Soils and Foundations最新文献

Ground water lowering at Minami-Kurihashi in Kuki City, Japan as countermeasure against liquefaction

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-03-19 DOI: 10.1016/j.sandf.2025.101597

Junichi Koseki , Kazue Wakamatsu , Katsuya Matsushita , Tomoaki Yahaba

Extensive liquefaction took place in Minami-Kurihashi, Kuki City, Saitama, Japan during the 2011 Off the Pacific Coast of Tohoku Earthquake, which induced damage to houses and infrastructures. Based on the results of a detailed geotechnical investigation, the ground water lowering method has been adopted and executed as a countermeasure against liquefaction. This report summarizes how this countermeasure could be implemented, including the results from field monitoring and relevant analyses of the local ground water level and surface settlement that were conducted during and after the ground water lowering. By newly installing a network of drainage ditches, cut-off sheet pile walls, and operating manhole pumps, it was possible to lower the ground water level in order to prevent/reduce future liquefaction damage. In the non-execution areas outside the cut-off walls, the ground water level was not affected by this operation. As of the end of the monitoring period, the measured maximum settlement and tilting ratio were 36 mm and 1.03/1000, respectively. All the monitoring data satisfied the pre-assigned control limits of 40 mm and 2/1000, respectively. In order to numerically simulate the monitored behavior, modification of the compression index and coefficient of permeability was required. Based on the results of a long-term behavior analysis using the modified parameters, the final settlement and tilting ratio were predicted to be, at maximum, 54 mm and 1.50/1000, respectively. The latter value satisfied the pre-assigned threshold limit of 3/1000.

{"title":"Ground water lowering at Minami-Kurihashi in Kuki City, Japan as countermeasure against liquefaction","authors":"Junichi Koseki , Kazue Wakamatsu , Katsuya Matsushita , Tomoaki Yahaba","doi":"10.1016/j.sandf.2025.101597","DOIUrl":"10.1016/j.sandf.2025.101597","url":null,"abstract":"<div><div>Extensive liquefaction took place in Minami-Kurihashi, Kuki City, Saitama, Japan during the 2011 Off the Pacific Coast of Tohoku Earthquake, which induced damage to houses and infrastructures. Based on the results of a detailed geotechnical investigation, the ground water lowering method has been adopted and executed as a countermeasure against liquefaction. This report summarizes how this countermeasure could be implemented, including the results from field monitoring and relevant analyses of the local ground water level and surface settlement that were conducted during and after the ground water lowering. By newly installing a network of drainage ditches, cut-off sheet pile walls, and operating manhole pumps, it was possible to lower the ground water level in order to prevent/reduce future liquefaction damage. In the non-execution areas outside the cut-off walls, the ground water level was not affected by this operation. As of the end of the monitoring period, the measured maximum settlement and tilting ratio were 36 mm and 1.03/1000, respectively. All the monitoring data satisfied the pre-assigned control limits of 40 mm and 2/1000, respectively. In order to numerically simulate the monitored behavior, modification of the compression index and coefficient of permeability was required. Based on the results of a long-term behavior analysis using the modified parameters, the final settlement and tilting ratio were predicted to be, at maximum, 54 mm and 1.50/1000, respectively. The latter value satisfied the pre-assigned threshold limit of 3/1000.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 3","pages":"Article 101597"},"PeriodicalIF":3.3,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143644395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Particle crushing and critical state surface of porous granular materials derived from artificial pumice

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-03-12 DOI: 10.1016/j.sandf.2025.101590

Itsuki Sato , Reiko Kuwano , Masahide Otsubo

Crushable porous soils, such as volcanic pumice, are distributed worldwide and cause a variety of engineering problems, such as slope hazards. The mechanical properties of these soils are complicated by their high compressibility due to voids in the particles themselves and changes in the soil gradation due to particle crushing. They are usually classified as problematic soils and discussed separately from ordinary granular soils, and their behaviour is not systematically understood. In this study, isotropic and triaxial compression tests were conducted on artificial pumice in order to determine the relationship between the mechanical properties and the particle crushing of crushable porous granular materials. The results showed that the mechanical behaviour of artificial pumice, representative of such materials, can be explained using a particle crushing index, which is related to the degree of efficient packing. Furthermore, a new critical state surface equation was proposed. It is applicable to crushable porous granular materials and shows the potential for expressing the critical state or isotropic consolidation state of such materials as a single surface in a three-dimensional space consisting of three axes: the stress − void ratio − crushing index. The validity of this new equation was confirmed by applying it to natural pumice from previous research.

