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True triaxial modeling test of high-sidewall underground caverns subjected to dynamic disturbances
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作者 Chuanqing Zhang Jinping Ye +3 位作者 Ning Liu Qiming Xie Mingming Hu Lingyu Li 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第4期2109-2132,共24页
Seismicity resulting from the near-or in-field fault activation significantly affects the stability of large-scale underground caverns that are operating under high-stress conditions.A comprehensive scientific assessm... Seismicity resulting from the near-or in-field fault activation significantly affects the stability of large-scale underground caverns that are operating under high-stress conditions.A comprehensive scientific assessment of the operational safety of such caverns requires an in-depth understanding of the response characteristics of the rock mass subjected to dynamic disturbances.To address this issue,we conducted true triaxial modeling tests and dynamic numerical simulations on large underground caverns to investigate the impact of static stress levels,dynamic load parameters,and input directions on the response characteristics of the surrounding rock mass.The findings reveal that:(1)When subjected to identical incident stress waves and static loads,the surrounding rock mass exhibits the greatest stress response during horizontal incidence.When the incident direction is fixed,the mechanical response is more pronounced at the cavern wall parallel to the direction of dynamic loading.(2)A high initial static stress level specifically enhances the impact of dynamic loading.(3)The response of the surrounding rock mass is directly linked to the amplitude of the incident stress wave.High amplitude results in tensile damage in regions experiencing tensile stress concentration under static loading and shear damage in regions experiencing compressive stress concentration.These results have significant implications for the evaluation and prevention of dynamic disasters in the surrounding rock of underground caverns experiencing dynamic disturbances. 展开更多
关键词 High-sidewall underground cavern modeling test Coupling effect of dynamic and static loads Incident wave Response characteristics Risk coefficient
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Deformation characteristics of unsaturated slope during post-rainfall earthquake:Insights from centrifuge and numerical modeling
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作者 Jiawei Xu Kun Fang 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期380-397,共18页
Slopes are likely to fail in areas with frequent rainfall and earthquakes.The deformation characteristics of unsaturated slopes subjected to post-rainfall earthquakes are investigated using centrifuge model tests and ... Slopes are likely to fail in areas with frequent rainfall and earthquakes.The deformation characteristics of unsaturated slopes subjected to post-rainfall earthquakes are investigated using centrifuge model tests and finite element analyses.Three tests of the slope deformation under earthquake and post-rainfall earthquakes are first studied using image analysis techniques.Then,based on an elastoplastic constitutive model,numerical simulations are carried out using the finite element method and compared with the centrifuge test results.Finally,a parametric study is performed to clarify the effects of antecedent rainfall on earthquake-induced slope deformation.The results show that slope deformation caused by post-rainfall earthquakes differs from that caused by earthquakes without antecedent rainfall.The seepage flow and soil strength of the slope are affected by previous rainfall conditions,such as intensity and duration,which directly influence the slope deformation caused by the subsequent earthquake.Soil displacement and strain become greater and the slip surface is more noticeable during the post-rainfall earthquake of higher intensity.In addition,the time interval between the rainfall and the earthquake has a considerable impact on the detailed characteristics of the slope deformation,and the significant deformation occurs at the time of lowest soil strength when seepage flow reaches the lower part of the slope.Moreover,the repeated intermittent rainfall greatly affects the subsequent earthquake-induced slope deformation,the main characteristics of which are closely related to the changes in saturation and strength of the slope.However,with the prolonged time gap between each round of rainfall,the earthquake-induced slope deformation becomes insignificant. 展开更多
关键词 SLOPE Deformation Post-rainfall earthquake Centrifuge model test Finite element analysis
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On modeling approach for embedded real-time software simulation testing 被引量:6
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作者 Yin Yongfeng Liu Bin +1 位作者 Zhong Deming Jiang Tongmin 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第2期420-426,共7页
