Canadian Geotechnical Journal最新文献

Effect of compressibility on the stress state of wet and dry bauxite residue 压缩率对干湿铝土矿渣应力状态的影响

3区工程技术

Canadian Geotechnical Journal Pub Date : 2024-12-19 DOI: 10.1139/cgj-2024-0090

Erwin Mmbando, Andy Fourie, David Reid, Jinglong Gao

{"title":"Effect of compressibility on the stress state of wet and dry bauxite residue","authors":"Erwin Mmbando, Andy Fourie, David Reid, Jinglong Gao","doi":"10.1139/cgj-2024-0090","DOIUrl":"https://doi.org/10.1139/cgj-2024-0090","url":null,"abstract":"The construction of filtered tailings storage facilities (TSFs) provides an alternative deposition strategy to mitigate the risk of liquefaction of loose and saturated hydraulically placed tailings through the processes of filtration and compaction. However, challenges in depositing and compacting filtered tailings can impede efforts to achieve unsaturated and/or dilative conditions. For example, it is shown that for the same compaction degree and initial void ratio, clays compacted wet of optimum moisture content (OMC) are more compressible than those compacted dry of OMC. Further, increasing stress in initially dilative soils can result in intersection of the normal compression line with the critical state line (CSL), thereby transitioning from a dilative to a contractive state. To assess the effect of compressibility on this transition stress of filtered tailings, one-dimensional compression behavior of wet and dry compacted bauxite residue (red mud) was compared with the CSL for the same material. Soil-water retention tests were also carried out on one-dimensionally compressed samples to estimate the matric suction and effective stress while considering the effects of salinity in red muds. The results showed that for the same compaction conditions, dry filtered tailings transitioned from dilative to contractive conditions at lower transition stress than wet filtered tailings. The implications of these findings on minimizing the risks of flow liquefaction in filtered TSFs were outlined.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"62 1","pages":"1-13"},"PeriodicalIF":0.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147901958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 microwave heating on rock damage and energy evolution 微波加热对岩石损伤和能量演化的影响

IF 3.6 3区工程技术

Canadian Geotechnical Journal Pub Date : 2024-09-05 DOI: 10.1139/cgj-2024-0071

Tan Li, Wei Wang, Guangbo Chen, Qinghai Li

{"title":"Effect of microwave heating on rock damage and energy evolution","authors":"Tan Li, Wei Wang, Guangbo Chen, Qinghai Li","doi":"10.1139/cgj-2024-0071","DOIUrl":"https://doi.org/10.1139/cgj-2024-0071","url":null,"abstract":"Canadian Geotechnical Journal, Ahead of Print. Rock fragmentation efficiency can be increased by microwave heating. The mechanical properties and energy evolution characteristics of coarse sandstone specimens under different microwave heating conditions are compared in this paper. The effects of microwave heating time and power on coarse sandstone specimens of peak stress, elastic modulus, brittleness index, damage variable, and impact energy index are analyzed. The results indicate that the microwave heating power and microwave heating time are inversely proportional to peak stress and elastic modulus and directly proportional to peak strain. With the increase of microwave heating power and microwave heating time, the brittleness index and damage variable of rock specimens increase, the impact energy index decreases. The microwave heating power and microwave heating time increase the rock brittleness index. The energy absorption rate of rock specimens decreases with the increase of microwave heating time. The impact energy index is inversely proportional to microwave heating power and microwave heating time. High-power and long-time microwave heating can reduce the possibility of rockbursts and the intensity of potential dynamic disasters. The research conclusion can provide the theoretical and technical basis for breaking rock by microwave heating.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"26 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142196097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Correction: Experimental study on the shear mechanical behavior of ice-rich debris–rock interface: effects of temperature, stress, and ice content 更正：富冰碎石-岩石界面剪切力学行为实验研究：温度、应力和含冰量的影响

IF 3.6 3区工程技术

Canadian Geotechnical Journal Pub Date : 2024-09-04 DOI: 10.1139/cgj-2024-0440

Da Huang, Qiujie Meng, Yixiang Song, Dongming Gu, Duofeng Cen, Zhu Zhong

引用次数: 0

An energy-saving loading strategy: cyclic vacuum preloading treatment of soft ground 节能加载策略：软土地基的循环真空预加载处理

