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Earthquake response of wrap faced embankment on soft clay soil in Bangladesh
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作者 Ripon Hore Sudipta Chakraborty +2 位作者 Kamruzzaman Kamrul Ayaz Mahmud Shuvon Mehedi AAnsary 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第3期703-718,共16页
A wrap-faced embankment model on soft clay soil subjected to earthquake motion was investigated in this study.The study was conducted both experimentally using a shaking table and numerically using PLAXIS 3D software.... A wrap-faced embankment model on soft clay soil subjected to earthquake motion was investigated in this study.The study was conducted both experimentally using a shaking table and numerically using PLAXIS 3D software.The amplification of acceleration,displacement,pore water pressure,and strain response were measured while varying input accelerations and surcharge pressures.Time histories of the Kobe record of the 1995 Hanshin earthquake were used as the input seismic motion.The input acceleration was 0.05 g,0.1 g,0.15 g,and 0.2 g,and different surcharge pressures were 0.70 kPa,1.12 kPa,and 1.72 kPa with relative density of Sylhet sand fixed to 48%.The output data from the shaking table tests and the numerical analysis performed through the PLAXIS 3D software were compared,and these findings were also compared with some earlier similar studies.The acceleration amplification,displacement,pore water pressure,and strain(%)changed along the elevation of the embankment and acceleration response increased with the increase in base acceleration.The increase was more noticeable at higher elevations.These findings enrich the knowledge of predicting the dynamic behavior of wrap-faced embankments and enable the design parameters to be adjusted more accurately. 展开更多
关键词 shaking table test soft clayey soil kobe earthquake seismic wave wrap-faced soil embankment
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Dynamic soil arching in piled embankment under train load of high-speed railways
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作者 Niu Tingting Yang Yule +2 位作者 Ma Qianli Zou Jiuqun Lin Bin 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2023年第3期719-730,共12页
Piled embankments have many advantages that have been applied in high-speed railway construction engineering.However,the load transfer mechanism of piled embankments,such as soil arching and tension membranes,is still... Piled embankments have many advantages that have been applied in high-speed railway construction engineering.However,the load transfer mechanism of piled embankments,such as soil arching and tension membranes,is still unclear,especially under dynamic loads.To investigate the soil arching and tension membrane under dynamic train loads on high-speed railways,a large-scale piled embankment model test with X-shaped piles as vertical reinforcement was performed,in which twenty-eight earth pressure cells were installed in the piled embankment and an M-shaped wave was adopted to simulate the high-speed railway train load.The results show that dynamic soil arching only occurs when two bogies of a carriage pass by and disappears at other times.The dynamic soil arching and membrane effect are the most significant under the concrete base.The arching height,stress concentration ratio and pile-soil load sharing ratio have a minimal value at 25 Hz.The dynamic soil arching degrades severely at 25 Hz,whose height at 25 Hz is only 0.35 times that at 5 Hz.The arching height fluctuates over a narrow range with increasing loading amplitude.The stress concentration ratio and the pile-soil load sharing ratio increase monotonically as the loading amplitude increases. 展开更多
关键词 dynamic soil arching membrane effect piled embankment train load model test
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Numerical analysis of crack generation within embankment built on expansive soil foundation 被引量:2
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作者 程永振 黄晓明 +1 位作者 李昶 李连友 《Journal of Southeast University(English Edition)》 EI CAS 2017年第2期224-229,共6页
In order to analyze the initial cracking behavior of highway embankment in the regions of expansive soil, the changes in peaks of tensile stress and their location on top of the embankment for a typical highway embank... In order to analyze the initial cracking behavior of highway embankment in the regions of expansive soil, the changes in peaks of tensile stress and their location on top of the embankment for a typical highway embankment section were simulated by ABAQUS. The simulation results indicate that the matric suction was a concave distribution on top of the expansive soil foundation and that it induced differential deformation of foundation and embankment. The peaks of tensile stress on top of the embankment are not located at a fixed site, but gradually move