{"title":"Particle crushing and critical state surface of porous granular materials derived from artificial pumice","authors":"Itsuki Sato , Reiko Kuwano , Masahide Otsubo","doi":"10.1016/j.sandf.2025.101590","DOIUrl":"10.1016/j.sandf.2025.101590","url":null,"abstract":"<div><div>Crushable porous soils, such as volcanic pumice, are distributed worldwide and cause a variety of engineering problems, such as slope hazards. The mechanical properties of these soils are complicated by their high compressibility due to voids in the particles themselves and changes in the soil gradation due to particle crushing. They are usually classified as problematic soils and discussed separately from ordinary granular soils, and their behaviour is not systematically understood. In this study, isotropic and triaxial compression tests were conducted on artificial pumice in order to determine the relationship between the mechanical properties and the particle crushing of crushable porous granular materials. The results showed that the mechanical behaviour of artificial pumice, representative of such materials, can be explained using a particle crushing index, which is related to the degree of efficient packing. Furthermore, a new critical state surface equation was proposed. It is applicable to crushable porous granular materials and shows the potential for expressing the critical state or isotropic consolidation state of such materials as a single surface in a three-dimensional space consisting of three axes: the stress − void ratio − crushing index. The validity of this new equation was confirmed by applying it to natural pumice from previous research.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 3","pages":"Article 101590"},"PeriodicalIF":3.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Field test study on uplift bearing characteristics of rock socketed piles in sandstone stratum

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-03-12 DOI: 10.1016/j.sandf.2025.101598

Yang Bai , Qin Chao , Yang Yuan-hao , Cheng Feng , Zhao Shan-shan

Based on the field ultimate load test, the uplift bearing characteristics of reinforced cement concrete (RCC) bored piles in clay and sandstone strata were analyzed, and semi empirical methods for calculating the ultimate uplift capacity of rock socketed pile were proposed. This method was compared with the design codes of pile foundations in China and Europe, and its reliability was verified by engineering case analysis. The results show that the relationship curves between pile top displacement and uplift load are of steep deformation type. In the field test, the ultimate uplift capacity increases with the increase of rock socketed depth or pile diameter. The failure mode of uplift pile is the relative sliding failure of pile body and surrounding rock and soil. In this technical report, the relationship between ultimate side resistance

f_{r}

and unconfined compressive strength

σ_{c}

of sandstone is proposed,

f_{r} = 0.18 σ_{c}^{0.5}

(MPa). And the calculation method of ultimate uplift capacity of the pile in clay and sandstone strata is proposed. The calculated results are in good agreement with the test results, with an error of −11.4 % to 9.5 %, which is smaller than that of the design codes of pile foundations in China and Europe. This calculated method has a certain reference for the design of uplift piles in similar strata.

{"title":"Field test study on uplift bearing characteristics of rock socketed piles in sandstone stratum","authors":"Yang Bai , Qin Chao , Yang Yuan-hao , Cheng Feng , Zhao Shan-shan","doi":"10.1016/j.sandf.2025.101598","DOIUrl":"10.1016/j.sandf.2025.101598","url":null,"abstract":"<div><div>Based on the field ultimate load test, the uplift bearing characteristics of reinforced cement concrete (RCC) bored piles in clay and sandstone strata were analyzed, and semi empirical methods for calculating the ultimate uplift capacity of rock socketed pile were proposed. This method was compared with the design codes of pile foundations in China and Europe, and its reliability was verified by engineering case analysis. The results show that the relationship curves between pile top displacement and uplift load are of steep deformation type. In the field test, the ultimate uplift capacity increases with the increase of rock socketed depth or pile diameter. The failure mode of uplift pile is the relative sliding failure of pile body and surrounding rock and soil. In this technical report, the relationship between ultimate side resistance <span><math><mrow><msub><mi>f</mi><mi>r</mi></msub></mrow></math></span> and unconfined compressive strength <span><math><mrow><msub><mi>σ</mi><mi>c</mi></msub></mrow></math></span> of sandstone is proposed,<span><math><mrow><msub><mi>f</mi><mi>r</mi></msub><mo>=</mo><mn>0.18</mn><msubsup><mi>σ</mi><mi>c</mi><mrow><mn>0.5</mn></mrow></msubsup></mrow></math></span> (MPa). And the calculation method of ultimate uplift capacity of the pile in clay and sandstone strata is proposed. The calculated results are in good agreement with the test results, with an error of −11.4 % to 9.5 %, which is smaller than that of the design codes of pile foundations in China and Europe. This calculated method has a certain reference for the design of uplift piles in similar strata.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 3","pages":"Article 101598"},"PeriodicalIF":3.3,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143609228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Centrifuge model tests on suffusion-induced deterioration and its consequences in seismic response of levees