Modeling technology has been introduced into software testing field.However,how to carry through the testing modeling effectively is still a difficulty.Based on combination of simulation modeling technology and embedd... Modeling technology has been introduced into software testing field.However,how to carry through the testing modeling effectively is still a difficulty.Based on combination of simulation modeling technology and embedded real-time software testing method,the process of simulation testing modeling is studied first.And then,the supporting environment of simulation testing modeling is put forward.Furthermore,an approach of embedded real-time software simulation testing modeling including modeling of cross-linked equipments of system under testing(SUT),test case,testing scheduling,and testing system service is brought forward.Finally,the formalized description and execution system of testing models are given,with which we can realize real-time,closed loop,mad automated system testing for embedded real-time software. 展开更多
关键词 embedded real-time software software testing testing modeling SIMULATION
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Model tests and numerical analysis of emergency treatment of cohesionless soil landslide with quick-setting polyurethane 被引量:1
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作者 ZHANG Zhichao TANG Xuefeng +2 位作者 HUANG Rufa CAI Zhenjie GAO Anhua 《Journal of Mountain Science》 2025年第1期110-121,共12页
Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the... Shotcrete is one of the common solutions for shallow sliding.It works by forming a protective layer with high strength and cementing the loose soil particles on the slope surface to prevent shallow sliding.However,the solidification time of conventional cement paste is long when shotcrete is used to treat cohesionless soil landslide.The idea of reinforcing slope with polyurethane solidified soil(i.e.,mixture of polyurethane and sand)was proposed.Model tests and finite element analysis were carried out to study the effectiveness of the proposed new method on the emergency treatment of cohesionless soil landslide.Surcharge loading on the crest of the slope was applied step by step until landslide was triggered so as to test and compare the stability and bearing capacity of slope models with different conditions.The simulated slope displacements were relatively close to the measured results,and the simulated slope deformation characteristics were in good agreement with the observed phenomena,which verifies the accuracy of the numerical method.Under the condition of surcharge loading on the crest of the slope,the unreinforced slope slid when the surcharge loading exceeded 30 k Pa,which presented a failure mode of local instability and collapse at the shallow layer of slope top.The reinforced slope remained stable even when the surcharge loading reached 48 k Pa.The displacement of the reinforced slope was reduced by more than 95%.Overall,this study verifies the effectiveness of polyurethane in the emergency treatment of cohesionless soil landslide and should have broad application prospects in the field of geological disasters concerning the safety of people's live. 展开更多
关键词 Cohesionless soil landslide POLYURETHANE Emergency treatment Reinforcement effect Model test Finite element analysis
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Development of a Model Material Suitable for Reservoir Landslide Model Tests
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作者 Minghao Miao Huiming Tang +4 位作者 Sha Lu Changdong Li Kun Fang Yixiao Gu Chunyan Tang 《Journal of Earth Science》 2025年第5期1989-2004,共16页
In the physical model test of landslides,the selection of analogous materials is the key,and it is difficult to consider the similarity of mechanical properties and seepage performance at the same time.To develop a mo... In the physical model test of landslides,the selection of analogous materials is the key,and it is difficult to consider the similarity of mechanical properties and seepage performance at the same time.To develop a model material suitable for analysing the deformation and failure of reservoir landslides,based on the existing research foundation of analogous materials,5 materials and 5 physical-mechanical parameters were selected to design an orthogonal test.The factor sensitivity of each component ratio and its influence on the physical-mechanical indices were studied by range analysis and stepwise regression analysis,and the proportioning method was determined.Finally,the model material was developed,and a model test was carried out considering Huangtupo as the prototype application.The results showed that(1)the model material composed of sand,barite powder,glass beads,clay,and bentonite had a wide distribution of physical-mechanical parameters,which could be applied to model tests under different conditions;(2)the physical-mechanical parameters of analogous materials matched the application prototype;and(3)the mechanical properties and seepage performance of the model material sample met the requirements of reservoir landslide model tests,which could be used to simulate landslide evolution and analyse the deformation process. 展开更多
关键词 analogous material physical model test reservoir landslide range analysis stepwise regression stage division PIVlab LANDSLIDES engineering geology
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Physical and numerical modeling of a framed anti-sliding structure for a mountainous railway line