towards the shoulder following the evaporation duration. When the evaporation intensity is larger, the peak of tensile stress on top of embankment increases at a faster rate following the evaporation duration,and its location is closer to the shoulder. The thicker expansive soil layer helps the peaks of tensile stress to reach the critical tensile stress quickly, but the embankment cannot crack when the expansive soil layer is no more than 1.5m after 30d soil surface evaporation; the higher the embankment, the smaller the peak of tensile stress occurring on top of the highway embankment, and its location will be further away from the shoulder. Therefore, a higher embankment constructed on a thinner expansive soil layer can reduce the crack generation within the highway embankment. 展开更多
关键词 expansive soil foundation soil shrinkage CONSOLIDATION tensile stress embankment cracks
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ANALYSIS OF GEOSYNTHETICS REINFORCED EMBANKMENT ON SOFT SOIL BY FEM
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作者 周建萍 严驰 +3 位作者 陆红 秦丰 顾广平 闫澍旺 《Transactions of Tianjin University》 EI CAS 2001年第3期187-191,共5页
The reinforcement effects of geosynthetics in thick soft subsoil case and thin soft subsoil case are studied in this paper,and a Duncan Chang nonlinear numerical model based on the finite element method (FEM) is deve... The reinforcement effects of geosynthetics in thick soft subsoil case and thin soft subsoil case are studied in this paper,and a Duncan Chang nonlinear numerical model based on the finite element method (FEM) is developed.Moreover,an important conclusion that the thickness of soft subsoil affects greatly the geotechnical behavior of geosynthetic reinforced embankments is drawn.A series of embankment built on soft subsoil is calculated using the FEM program.The results of the computer program,such as the lateral displacements,settlements,and stress level and shear stresses in the subsoil,are presented in great detail and the comparison of those results disposes clearly the huge discrepancy of reinforce benefit between the thick subsoil embankment and thin subsoil embankment.Reinforcement mechanism of geosynthetics is also discussed in this paper and several conclusions are reached.This paper also gives recommendations for design. 展开更多
关键词 GEOSYNTHETICS reinforcement mechanism embankment finite element method soft soil
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Centrifugal Model Tests on Railway Embankments of Expansive Soils
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作者 王鹰 《Journal of Modern Transportation》 1999年第1期65-72,共8页
Based on the centrifugal model tests on railway embankments of expansive soil in Nanning Kunming railway,the author studied several embankments under different physical conditions. The stress and strain states and s... Based on the centrifugal model tests on railway embankments of expansive soil in Nanning Kunming railway,the author studied several embankments under different physical conditions. The stress and strain states and settlement of the embankments were analyzed, and the obtained results can be used as a reference to field construction. 展开更多
关键词 Centrifuge model tests expansive soil railway embankment
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Stability analysis of cohesive soil embankment slope based on discrete element method 被引量:4
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作者 XU Guang-ji ZHONG Kun-zhi +2 位作者 FAN Jian-wei ZHU Ya-jing ZHANG Yu-qing 《Journal of Central South University》 SCIE EI CAS CSCD 2020年第7期1981-1991,共11页
In order to study the safety factor and instability process of cohesive soil slope, the discrete element method(DEM) was applied. DEM software PFC2 D was used to simulate the triaxial test to study the influence of th... In order to study the safety factor and instability process of cohesive soil slope, the discrete element method(DEM) was applied. DEM software PFC2 D was used to simulate the triaxial test to study the influence of the particle micro parameters on the macroscopic characteristics of cohesive soil and calibrate the micro parameters of DEM model on this basis. Embankment slope stability analysis was carried out by strength reduction and gravity increase method, it is shown that the safety factor obtained by strength reduction method is more conservative, and the arc-shaped feature of the sliding surface under the gravity increase method is more obvious. Throughout the progressive failure process, the failure trends, maximum displacements, and velocity changes obtained by the two methods were consistent. When slope was destroyed, the upper part was cracked, the middle part was sheared, and the lower part was destroyed by extrusion. The conclusions of this paper can be applied to the safety factor calculation of cohesive soil slopes and the analysis of the instability process. 展开更多
