced by floating-type cement treatment method","authors":"Masahide Otsubo , Yuta Miura, Kazuya Ueda, Shunsuke Tanimoto, Masanori Ishihara, Tetsuya Sasaki","doi":"10.1016/j.sandf.2025.101633","DOIUrl":"10.1016/j.sandf.2025.101633","url":null,"abstract":"<div><div>Loose sandy soil layers are prone to liquefaction under strong earthquakes, causing damage to civil engineering structures inside or upon the liquefied ground. According to the present Japanese design guideline on liquefaction countermeasures for river levees, the entire depth of the liquefiable subsoil below river embankments should be improved. However, this approach is not economical against deep liquefiable subsoil. To rationalize the design approach, this contribution investigated the performance of a floating-type cement treatment method, in which only the shallower part of the liquefiable subsoil is reinforced. A series of centrifuge shaking table model tests was conducted under a 50<span><math><mrow><mi>g</mi></mrow></math></span> environment. The depth of improvement (cement treatment) was varied systematically, and the effect of the sloping ground was examined. The experimental results revealed that the settlements of river embankments can be reduced linearly by increasing the depth of improvement. Moreover, the acceleration of embankments can be reduced drastically by the vibration-isolation effect between the cement-treated soil and the liquefiable soil. These effects contribute to the safe retention of the embankment shape even when the liquefied sloping ground causes lateral flows. Towards practical implementation, discussions on the effect of permeability on cement-treated soil were expanded. Furthermore, the stress acting on cement-treated soil during shaking was measured using an acrylic block to explain the occurrence of cracks in the soil.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101633"},"PeriodicalIF":3.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144271980","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}
Pub Date : 2025-08-01Epub Date: 2025-06-25DOI: 10.1016/j.sandf.2025.101636
Rodrigo Zorzal Velten , Carina Ulsen , João Paulo Rodrigues da Costa , Carlos Alex Alves Lima , Maiki Mafessoli , João Vítor de Azambuja Carvalho , Nilo Cesar Consoli
Tailings are anthropic materials whose behavior can be greatly affected by the mineralogy of their particles and the fabric formed. This paper focuses on the effects of tailings composition under plane strain conditions. For this, two copper tailings from distinct mines are studied. The tailings present a similar particle grading and morphology, so the main difference between them is restricted to mineralogy. Three compaction degrees and four effective confining pressure values (ranging from 50 to 400 kPa) were adopted. For the first time, the results of copper tailings under plane strain conditions are presented in the light of critical state soil mechanics due to the use of a simple shear apparatus equipped with backpressure and known horizontal stresses. The results revealed the influence of mineralogy on the critical state parameter M and the shape of the v – log p′ critical state lines. This highlights the importance of acknowledging mineralogy influence for properly designing tailings storage facilities.
尾矿是一种人为物质，其行为受其颗粒的矿物学特征和所形成的织物的影响很大。研究了平面应变条件下尾砂成分对尾砂的影响。为此，对两个不同矿山的铜尾矿进行了研究。两种尾矿的颗粒级配和形态相似，主要区别在于矿物学。采用3种压实度和4种有效围压值（50 ~ 400kpa）。利用具有背压和已知水平应力的简易剪切装置，首次从临界状态土力学角度给出了平面应变条件下铜尾砂的剪切结果。结果揭示了矿物学对临界状态参数M和v - log p '临界状态线形状的影响。这突出了认识矿物学影响对合理设计尾矿储存设施的重要性。
{"title":"Role of mineralogy on the undrained monotonic simple shear response of compacted filtered copper tailings","authors":"Rodrigo Zorzal Velten , Carina Ulsen , João Paulo Rodrigues da Costa , Carlos Alex Alves Lima , Maiki Mafessoli , João Vítor de Azambuja Carvalho , Nilo Cesar Consoli","doi":"10.1016/j.sandf.2025.101636","DOIUrl":"10.1016/j.sandf.2025.101636","url":null,"abstract":"<div><div>Tailings are anthropic materials whose behavior can be greatly affected by the mineralogy of their particles and the fabric formed. This paper focuses on the effects of tailings composition under plane strain conditions. For this, two copper tailings from distinct mines are studied. The tailings present a similar particle grading and morphology, so the main difference between them is restricted to mineralogy. Three compaction degrees and four effective confining pressure values (ranging from 50 to 400 kPa) were adopted. For the first time, the results of copper tailings under plane strain conditions are presented in the light of critical state soil mechanics due to the use of a simple shear apparatus equipped with backpressure and known horizontal stresses. The results revealed the influence of mineralogy on the critical state parameter <em>M</em> and the shape of the <em>v</em> – log <em>p′</em> critical state lines. This highlights the importance of acknowledging mineralogy influence for properly designing tailings storage facilities.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101636"},"PeriodicalIF":3.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144481273","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}
Pub Date : 2025-08-01Epub Date: 2025-07-14DOI: 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 () is often used for risk assessments of cave-ins. However, it is questionable whether 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 , 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 , 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 , will lead to enhanced assessments of the cave-in potential of subsurface cavities.