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作者 QIU Ruizhe LIU Kaiwen +3 位作者 YANG Zhixiang MA Chiyuan XIAO Jian SU Qian 《Journal of Southeast University(English Edition)》 2025年第1期12-19,共8页
To ensure the operational safety of railways in the landslide-prone areas of mountainous regions,a large-scale model test and numerical simulation were conducted to study the bending moment distribution,internal force... To ensure the operational safety of railways in the landslide-prone areas of mountainous regions,a large-scale model test and numerical simulation were conducted to study the bending moment distribution,internal force distribution,deformation development,and crack propagation characteristics of a framed anti-sliding structure(FAS)under landslide thrust up to the point of failure.Results show that the maximum bending moment and its increase rate in the fore pile are greater than those in the rear pile,with the maximum bending moment of the fore pile approximately 1.1 times that of the rear pile.When the FAS fails,the displacement at the top of the fore pile is significantly greater,about 1.27 times that of the rear pile in the experiment.Major cracks develop at locations corresponding to the peak bending moments.Small transverse cracks initially appear on the upper surface at the intersection between the primary beam and rear pile and then spread to the side of the structure.At the failure stage,major cracks are observed at the pil-beam intersections and near the anchor points.Strengthening flexural stiffness at intersections where major cracks occur can improve the overall thrust-deformation coordination of the FAS,thereby maximizing its performance. 展开更多
关键词 mountainous railway SLOPE framed anti-sliding structure model test finite element modeling mechanical responses
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Dynamic modeling of minimum mass of pore-gas for triggering landslide in stable gentle soil slope
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作者 Xingyu Kang Zhongqi Quentin Yue 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第2期652-670,共19页
This paper presents a dynamic modeling method to test and examine the minimum mass of pressurized pore-gas for triggering landslides in stable gentle soil slopes.A stable gentle soil slope model is constructed with a ... This paper presents a dynamic modeling method to test and examine the minimum mass of pressurized pore-gas for triggering landslides in stable gentle soil slopes.A stable gentle soil slope model is constructed with a dry cement powder core,a saturated clay middle layer,and a dry sand upper layer.The test injects H_(2)O_(2)solution into the cement core to produce new pore-gas.The model test includes three identical H_(2)O_(2)injections.The small mass of generated oxygen gas(0.07%of slope soil mass and landslide body)from the first injection can build sufficient pore-gas pressure to cause soil upheaval and slide.Meanwhile,despite the first injection causing leak paths in the clay layer,the generated small mass of gas from the second and third injections can further trigger the landslide.A dynamic theoretical analysis of the slope failure is carried out and the required minimum pore-gas pressure for the landslide is calculated.The mass and pressure of generated gas in the model test are also estimated based on the calibration test for oxygen generation from H_(2)O_(2)solution in cement powder.The results indicate that the minimum mass of the generated gas for triggering the landslide is 2 ppm to 0.07%of the landslide body.Furthermore,the small mass of gas can provide sufficient pressure to cause soil upheaval and soil sliding in dynamic analysis. 展开更多
关键词 LANDSLIDE Gentle soil slope Physical model test Minimum pore-gas mass Soil upheaval Dynamic modeling
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A moving model test of a maglev train passing through tunnels:Effect of train speed and buffer structure on aerodynamic environment
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作者 GUO Zi-jian CHEN Zheng-wei +2 位作者 GUO Zhan-hao ZENG Guang-zhi PENG Cheng 《Journal of Central South University》 2025年第12期4868-4884,共17页
Maglev trains experience significant aerodynamic effects when passing through tunnels.A moving model test was conducted to explore the practical effects of speed reduction and entrance buffer structures on mitigating ... Maglev trains experience significant aerodynamic effects when passing through tunnels.A moving model test was conducted to explore the practical effects of speed reduction and entrance buffer structures on mitigating tunnel/maglev aerodynamic effects.It is found that both have an overall positive effect on mitigating the aerodynamic environment inside and outside the tunnel.Trains operating at 200 km/h show a 49.8%decrease in peak-to-peak pressure and a 50.7%decrease in transient pressure instability on inner walls compared to those at 280 km/h.Lower speeds resulted in a 65.6%decrease in amplitude and a 24.5%decrease in decay rate,both of which are parameters for exponential fittings of pressure peaks that decay naturally after the train leaves.The buffer structures result in a reduction of up to 25.7%in the maximum positive pressure and a 29.0%decrease in transient pressure instability.Additionally,a reduction in amplitude of up to 21.2%and a 32.2%increase in decay rate were observed with the use of buffer structures.Nevertheless,it is difficult to conclude direct correlations between the maximum pressure,peak-to-peak values,etc.,and the speeds or buffer structures due to the complex wave propagation in tunnels.However,speed reduction and buffer structures are proven to be effective in reducing the micro-pressure wave levels with a simpler monotonic relationship. 展开更多