关键词 embankment slope cohesive soil stability analysis numerical simulation PFC2D software safety factor
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Research on replacement depth of black cotton soil based on cracking behavior of embankment 被引量:1
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作者 Cheng Yongzhen Huang Xiaoming 《Journal of Southeast University(English Edition)》 EI CAS 2020年第4期436-443,共8页
In order to analyze the influence of replacement depth of black cotton soil(BCS)foundation on the initial cracking depth of a highway embankment,the laboratory tests were performed to construct the constitutive relati... In order to analyze the influence of replacement depth of black cotton soil(BCS)foundation on the initial cracking depth of a highway embankment,the laboratory tests were performed to construct the constitutive relationship between state variables and stress variables of BCS,and the coupled consolidation theory for unsaturated soils was employed to simulate the change in the major principal stress of the subgrade soils caused by water loss shrinkage of BCS with the help of Abaqus 6.11 codes.The simulation results indicate that the water losing shrinkage of BCS causes tensile stress within the subgrade,which leads to embankment cracking.The crack depth decreases with the increase in the BCS replacement depth and the embankment height,and increases with the increase in the burial depth of BCS.In the distribution area of deep BCS,the key values of foundation replacement depth for controlling the crack depth of the embankment with the height of 1 to 4 m are 1.2 and 1.5 m.In the low filling section,when the buried depth of BCS is 2,3 and 4 m,the key values of the foundation replacement depth to control the crack depth of the embankment are 0.8 and 1.2 m.In order to control the embankment cracking induced by the water losing shrinkage of BCS,a reasonable replacement depth of the foundation should be selected while slope protection is carried out well. 展开更多
关键词 black cotton soil coupled consolidation theory for unsaturated soils major principal stress embankment crack replacement depth
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Dynamic compaction treatment technology research of red clay soil embankment in southern mountains
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作者 刘建华 袁剑波 +1 位作者 熊虎 陈伟 《Journal of Central South University》 SCIE EI CAS 2008年第S2期50-57,共8页
High liquid limit soil generally adopted in expressway embankment construction of southern mountains, which often expresses some characteristics including high moisture content, high porosity ratio, low permeability, ... High liquid limit soil generally adopted in expressway embankment construction of southern mountains, which often expresses some characteristics including high moisture content, high porosity ratio, low permeability, high compressibility, certain disintegration, and so on. Spring soil phenomenon and inhomogeneous compaction have effects on the quality of embankment construction, just because the water in soil is difficult to evaporate. Based on the study of reinforcement mechanism for high liquid limit soil, in situ tests for dynamic compaction treatment in Yizhang-Fengtouling expressway embankment were developed. The reliable and economical dynamic compaction treatment methods and the construction technology for large range high liquid limit soil embankment in southern mountains expressway were discussed. In the process, convenient measurement methods were adopted to evaluate the treatment effects. The test results show that the dynamic compaction method has good treatment effects on the local red clay embankment. The embankment compaction degree is improved with compactness coming to 90% around tamping pits and compactness over 95% in tamping pits interior after tamping. The bearing capacity, the physical mechanic-property and the shear strength for soil are obviously improved, which are enhanced with cohesive strength increasing over 10 kPa and compression modulus increasing over 3 MPa. 展开更多
关键词 dynamic COMPACTION embankment high liquid LIMIT soil in SITU test REINFORCEMENT mechanism
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Finite Element Modeling of Geotextile Reinforced Embankments on Soft Clay
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作者 Diaa W. El Hourani Ify L. Nwaogazie Godfrey Waribo TomJaja 《Open Journal of Civil Engineering》 CAS 2023年第1期48-57,共10页
