TY - JOUR AU - Oberhollenzer, Simon AU - Hauser, Laurin AU - Ehall, Martin AU - Marte, Roman AU - Tschuchnigg, Franz AU - Schweiger, Helmut F. TI - Quality control of fine-grained embankments using penetration tests JF - CANADIAN GEOTECHNICAL JOURNAL J2 - CAN GEOTECH J PY - 2024 PG - 16 SN - 0008-3674 DO - 10.1139/cgj-2022-0055 UR - https://m2.mtmt.hu/api/publication/34609221 ID - 34609221 AB - The compaction control of earth works is an essential task in geotechnical engineering. In order to build more sustainably and to reduce project costs, fine-grained materials are more often used for embankment construction nowadays. The quality control of compacted soil layers is usually defined in terms of deformation moduli obtained from static and dynamic plate load tests or based on the degree of compaction, which is generally related to the Proctor density. Penetration tests, such as cone penetration tests (CPT), seismic flat dilatometer tests (SDMT) or dynamic probings (medium heavy dynamic probings (DPM)), show a potential for assessing the compaction along vertical profiles but no standardized quality criteria have been elaborated yet. The present work investigates the effects of different water contents and degrees of soil stabilization on results of CPT, SDMT, DPM, plate load tests and Proctor tests for an 8 m high trial embankment, characterized by a clayey to silty material. CPT and DMT results were found to strongly correlate with deformation moduli of static and dynamic plate load tests, enabling the definition of new quality criteria for compaction control. LA - English DB - MTMT ER - TY - JOUR AU - Wang, H AU - Ni, W TI - Soil-water retention behavior of a loess-paleosol sequence and its significance for hydrology and paleoclimate: a case study from the Luochuan profile of the Loess Plateau, China JF - CANADIAN GEOTECHNICAL JOURNAL J2 - CAN GEOTECH J VL - 61 PY - 2024 IS - 4 SP - 700 EP - 716 PG - 17 SN - 0008-3674 DO - 10.1139/cgj-2023-01441 UR - https://m2.mtmt.hu/api/publication/34716003 ID - 34716003 N1 - Funding Agency and Grant Number: National Nature Science Foundation of China [41931285]; Key research and development program of Shaanxi Province [2020SF-436, 2019ZDLSF05-07] Funding text: This study was financially supported by the National Nature Science Foundation of China (Grant No. 41931285) and the key research and development program of Shaanxi Province (Grant No. 2020SF-436; 2019ZDLSF05-07) . AB - The soil water retention behavior of the loess-paleosol sequence has important significance for hydrology and paleoclimate. This report examines the soil-water retention curves and microstructures of the Luochuan loess-paleosol sequence. The experimental results demonstrated that as burial depth increases, there is a significant change in the soil-water retention curve of loess-paleosol sequence. Simultaneously, the saturated volumetric water content and water loss rate gradually decrease, while the air entry value and residual water content increase. As a whole, the loess layer has a lower water-holding capacity than the adjacent paleosol layer. Accordingly, the microstructure of the loess-paleosol sequence changes considerably with the burial depth. The microstructure changes from overhead structure to matrix structure. The results suggest that the loess layer deposited in cold and dry climate conditions can act as an aquifer, which is related to weak pedogenic weathering. In contrast, paleosol layers that were formed in warm, humid climates underwent significant pedogenic weathering and can behave as an aquiclude. Based on the previously mentioned results, the link between paleoclimate changes and the current hydrological system has been explored. LA - English DB - MTMT ER - TY - JOUR AU - Zhang, Deng AU - Zhang, Liming AU - Liu, Yan AU - Wang, Zaiquan AU - Zhang, Faxing TI - Creep failure characteristics and characterization of constitutive behaviors of jointed sandstone under multi-level loading of seepage pressure JF - CANADIAN GEOTECHNICAL JOURNAL J2 - CAN GEOTECH J VL - 61 PY - 2024 IS - 3 SP - 485 EP - 499 PG - 15 SN - 0008-3674 DO - 10.1139/cgj-2023-0069 UR - https://m2.mtmt.hu/api/publication/34549954 ID - 34549954 N1 - School of Civil Engineering, Qingdao