Soils and Foundations最新文献_第6页

Experimental investigations and sustainability assessments of ground improvement studies of expansive soils 膨胀土地基改良试验研究及可持续性评价

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-06-26 DOI: 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.

在收缩膨胀土上扩展和维护交通网络资产是世界各地民用基础设施所有者和机构面临的主要问题。特别是，轻质结构，如路面，由于不同的起伏，开裂，肩下垂，和其他的痛苦。它们主要归因于不均匀的水分循环，这严重影响了结构的短期和长期性能。在现有的地基改善技术中，传统和非传统的方法都被有效地用于改善基础设施资产使用寿命期间的土壤工程特性和减少困扰。采用了新的化学处理方法和创新的土工合成材料来减轻下伏膨胀土的收缩/膨胀运动所造成的痛苦。研究小组研究了共添加剂的应用，如土工聚合物和二氧化硅粉，以稳定富含硫酸盐的膨胀底土。本文概述了化学添加剂稳定研究的概况，以及这些方法的综合可持续性分析。此外，还提供了应用土工合成产品的案例研究，包括土工细胞和吸芯土工织物，以改善在膨胀土壤上建造的路面性能。总的来说，这些新的地面改善技术的应用将对基础设施和运输部门和机构有巨大的帮助，因为它们的使用将促进可持续的利益，并带来更高的投资回报。

{"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":"2025-06-26","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}

引用次数: 0

Role of mineralogy on the undrained monotonic simple shear response of compacted filtered copper tailings 矿物学对压实过滤铜尾矿不排水单调单剪响应的影响

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-06-25 DOI: 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":"2025-06-25","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}

引用次数: 0

Effect of fines contents on uplift behavior of underground structures in liquefiable ground 细粒含量对液化地基地下结构上拔性能的影响

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-06-20 DOI: 10.1016/j.sandf.2025.101623

Fernaldy Sebastian Santoso , Kenji Watanabe

Research on liquefaction began decades ago, with clean sand being the main material . Recently, as it has been proven that fines-containing materials are also suspected to be liquefied, additional studies, mainly elementary tests, have been conducted. However, few liquefaction model experiments have been conducted in which the fines content is varied. This is because it is difficult to completely saturate a model ground with fines and conduct highly reproducible model experiments. In the present study, therefore, a modified vacuum container sand box and large-size vacuum saturation method were adopted to perfectly saturate model grounds with different non-plastic fines contents. A pipe model was placed in the ground to investigate the uplift behavior of an underground structure induced by liquefaction.

The experiments revealed that a ground with a higher fines content induced a lower total uplift displacement in the pipe model than grounds with a lower or no fines content. Interestingly, these results differ from the liquefaction properties of the fines-mixed sand observed in previous elementary tests. The discrepancy is probably due to the effects of the strength recovery of the ground, low void ratio, low permeability, and high viscous resistance of such a soil with fines.

液化的研究开始于几十年前，以干净的沙子为主要材料。最近，由于已证明含有细颗粒的材料也被怀疑是液化的，因此进行了更多的研究，主要是初级试验。然而，很少进行细粒含量变化的液化模型实验。这是因为很难用细粉使模型地面完全饱和并进行高重复性的模型实验。因此，本研究采用改进的真空容器砂箱和大尺寸真空饱和法对不同非塑性细粒含量的模型地基进行了完全饱和。为了研究液化引起地下结构的隆升行为，在地下放置了一个管道模型。试验结果表明，细粒含量较高的地基比细粒含量较低或不含细粒的地基在管道模型中引起的总上拔位移较小。有趣的是，这些结果不同于在以前的初级试验中观察到的细混合砂的液化特性。这种差异可能是由于地基的强度恢复、低空隙比、低渗透性和高粘阻等因素的影响。