The use of geotextiles as a reinforcement material for improving the factor of safety against slope failure in embankments built on soft clay is becoming a common practice. This work is intended to help understand the... The use of geotextiles as a reinforcement material for improving the factor of safety against slope failure in embankments built on soft clay is becoming a common practice. This work is intended to help understand the effect of the geotextile reinforcement has on such embankments and to provide a design aid for civil engineers that enables them to quickly estimate the factor of safety against slope failure. Seventy four different cases were modelled and analyzed using a finite element software, GeoStudio 2018 R2. The results showed that the optimum improvement was achieved when using a single layer of geotextile reinforcement placed at the base of the embankment, by which the factor of safety increased by up to 40%. Adding a second layer, a third layer and a fourth layer, increases the safety factor by 2.5%, 1% and 0.5% respectively. Different charts for different heights of embankments were presented to aid in finding the most suitable slope angle and number of reinforcement layers required to achieve a certain safety factor. 展开更多
关键词 Reinforced soil embankmentS Soft soils Slope Stability
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Performance of fixed geosynthetic technique of GRPS embankment 被引量:3
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作者 ZHANG Jun ZHENG Jun-jie MA Qiang 《Journal of Central South University》 SCIE EI CAS 2013年第8期2245-2254,共10页
Geosynthetic-reinforced and pile-supported (GRPS) embankment has been increasingly constructed in a large number of regions and for a wide range of projects in the past decades. However, many disadvantages are expos... Geosynthetic-reinforced and pile-supported (GRPS) embankment has been increasingly constructed in a large number of regions and for a wide range of projects in the past decades. However, many disadvantages are exposed through a lot of applications on conventional technique of GRPS embankment (called CT embankment), i.e., intolerable settlement and lateral displacement, low geosynthetic efficiency, etc. In view of these disadvantages, the fixed geosynthetic technique of GRPS embankment (called FGT embankment) is developed in this work. In this system, the geosynthetic is fixed on the pile head by the steel bar fulcrum and concrete fixed top. The principles and construction techniques involved in the FGT embankment are described firstly. Then, the numerical analysis method and two-stage analysis method are used to study the performance of FGT embankment, respectively. It is shown that the FGT embankment can provide a better improvement technique to construct a high embankment over soft ground. 展开更多
关键词 geosynthetic-reinforced and pile-supported embankment fixed geosynthetic technique numerical analysis two-stageanalysis method soft soil
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Analysis of the Cooling Mechanism of a Crushed Rock Embankment in Warm and Lower Temperature Permafrost Regions along the Qinghai-Tibet Railway 被引量:2
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作者 Wei Ma Qingbai Wu +1 位作者 Yongzhi Liu Hui Bing 《Research in Cold and Arid Regions》 2008年第1期14-25,共12页
Based on data monitored in situ and theoretical analysis,the characteristics of the temperature field and mechanism of thermal conduction of a crushed rock embankment were studied along the Qinghai-Tibet Railway.The r... Based on data monitored in situ and theoretical analysis,the characteristics of the temperature field and mechanism of thermal conduction of a crushed rock embankment were studied along the Qinghai-Tibet Railway.The results of experi-ments in the field revealed that the cooling effect of a crushed rock embankment is influenced mainly by the natural con-vection in winter and shield effect in summer,the ventilation of crushed rocks,and the ground temperature regime be-neath the embankment.Consequently,these three factors should be taken into account in numerical simulations,but it is as a result of natural convection only. 展开更多
关键词 Qinghai-Tibet Railway permafrost region crushed rock embankment cooling mechanism
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Mechanical analysis of fixed geosynthetic technique of GRPS embankment
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作者 张军 郑俊杰 马强 《Journal of Central South University》 SCIE EI CAS 2013年第5期1368-1375,共8页
To overcome the deficiencies of conventional geosynthetic-reinforced and pile-supported (GRPS) embankment, a new improvement technique, fixed geosynthetic technique of GRPS embankment (FGT embankment), was developed a... To overcome the deficiencies of conventional geosynthetic-reinforced and pile-supported (GRPS) embankment, a new improvement technique, fixed geosynthetic technique of GRPS embankment (FGT embankment), was developed and introduced. Based on the discussion about the load transfer mechanism of FGT embankment, a simplified check method of the requirement of geosynthetic tensile strength and a mechanical model of the FGT embankment were proposed. Two conditions, the pile cap and pile beam conditions are considered in the mechanical model. The finite difference method is used to solve the mechanical model owing to the complexity of the differential equations and the soil strata. Then, the numerical procedure is programmed. Finally, a field test is conducted to verify the mechanical model and the calculated results are in good agreement with field measured data. 展开更多