IF 3.6 3区工程技术

Canadian Geotechnical Journal Pub Date : 2024-05-31 DOI: 10.1139/cgj-2023-0120

Jiahao Wang, Li Shi, Honglei Sun, Yuanqiang Cai, Yanming Yu

{"title":"An energy-saving loading strategy: cyclic vacuum preloading treatment of soft ground","authors":"Jiahao Wang, Li Shi, Honglei Sun, Yuanqiang Cai, Yanming Yu","doi":"10.1139/cgj-2023-0120","DOIUrl":"https://doi.org/10.1139/cgj-2023-0120","url":null,"abstract":"Canadian Geotechnical Journal, Ahead of Print. Vacuum preloading is a commonly adopted method for improving soft ground. During the preloading period, the applied vacuum pressure is constant or multistaged, implying that the vacuum pump must work continuously with constant or increasing operating power. To reduce the energy consumption of the vacuum pump, a new loading strategy of cyclic vacuum loading was proposed in this study, whereby the pump is periodically switched on and off, and hence the vacuum pressure ascends and descends accordingly. To guide the design of cyclic vacuum preloading, a large-strain radial consolidation theory incorporating the shifting of the consolidation status of ground soil from normally consolidated to overconsolidated (and vice versa) was established in the present study. Based on the established theory, the treatment effects of cyclic vacuum loading can be quantitatively determined, including the ground settlement and the degree of consolidation, while the energy consumption can be simply determined by multiplying the power by the operating time of the vacuum pump, which works only during the ascending stage of cyclic vacuum pressure. Two cases of the cyclic vacuum preloading strategy were evaluated herein, that is, the complete cyclic vacuum loading and combined cyclic/constant vacuum loading cases. Finally, experimental tests were conducted to demonstrate the energy-saving effect of cyclic vacuum preloading. Compared to the conventional vacuum preloading strategy (i.e., constant vacuum pressure), the energy consumption of the cyclic vacuum loading strategy can be drastically reduced (80% reduction), while the treatment effects remain basically unaffected.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"24 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141255893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Shear resistance evolution of geogrid–aggregate interfaces under direct shear: insights from 3D DEM simulations 直接剪切作用下土工格栅-集料界面的抗剪演变：三维 DEM 模拟的启示

IF 3.6 3区工程技术

Canadian Geotechnical Journal Pub Date : 2024-02-29 DOI: 10.1139/cgj-2023-0531

Yafei Jia, Jun Zhang, Trung Ngo, Yewei Zheng

{"title":"Shear resistance evolution of geogrid–aggregate interfaces under direct shear: insights from 3D DEM simulations","authors":"Yafei Jia, Jun Zhang, Trung Ngo, Yewei Zheng","doi":"10.1139/cgj-2023-0531","DOIUrl":"https://doi.org/10.1139/cgj-2023-0531","url":null,"abstract":"Canadian Geotechnical Journal, Ahead of Print. This paper presents a mesoscopic evaluation of the shear resistance evolution of geogrid–aggregate interfaces subjected to direct shear loading. A three-dimensional discrete element method model was developed based on experimental data. The tensile response of geogrid were simulated through a series of calibration tests. Aggregate with complex particle shapes were simulated to accurately capture the interlocking effect among aggregates based on the real particle surface. The individual shear resistance components were quantified based on particle displacement field and contact distribution characteristics. The influences of aperture–aggregate size ratio and geogrid stiffness on the shear resistance components are discussed. The results indicate that the peak value of shear resistance component follows a descending order from frictional resistance of aggregate, to passive resistance of transverse rib, and to geogrid–aggregate interface frictional resistance. During the shear process, the frictional resistance of aggregate becomes active first, followed by the geogrid–aggregate interface frictional resistance, and then the development of passive resistance of transverse ribs starts with a certain lag. Optimizing the geogrid–aggregate size ratio and utilizing geogrids with higher rib stiffness could enhance the passive resistance of transverse ribs but would not significantly affect the geogrid–aggregate interface frictional resistance and frictional resistance of aggregate.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"20 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-02-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142252166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Discussion of “Measuring strength and consolidation properties in lacustrine clay using piezocone and self-boring pressuremeter tests” 讨论 "利用压陷试验和自钻孔压力计试验测量湖沼粘土的强度和固结特性"

IF 3.6 3区工程技术

Canadian Geotechnical Journal Pub Date : 2024-02-07 DOI: 10.1139/cgj-2023-0053

G. Mesri, L. Zhang

引用次数: 0

Iron ore tailings stabilization with alternative alkali-activated cement for dry stacking: mechanical and microstructural insights 使用替代碱活性水泥稳定铁矿尾矿以进行干堆放：机械和微观结构分析

IF 3.6 3区工程技术

Canadian Geotechnical Journal Pub Date : 2024-02-02 DOI: 10.1139/cgj-2023-0125

Helena Portela Farenzena, Giovani Jordi Bruschi, Guilherme Schmitt Medina, João Paulo de Sousa Silva, Andres Lotero, Nilo Cesar Consoli