{"title":"Effect of fines contents on uplift behavior of underground structures in liquefiable ground","authors":"Fernaldy Sebastian Santoso , Kenji Watanabe","doi":"10.1016/j.sandf.2025.101623","DOIUrl":"10.1016/j.sandf.2025.101623","url":null,"abstract":"<div><div>Research on liquefaction began decades ago, with clean sand being the main material . Recently, as it has been proven that fines-containing materials are also suspected to be liquefied, additional studies, mainly elementary tests, have been conducted. However, few liquefaction model experiments have been conducted in which the fines content is varied. This is because it is difficult to completely saturate a model ground with fines and conduct highly reproducible model experiments. In the present study, therefore, a modified vacuum container sand box and large-size vacuum saturation method were adopted to perfectly saturate model grounds with different non-plastic fines contents. A pipe model was placed in the ground to investigate the uplift behavior of an underground structure induced by liquefaction.</div><div>The experiments revealed that a ground with a higher fines content induced a lower total uplift displacement in the pipe model than grounds with a lower or no fines content. Interestingly, these results differ from the liquefaction properties of the fines-mixed sand observed in previous elementary tests. The discrepancy is probably due to the effects of the strength recovery of the ground, low void ratio, low permeability, and high viscous resistance of such a soil with fines.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101623"},"PeriodicalIF":3.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331300","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

Deformation, resistance characteristics, and scale effects of rockfall protection soil embankments under static loading 静力荷载作用下防落石土路堤变形、阻力特性及尺度效应

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-06-20 DOI: 10.1016/j.sandf.2025.101634

Yoshiyuki Oguri , Kenichi Maeda , Keisuke Kondo , Takuro Nakamura , Yuji Ushiwatari , Naoto Naito , Masato Komuro

Rockfall protection soil embankments are structures that can effectively reduce rockfall hazards along roads. They are economical and easy to construct and maintain by using locally available soil. However, a performance design method for rockfall protection soil embankments has not yet been established, and is the goal of this study. In the present study, static loading tests were conducted using two different weight shapes to clarify the influence of the weight shape on the deformation behavior of soil embankments. Based on these tests, the punching shear failure mechanism of the soil embankments was investigated. The influence of the model scale (the scale effect) on the deformation failure behavior of the soil embankments was clarified through static loading tests on reduced models at three different scales. From these model experiments, the surface deformation, internal deformation, and load–penetration relationships of the soil embankments were summarized. The results indicated that the spherical weight damaged a wider area than the polyhedral weight, and the maximum and ultimate loads exhibited a constant relationship with the deformation of the soil embankment extension between the model scales.

防落石土路堤是一种能有效减少道路沿线落石灾害的结构。它们经济且易于使用当地可用的土壤来建造和维护。然而，目前还没有建立起防落土路堤的性能设计方法，这也是本研究的目标。本研究采用两种不同重量形状进行静载试验，以阐明重量形状对土路堤变形行为的影响。在此基础上，对土路堤冲剪破坏机理进行了研究。通过对三种不同尺度的模型进行静载试验，阐明了模型尺度（尺度效应）对土路堤变形破坏行为的影响。通过这些模型试验，总结了土路堤的表面变形、内部变形和荷载-侵彻关系。结果表明，球形荷载比多面体荷载的破坏面积更大，最大和极限荷载与模型尺度之间的土路堤延伸变形呈恒定关系。

{"title":"Deformation, resistance characteristics, and scale effects of rockfall protection soil embankments under static loading","authors":"Yoshiyuki Oguri , Kenichi Maeda , Keisuke Kondo , Takuro Nakamura , Yuji Ushiwatari , Naoto Naito , Masato Komuro","doi":"10.1016/j.sandf.2025.101634","DOIUrl":"10.1016/j.sandf.2025.101634","url":null,"abstract":"<div><div>Rockfall protection soil embankments are structures that can effectively reduce rockfall hazards along roads. They are economical and easy to construct and maintain by using locally available soil. However, a performance design method for rockfall protection soil embankments has not yet been established, and is the goal of this study. In the present study, static loading tests were conducted using two different weight shapes to clarify the influence of the weight shape on the deformation behavior of soil embankments. Based on these tests, the punching shear failure mechanism of the soil embankments was investigated. The influence of the model scale (the scale effect) on the deformation failure behavior of the soil embankments was clarified through static loading tests on reduced models at three different scales. From these model experiments, the surface deformation, internal deformation, and load–penetration relationships of the soil embankments were summarized. The results indicated that the spherical weight damaged a wider area than the polyhedral weight, and the maximum and ultimate loads exhibited a constant relationship with the deformation of the soil embankment extension between the model scales.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101634"},"PeriodicalIF":3.3,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321400","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