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-03-01 DOI: 10.1016/j.sandf.2025.101592

Akihiro Takahashi , Tamaki Inoue , Saki Yamagata , Kazuki Horikoshi

Shake table tests on a levee deteriorated by seepage-induced internal erosion are performed in a geotechnical centrifuge to investigate the effects of erosion-induced heterogeneity and mechanical characteristics change on the seismic response of the levee. Among the several forms of internal erosion, suffusion, in which the seepage-induced loss of soil integrity occurs with the migration and loss of finer particles, is the focus of this study, since it progresses and puts structures in danger, while going unnoticed. In the tests, the model levee made of gap-graded soil is firstly subjected to repeated seepage flow by changing the water level in the flood channel. After lowering the water level and making the levee dry, earthquake motions are applied to the model deteriorated by suffusion. The progression of suffusion in the levee is confirmed by comparing the results of tests having the same initial condition, but subjected to a different number of seepage cycles. The shake table tests reveal that the natural frequency of the levee and the equivalent shear wave velocity in the levee significantly decrease with suffusion, suggesting that a reduction in soil stiffness occurs due to suffusion. However, no significant difference can be confirmed in the earthquake-induced crest settlement depending on the seepage cycles, suggesting that no marked change in strength or cyclic-shearing-induced compression occurs with suffusion within the scope of this study.

{"title":"Centrifuge model tests on suffusion-induced deterioration and its consequences in seismic response of levees","authors":"Akihiro Takahashi , Tamaki Inoue , Saki Yamagata , Kazuki Horikoshi","doi":"10.1016/j.sandf.2025.101592","DOIUrl":"10.1016/j.sandf.2025.101592","url":null,"abstract":"<div><div>Shake table tests on a levee deteriorated by seepage-induced internal erosion are performed in a geotechnical centrifuge to investigate the effects of erosion-induced heterogeneity and mechanical characteristics change on the seismic response of the levee. Among the several forms of internal erosion, suffusion, in which the seepage-induced loss of soil integrity occurs with the migration and loss of finer particles, is the focus of this study, since it progresses and puts structures in danger, while going unnoticed. In the tests, the model levee made of gap-graded soil is firstly subjected to repeated seepage flow by changing the water level in the flood channel. After lowering the water level and making the levee dry, earthquake motions are applied to the model deteriorated by suffusion. The progression of suffusion in the levee is confirmed by comparing the results of tests having the same initial condition, but subjected to a different number of seepage cycles. The shake table tests reveal that the natural frequency of the levee and the equivalent shear wave velocity in the levee significantly decrease with suffusion, suggesting that a reduction in soil stiffness occurs due to suffusion. However, no significant difference can be confirmed in the earthquake-induced crest settlement depending on the seepage cycles, suggesting that no marked change in strength or cyclic-shearing-induced compression occurs with suffusion within the scope of this study.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 2","pages":"Article 101592"},"PeriodicalIF":3.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mesoscopic mechanism behind the inherent reliquefaction resistance subjected to repeated earthquakes using centrifuge modelling and advanced digital image processing

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-03-01 DOI: 10.1016/j.sandf.2025.101589