University of Technology, Qingdao, 266520, China Cooperative Innovation Center of Engineering Construction and Safety in Shandong Blue Economic Zone, Qingdao University of Technology, Qingdao, 266520, China School of Civil Engineering and Architecture, University of Jinan, Jinan, 250022, China Export Date: 11 April 2024 CODEN: CGJOA Correspondence Address: Zhang, L.; School of Civil Engineering, China; email: dryad_274@163.com AB - To study creep failure behaviors of jointed rock mass with seepage pressure as the main damage driving force, creep tests under multi-level loading of seepage pressure were conducted on sandstone with different joint dip angles. In addition, a memory-dependent nonlinear seepage–creep model was established for jointed sandstone. The results show that jointed sandstone experiences three creep stages (initial, steady-state, and accelerated creep stages) in creep tests under multi-level loading paths of seepage pressure. Jointed sandstone with joint dip angles of 30° and 60° undergoes shear failure, while that with the joint dip angle of 45° is subject to tensile–shear failure. Under the same seepage pressure, the sandstone with the joint dip angle of 45° has a greater creep rate in the steady-state creep stage than that with joint dip angles of 30° and 60°. In the volumetric compression stage, the permeability increases at the instant of applying each level of seepage pressure, followed by gradual reduction and stabilization of permeability. In the volumetric dilation stage, the permeability gradually rises. The theory of memory-dependent derivative reflecting the time memory effect was introduced to establish the memory-dependent nonlinear viscoelastic–plastic seepage–creep model for jointed sandstone. The results obtained using the theoretical model conform to the test data. Moreover, the creep failure criterion of the rock was proposed. The creep acceleration starts to increase from 0 and the critical steady state transitions to a non-steady state, suggesting that the rock will soon be damaged. The calculation formula for critical time corresponding to the critical steady state of creep was also deduced. The critical time to onset of creep can serve as an early warning of the creep failure of rocks. LA - English DB - MTMT ER - TY - JOUR AU - Ling, Fanlin AU - Wang, Shuying AU - Hu, Qinxin AU - Huang, Shuo AU - Feng, Zhiyao TI - Effect of bentonite slurry on the function of foam for changing the permeability characteristics of sand under high hydraulic gradients JF - CANADIAN GEOTECHNICAL JOURNAL J2 - CAN GEOTECH J VL - 59 PY - 2022 IS - 7 SP - 1061 EP - 1070 PG - 10 SN - 0008-3674 DO - 10.1139/cgj-2021-0196 UR - https://m2.mtmt.hu/api/publication/32950046 ID - 32950046 AB - During earth pressure balance (EPB) shield tunnelling in sandy ground, not only foam but also other conditioning agents need to be injected to reduce the permeability of muck and avoid water spewing out of the screw conveyor. Permeability tests were carried out to study the permeability characteristics of conditioned sand under high hydraulic gradients. A low bentonite slurry injection ratio (BIR) enhanced the workability of foam-conditioned sand. As the hydraulic gradient increased, the initial permeability coefficient of conditioned sand increased, and the initial stable period became shorter or disappeared. The BIR had a more significant effect on the permeability of conditioned sand than the foam injection ratio (FIR), and this effect gradually weakened as the hydraulic gradient increased. The initial permeability coefficient of the foam-bentonite slurry-conditioned sand decreased by approximately an order of magnitude compared with that of the foam-conditioned sand. With the addition of bentonite slurry, suitable sand conditioning can accept a higher water content (w) and lower FIR, resulting in suitable ranges of w and FIR that are more flexible. Finally, the mechanism of stabilizing foam under the action of bentonite slurry was discussed by considering the interaction between foam bubbles and fine particles. LA - English DB - MTMT ER - TY - JOUR AU - Zhang, J. AU - Yang, S. AU - Zhang, L.L. AU - Zhou, M.L. TI - Bayesian estimation of soil-water characteristic