关键词 maglev train TUNNEL moving model test buffer structure micro-pressure wave
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Uniformity of microbial injection for reinforcing saturated calcareous sand: A multi-test approach
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作者 Xinlei Zhang Yue Sun +3 位作者 Yumin Chen Lu Liu Wenwen Li Yi Han 《Biogeotechnics》 2025年第2期52-61,共10页
The mineralization process of microbial-induced calcium carbonate precipitation(MICP)is influenced by many factors,and the uniformity of the calcium carbonate precipitation has become the main focus and challenge for ... The mineralization process of microbial-induced calcium carbonate precipitation(MICP)is influenced by many factors,and the uniformity of the calcium carbonate precipitation has become the main focus and challenge for MICP technology.In this study,the uniformity of the saturated calcareous sand treated with MICP was in-vestigated through one-dimensional calcareous sand column tests and model tests.The coefficient of variation was employed in one-dimensional sand column tests to investigate the impact of injection rate,cementation solution concentration,and number of injection cycles on the uniformity of the MICP treatment.Additionally,model tests were conducted to investigate the impact of injection pressure and methods on the treatment range and uniformity under three-dimensional seepage conditions.Test results demonstrate that the reinforcement strength and uniformity are significantly influenced by the injection rate of the cementation solution,with a rate of 3 mL/min,yielding a favorable treatment effect.Excessive concentration of the cementation solution can lead to significant non-uniformity and a reduction in the compressive strength of MICP-treated samples.Conversely,excessively low concentrations may result in decreased bonding efficiency.Among the four considered con-centrations,0.5 mol/L and 1 mol/L exhibit superior reinforcing effects.The morphological development of calcareous sandy foundation reinforcement is associated with the spatial distribution pattern of the bacterial solution,exhibiting a relatively larger reinforcement area in proximity to the lower region of the model and a gradually decreasing range towards the upper part.Under three-dimensional seepage conditions,in addition to the non-uniform radial cementation along the injection pipe,there is also vertical heterogeneity of cementation along the length of the injection pipe due to gravitational effects,resulting in preferential deposition of calcium carbonate at the lower section,The application of injection pressure and a double-pipe circulation injection method can mitigate the accumulation of bacterial solution and cementation solution at the bottom,thereby improving the reinforcement range and uniformity. 展开更多
关键词 MICP Calcareous sand Reinforcement uniformity One-dimensional sand column tests Model tests
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Structure-type rockburst in deep tunnels: Physical modeling and numerical simulation
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作者 Guo-Qiang Zhu Yan Zhang +3 位作者 Shaojun Li Yang-Yi Zhou Jialiang Zhou Minglang Zou 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第6期3502-3523,共22页
Structure-type rockbursts frequently occur in deep tunnels,with structural planes and stress conditions being critical factors in their formation.In this study,we utilized specially developed analogous materials that ... Structure-type rockbursts frequently occur in deep tunnels,with structural planes and stress conditions being critical factors in their formation.In this study,we utilized specially developed analogous materials that exhibit the high brittleness and strength characteristics of deep hard rock to construct physical models representing different types of structural planes,including composite,exposed,non-exposed,and throughgoing structural planes.Physical simulation experiments were conducted on structuretype rockbursts in deep horseshoe-shaped tunnels,focusing on strain differentiation characteristics,critical triggering conditions,critical crack opening displacement,the incubation process,the reduction effects of structural planes on failure intensity,and formation mechanisms.These experiments were complemented by acoustic and optical monitoring,as well as discrete element numerical simulations,to provide a comprehensive analysis.The results revealed that the most significant strain heterogeneity in the surrounding rock occurs at the tip of the structural plane along the tunnel's minimum principal stress direction,driven by the combined effects of tensile and shear forces.We quantitatively determined the critical stress and strain conditions for structure-type