Acta Geotechnica最新文献

{"title":"Effect of particle size distribution on the thermal conductivity of crushed GMZ bentonite pellet mixtures","authors":"Xiangyun Zhou,&nbsp;De’an Sun,&nbsp;Junran Zhang,&nbsp;Fan Peng,&nbsp;Mingyu Li,&nbsp;Yunshan Xu,&nbsp;You Gao","doi":"10.1007/s11440-024-02437-2","DOIUrl":"10.1007/s11440-024-02437-2","url":null,"abstract":"<div><p>Crushed high-density bentonite pellet mixtures have been proposed to fill the construction gaps of the high-level radioactive nuclear waste repository. Compared with compacted bentonite block, the thermal conductivity of bentonite pellet mixture is relatively low, which can cause a significant increase in the peak temperature of the buffer layer. In this regard, it is crucial to investigate the thermal conductivity of bentonite pellet mixtures for the repository’s long-term safety assessment. In this study, crushed high-density GMZ bentonite pellets with six size classes were produced. The thermal conductivities of mono-size, binary-size, and multi-size class mixtures of crushed bentonite pellets were measured. The effect of particle size distributions of pellet mixtures on the thermal conductivity was analyzed. The results reveal that the thermal conductivity of a mono-size class mixture increases as the mean particle size increases. The influence of mean particle size on thermal conductivity lessens as dry density increases. The thermal conductivity of a binary-size class mixture decreases initially and subsequently increases as the mass fraction of the fine size class increases. The thermal conductivity of a multi-size class mixture firstly increases and then decreases with increasing the distribution modulus <i>q</i>, reaching a peak value in the range of <i>q</i> = 0.6 ~ 0.8.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"563 - 581"},"PeriodicalIF":5.6,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dense granular flow described by micropolar fluid and its peridynamic implementation","authors":"Ji Wan,&nbsp;Wenzhong Qu,&nbsp;Xihua Chu","doi":"10.1007/s11440-024-02435-4","DOIUrl":"10.1007/s11440-024-02435-4","url":null,"abstract":"<div><p>This work presents a nonlocal mesh-free peridynamic model for micropolar fluids that describe fluids enriched with the micro-rotational and length scale effects. The stabilized force state is applied to remedy the zero-energy mode instability in the micropolar viscous term. The present model is validated with the planar Couette flow and Poiseuille flow simulation. Considering the natural inheritance of micro-spinning and microstructures in granular flows, the peridynamic micropolar fluid model is also applied to simulate the dense, dry granular flow with a modified <span>(mu (I))</span> rheology flow law. The effects of the coupling number, the micro-inertia, the characteristic length, and the peridynamic horizon size on the granular <span>(mu (I))</span> flow are discussed in a two-dimensional column collapse example. The numerical results of column collapse show that the micropolar coupling number can significantly affect column collapse behavior. A larger coupling number can slow down the translational movement of the granular flow, resulting in a larger angle of repose. The micro-rotational velocity increases by enlarging the coupling number. The micro-inertia and characteristic length have a significant influence on the micro-rotational behavior of the granular flow. Increasing either micro-inertia or characteristic length value decreases the micro-rotational velocity. However, the characteristic length and micro-inertia have an insignificant influence on translational velocity. Slight differences are observed in the translational velocity distribution or free surface profile. For the horizon size, we find it affects the granular flow only on the micro-rotational velocity and runout distance.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 1","pages":"413 - 438"},"PeriodicalIF":5.6,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142962963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deteriorated characteristics, elemental zonation, and phase changes in the surface of cemented soil exposed to marine environment","authors":"Yalei Wu,&nbsp;Junjie Yang,&nbsp;Nan Yan,&nbsp;Xiaoyu Bai","doi":"10.1007/s11440-024-02428-3","DOIUrl":"10.1007/s11440-024-02428-3","url":null,"abstract":"<div><p>The deterioration issues of surface strength reduction occur in cemented soil exposed to marine corrosion environment for long-term, which seriously affects the durability and safety of the structure. Therefore, it is urgent to reveal the tempo-spatial deterioration mechanisms of cemented soil, which can provide a theoretical basis for practical anti-deterioration measures. In this study, the micro-cone penetration test of cemented soil exposed to seawater was conducted, and the ion profiles, pH, X-ray diffraction (XRD), and scanning electron microscopy with energy disperse spectroscopy (SEM–EDS) tests of different slice layers from the exposed surface