Strengthening the subgrade clay soil using nano chemical stabilisation 利用纳米化学稳定技术加固路基粘土

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-06-18 DOI: 10.1016/j.sandf.2025.101638

Kodi Rangaswamy, Regi P. Mohan

Nowadays, non-traditional eco-friendly nanomaterial additives are widely utilized in the geotechnical stabilization of soft soils. The application of materials developed using nanotechnology in stabilizing soils effectively reduces or replaces the utility of cementation products like cement and lime, which leads to environmental pollution. This article evaluates the efficacy of organosilane nano-chemical additive with 1 % cement binder in improving the strength properties of soft soil used for road-based applications. A series of experimental tests were conducted to characterize the geotechnical properties of soft clay and nano-chemical-treated soft soils with 1 % cement binder, including soil gradation, consistency limits, compaction, unconfined compression, and California bearing ratio (CBR) strength, and microstructural and chemical analysis. A small dosage of 1 % cement was added to the parent clay to accelerate the cementitious reactions in soil treated with a nano-chemical additive. The dosage of nano-chemical additives used was varied from 0.03 to 0.05 % for the present study. The treated clayey soil is examined for the optimum dosage corresponding to the highest unconfined compression strength of soil samples cured up to 28 days. Test results show that the soft clay treated with organosilane-based nano-chemical at an optimum dosage of 0.045 % and 1 % cement binder has attained the maximum unconfined compression and CBR strengths. SEM and FTIR results postulate the microstructural and chemical interactions involved in supporting the mechanism of improvement in the strength of treated soils.

目前，非传统的环保纳米材料添加剂在软土的岩土稳定中得到了广泛的应用。利用纳米技术开发的材料在稳定土壤中的应用，有效地减少或取代了水泥和石灰等胶结产品的使用，从而导致环境污染。本文评价了有机硅烷纳米化学添加剂添加1%水泥粘结剂对改善道路用软土强度性能的效果。研究人员进行了一系列实验测试，以表征含有1%水泥粘合剂的软粘土和纳米化学处理软土的岩土力学特性，包括土壤级配、稠度极限、压实、无侧限压缩和加州承载比（CBR）强度，以及微观结构和化学分析。在母质粘土中加入少量1%的水泥，以加速纳米化学添加剂处理过的土壤的胶凝反应。在本研究中，纳米化学添加剂的用量为0.03% ~ 0.05%。对处理后的粘土进行了试验，以确定固化至28天的土样的最高无侧限抗压强度所对应的最佳用量。试验结果表明，有机硅基纳米化学剂在掺量为0.045%、水泥粘结剂掺量为1%的条件下处理软粘土获得了最大的无侧限抗压强度和CBR强度。SEM和FTIR结果假设微观结构和化学相互作用参与支持改善处理土壤强度的机制。

{"title":"Strengthening the subgrade clay soil using nano chemical stabilisation","authors":"Kodi Rangaswamy, Regi P. Mohan","doi":"10.1016/j.sandf.2025.101638","DOIUrl":"10.1016/j.sandf.2025.101638","url":null,"abstract":"<div><div>Nowadays, non-traditional eco-friendly nanomaterial additives are widely utilized in the geotechnical stabilization of soft soils. The application of materials developed using nanotechnology in stabilizing soils effectively reduces or replaces the utility of cementation products like cement and lime, which leads to environmental pollution. This article evaluates the efficacy of organosilane nano-chemical additive with 1 % cement binder in improving the strength properties of soft soil used for road-based applications. A series of experimental tests were conducted to characterize the geotechnical properties of soft clay and nano-chemical-treated soft soils with 1 % cement binder, including soil gradation, consistency limits, compaction, unconfined compression, and California bearing ratio (CBR) strength, and microstructural and chemical analysis. A small dosage of 1 % cement was added to the parent clay to accelerate the cementitious reactions in soil treated with a nano-chemical additive. The dosage of nano-chemical additives used was varied from 0.03 to 0.05 % for the present study. The treated clayey soil is examined for the optimum dosage corresponding to the highest unconfined compression strength of soil samples cured up to 28 days. Test results show that the soft clay treated with organosilane-based nano-chemical at an optimum dosage of 0.045 % and 1 % cement binder has attained the maximum unconfined compression and CBR strengths. SEM and FTIR results postulate the microstructural and chemical interactions involved in supporting the mechanism of improvement in the strength of treated soils.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 4","pages":"Article 101638"},"PeriodicalIF":3.3,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144308095","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