rockbursts and evaluated the intensity of rockbursts induced by different structural planes using critical crack opening displacement(COD)values,the uniformity coefficient,and the curvature coefficient.Analysis of acoustic emission events,including frequency,amplitude,and b-value,indicated that the macro-fracture process is governed by both the principal stress differential and the characteristics of the structural plane.Furthermore,using the bearing capacity reduction coefficient,we found that exposed structural planes have the most significant weakening effect on rock mass strength,followed by non-exposed and throughgoing structural planes.The analysis of average frequency(AF)and rise angle(RA)parameters revealed a close correlation between the failure modes of structure-type rockbursts,the rock mass structure,and the stress levels.These findings provide critical theoretical support for the prediction and prevention of structure-type rockburst disasters. 展开更多
关键词 Deep tunnel ROCKBURST Structural plane Strain heterogeneity Physical model test Particle flow code(PFC)
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CFD-based Determination of Load Cell Capacity for Submarine HPMM Model Tests
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作者 Aliasghar Moghaddas Hossein nourozi +1 位作者 Morteza Ebrahimi Alireza Naderi 《哈尔滨工程大学学报(英文版)》 2025年第5期1064-1074,共11页
Captive model tests are one of the most common methods to calculate the maneuvering hydrodynamic coefficients and characteristics of surface and underwater vehicles.Considerable attention must be paid to selecting and... Captive model tests are one of the most common methods to calculate the maneuvering hydrodynamic coefficients and characteristics of surface and underwater vehicles.Considerable attention must be paid to selecting and designing the most suitable laboratory equipment for towing tanks.A computational fluid dynamics(CFD)-based method is implemented to determine the loads acting on the towing facility of the submarine model.A reversed topology is also used to ensure the appropriateness of the load cells in the developed method.In this study,the numerical simulations were evaluated using the experimental results of the SUBOFF benchmark submarine model of the Defence Advanced Research Projects Agency.The maximum and minimum loads acting on the 2.5-meter submarine model were measured by determining the body’s lightest and heaviest maneuvering test scenarios.In addition to having sufficient endurance against high loads,the precision in measuring the light load was also investigated.The horizontal planar motion mechanism(HPMM)facilities in the National Iranian Marine Laboratory were developed by locating the load cells inside the submarine model.The results were presented as a case study.A numerical-based method was developed to obtain the appropriate load measurement facilities.Load cells of HPMM test basins can be selected by following the two-way procedure presented in this study. 展开更多
关键词 Captive model tests Hydrodynamic coefficients SUBMARINE Computational fluid dynamics Horizontal planar motion mechanism Load cell capacity
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Synergistic reinforcement using pressure releasing and energy absorbing method under hard roof:Physical model test
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作者 Qi Wang Jiting Liu +3 位作者 Bei Jiang Zhenhua Jiang Yusong Deng Chuanjie Xu 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第9期5845-5860,共16页
During fully mechanized caving mining of thick coal seams,a large amount of strain energy accumulates in the roof,especially when the roof is thick and hard,making it difficultfor the roof to collapse naturally.When t... During fully mechanized caving mining of thick coal seams,a large amount of strain energy accumulates in the roof,especially when the roof is thick and hard,making it difficultfor the roof to collapse naturally.When the roof eventually collapses,the accumulated energy is released instantaneously,exerting a strong impact on the roadway.To address this issue,we proposed the synergistic control method of directional comprehensive pressure relief and energy-absorbing support(PREA)for roadways with hard roofs.In this study,we developed a three-dimensional physical model test apparatus for roof cutting and pressure relief.The 122108 ventilation roadway at the Caojiatan Coal Mine,which has a thick and hard roof,was taken as the engineering example.We analyzed the evolution patterns of stress and displacement in both the stope and the roadway surrounding rocks under different schemes.The PREA reinforcement mechanism for the roadway was investigated through comparative model tests between the new and original methods.The results showed that,compared to the original method,the new method reduced surrounding rock stress by up to 60.4%,and the roadway convergence decreased by up to 52.1%.Based on these results,we proposed corresponding engineering recommendations,which can guide fieldreinforcement design and application.The results demonstrate that the PREA method effectively reduces stress and ensures the safety and stability of the roadway. 展开更多
关键词 Directional comprehensive pressure relief High-strength support Three-dimensional model test Reinforcing method Synergistic control