关键词 mechanical model load transfer mechanism fixed geosynthetic technique GRPS embankment field test
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Calibrating partial factors for Danish railway embankments using probabilistic analyses
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作者 Michael R.Lodahl Kristian T.Brdbk Carsten S.Srensen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2014年第2期150-155,共6页
High costs are connected with upgrading railway embankments throughout Denmark using the partial factors for geotechnical design calibrated for general application. One way to reduce the costs is reliability-based cal... High costs are connected with upgrading railway embankments throughout Denmark using the partial factors for geotechnical design calibrated for general application. One way to reduce the costs is reliability-based calibration of the partial factors to a reasonable safety level taking into account the specific design situations and uncertainties relevant to railway embankments. A reliability-based design has been investigated, resulting in an optimal partial factor for the considered subsoil. With a stochastic soil model to simulate the undrained shear strength of soft soil deposits, the partial factor is calibrated using asymptotic sampling for the reliability assessment. The calibration shows that the partial factor can be reduced significantly compared to the value specified in the Danish National Annex to DS/EN 1997-1 (2007), Eurocode 7. 展开更多
关键词 Railway embankment Reliability index Partial factor Stochastic soil modelling
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A simplified method for prediction of embankment settlement in clays 被引量:2
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作者 Chunlin Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2014年第1期61-66,共6页
The prediction of embankment settlement is a critically important issue for the serviceability of subgrade projects,especially the post-construction settlement.A number of methods have been proposed to predict embankm... The prediction of embankment settlement is a critically important issue for the serviceability of subgrade projects,especially the post-construction settlement.A number of methods have been proposed to predict embankment settlement;however,all of these methods are based on a parameter,i.e.the initial time point.The difference of the initial time point determined by different designers can de?nitely induce errors in prediction of embankment settlement.This paper proposed a concept named"potential settlement"and a simpli?ed method based on the in situ data.The key parameter"b"in the proposed method was veri?ed using theoretical method and?eld data.Finally,an example was used to demonstrate the advantages of the proposed method by comparing with other methods and the observation data. 展开更多
关键词 Simplified method Settlement prediction embankment Consolidation theory Clayey soil
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Delta River Swampy Areas Earth Fill Embankments Primary Consolidation Management Issues 被引量:1
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作者 Ampeglio Diego Garini 《Journal of Civil Engineering and Architecture》 2021年第7期370-373,共4页
It is well known that soft silty clayey and even peaty soils especially existing in Great River Deltas Swampy Areas,under important Earth Fill Embankment Construction experience huge and hardly bearable primary consol... It is well known that soft silty clayey and even peaty soils especially existing in Great River Deltas Swampy Areas,under important Earth Fill Embankment Construction experience huge and hardly bearable primary consolidations settlements along with the minor but not negligible consequent secondary consolidation effects.In order to properly manage these particular huge settlements environments,it is very important to follow up the settlements monitoring data,by a macroscopic soil volume interpretation along with some amendments namely some mathematical added variabilities of the classic Terzaghi Primary Consolidation Equation,which are examined in a companion paper recently published in this Journal.In this paper some indications are given about how to face the macroscopic soil volume primary consolidation settlements,and especially it is suggested how to interpret the misleading laboratory consolidation test values of the coefficient of consolidation.Moreover,some design alternative solutions are examined to grasp both the potential technical and economic benefits along with their consequent disadvantages.Finally,this paper underlined the primary role of the supervision engineer to get a good estimate in the settlements forecasting and his related ability to understand the meaning of anomalous monitoring data and to timely make and match the primary consolidation settlements forecasting calculation adjustments. 展开更多