Centrifuge model tests on liquefaction-induced settlement of river embankments reinforced by floating-type cement treatment method 浮式水泥加固河堤液化沉降离心模型试验

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-06-12 DOI: 10.1016/j.sandf.2025.101633

Masahide Otsubo , Yuta Miura, Kazuya Ueda, Shunsuke Tanimoto, Masanori Ishihara, Tetsuya Sasaki

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

g

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.

松散的沙质土层在强震作用下容易发生液化，对液化地面内部或上面的土木工程结构造成破坏。根据日本现行的河堤液化对策设计指南，应提高河堤以下可液化底土的整体深度。然而，对于深层可液化地基，这种方法并不经济。为了使设计方法合理化，本文研究了浮式水泥处理方法的性能，该方法仅对可液化地基的较浅部分进行加固。在50g环境下进行了一系列离心振动台模型试验。系统地改变了改善（水泥处理）的深度，并对倾斜地面的效果进行了检验。试验结果表明，增加堤防加固深度可以线性降低堤防沉降。此外，水泥处理土与液化土之间的隔振效应可以显著降低路堤的加速度。这些影响有助于即使在液化的倾斜地面引起横向流动时也能安全保持路堤形状。面向实际应用，扩展了对水泥土渗透性影响的讨论。此外，使用丙烯酸块测量了震动过程中作用在水泥处理土壤上的应力，以解释土壤中裂缝的发生。

{"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":"2025-06-12","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}

引用次数: 0

Rheological properties of deep-sea shallow sediments in the Western Pacific mining area 西太平洋矿区深海浅层沉积物的流变特性

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-06-01 DOI: 10.1016/j.sandf.2025.101632

Hao Liu , Zongxiang Xiu , Lejun Liu , Jie Dong , Qiuhong Xie , Mu Huang , Chenwei Luo , Yifeng Zeng , Xingsen Guo

Studying the rheological properties of deep-sea shallow sediments can provide basic mechanical characteristics for designing deep-sea mining vehicles driving on the soft seabed, providing anchoring stability of semi-submersible mining platforms, and assessing submarine landslide hazards. Shallow sediment column samples from the Western Pacific mining area were obtained, and their rheological properties were studied. A series of rheological tests was conducted under different conditions using an RST rheometer. In addition, conventional physical property, mineral composition, and microstructure analyses were conducted. The results showed that shallow sediments have a high liquid limit and plasticity, with flocculent and honeycomb-like flaky structures as the main microstructure types. The rheological properties exhibited typical non-Newtonian fluid characteristics with yield stress and shear-thinning phenomena during the shearing process. In contrast to previous studies on deep-sea soft soil sediments, a remarkable long-range shear-softening stage, called the thixotropic fluid stage, was discovered in the overall rheological curve. A four-stage model is proposed for the transition mechanism of deep-sea shallow sediments from the solid to liquid–solid, solid–liquid transition, thixotropic fluid, and stable fluid stages. The mechanism of the newly added thixotropic fluid stage was quantitatively analyzed using a modified Cross rheological model, and this stage was inferred from the perspective of mineralogy and microstructure. The results of this study can be useful for improving the operational safety and work efficiency of submarine operation equipment for deep-sea mining in the Western Pacific Ocean.