were performed. The results show that the deteriorated cemented soil along the erosion direction can be classified into completely deteriorated layer with zero-strength, deteriorated transition layer with only about 10% strength remaining, and an undeteriorated zone with no strength reduction. The depth of the deteriorated zone increased with corrosion time and decreased with cement content, but the strength reduction was not affected. The micro-cone penetration, ion concentration, pH, XRD and SEM–EDS results illustrated that the essential nature of deterioration of cemented soils is the tempo-spatial evolution of corrosive ions enriched by corrosion reactions and gradually induced the phase change of hydration products into non-cementitious or secondary expansion products, which ultimately leads to the strength reduction in surface layers. Moreover, Mg²⁺ and SO₄²⁻ were mainly enriched in the deteriorated zone, and Cl⁻ could invade and enrich in the undeteriorated zone. Besides, the leaching of Ca²⁺ and OH⁻ was associated with the invasion of all these corrosive ions. This study contributes to the deterioration mechanism of cemented soil and provides useful reference for the development of seawater anti-corrosion binder.</p><h3>Graphical abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 3","pages":"1157 - 1176"},"PeriodicalIF":5.6,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance of debris flow barriers: an energy perspective","authors":"Hongyu Luo,&nbsp;Limin Zhang,&nbsp;Jian He,&nbsp;Jiawen Zhou","doi":"10.1007/s11440-024-02430-9","DOIUrl":"10.1007/s11440-024-02430-9","url":null,"abstract":"<div><p>Barrier systems are widely applied to impede or retain debris flows. Due to complex flow characteristics and the lack of accurate measurements, the performance of different types of debris flow barriers is difficult to quantify. In this study, a coupled DEM-ALE-FEM method is employed to offer an insight into energy dissipation mechanisms in flow-barrier interactions. Two energy criteria are proposed to evaluate the energy dissipation efficiencies and impact forces of three common types of barriers (rigid barriers, baffles and flexible barriers). The simulation results reveal that a large channel slope or a high solid concentration of debris flow enhances the energy transfer process for all barrier types. The overflow effect is a key factor for barrier type selection. Under significant overflow conditions, the baffle structure outperforms the other two barrier types in terms of both energy transfer and dissipation efficiency. The efficiency of a rigid barrier is sensitive to the barrier height, which is determined by the runup height. The rigid barrier performs better with the increase in barrier height. The flexible net barrier with a smaller net opening than the solid particle size is a good option that balances energy dissipation efficiency and construction cost, especially for flows of high solid concentrations. The rigid barrier outperforms the other two barrier types for debris flows of low solid concentrations. The in-depth study of the barrier energy dissipation efficiency as carried out here facilitates the selection and design of barriers in mitigating debris flow hazards.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"987 - 1000"},"PeriodicalIF":5.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Formulation and implementation of an isotropic plasticity model enriched with shift stress and fractional flow rule","authors":"Xingbo Huang,&nbsp;Yifei Sun,&nbsp;Wojciech Sumelka,&nbsp;Yufeng Gao","doi":"10.1007/s11440-024-02439-0","DOIUrl":"10.1007/s11440-024-02439-0","url":null,"abstract":"<div><p>Clay and sand were often treated as two different materials that required respective constitutive models to capture the state-dependent nonassociated responses. This study developed a three-dimensional isotropic plasticity model for clay with different over-consolidation ratios (OCRs) and sand with particle breakage, through adopting shift stress-enriched loading/bounding surface, fractional flow rule and flexible critical state line, in the transformed stress space. The model was implemented in Abaqus through UMAT subroutine with an explicit adaptive substepping integration algorithm. Validation against a series of element tests on clay and sand showed that the unified model can well reproduce the stress–strain and critical state behavior of clay and sand. To further demonstrate the capability of the model, two typical boundary value problems, i.e., shear band and ground settlement, were simulated. It was found that as the shear band initiated, higher shear strain and dilatancy were accumulated within the shear band, whereas dilatancy outside the shear band ceased soon with further shearing. Ground settlement and the associated excess pore water pressure at the same consolidation time decreased with the increasing OCR, which agreed well with other studies. The simulation performances verified the capability of the unified model in resolving practical engineering problems.