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Landslide model tests with a miniature 2D principal stress sensor
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作者 Kun Fang Yulei Fu +3 位作者 Huiming Tang Tangzhe Gao Pengju An Qiong Wu 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第1期94-105,共12页
Understanding the stress distribution derived from monitoring the principal stress(PS)in slopes is of great importance.In this study,a miniature sensor for quantifying the two-dimensional(2D)PS in landslide model test... Understanding the stress distribution derived from monitoring the principal stress(PS)in slopes is of great importance.In this study,a miniature sensor for quantifying the two-dimensional(2D)PS in landslide model tests is proposed.The fundamental principle and design of the sensor are demonstrated.The sensor comprises three earth pressure gages and one gyroscope,with the utilization of three-dimensional(3D)printing technology.The difficulties of installation location during model preparation and sensor rotation during testing can be effectively overcome using this sensor.Two different arrangements of the sensors are tested in verification tests.Additionally,the application of the sensor in an excavated-induced slope model is tested.The results demonstrate that the sensor exhibits commendable performance and achieves a desirable level of accuracy,with a principal stress angle error of±5°in the verification tests.The stress transformation of the slope model,generated by excavation,is demonstrated in the application test by monitoring the two miniature principal stress(MPS)sensors.The sensor has a significant potential for measuring primary stress in landslide model tests and other geotechnical model experiments. 展开更多
关键词 LANDSLIDE Model test Principal stress(PS) Stress measurement
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Test and Evaluation of Relative Humidity Forecast in Each Competition Area of the "14 th National Winter Games" by Intelligent Forecasting Methods
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作者 Sitong LIU Xuefeng YANG 《Meteorological and Environmental Research》 2025年第1期37-40,共4页
Based on ground observation data of relative humidity,the prediction performance of STNF and MIFS in each competition area during February 13-26,2024 was tested and evaluated by using two intelligent forecasting metho... Based on ground observation data of relative humidity,the prediction performance of STNF and MIFS in each competition area during February 13-26,2024 was tested and evaluated by using two intelligent forecasting methods(STNF and MIFS).The results show that STNF had better performance in forecasting relative humidity in high-altitude areas,and was suitable for fine forecasting under complex terrain.MIFS improved the short-term forecast of some low-altitude stations,but the long-term reliability was insufficient.STNF method performed better than MIFS during 0-24 h.As the prediction time extended to 24-72 h,the errors of both methods showed a systematic increase trend.STNF had higher precision,lower root mean square error and smaller mean error in most regions under the background of most weather systems,showing its superiority as a forecasting method of relative humidity.However,the precision of MIFS was slightly higher than that of STNF in Liangcheng without system background,revealing that MIFS may also be an effective option in some specific conditions. 展开更多
关键词 Intelligent forecast Relative humidity Model test
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Dynamic characterization of viscoelasticity during polymer flooding:A two-phase numerical well test model and field study
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作者 Yang Wang Shi-Long Yang +3 位作者 Hang Xie Yu Jiang Shi-Qing Cheng Jia Zhang 《Petroleum Science》 2025年第6期2493-2501,共9页
Polymer flooding is an important means of improving oil recovery and is widely used in Daqing,Xinjiang,and Shengli oilfields,China.Different from conventional injection media such as water and gas,viscoelastic polymer... Polymer flooding is an important means of improving oil recovery and is widely used in Daqing,Xinjiang,and Shengli oilfields,China.Different from conventional injection media such as water and gas,viscoelastic polymer solutions exhibit non-Newtonian and nonlinear flow behavior including shear thinning and shear thickening,polymer convection,diffusion,adsorption,retention,inaccessible pore volume,and reduced effective permeability.However,available well test model of polymer flooding wells generally simplifies these characteristics on pressure transient response,which may lead to inaccurate results.This work proposes a novel two-phase numerical well test model to better describe the polymer viscoelasticity and nonlinear flow behavior.Different influence factors that related to near-well blockage during polymer flooding process,including the degree of blockage(inner zone permeability),the extent of blockage(composite radius),and polymer flooding front radius are explored to investigate these impacts on bottom hole pressure responses.Results show that polymer viscoelasticity has a significant impact on the transitional flow segment of type curves,and the effects of near-well formation blockage and polymer concentration distribution on well test curves are very similar.Thus,to accurately interpret the degree of near-well blockage in injection wells,it is essential to first eliminate the influence of polymer viscoelasticity.Finally,a field case is comprehensively analyzed and discussed to illustrate the applicability of the proposed model. 展开更多