curves JF - CANADIAN GEOTECHNICAL JOURNAL J2 - CAN GEOTECH J VL - 59 PY - 2022 IS - 4 SP - 569 EP - 582 PG - 14 SN - 0008-3674 DO - 10.1139/cgj-2021-0070 UR - https://m2.mtmt.hu/api/publication/32908132 ID - 32908132 N1 - Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, Department of Geotechnical Engineering, Tongji University, Shanghai, 200092, China State Key Laboratory of Ocean Engineering, Department of Civil Engineering, Shanghai Jiao Tong University, Shanghai, China Export Date: 27 June 2022 CODEN: CGJOA Correspondence Address: Zhou, M.L.; Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education, China; email: zhoum@tongji.edu.cn LA - English DB - MTMT ER - TY - JOUR AU - Li, Y. AU - Vanapalli, S.K. TI - Prediction of soil-water characteristic curves using two artificial intelligence (AI) models and AI aid design method for sands JF - CANADIAN GEOTECHNICAL JOURNAL J2 - CAN GEOTECH J VL - 59 PY - 2022 IS - 1 SP - 129 EP - 143 PG - 15 SN - 0008-3674 DO - 10.1139/cgj-2020-0562 UR - https://m2.mtmt.hu/api/publication/32908135 ID - 32908135 N1 - Cited By :2 Export Date: 27 June 2022 CODEN: CGJOA Correspondence Address: Vanapalli, S.K.; Department of Civil Engineering, Canada; email: vanapall@eng.uottawa.ca LA - English DB - MTMT ER - TY - JOUR AU - Chen, Zheng AU - Xiao, Tao AU - Feng, Jianxue AU - Ni, Pengpeng AU - Chen, Deqiang AU - Mei, Guoxiong AU - Chen, Yifeng TI - Mathematical characterization of pile-soil interface boundary for consolidation analysis of soil around permeable pipe pile JF - CANADIAN GEOTECHNICAL JOURNAL J2 - CAN GEOTECH J VL - 58 PY - 2021 IS - 9 SP - 1277 EP - 1288 PG - 12 SN - 0008-3674 DO - 10.1139/cgj-2020-0337 UR - https://m2.mtmt.hu/api/publication/33427698 ID - 33427698 AB - A permeable pipe pile is proposed to accelerate the dissipation of excess pore-water pressure through drainage holes around the pile circumference into the pile's cavity. This investigation generalizes the permeable pile- soil interface as an impeded boundary, based on which a mathematical model for soil consolidation around the permeable pile is derived. Subsequently, the influence of opening pattern, drainage hole-to-pipe pile radius ratio, and opening ratio on the consolidation efficiency is numerically investigated. A total of 240 numerical cases with different drainage hole-to-pipe pile radius ratios, opening ratios, and hydraulic conductivity ratios are calculated to determine the permeable pile-soil interface parameter using back-analysis, and an approximate expression for interface parameter is obtained. Comparing against experimentally measured excess pore-water pressure dissipation, the proposed technique with impeded drainage boundary can provide good evaluations for drainage characteristics at the permeable pile-soil interface and consolidation behavior of the surrounding soil. It is found that the spatial distribution pattern of drainage holes has negligible influence on the consolidation efficiency. Increasing the opening ratio (with constant opening size) or reducing the drainage hole-to-pipe pile radius ratio (with constant opening ratio) can both accelerate the consolidation efficiency. LA - English DB - MTMT ER - TY - JOUR AU - Ma, Guoliang AU - He, Xiang AU - Jiang, Xiang AU - Liu, Hanlong AU - Chu, Jian AU - Xiao, Yang TI - Strength and permeability of bentonite-assisted biocemented coarse sand JF - CANADIAN GEOTECHNICAL JOURNAL J2 - CAN GEOTECH J VL - 58 PY - 2021 IS - 7 SP - 969 EP - 981 PG - 13 SN - 0008-3674 DO - 10.1139/cgj-2020-0045 UR - https://m2.mtmt.hu/api/publication/32178779 ID - 32178779 AB - To effectively stabilize coarse sand, bentonite was introduced in microbially induced carbonate precipitation (MICP) grouting. Varying concentrations (0, 20, 40, and 80 g/L) of bentonite were added to bacterial suspensions (BSs), which were magnetically stirred to form bacterial-bentonite suspensions (BBSs). Then, coarse sand specimens were treated with BBSs and cementation solutions (CSs) to different cementation levels. The results showed that the addition of bentonite could increase the volume fractions of the precipitates consisting of calcium carbonate (CaCO3) and bentonite. The permeability decreased exponentially as the volume fraction