Gowtham Padmanabhan , Bal Krishna Maheshwari , Kyohei Ueda , Ryosuke Uzuoka

Around the world severe damages were observed due to reliquefaction during repeated earthquakes, whereas precise understanding of its mesoscopic mechanism is not much discovered. Influence of these earthquakes on reliquefaction needs to be investigated to understand its significance in contributing to inherent sand resistance. In the present study, centrifuge model experiments were performed to examine the influence of foreshocks/aftershocks and mainshock sequence on resistance to reliquefaction. Two different shaking sequences comprising six shaking events were experimented with Toyoura sand specimen with 50 % relative density. Acceleration amplitude and shaking duration of a mainshock is twice that of foreshock/aftershock. In-house developed advanced digital image processing (DIP) technology was used to estimate mesoscopic characteristics from the images captured during the experiment. The responses were recorded in the form of acceleration, excess pore pressure (EPP), subsidence, induced sand densification, cyclic stress ratio, void ratio and average coordination number. Presence of foreshocks slightly increased the resistance against EPP before it gets completely liquefied during the mainshock. Similarly, aftershocks also regained the resistance of liquefied soil due to reorientation of particles and limited generation of EPP. However, application of mainshocks triggered liquefaction and reliquefaction and thus eliminated the beneficial effects achieved from the prior foreshocks. Reliquefaction was observed to be more damaging than the first liquefaction, meanwhile the induced sand densification from repeated shakings did not contribute to increased resistance to reliquefaction. The apparent void ratio estimated from the DIP technology was in good agreement with real void ratio values. Average coordination number indicated that the sand particles moved closer to each other which resulted in increased resistance during foreshocks/aftershocks. In contrast, complete liquefaction and reliquefaction have destroyed the dense soil particle interlocking and made specimen more vulnerable to higher EPP generation.

{"title":"Mesoscopic mechanism behind the inherent reliquefaction resistance subjected to repeated earthquakes using centrifuge modelling and advanced digital image processing","authors":"Gowtham Padmanabhan , Bal Krishna Maheshwari , Kyohei Ueda , Ryosuke Uzuoka","doi":"10.1016/j.sandf.2025.101589","DOIUrl":"10.1016/j.sandf.2025.101589","url":null,"abstract":"<div><div>Around the world severe damages were observed due to reliquefaction during repeated earthquakes, whereas precise understanding of its mesoscopic mechanism is not much discovered. Influence of these earthquakes on reliquefaction needs to be investigated to understand its significance in contributing to inherent sand resistance. In the present study, centrifuge model experiments were performed to examine the influence of foreshocks/aftershocks and mainshock sequence on resistance to reliquefaction. Two different shaking sequences comprising six shaking events were experimented with Toyoura sand specimen with 50 % relative density. Acceleration amplitude and shaking duration of a mainshock is twice that of foreshock/aftershock. In-house developed advanced digital image processing (DIP) technology was used to estimate mesoscopic characteristics from the images captured during the experiment. The responses were recorded in the form of acceleration, excess pore pressure (EPP), subsidence, induced sand densification, cyclic stress ratio, void ratio and average coordination number. Presence of foreshocks slightly increased the resistance against EPP before it gets completely liquefied during the mainshock. Similarly, aftershocks also regained the resistance of liquefied soil due to reorientation of particles and limited generation of EPP. However, application of mainshocks triggered liquefaction and reliquefaction and thus eliminated the beneficial effects achieved from the prior foreshocks. Reliquefaction was observed to be more damaging than the first liquefaction, meanwhile the induced sand densification from repeated shakings did not contribute to increased resistance to reliquefaction. The apparent void ratio estimated from the DIP technology was in good agreement with real void ratio values. Average coordination number indicated that the sand particles moved closer to each other which resulted in increased resistance during foreshocks/aftershocks. In contrast, complete liquefaction and reliquefaction have destroyed the dense soil particle interlocking and made specimen more vulnerable to higher EPP generation.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 2","pages":"Article 101589"},"PeriodicalIF":3.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Prediction of hydraulic gradient for backward erosion piping in river levees considering flow regime and pipe geometry

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-03-01 DOI: 10.1016/j.sandf.2025.101591

Mitsu Okamura , Nene Kusube

The hydraulic gradient that causes backward erosion piping in river levees is of significant concern in geotechnical engineering. Traditionally, the mechanism of pipe progression beneath levees has primarily been studied using small-scale model experiments. Prediction methods for the critical hydraulic gradient have been developed in which the simple pipe geometry and laminar pipe flow were assumed. However, recent studies have suggested that turbulent flow is more likely in the pipes of prototype-scale levees and that both the pipe geometry and flow regime significantly influence pipe progression and the resulting gradient. The present study proposes a prediction method that accounts for the effects of the foundation’s soil properties, levee scale, flow regime, and pipe geometry. The method is validated by comparing the predicted results with those from centrifuge tests. All the analytical results are found to be consistent with the test observations, demonstrating that the proposed method can satisfactorily predict the effects of the testing parameters on the hydraulic gradient. The scale effect of levees on the critical hydraulic gradient remains a critical issue, as the direct application of small-scale test results to prototype levees often results in the overprediction of the gradient. The method is also used to evaluate the progression gradient of full-scale levees, confirming that the gradient is inversely proportional to the square root of the levee width (L^−1/2) under laminar pipe flow conditions. Under turbulent flow conditions, which are more likely in field-scale levees, the exponent may be even smaller.