关键词 Polymer flooding Two-phase flow Numerical well test model Viscoelastic characteristic Nonlinear flow Near-well blockage
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CENTRIFUGAL TEST STUDY ON THE BEHAVIOR OF SOFT CLAY AT SEA BOTTOM UNDER THE ACTION OF WAVE FORCE 被引量:1
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作者 闫澍旺 李飒 邓卫东 《Transactions of Tianjin University》 EI CAS 1999年第2期104-108,共5页
The importance of studying the behavior of the soil at the sea bottom under the action of wave force has arisen with the development of offshore engineering.In this paper,the behavior of the soft clay under the action... The importance of studying the behavior of the soil at the sea bottom under the action of wave force has arisen with the development of offshore engineering.In this paper,the behavior of the soft clay under the action of wave forces is studied by performing centrifugal tests.The soil profile and the wave characters were simulated in the centrifugal model cell according to the typical environmental conditions of the oil fields in the Bohai gulf.Test results show that the soft clay layer will be seriously softened near the upper surface under the maximum wave height and slightly affected in the deeper layer,and that no liquefaction was recorded in the silty sand sublayer during the test.It is proven that the centrifugal test is a valid technique for simulating the interaction between soil and wave. 展开更多
关键词 wave soft clay SOFTENING centrifugal model test
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Numerical Calculations and Cold Tests for Flow Fields of a 220t/h Retrofitted Oil-Boiler
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作者 朱世钧 程永元 +1 位作者 蔡崧 肖军 《Journal of Southeast University(English Edition)》 EI CAS 2000年第1期70-74,共5页
In this paper, cold simulation experiments and numerical calculations are conducted to predict 3 D flow field aerodynamics for an oil furnace after being retrofitted due to its fuel variation. K ε model and SIMPLE ... In this paper, cold simulation experiments and numerical calculations are conducted to predict 3 D flow field aerodynamics for an oil furnace after being retrofitted due to its fuel variation. K ε model and SIMPLE program under body fit coordination (BFC) system, in which TTM non orthogonal method is used to control the irregular geometric boundary, are adopted to solve the control equations. Model tests are conducted to check the calculation results, showing that they are in agreement with each other. Three different alternatives with different side window locations are also calculated to optimize the designs. The field retrofitting results show that the combination of cold tests with numerical calculations has prosperous application in retrofitting or renewing medium and small boilers. 展开更多
关键词 cold model test numerical calculation BFC boiler retrofitting
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Effects of confinedaquifer on water-sand gushing disasters in soft soil
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作者 Liangjin Li Yafei Qiao +1 位作者 Jinchun Chai Wenqi Ding 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期1126-1137,共12页
Water-sand gushing(WSG)disasters in confinedaquifers pose significantchallenges to the utilization of deep underground spaces in soft soil areas.Since few studies have considered the impact of confined aquifer thickne... Water-sand gushing(WSG)disasters in confinedaquifers pose significantchallenges to the utilization of deep underground spaces in soft soil areas.Since few studies have considered the impact of confined aquifer thickness and confinedwater pressure on WSG disasters,a novel visual model test system was developed to investigate the influencingcharacteristics and mechanisms of the two aforementioned factors.The test results showed that the WSG process in clay aquiclude-confinedaquifer composite strata exhibits two prominent stages.First,the sand loss zone expands vertically in an ellipsoid shape.Then,it expands horizontally once the ellipsoid reaches the boundary of the clay layer.The sand loss continues until the overlying clay sinks to the bottom to clog the gushing crack,creating a large sinkhole at the surface.Increasing the confinedaquifer thickness can increase the vertical expansion of the ellipsoid and delay the clay-clogging effects,thereby considerably increasing the severity of sand loss,stratum deformation,and surface settlement.An increase in the confinedwater pressure markedly increases the hydraulic gradient along the seepage path,which contributes to increasing the gushing rates of water and sand.As a result,substantial sand loss occurs before the clay clogs the gushing crack,inducing more cracks and deeper sinkholes at the surface.All the aforementioned results provide insights into the effects of confinedaquifer on WSG disasters in clay aquiclude-confinedaquifer composite strata. 展开更多