of precipitates increased. As the active precipitates increased when a lower concentration (e.g., 20 g/L) of bentonite was added to the MICP grouting, the unconfined compressive strength (UCS) was substantially improved. However, detrimental effects were observed for specimens treated with a high concentration of bentonite. These results indicate that the effective concentration of natural clay aggregates used in MICP grouting was different for different engineering applications, e.g., seepage control and strength enhancement. The current work provides an encouraging method of improving the MICP technique. LA - English DB - MTMT ER - TY - JOUR AU - Morsy, M. S. AU - Rowe, R. Kerry AU - Abdelaal, F. B. TI - Longevity of 12 geomembranes in chlorinated water JF - CANADIAN GEOTECHNICAL JOURNAL J2 - CAN GEOTECH J VL - 58 PY - 2021 IS - 4 SP - 479 EP - 495 PG - 17 SN - 0008-3674 DO - 10.1139/cgj-2019-0520 UR - https://m2.mtmt.hu/api/publication/32451309 ID - 32451309 AB - The long-term performance of geomembranes with 12 different resin-antioxidant master-batch combinations, including eight high-density polyethylene (HDPE), three linear low-density polyethylene (LLDPE), and one blended polyolefin (BPO) base resins, is investigated. Results are reported for immersion tests in chlorinated water (0.5 ppm) for 35 months at 85 degrees C. The degradation trends show that the choice of resin type played a key role in the longevity of the geomembranes but also that some hindered amine light stabilizer (HALS) packages contributed to better resistance to degradation in chlorinated water. The results show that the specific antioxidant package is more important than the initial oxidative induction time (OIT) in terms of long- term performance. Finally, it is shown that while increased thickness may be beneficial, a more resistant resin or antioxidant-stabilizer package can be more effective than increasing thickness in improving geomembrane performance in chlorinated water. The conclusion regarding the beneficial role of HALS is specific to chlorinated water and generally is not true in other cases of submerged or buried geomembranes. LA - English DB - MTMT ER - TY - JOUR AU - Sandeep, C. S. AU - Senetakis, K. AU - Cheung, D. AU - Choi, C. E. AU - Wang, Y. AU - Coop, M. R. AU - Ng, C. W. W. TI - Experimental study on the coefficient of restitution of grain against block interfaces for natural and engineered materials JF - CANADIAN GEOTECHNICAL JOURNAL J2 - CAN GEOTECH J VL - 58 PY - 2021 IS - 1 SP - 35 EP - 48 PG - 14 SN - 0008-3674 DO - 10.1139/cgj-2018-0712 UR - https://m2.mtmt.hu/api/publication/32385153 ID - 32385153 AB - The coefficient of restitution (COR) is an important input parameter in the numerical simulation of granular flows, as it governs the travel distance, the lateral spreading, and the design of barriers. In this study, a new custom-built micromechanical impact loading apparatus is presented along with impact experiments on engineered and natural materials. The COR and energy loss of various grains and base block combinations are studied, including fairly regular-shaped Leighton Buzzard sand (LBS) grains as a natural soil and granite or rubber as base blocks, apart from the use of engineered materials for the grains (chrome steel balls, glass balls) and blocks (stainless steel, brass). The repeatability of the new micromechanical impact loading apparatus was checked by impacting chrome steel balls on stainless steel block. In all the test combinations, the higher and lower values of the COR are found for granite block (ranging between 0.75 and 0.95) and rubber block (ranging between 0.37 and 0.44) combinations, respectively. For the tested grain-block combinations, lower values of COR were observed for impacts between materials of low values ofcomposite Young's modulus. However, within the narrow range ofcomposite surface roughness of the tested grain-block interfaces no particular trend was observed in the COR values. Compared to glass balls and chrome steel balls, greater scatter in the COR values is observed for natural sand grains. This is due to the variation of the elastic and morphological characteristics among individual LBS grains. LA - English DB - MTMT ER -