{"title":"Prediction of hydraulic gradient for backward erosion piping in river levees considering flow regime and pipe geometry","authors":"Mitsu Okamura , Nene Kusube","doi":"10.1016/j.sandf.2025.101591","DOIUrl":"10.1016/j.sandf.2025.101591","url":null,"abstract":"<div><div>The hydraulic gradient that causes backward erosion piping in river levees is of significant concern in geotechnical engineering. Traditionally, the mechanism of pipe progression beneath levees has primarily been studied using small-scale model experiments. Prediction methods for the critical hydraulic gradient have been developed in which the simple pipe geometry and laminar pipe flow were assumed. However, recent studies have suggested that turbulent flow is more likely in the pipes of prototype-scale levees and that both the pipe geometry and flow regime significantly influence pipe progression and the resulting gradient. The present study proposes a prediction method that accounts for the effects of the foundation’s soil properties, levee scale, flow regime, and pipe geometry. The method is validated by comparing the predicted results with those from centrifuge tests. All the analytical results are found to be consistent with the test observations, demonstrating that the proposed method can satisfactorily predict the effects of the testing parameters on the hydraulic gradient. The scale effect of levees on the critical hydraulic gradient remains a critical issue, as the direct application of small-scale test results to prototype levees often results in the overprediction of the gradient. The method is also used to evaluate the progression gradient of full-scale levees, confirming that the gradient is inversely proportional to the square root of the levee width (<em>L</em><sup>−1/2</sup>) under laminar pipe flow conditions. Under turbulent flow conditions, which are more likely in field-scale levees, the exponent may be even smaller.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 2","pages":"Article 101591"},"PeriodicalIF":3.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143511679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of the soil-structure interface on seepage characteristics in uniformly-grained soils: Microscopical insights from transparent soil experiments

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-03-01 DOI: 10.1016/j.sandf.2025.101596

Guo Yu , Ying Cui , Lei He , Yubo Li , Huaiping Feng

Seepage failure of hydraulic structures is more likely at the soil-structure interface due to factors such as lower compaction and differing flow paths; however, detailed evidence is scarce. In this research, internal structures and flow velocities in uniformly-grained soils are successfully observed using transparent soil techniques. Experimental results showed that both porosity and flow velocity were highest at the interface. Significant variations in these parameters occurred within a range roughly equal to the average particle size from the interface, indicating that the interface effect is due to particle arrangement at the boundary, with minimal impact further away. Furthermore, three-dimensional modelling of flow paths based on flow velocities was conducted, and flow path distributions and their tortuosity were analyzed. The tortuosity at the interface was low (<1.2), and widely connected pores were observed. Fluid at the interface flowed upward along the two-dimensional plane, while within the soil, it meandered three-dimensionally along particle edges. In summary, this research revealed through microscopic observation using transparent soil that the pronounced flow at the boundary is due to the soil-structure interface having larger pores and straighter flow paths.

{"title":"Influence of the soil-structure interface on seepage characteristics in uniformly-grained soils: Microscopical insights from transparent soil experiments","authors":"Guo Yu , Ying Cui , Lei He , Yubo Li , Huaiping Feng","doi":"10.1016/j.sandf.2025.101596","DOIUrl":"10.1016/j.sandf.2025.101596","url":null,"abstract":"<div><div>Seepage failure of hydraulic structures is more likely at the soil-structure interface due to factors such as lower compaction and differing flow paths; however, detailed evidence is scarce. In this research, internal structures and flow velocities in uniformly-grained soils are successfully observed using transparent soil techniques. Experimental results showed that both porosity and flow velocity were highest at the interface. Significant variations in these parameters occurred within a range roughly equal to the average particle size from the interface, indicating that the interface effect is due to particle arrangement at the boundary, with minimal impact further away. Furthermore, three-dimensional modelling of flow paths based on flow velocities was conducted, and flow path distributions and their tortuosity were analyzed. The tortuosity at the interface was low (<1.2), and widely connected pores were observed. Fluid at the interface flowed upward along the two-dimensional plane, while within the soil, it meandered three-dimensionally along particle edges. In summary, this research revealed through microscopic observation using transparent soil that the pronounced flow at the boundary is due to the soil-structure interface having larger pores and straighter flow paths.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 2","pages":"Article 101596"},"PeriodicalIF":3.3,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143551912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A mixed total Lagrangian-updated Lagrangian Smoothed Particle Hydrodynamics method for geomechanics simulations with discontinuities