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"803 - 821"},"PeriodicalIF":5.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fault rupture propagation through stratified sand–clay deposits and engineered earth structures: a meshfree and critical-state modeling approach","authors":"Enrique M. del Castillo,&nbsp;Alomir H. Fávero Neto,&nbsp;Ronaldo I. Borja","doi":"10.1007/s11440-024-02421-w","DOIUrl":"10.1007/s11440-024-02421-w","url":null,"abstract":"<div><p>Permanent deformation and uplift caused by fault rupture is one of the most significant hazards posed by earthquakes on the built environment. In this paper, we use smoothed particle hydrodynamics (SPH) to explore the effects of soil layering or stratification on the trajectories and deformation patterns caused by rupturing reverse faults in bedrock, as well as in the foundations of engineered earth structures. SPH is a continuum meshfree numerical method highly adept at modeling large deformation problems in geotechnics. Through the use of constitutive models involving softening behavior as well as critical state type models, we isolate the effects of rigid body rotation from critical state behavior of soil in helping explain the frequently observed rotation of shear bands emanating from the bedrock fault. This analysis is facilitated by the fact that the SPH method allows us to track the propagation of shear bands over substantial amounts of vertical uplift (more than 50% of the total height of the soil deposit), far beyond many previous computational studies employing the finite element method (FEM). We observe and characterize various emergent features including fault bifurcations, stunted faults, and tension cracking, while providing insights into practical guidelines regarding the potential surface distortion width, and the critical amount of fault displacement required for surface rupture depending on the multilayered constitution of the soil deposit. Finally, we predict the expected amount of surface distortion and internal damage to earthen embankments depending on varying fault location and soil makeup.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"19 12","pages":"7767 - 7798"},"PeriodicalIF":5.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142754317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Practical estimation of the thermal conductivity of granular soils considering grading and relative density using three physical parameters","authors":"Xiusong Shi,&nbsp;Jinzhi Lin,&nbsp;Hao Xiong,&nbsp;Jiaying Liu,&nbsp;Yiwen Zeng","doi":"10.1007/s11440-024-02431-8","DOIUrl":"10.1007/s11440-024-02431-8","url":null,"abstract":"<div><p>The thermal conductivity of granular soils is widely used for analyzing the thermal stability in geo-structure. Particle size distribution is a crucial feature in characterizing the inter-granular structure of granular materials, and the mechanism governing the grading effect on thermal properties is not fully understood. Therefore, 154 laboratory tests have been performed to investigate the thermal conductivity of quartz sands with different gradings, including continuous gradings with various uniformity coefficient (2–10.6) and mean particle size (0.25–1.33 mm) and gap gradings with different fine content (0–100%), size ratio (2.7–9.5), and uniformity coefficient of coarse particles (1.3–3.9). The result indicates that the variation of thermal conductivity with grading is inversely related to the change of void ratio with grading at the same initial state. For a given void ratio, the thermal conductivity of the continuously graded sands is affected by both the uniformity coefficient and mean particle size. Besides, the thermal conductivity of the gap-graded sands varies with fine content and size ratio, but has no significant correlation with the uniformity coefficient of coarse particles under the fine-dominated structure. Based on the experimental data in this study, an empirical model is formulated for dry quartz sands with broad spectrum of grading. The model has only three physical parameters (representative particle size and limiting void ratios), which can be readily determined from conventional laboratory tests. The error of the proposed model is basically less than 10% and 20–25% for crushed and natural quartz sands, respectively, indicating that this model is effective for quartz sands with a broad spectrum of grading and wide range of void ratio.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"965 - 985"},"PeriodicalIF":5.