研究深海浅层沉积物的流变特性，可以为设计在软海底行驶的深海采矿车、提供半潜式采矿平台的锚固稳定性以及评估海底滑坡灾害提供基本的力学特性。获取了西太平洋矿区浅层沉积物柱样，对其流变特性进行了研究。利用RST流变仪在不同条件下进行了一系列流变试验。此外，还进行了常规物性、矿物组成和微观结构分析。结果表明：浅层沉积物具有较高的液限和塑性，以絮状和蜂窝状片状结构为主要微观结构类型；剪切过程中出现屈服应力和剪切变薄现象，流变特性表现出典型的非牛顿流体特性。与以往对深海软土沉积物的研究相比，在整体流变曲线中发现了一个显著的长时间剪切软化阶段，即触变流体阶段。提出了深海浅层沉积物从固体到液-固、固-液过渡、触变流体和稳定流体四个阶段的过渡机理模型。采用改进的Cross流变模型定量分析了新增触变流体阶段的机理，并从矿物学和微观结构的角度对该阶段进行了推断。研究结果可为提高西太平洋深海采矿潜艇作业设备的作业安全性和工作效率提供参考。

{"title":"Rheological properties of deep-sea shallow sediments in the Western Pacific mining area","authors":"Hao Liu , Zongxiang Xiu , Lejun Liu , Jie Dong , Qiuhong Xie , Mu Huang , Chenwei Luo , Yifeng Zeng , Xingsen Guo","doi":"10.1016/j.sandf.2025.101632","DOIUrl":"10.1016/j.sandf.2025.101632","url":null,"abstract":"<div><div>Studying the rheological properties of deep-sea shallow sediments can provide basic mechanical characteristics for designing deep-sea mining vehicles driving on the soft seabed, providing anchoring stability of semi-submersible mining platforms, and assessing submarine landslide hazards. Shallow sediment column samples from the Western Pacific mining area were obtained, and their rheological properties were studied. A series of rheological tests was conducted under different conditions using an RST rheometer. In addition, conventional physical property, mineral composition, and microstructure analyses were conducted. The results showed that shallow sediments have a high liquid limit and plasticity, with flocculent and honeycomb-like flaky structures as the main microstructure types. The rheological properties exhibited typical non-Newtonian fluid characteristics with yield stress and shear-thinning phenomena during the shearing process. In contrast to previous studies on deep-sea soft soil sediments, a remarkable long-range shear-softening stage, called the thixotropic fluid stage, was discovered in the overall rheological curve. A four-stage model is proposed for the transition mechanism of deep-sea shallow sediments from the solid to liquid–solid, solid–liquid transition, thixotropic fluid, and stable fluid stages. The mechanism of the newly added thixotropic fluid stage was quantitatively analyzed using a modified Cross rheological model, and this stage was inferred from the perspective of mineralogy and microstructure. The results of this study can be useful for improving the operational safety and work efficiency of submarine operation equipment for deep-sea mining in the Western Pacific Ocean.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 3","pages":"Article 101632"},"PeriodicalIF":3.3,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144221511","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

Drilling parameters as predictors of the measured full scale performance of CFA piles by using statistical analysis of CPT profiles: a case study 利用CPT剖面的统计分析将钻孔参数作为CFA桩全尺寸性能的预测指标：一个案例研究

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-05-30 DOI: 10.1016/j.sandf.2025.101631

Gianpiero Russo , Ilaria Esposito , Massimo Ramondini , Alessia Vecchietti , Giacomo Russo