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-02-25 DOI: 10.1016/j.sandf.2025.101593

Daniel S. Morikawa , Mitsuteru Asai

This study presents a novel approach for simulating geotechnical problems including the initiation and post-failure behavior of landslides triggered by discontinuities. The developed method is constituted by a mixed total Lagrangian–updated Lagrangian Smoothed Particle Hydrodynamics (SPH) method, which the main characteristic is to distinguish between internal forces within a body, represented by the internal stress, from contact forces interactions with other bodies, represented by the contact stress. Internal stress effects are calculated using total Lagrangian SPH interpolations, while contact stress effects are computed with updated Lagrangian. Discontinuities are simulated by employing a threshold on plastic deformation, in which highly plastic deformed particles detached from their original body are treated as a separate particulate material with neighboring interactions via contact stress. Numerical tests confirm the method’s capability in accurately modeling elastic collisions, friction forces and discontinuities from both tension and shear stresses, and the results are validated against experimental data. Finally, we show the applicability of the proposed method by simulating a real-scale landslide scenario, the Selborne experiment. This final numerical test demonstrates the capability of the method to simulate a landslide detached from the main soil mass as observed in the experiment.

{"title":"A mixed total Lagrangian-updated Lagrangian Smoothed Particle Hydrodynamics method for geomechanics simulations with discontinuities","authors":"Daniel S. Morikawa , Mitsuteru Asai","doi":"10.1016/j.sandf.2025.101593","DOIUrl":"10.1016/j.sandf.2025.101593","url":null,"abstract":"<div><div>This study presents a novel approach for simulating geotechnical problems including the initiation and post-failure behavior of landslides triggered by discontinuities. The developed method is constituted by a mixed total Lagrangian–updated Lagrangian Smoothed Particle Hydrodynamics (SPH) method, which the main characteristic is to distinguish between internal forces within a body, represented by the internal stress, from contact forces interactions with other bodies, represented by the contact stress. Internal stress effects are calculated using total Lagrangian SPH interpolations, while contact stress effects are computed with updated Lagrangian. Discontinuities are simulated by employing a threshold on plastic deformation, in which highly plastic deformed particles detached from their original body are treated as a separate particulate material with neighboring interactions via contact stress. Numerical tests confirm the method’s capability in accurately modeling elastic collisions, friction forces and discontinuities from both tension and shear stresses, and the results are validated against experimental data. Finally, we show the applicability of the proposed method by simulating a real-scale landslide scenario, the Selborne experiment. This final numerical test demonstrates the capability of the method to simulate a landslide detached from the main soil mass as observed in the experiment.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 2","pages":"Article 101593"},"PeriodicalIF":3.3,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143480548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Resistance factors for design of square foundations on 3D cohesive soils against bearing capacity failure

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-02-15 DOI: 10.1016/j.sandf.2025.101579

Yongbo Gan , Yajun Li , Honghu Zhu , Bin Zhang

Reliability-based designs have seen extensive use in structural engineering but face slower adoption in geotechnical practices due to the complexities in understanding uncertainties in the ground. This paper aims to bridge geotechnical and structural designs in sophisticated engineering systems, focusing on shallow square foundations that transfer structural loads to the underlying ground. The study introduces a semi-analytical method to assess the bearing capacity failure probability of shallow square foundations on 3D undrained cohesive soils using local average theory. The failure probability is efficiently calculated through fast evaluations of variances and covariance of locally averaged soil properties without relying on time-consuming computations via 3D non-linear random finite element analysis (RFEA). Confirmed through Monte Carlo simulation validation, the approach accurately determines the necessary resistance factors for designs against bearing capacity failure. Parameters specific to each site, such as sample location, variation coefficient, and fluctuation scale of spatially variable shear strength, influence the resistance factors. The approach suggests a practical method that aligns resistance factors with reliability theories, aiding engineers in transitioning to reliability-based designs without the need for extensive computations.