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143362189","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of layering and pre-loading on the dynamic properties of sand-rubber specimens in resonant column tests","authors":"Magdalena Kowalska,&nbsp;Christos Vrettos","doi":"10.1007/s11440-024-02398-6","DOIUrl":"10.1007/s11440-024-02398-6","url":null,"abstract":"<div><p>Several studies show that scrap tyre rubber mixed with sand is an effective and sustainable method for mitigating vibrations. The dynamic and cyclic response of this composite soil has already been investigated. However, layered sand-rubber configurations have not been considered yet. This study reports findings of resonant column tests on three types of specimen: (a) sand-only or rubber-only, (b) layered sand-rubber, and (c) sand-rubber mixtures. The analysis allowed for an evaluation of the maximum shear modulus and its degradation with strain over a wide range of confining stress and shear strain. The evolution of the damping ratio with strain was determined analogously. Effects of pre-loading and pre-straining were also considered. The results show that the behaviour of layered specimens is much more similar to that of pure rubber than to sand-rubber mixtures, with very low shear modulus values, smaller degradation of stiffness with strain and pre-loading, and higher damping. For example, at the confining stress of 100 kPa and rubber content of 0/33.3/50/67.7/100% by volume, the small strain shear moduli for sand-rubber mixtures are equal to 98.3/30.4/15.4/7.1/1.3 MPa and 98.3/3.6-4.2/2.4-2.8/2.1/1.3 MPa for sand-rubber layered specimens, depending on the arrangement of layers. A shear beam model is shown to be adequate for calculating the response of the layered specimens comprising layers of large stiffness contrast.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"607 - 624"},"PeriodicalIF":5.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s11440-024-02398-6.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A theoretical model for trapdoor tests considering the interaction of soil arches","authors":"Rui-Xiao Zhang,&nbsp;Dong Su,&nbsp;Xing-Tao Lin,&nbsp;Xiang-Sheng Chen","doi":"10.1007/s11440-024-02420-x","DOIUrl":"10.1007/s11440-024-02420-x","url":null,"abstract":"<div><p>Precisely evaluating the soil pressure above parallel tunnels is of paramount importance. In this study, the deformation characteristics of soil above dual trapdoors were analyzed firstly. A novel multi-arch model for calculating the distribution of the vertical earth pressure on deep-buried parallel tunnel was then proposed based on the limit equilibrium method. The height of the dual arch zone caused by the displacement of the dual trapdoors was calculated with consideration of internal friction angle of the soil, width of the trapdoors, spacing between the dual trapdoors, and elastic modulus of the soil. By comparing with numerical simulation results and existing theoretical calculation models that do not account for the interaction of soil arching effect, it is evident that the proposed model in this study adeptly predicts the vertical stress above the trapdoor. Additionally, it captures the characteristic of upwardly convex stress distribution above the trapdoor. The analysis of parameters conducted on the theoretical calculation model showed that the depth of the trapdoor and the internal friction angle of the soil have a substantial impact, whereas the expansion coefficient exerts a negligible effect on the soil arching ratio above the trapdoor.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 2","pages":"707 - 721"},"PeriodicalIF":5.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143361753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Airtightness failure analysis of filter cake during shield tunneling machine hyperbaric intervention","authors":"Dalong Jin,&nbsp;Bowen Cai,&nbsp;Xinggao Li,&nbsp;Zheng Mou,&nbsp;Jicheng Shu","doi":"10.1007/s11440-024-02438-1","DOIUrl":"10.1007/s11440-024-02438-1","url":null,"abstract":"<div><p>During shield tunneling in areas of high groundwater or soft ground, the hyperbaric intervention method is widely used to access the excavation chamber of the TBM to perform inspections and repair cutters. The airtight capability of the filter cake is the key to safety in the hyperbaric intervention. If the airtightness of the filter cake fails, the compressed air can escape into the crevasses of the soil and rock rendering the face unstable. This paper focuses on the airtightness failure behavior of the filter cake under air pressure. A multiphase flow-evaporation coupling model is developed to assess the failure of airtightness and the permissible pressure maintenance time during compressed air operations. The proposed model is validated by the airtightness test of the filter cake in the laboratory. The results show that the external filter cake plays a primary role, while the infiltration zone plays an auxiliary role in the effective airtightness mechanism of the filter cake. The proposed model can be applied to evaluate the duration of airtightness during maintenance work. The findings of this study have significant implications for ensuring the safety of the tunnel face during hyperbaric interventions in slurry TBM operations.</p></div>","PeriodicalId":49308,"journal":{"name":"Acta Geotechnica","volume":"20 3","pages":"1089 - 1102"},"PeriodicalIF":5.6,"publicationDate":"2024-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}