{"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":"2025-08-01","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}
Pub Date : 2025-08-01Epub Date: 2025-06-26DOI: 10.1016/j.sandf.2025.101637
Anand J. Puppala , Nripojyoti Biswas , Md Ashrafuzzaman Khan , Surya S.C. Congress
Expanding and maintaining transportation network assets on shrink-swell soils is a major problem for civil infrastructure owners and agencies across the world. Particularly, lightweight structures such as pavements experience distress due to differential heaving, cracking, shoulder dropping, and others. They can be primarily attributed to non-uniform moisture cycles, which severely impact both the short- and long-term performance of the structures. Among the available ground improvement techniques, both traditional and non-traditional methods are being effectively used to improve soil engineering properties and reduce distress during the service life period of the infrastructure asset. Novel chemical treatment methods and innovative geosynthetics have been employed to mitigate the distresses caused by shrink/swell movements from underlying expansive soils. The research team has studied applications of co-additives such as Geo-polymers and silica fines for stabilizing sulfate-rich expansive subsoils. An overview of stabilization studies using chemical additives, along with comprehensive sustainability analyses of these methods, were discussed in this paper. In addition, case studies on the application of geosynthetic products, including geocells and wicking geotextiles, for improvements of pavement performance built over expansive soils, are provided. Overall, the application of these new ground improvement techniques will be of immense help to infrastructure and transportation sectors and agencies as their usage would promote sustainable benefits with a higher return on investment.
{"title":"Experimental investigations and sustainability assessments of ground improvement studies of expansive soils","authors":"Anand J. Puppala , Nripojyoti Biswas , Md Ashrafuzzaman Khan , Surya S.C. Congress","doi":"10.1016/j.sandf.2025.101637","DOIUrl":"10.1016/j.sandf.2025.101637","url":null,"abstract":"<div><div>Expanding and maintaining transportation network assets on shrink-swell soils is a major problem for civil infrastructure owners and agencies across the world. Particularly, lightweight structures such as pavements experience distress due to differential heaving, cracking, shoulder dropping, and others. They can be primarily attributed to non-uniform moisture cycles, which severely impact both the short- and long-term performance of the structures. Among the available ground improvement techniques, both traditional and non-traditional methods are being effectively used to improve soil engineering properties and reduce distress during the service life period of the infrastructure asset. Novel chemical treatment methods and innovative geosynthetics have been employed to mitigate the distresses caused by shrink/swell movements from underlying expansive soils. The research team has studied applications of co-additives such as Geo-polymers and silica fines for stabilizing sulfate-rich expansive subsoils. An overview of stabilization studies using chemical additives, along with comprehensive sustainability analyses of these methods, were discussed in this paper. In addition, case studies on the application of geosynthetic products, including geocells and wicking geotextiles, for improvements of pavement performance built over expansive soils, are provided. Overall, the application of these new ground improvement techniques will be of immense help to infrastructure and transportation sectors and agencies as their usage would promote sustainable benefits with a higher return on investment.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101637"},"PeriodicalIF":3.3,"publicationDate":"2025-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144491129","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号