{"title":"Resistance factors for design of square foundations on 3D cohesive soils against bearing capacity failure","authors":"Yongbo Gan , Yajun Li , Honghu Zhu , Bin Zhang","doi":"10.1016/j.sandf.2025.101579","DOIUrl":"10.1016/j.sandf.2025.101579","url":null,"abstract":"<div><div>Reliability-based designs have seen extensive use in structural engineering but face slower adoption in geotechnical practices due to the complexities in understanding uncertainties in the ground. This paper aims to bridge geotechnical and structural designs in sophisticated engineering systems, focusing on shallow square foundations that transfer structural loads to the underlying ground. The study introduces a semi-analytical method to assess the bearing capacity failure probability of shallow square foundations on 3D undrained cohesive soils using local average theory. The failure probability is efficiently calculated through fast evaluations of variances and covariance of locally averaged soil properties without relying on time-consuming computations via 3D non-linear random finite element analysis (RFEA). Confirmed through Monte Carlo simulation validation, the approach accurately determines the necessary resistance factors for designs against bearing capacity failure. Parameters specific to each site, such as sample location, variation coefficient, and fluctuation scale of spatially variable shear strength, influence the resistance factors. The approach suggests a practical method that aligns resistance factors with reliability theories, aiding engineers in transitioning to reliability-based designs without the need for extensive computations.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 2","pages":"Article 101579"},"PeriodicalIF":3.3,"publicationDate":"2025-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143422073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Seismic performance of bridge pier integrated by multiple steel pipes with directly-connected piles using soil-water coupled three-dimensional elasto-plastic finite element analysis

IF 3.3 2区工程技术 Q2 ENGINEERING, GEOLOGICAL

Soils and Foundations

Pub Date : 2025-02-10 DOI: 10.1016/j.sandf.2025.101571

Muhammad Mahmood Ul Hassan , Koichi Isobe , Yasumasa Soga , Yasuo Sawamura , Hiroki Sugiyama , Masatsugu Shinohara

A bridge pier integrated by multiple steel pipes with directly-connected piles was proposed as a way to design a rational foundation for bridge pier structures, and its feasibility was examined by comparing its seismic behaviour with that of a bridge pier with a conventional footing. Through large-scale shaking table tests, employing bridge pier and foundation models at a scale of 1:20, it was verified that the seismic performance of such a bridge pier is comparable to, if not better than, that of a bridge pier with a conventional footing. However, as the shaking table tests utilized only a 2-Hz sine wave as the input, the impact of the relationship between the structure’s natural frequency and the input frequency on the seismic performance, and the response of the structure to irregular ground motion, need further investigation. Therefore, the aim of the present paper is to conduct a reproduction analysis of the results of the above experiment using the soil–water coupled three-dimensional elasto-plastic dynamic finite element analysis method. The analysis will employ a different seismic motion input from that used in the above tests. Through this analytical approach, the paper will elucidate the characteristics related to employing a bridge pier comprised of multiple steel pipes with directly-connected piles.

{"title":"Seismic performance of bridge pier integrated by multiple steel pipes with directly-connected piles using soil-water coupled three-dimensional elasto-plastic finite element analysis","authors":"Muhammad Mahmood Ul Hassan , Koichi Isobe , Yasumasa Soga , Yasuo Sawamura , Hiroki Sugiyama , Masatsugu Shinohara","doi":"10.1016/j.sandf.2025.101571","DOIUrl":"10.1016/j.sandf.2025.101571","url":null,"abstract":"<div><div>A bridge pier integrated by multiple steel pipes with directly-connected piles was proposed as a way to design a rational foundation for bridge pier structures, and its feasibility was examined by comparing its seismic behaviour with that of a bridge pier with a conventional footing. Through large-scale shaking table tests, employing bridge pier and foundation models at a scale of 1:20, it was verified that the seismic performance of such a bridge pier is comparable to, if not better than, that of a bridge pier with a conventional footing. However, as the shaking table tests utilized only a 2-Hz sine wave as the input, the impact of the relationship between the structure’s natural frequency and the input frequency on the seismic performance, and the response of the structure to irregular ground motion, need further investigation. Therefore, the aim of the present paper is to conduct a reproduction analysis of the results of the above experiment using the soil–water coupled three-dimensional elasto-plastic dynamic finite element analysis method. The analysis will employ a different seismic motion input from that used in the above tests. Through this analytical approach, the paper will elucidate the characteristics related to employing a bridge pier comprised of multiple steel pipes with directly-connected piles.</div></div>","PeriodicalId":21857,"journal":{"name":"Soils and Foundations","volume":"65 2","pages":"Article 101571"},"PeriodicalIF":3.3,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0