关键词 Coefficient of consolidation embankment construction management primary consolidation soil permeability SETTLEMENTS vertical settlements void ratio
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Numerical analysis of pile lateral behavior of pile supported embankment
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作者 荆志东 刘力 +1 位作者 郑刚 姜岩 《Journal of Central South University》 SCIE EI CAS 2008年第S2期87-92,共6页
A finite difference numerical method was adopted to evaluate the pile lateral behavior of pile supported embankment. A published case history was used to verify the proposed methodology. By simulating the case history... A finite difference numerical method was adopted to evaluate the pile lateral behavior of pile supported embankment. A published case history was used to verify the proposed methodology. By simulating the case history, the determination of parameters needed were verified. Then three embankments constructed on different ground conditions with different soil-pile relative stiffnesses were analyzed to study pile lateral behaviors including pile deflection and bending moment. The results show that pile deflections and bending moments induced by soil lateral deformation and embankment vertical load are different for piles at different positions under the same embankment. The relative stiffness between pile and soil affected by the properties of different reinforcing piles such as concrete pile and deep mixing method pile exert important effects on the pile lateral behavior and the pile's failure modes. Consequently, it is necessary to consider the different piles lateral behaviors and possible failure modes at different positions and the different piles proprieties with different reinforcing methods in the embankment stability analysis. 展开更多
关键词 PILE SUPPORTED embankment stability ANALYSIS LATERAL soil deformation soil-pile interaction three-dimensional ANALYSIS
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Thermal features of Qinghai-Tibet Railway Embankment with Crushed-stone Slope Protection in Permafrost Regions
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作者 Guoyu Li,Ning Li,Wei Ma,Huijun Jin,Yu Sheng State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science,Lanzhou 730000,China. 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期58-58,共1页
The Embankment with Crushed-Stone Slope Protection(ECSSP) in permafrost regions is an effective measure to cool subgrade and protect permafrost.It can mitigate the engineering hazards of the Qinghai-Tibet railway in t... The Embankment with Crushed-Stone Slope Protection(ECSSP) in permafrost regions is an effective measure to cool subgrade and protect permafrost.It can mitigate the engineering hazards of the Qinghai-Tibet railway in the permafrost regions. Considering the influence of the noctumal cold air during summer months in Qinghai-Tibet Plateau。 展开更多
关键词 Qinghai-Tibet railway embankment with crushed-stone SLOPE protection mechanisms of cooling effect THERMAL REGIME heat flow
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Analysis of the effects of rising temperature for embankments under seismic loads in cold regions
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作者 ZhiQiang Liu 1,2,Hao Lu 1 1.School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China.2.State Key Laboratory of Frozen Soil Engineering,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou,Gansu 730000,China. 《Research in Cold and Arid Regions》 2009年第4期316-321,共6页
The effect of temperature rising for frozen soil because of dynamic load was investigated by indoor tests.Roadway and railway embankments are always loaded by dynamic loads such as earthquakes and vehicles.Because the... The effect of temperature rising for frozen soil because of dynamic load was investigated by indoor tests.Roadway and railway embankments are always loaded by dynamic loads such as earthquakes and vehicles.Because the Qinghai-Tibetan Plateau is a re-gion where earthquakes occur frequently,it is essential to consider the temperature-rising effect of earthquakes or vehicles on railway and road embankment.In this paper and according to the theories of heat transfer and dynamic equilibrium equations,as-suming frozen soil as thermal elastic-viscoplastic material,taking the combination of thermal and mechanical stresses into account,we present the numerical formulae of this dynamic problem,and the computer program of the two-dimensional finite element is written.Using the program,the dynamic response analyses for embankments loaded by earthquake are worked out.Analysis in-dicated that the temperature-rising effect result from earthquakes for embankment in nonuniform distribution in some small areas,the maximum rising temperature is 0.16 ?C for consideration in this paper. 展开更多