The Continuous Flight Auger (CFA) piles, also known as Auger Cast In Place piles (ACIP), have a widespread use in the world market of replacement concrete piles. The installation of such piles is generally made by equipment which records several significant installation parameters, as the torque M_t and the axial force N, applied during the auger advancing step. In the auger retrieval stage other parameters that can influence the load-settlement performance of the pile are monitored. The paper presents a case study dealing with the CFA piles adopted as a foundation for a water treatment basin. In the paper first the equations governing the kinematical analysis of the augering and concreting stages of the pile construction are introduced. After the description of the test site with the subsoil conditions and the presentation of a typical sets of parameters recorded during pile installation the results of two pile loading tests to failure are reported. A new approach for determining the depth of the soil layers boundaries, based on the statistical analysis of CPT profiles with depth, is proposed and successfully applied confirming the qualitative geological analysis of the site. A further statistical analysis is carried out to find a robust correlation between the q_c of the CPT and the torque M_t needed to screw in depth the auger for pile construction. Finally, virtual CPT profiles generated from the torque M_t recorded during the tested piles installation are used for piles bearing capacity calculations which are compared with the results of pile loading tests. The successful comparison reported in the paper is a first step to validate the proposal to use parameters recorded during augering to calculate and/or to confirm design values of the bearing capacity.

连续螺旋钻（CFA）桩，又称螺旋钻钻孔灌注桩（ACIP），在世界混凝土置换桩市场上有着广泛的应用。这种桩的安装通常由记录几个重要安装参数的设备进行，如扭矩Mt和轴向力N，在螺旋钻推进步骤中施加。在螺旋钻回收阶段，对影响桩荷载沉降性能的其他参数进行监测。本文以某水处理池地基采用CFA桩为例进行了分析。本文首先介绍了管桩施工旋钻阶段和砼阶段的运动学分析方程。在描述了试验场地的地基条件和桩安装过程中记录的一组典型参数之后，报告了两次桩荷载试验的破坏结果。基于CPT剖面随深度的统计分析，提出了一种确定土层边界深度的新方法，并成功应用于现场的定性地质分析。进行了进一步的统计分析，发现CPT的qc与螺旋钻入桩深所需的扭矩Mt之间存在强大的相关性。最后，利用试验桩安装过程中记录的扭矩Mt生成的虚拟CPT曲线进行桩承载力计算，并与桩载试验结果进行比较。本文报道的成功对比是验证利用螺旋钻过程中记录的参数来计算和/或确定承载力设计值的建议的第一步。

{"title":"Drilling parameters as predictors of the measured full scale performance of CFA piles by using statistical analysis of CPT profiles: a case study","authors":"Gianpiero Russo , Ilaria Esposito , Massimo Ramondini , Alessia Vecchietti , Giacomo Russo","doi":"10.1016/j.sandf.2025.101631","DOIUrl":"10.1016/j.sandf.2025.101631","url":null,"abstract":"<div><div>The Continuous Flight Auger (CFA) piles, also known as Auger Cast In Place piles (ACIP), have a widespread use in the world market of replacement concrete piles. The installation of such piles is generally made by equipment which records several significant installation parameters, as the torque M<sub>t</sub> and the axial force N, applied during the auger advancing step. In the auger retrieval stage other parameters that can influence the load-settlement performance of the pile are monitored. The paper presents a case study dealing with the CFA piles adopted as a foundation for a water treatment basin. In the paper first the equations governing the kinematical analysis of the augering and concreting stages of the pile construction are introduced. After the description of the test site with the subsoil conditions and the presentation of a typical sets of parameters recorded during pile installation the results of two pile loading tests to failure are reported. A new approach for determining the depth of the soil layers boundaries, based on the statistical analysis of CPT profiles with depth, is proposed and successfully applied confirming the qualitative geological analysis of the site. A further statistical analysis is carried out to find a robust correlation between the q<sub>c</sub> of the CPT and the torque M<sub>t</sub> needed to screw in depth the auger for pile construction. Finally, virtual CPT profiles generated from the torque M<sub>t</sub> recorded during the tested piles installation are used for piles bearing capacity calculations which are compared with the results of pile loading tests. The successful comparison reported in the paper is a first step to validate the proposal to use parameters recorded during augering to calculate and/or to confirm design values of the bearing capacity.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 3","pages":"Article 101631"},"PeriodicalIF":3.3,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144170332","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

Effect of pumice content on the undrained cyclic behaviour of pumiceous soil 浮石含量对浮石土不排水循环特性的影响

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-05-27 DOI: 10.1016/j.sandf.2025.101629