{"title":"Iron ore tailings stabilization with alternative alkali-activated cement for dry stacking: mechanical and microstructural insights","authors":"Helena Portela Farenzena, Giovani Jordi Bruschi, Guilherme Schmitt Medina, João Paulo de Sousa Silva, Andres Lotero, Nilo Cesar Consoli","doi":"10.1139/cgj-2023-0125","DOIUrl":"https://doi.org/10.1139/cgj-2023-0125","url":null,"abstract":"Canadian Geotechnical Journal, Ahead of Print. Upstream tailings dams are high-risk structures that have experienced several failures worldwide, particularly with iron ore tailings (IOT). In this study, new disposal methods/techniques, such as cement-stabilized dry stacking, are discussed that provide enhanced mechanical behavior while reducing failure risks. Alkali-activated materials are used as cementing agents due to their mechanical and environmental advantages compared to ordinary Portland cement. This study evaluates the mechanical and microstructural behavior of IOT stabilized with an alkali-activated cement (AAC) composed of two by-products from the IOT beneficiation process, metakaolin and sodium silicate, tested under plane strain conditions. Simple shear tests and microstructural analysis were performed. Mixtures of IOT were produced with 0%, 1%, 3%, and 5% AAC to examine the influence of such variables on strength and deformability parameters under undrained conditions. The mixtures with 3% and 5% AAC showed the greatest impact on the strength; however, the addition of 1% AAC was able to reduce positive pore-pressure generation. Cementitious bounds were evidenced by forming a sodium aluminosilicate hydrate gel. The studied AAC was effective in stabilizing IOT, even at small contents.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"23 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139666026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Structural evolutions of MX80 bentonite pellet/powder mixtures under wetting and suction-controlled oedometer loading MX80膨润土颗粒/粉末混合物在湿润和吸力控制的比重计加载条件下的结构演变

IF 3.6 3区工程技术

Canadian Geotechnical Journal Pub Date : 2024-01-22 DOI: 10.1139/cgj-2023-0033

J.W. Yang, Y.J. Cui, N. Mokni

{"title":"Structural evolutions of MX80 bentonite pellet/powder mixtures under wetting and suction-controlled oedometer loading","authors":"J.W. Yang, Y.J. Cui, N. Mokni","doi":"10.1139/cgj-2023-0033","DOIUrl":"https://doi.org/10.1139/cgj-2023-0033","url":null,"abstract":"Canadian Geotechnical Journal, Ahead of Print. The compression behaviour of MX80 bentonite pellet/powder mixture was investigated by performing suction-controlled oedometer tests. The suction from 113 to 4.2 MPa was imposed by vapour equilibrium technique (VET), and zero suction by water circulation (WC). After instantaneously unloaded from various target vertical stresses, the structural observation was conducted by mercury intrusion porosimetry and micro-computed tomography. Results showed that during wetting, the intra-grain micro- and macro-pores increased due to the swelling of pellets and powder grains. During loading, the variation of intra-grain micro-pores was characterised by the loading effect, while that of intra-grain micro-pores was controlled by the suction and loading effects. The inter-grain pores, for the VET samples, were reduced by the swelling of pellets and powder grains during wetting on one hand, and by the movement of pellets and powder grains during loading on the other hand. For the WC samples, most inter-grain pores were closed during wetting, with a few pores in the top closed by further loading. The global compression of bentonite mixture samples during loading was mainly governed by the filling of inter-grain pores for the VET samples, but controlled by the compression of intra-grain pores for the WC samples.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"9 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139553353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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

Note of appreciation 感谢信

IF 3.6 3区工程技术

Canadian Geotechnical Journal Pub Date : 2024-01-01 DOI: 10.1139/cgj-2023-0494

引用次数: 0

Estimation of confidence in the calculated resistance factor for simple limit states with limited data for load and resistance model bias 在载荷和阻力模型偏差数据有限的情况下，估算简单极限状态下计算阻力系数的置信度

IF 3.6 3区工程技术

Canadian Geotechnical Journal Pub Date : 2023-12-20 DOI: 10.1139/cgj-2023-0424

R. Bathurst, Reza Jamshidi Chenari

{"title":"Estimation of confidence in the calculated resistance factor for simple limit states with limited data for load and resistance model bias","authors":"R. Bathurst, Reza Jamshidi Chenari","doi":"10.1139/cgj-2023-0424","DOIUrl":"https://doi.org/10.1139/cgj-2023-0424","url":null,"abstract":"Estimation of the resistance factor in load and resistance factor design (LRFD) calibration for simple soil-structure limit states is most often based on model bias data of limited size. Frequently, the bias data are only available or required for the resistance term. In this paper, the confidence in the estimate of the mean of the resistance factor is computed for the case of one resistance factor and one load factor where limited model bias data are available for both load and resistance terms. The bootstrap method is used to compute synthetic load and resistance bias data sets from which confidence intervals on the point (mean) estimate of the resistance factor and load factor are computed. A closed-form solution is used to calculate the resistance factor for a single prescribed load factor and target reliability index, bias data, and nominal load and resistance variables that are lognormally distributed. However, the approach is general using Monte Carlo simulation. The method is demonstrated using the case of the internal stability pullout limit state for steel strip mechanically stabilized earth (MSE) walls. The example demonstrates the quantitative influence on pullout design using upper and lower 95% confidence interval limits for load and resistance factors.","PeriodicalId":9382,"journal":{"name":"Canadian Geotechnical Journal","volume":"104 14","pages":""},"PeriodicalIF":3.6,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138958790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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