关键词 Qinghai-Tibetan railway temperature-rising effect frozen soil embankment
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Impact of mica on geotechnical behavior of weathered granitic soil using macro and micro investigations 被引量:1
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作者 Xianwei Zhang Xinyu Liu +3 位作者 Haodong Gao Gang Wang Ran An Zhu Liang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2250-2266,共17页
The micaceous weathered granitic soil(WGS)is frequently encountered in civil engineering worldwide,unfortunately little information is available regarding how mica affects the physico-mechanical behaviors of WGS.This ... The micaceous weathered granitic soil(WGS)is frequently encountered in civil engineering worldwide,unfortunately little information is available regarding how mica affects the physico-mechanical behaviors of WGS.This study prepares reconstituted WGS with different mica contents by removing natural mica in theWGS,and then mixes it with commercial mica powders.The geotechnical behavior as well as the microstructures of the mixtures are characterized.The addition of mica enables the physical indices of WGS to be specific combinations of coarser gradation and high permeability but high Atterberg limits.However,high mica content in WGS was found to be associated with undesirable mechanical properties,including increased compressibility,disintegration,and swelling potential,as well as poor compactability and low effective frictional angle.Microstructural analysis indicates that the influence of mica on the responses of mixtures originates from the intrinsic nature of mica as well as the particle packing being formed withinWGS.Mica exists in the mixture as stacks of plates that form a spongy structure with high compressibility and swelling potential.Pores among the plates give the soil high water retention and high Atterberg limits.Large pores are also generated by soil particles with bridging packing,which enhances the permeability and water-soil interactions upon immersion.This study provides a microlevel understanding of how mica dominates the behavior of WGS and provides new insights into the effective stabilization and improvement of micaceous soils. 展开更多
关键词 Weathered granitic soil(WGS) MICA Microstructure Physical properties Mechanical properties Mechanism
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Enhancing Deep Learning Soil Moisture Forecasting Models by Integrating Physics-based Models 被引量:1
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作者 Lu LI Yongjiu DAI +5 位作者 Zhongwang WEI Wei SHANGGUAN Nan WEI Yonggen ZHANG Qingliang LI Xian-Xiang LI 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第7期1326-1341,共16页
Accurate soil moisture(SM)prediction is critical for understanding hydrological processes.Physics-based(PB)models exhibit large uncertainties in SM predictions arising from uncertain parameterizations and insufficient... Accurate soil moisture(SM)prediction is critical for understanding hydrological processes.Physics-based(PB)models exhibit large uncertainties in SM predictions arising from uncertain parameterizations and insufficient representation of land-surface processes.In addition to PB models,deep learning(DL)models have been widely used in SM predictions recently.However,few pure DL models have notably high success rates due to lacking physical information.Thus,we developed hybrid models to effectively integrate the outputs of PB models into DL models to improve SM predictions.To this end,we first developed a hybrid model based on the attention mechanism to take advantage of PB models at each forecast time scale(attention model).We further built an ensemble model that combined the advantages of different hybrid schemes(ensemble model).We utilized SM forecasts from the Global Forecast System to enhance the convolutional long short-term memory(ConvLSTM)model for 1–16 days of SM predictions.The performances of the proposed hybrid models were investigated and compared with two existing hybrid models.The results showed that the attention model could leverage benefits of PB models and achieved the best predictability of drought events among the different hybrid models.Moreover,the ensemble model performed best among all hybrid models at all forecast time scales and different soil conditions.It is highlighted that the ensemble model outperformed the pure DL model over 79.5%of in situ stations for 16-day predictions.These findings suggest that our proposed hybrid models can adequately exploit the benefits of PB model outputs to aid DL models in making SM predictions. 展开更多
关键词 soil moisture forecasting hybrid model deep learning ConvLSTM attention mechanism
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