Emma Gardiner, Mark Stringer, Misko Cubrinovski, Sean Rees, Chris McGann

Pumice soil grains are characterized by their vesicular nature, which leads to lightweight, crushable grains with an extremely rough and angular surface texture. These characteristics give pumiceous soils particular engineering properties that are distinct from more commonly encountered hard-grained materials, making them problematic for engineers interested in assessing the risk and potential consequences of liquefaction. Natural pumice-rich soils are found with varying amounts of pumice; however, it remains unclear how the quantity of pumice present in a soil mixture alters the behaviour. This paper investigates the effect of pumice content on cyclic resistance using blends of a hard-grained sand and a pumice sand through a series of triaxial tests. Overall, the cyclic resistance was found to reduce with increasing pumice content. Furthermore, the cyclic resistances appeared to fall into three bands: (a) little apparent reduction in cyclic resistance for pumice contents up to 40%, (b) a reduction in cyclic resistance of approximately 20% at pumice contents of 80% and higher, and (c) a transitional zone. However, despite the lower cyclic resistance, the patterns of pore pressure generation and strain development did not appear to be affected by the amount of pumice in the soil mixture.

浮石土颗粒的特点是它们的水泡性质，这导致了重量轻，可破碎的颗粒，具有极其粗糙和棱角分明的表面纹理。这些特性赋予浮石土独特的工程特性，使其与更常见的硬颗粒材料不同，这使得工程师对评估液化的风险和潜在后果感兴趣。天然富浮石土壤含有不同数量的浮石；然而，目前还不清楚混合土中浮石的含量是如何改变这种行为的。通过一系列三轴试验，研究了浮石掺量对硬粒砂和浮石砂的循环阻力的影响。总体而言，循环阻力随浮石含量的增加而降低。此外，循环阻力表现为3个波段：(a)当浮石含量达到40%时，循环阻力下降幅度不大；(b)当浮石含量达到80%及以上时，循环阻力下降幅度约为20%；(c)处于过渡区。然而，尽管循环阻力较低，孔隙压力的产生和应变发展模式似乎不受混合土中浮石含量的影响。

{"title":"Effect of pumice content on the undrained cyclic behaviour of pumiceous soil","authors":"Emma Gardiner, Mark Stringer, Misko Cubrinovski, Sean Rees, Chris McGann","doi":"10.1016/j.sandf.2025.101629","DOIUrl":"10.1016/j.sandf.2025.101629","url":null,"abstract":"<div><div>Pumice soil grains are characterized by their vesicular nature, which leads to lightweight, crushable grains with an extremely rough and angular surface texture. These characteristics give pumiceous soils particular engineering properties that are distinct from more commonly encountered hard-grained materials, making them problematic for engineers interested in assessing the risk and potential consequences of liquefaction. Natural pumice-rich soils are found with varying amounts of pumice; however, it remains unclear how the quantity of pumice present in a soil mixture alters the behaviour. This paper investigates the effect of pumice content on cyclic resistance using blends of a hard-grained sand and a pumice sand through a series of triaxial tests. Overall, the cyclic resistance was found to reduce with increasing pumice content. Furthermore, the cyclic resistances appeared to fall into three bands: (a) little apparent reduction in cyclic resistance for pumice contents up to 40%, (b) a reduction in cyclic resistance of approximately 20% at pumice contents of 80% and higher, and (c) a transitional zone. However, despite the lower cyclic resistance, the patterns of pore pressure generation and strain development did not appear to be affected by the amount of pumice in the soil mixture.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 3","pages":"Article 101629"},"PeriodicalIF":3.3,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144154377","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

Load transfer behaviour of super long piles in multi-layer soft soil through field testing and numerical 3D FEM modelling 通过现场试验和三维有限元数值模拟研究了多层软土地基超长桩的荷载传递特性

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-05-23 DOI: 10.1016/j.sandf.2025.101627