关键词 Water-sand gushing(WSG)disasters Confinedaquifer thickness Confinedwater pressure Beam-bearing mechanism Clay-clogging effects Model test
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Experimental and theoretical investigation of face failure and ground collapse during slurry pressure-balanced shield tunneling in saturated sand
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作者 Mengzhe Huo Weizhong Chen +3 位作者 Jingqiang Yuan Yunfa Li Yubiao Liu Qun Sui 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期1320-1336,共17页
Shield tunneling in saturated ground poses challenges due to the potential risk of ground collapse resulting from seepage force and inadequate support pressure.This study employed a laboratory model test and a theoret... Shield tunneling in saturated ground poses challenges due to the potential risk of ground collapse resulting from seepage force and inadequate support pressure.This study employed a laboratory model test and a theoretical validation to elucidate the mechanisms of face failure and subsequent ground collapse in saturated ground during slurry pressure-balanced shield(SPBS)tunneling operations.A slurry circulation system was developed to ensure steady shield tunneling and to replicate the phenomena of ground collapse.Investigations into shield tunneling parameters and ground responses,including soil pressure,pore water pressure,and surface subsidence,were conducted to understand the mechanisms of face failure and subsequent ground collapse.The theoretical solution for the critical collapse pressure of the tunnel face,based on the rotational failure mechanism,was validated through the comparison with the experimentally determined critical collapse pressure.The results indicate that:(1)appropriate adjustments of tunneling parameters are crucial for promoting filtercake formation,maintaining chamber pressure,and minimizing ground subsidence;(2)chamber pressure,soil pressure,pore water pressure,and ground subsidence are closely correlated with shield tunneling parameters and the formation of filter cake;(3)ground collapse follows a continuous failure mode due to the destruction of filtercake and the decrease in chamber pressure;(4)the soil pressure at the cutterhead is more sensitive to disturbances from shield tunneling than chamber pressure;and(5)experimentally determined critical collapse pressures is consistent with the theoretical solution of limit analysis. 展开更多
关键词 Slurry shield model test Saturated sand Ground collapse Tunnel face stability Rotational failure mechanism
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Rutting performance of geosynthetic reinforced unbound pavements subjected to repetitive loading:A review
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作者 Arnold Fernando Shehan Mithila +1 位作者 Shiran Jayakody Chaminda Gallage 《Journal of Road Engineering》 2026年第1期34-50,共17页
The growing demands on global infrastructure highlight the critical need for durable and efficient pavement systems,particularly under the stress of repetitive heavy traffic loads.The use of geosynthetics within the p... The growing demands on global infrastructure highlight the critical need for durable and efficient pavement systems,particularly under the stress of repetitive heavy traffic loads.The use of geosynthetics within the pavement structure increases the load-carrying capacity of unbound pavement layers by providing lateral restraint,improving vertical stress distribution,and enhancing bearing capacity.Such reinforcement typically aims to either improve the service life of pavements or achieve equivalent performance with a reduced granular cover.Previous and ongoing research quantifies geosynthetic performance in pavement reinforcement using various testing methods.Among these,laboratory model box tests subjected to cyclic loading are pivotal,as they closely replicate real-world traffic conditions.Hence,these studies are essential for understanding how geosynthetics distribute loads and enhance pavement durability.This facilitates the development of optimized geosynthetic design and installation practices,accelerating the loading process to simulate years of traffic wear in a shorter period.This review discusses the improved rutting resistance of unbound pavements reinforced with geosynthetic materials,specifically drawing on data from cyclic plate load tests conducted on laboratory model boxes,as highlighted in the literature.Key variables such as optimum geosynthetic placement,geosynthetic material properties,performance of different geosynthetic materials and the effects of aperture shape and size on rutting resistance are discussed.Furthermore,the review assesses various predictive rutting models,analysing their applicability and accuracy in forecasting the rutting performance of geosynthetic-reinforced unbound pavements.This comprehensive literature review aids pavement engineers and researchers,in guiding the selection and design of geosynthetics to optimize pavement durability and functionality under repetitive traffic loads. 展开更多
关键词 GEOSYNTHETICS Unbound pavements Laboratory model box tests Cyclic loading Rutting resistance Predictive rutting models
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