Thoi Huu Tra , Thanh T. Nguyen , Thien Q. Huynh , Tatsuya Ishikawa

The load transfer mechanism of pile foundation has received considerable attention over the years, the simultaneous responses that skin friction and base resistances of super-long piles (length L > 60 m) can have in complex soft soil, however, still need greater understanding. This study employs 3D-finite element (FE) analysis incorporating virtual interface elements to simulate the mobilised skin friction and plastic failure (slippage) of pile under ultimate loading. Static pile load tests on 4 different long and large bored piles (1–1.5 m in diameter and 70–80 m in length) embedded in the soft soil region of Mekong Delta are studied in detail through extensive instrumentation along the piles. The results are then used to not only explore load-transfer process, but also validate numerical modelling through a comprehensive process combining multiple-soil layers and −loading stages. The coupled experimental (field) − numerical results reveal the predominant contribution of skin friction exceeding 90 % of the entire bearing capacity before a drop with swift rise in base resistance when reaching a critical condition (displacement s_h > 25 mm and load pressure p > 14,000 kPa). The ratio of active skin friction is defined to assess the simultaneous variation of skin friction at different depths, featuring the role of pile length on the mobilisation of skin friction. The study also proposes a novel dynamic method to calculate the strength reduction factor, R_i, based on fundamental soil and load parameters, giving a vital means to advancing the use of interface elements when modelling pile foundation in soft soil.

近年来，桩基荷载传递机制受到了广泛的关注，超长桩(长度L >；然而，在复杂的软土中，60 m)可以有更多的了解。本研究采用三维有限元（FE）分析，结合虚拟界面单元，模拟桩在极限荷载作用下的动摩和塑性破坏（滑移）。在湄公河三角洲软土地基地区，对4根直径1 ~ 1.5 m、长度70 ~ 80 m的大型钻孔灌注桩进行了静桩荷载试验研究。然后，研究结果不仅用于探索荷载传递过程，而且通过结合多个土层和加载阶段的综合过程验证数值模拟。耦合实验（场）-数值结果表明，在达到临界条件(位移sh >；25mm及负载压力p >；14000 kPa)。定义主动摩阻力比，以评价不同深度处摩阻力的同时变化，体现桩长对摩阻力调动的作用。本文还提出了一种基于基本土体和荷载参数计算强度折减系数Ri的动态方法，为在软土地基桩基础建模中推广界面单元的应用提供了重要手段。

{"title":"Load transfer behaviour of super long piles in multi-layer soft soil through field testing and numerical 3D FEM modelling","authors":"Thoi Huu Tra , Thanh T. Nguyen , Thien Q. Huynh , Tatsuya Ishikawa","doi":"10.1016/j.sandf.2025.101627","DOIUrl":"10.1016/j.sandf.2025.101627","url":null,"abstract":"<div><div>The load transfer mechanism of pile foundation has received considerable attention over the years, the simultaneous responses that skin friction and base resistances of super-long piles (length <em>L</em> > 60 m) can have in complex soft soil, however, still need greater understanding. This study employs 3D-finite element (FE) analysis incorporating virtual interface elements to simulate the mobilised skin friction and plastic failure (slippage) of pile under ultimate loading. Static pile load tests on 4 different long and large bored piles (1–1.5 m in diameter and 70–80 m in length) embedded in the soft soil region of Mekong Delta are studied in detail through extensive instrumentation along the piles. The results are then used to not only explore load-transfer process, but also validate numerical modelling through a comprehensive process combining multiple-soil layers and −loading stages. The coupled experimental (field) − numerical results reveal the predominant contribution of skin friction exceeding 90 % of the entire bearing capacity before a drop with swift rise in base resistance when reaching a critical condition (displacement <em>s<sub>h</sub></em> > 25 mm and load pressure <em>p</em> > 14,000 kPa). The ratio of active skin friction is defined to assess the simultaneous variation of skin friction at different depths, featuring the role of pile length on the mobilisation of skin friction. The study also proposes a novel dynamic method to calculate the strength reduction factor, <em>R<sub>i</sub></em>, based on fundamental soil and load parameters, giving a vital means to advancing the use of interface elements when modelling pile foundation in soft soil.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 3","pages":"Article 101627"},"PeriodicalIF":3.3,"publicationDate":"2025-05-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144124583","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