Cold Regions Science and Technology最新文献_第2页

Monitoring evolutionary damage of bended concrete beams subjected to freeze-thaw cycling through piezoelectric-enabled wave propagation method 通过压电波传播方法监测受冻融循环影响的弯曲混凝土梁的进化损伤

IF 3.8 2区工程技术

Cold Regions Science and Technology Pub Date : 2024-09-30 DOI: 10.1016/j.coldregions.2024.104337

{"title":"Monitoring evolutionary damage of bended concrete beams subjected to freeze-thaw cycling through piezoelectric-enabled wave propagation method","authors":"","doi":"10.1016/j.coldregions.2024.104337","DOIUrl":"10.1016/j.coldregions.2024.104337","url":null,"abstract":"<div><div>Tunnels in cold regions are often subjected to freeze-thaw cycling, which poses a great challenge to a large number of tunnels in operation or to be built in these regions. Therefore, structural health monitoring (SHM) for lining concrete in cold regions is essential to ensure the safety and long-term operation of tunnels. In this study, the wave propagation method (WPM) is applied for the first time to monitor the cyclic freeze-thaw damage of lining concrete. First of all, the failure behaviors of concrete beams subjected to the coupling effect of flexural loading and freeze-thaw cycling are investigated. Particularly, the authors propose a refined numerical model to simulate the freeze-thaw cycling damage process of concrete beams considering the ice-water phase transition and concrete elastoplastic damage. Based on the numerical results, the internal damage expansion and flexural strength attenuation of concrete beams are revealed. Furthermore, the dynamic attenuation characteristics of stress waves are analyzed by using the wavelet packet decomposition and continuous wavelet transform to reveal. In addition, the WPM-based energy index is proposed to characterize the freeze-thaw damage degree of the lining concrete. A strong correlation is found between the stress wave signal and freeze-thaw damage, with a favorable correlation coefficient of 0.932, suggesting the excellent performance of the WPM in assessing the freeze-thaw damage of lining concrete. This research sufficiently manifests the applicability of the WPM method to monitoring the freeze-thaw damage within cold regional tunnel linings.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental investigations of the shear strength and deformation behavior of a frozen unsaturated silt 冰冻非饱和淤泥的剪切强度和变形行为实验研究

IF 3.8 2区工程技术

Cold Regions Science and Technology Pub Date : 2024-09-24 DOI: 10.1016/j.coldregions.2024.104332

{"title":"Experimental investigations of the shear strength and deformation behavior of a frozen unsaturated silt","authors":"","doi":"10.1016/j.coldregions.2024.104332","DOIUrl":"10.1016/j.coldregions.2024.104332","url":null,"abstract":"<div><div>There are limited studies in literature with respect to the deformation and shear strength behavior of frozen unsaturated soils that consider sensitive changes in temperatures below 0 °C. For this reason, the focus of the present study is directed towards investigating the shear strength and deformation behavior of a frozen unsaturated silt. As a part of the study, one-dimensional freezing tests were performed on compacted silt samples with various initial water contents and dry densities. The pulsed nuclear magnetic resonance (P-NMR) method was used to obtain distribution of unfrozen water content of silt samples; this information was used to explain the deformation behavior during freezing. The volume change behavior in unsaturated soils due to freezing can be associated to three primary factors: expansion caused by the ice-water phase transition and shrinkage induced by ice-cementation and dehydration. A critical water saturation was also observed at which the frost heave is minimum, or no volume change occurs. In addition, conventional direct shear tests were performed on compacted unsaturated silt samples both in frozen and unfrozen conditions to determine and quantify the shear strength contribution arising from the different cohesion components. The investigations in this study provide valuable information that can be used in rational explanation of the strength and deformation behavior of unsaturated frozen soils.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142327027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A new method to estimate the soil freezing characteristic curve 估算土壤冻结特性曲线的新方法

IF 3.8 2区工程技术

Cold Regions Science and Technology Pub Date : 2024-09-24 DOI: 10.1016/j.coldregions.2024.104334

引用次数: 0

Experimental study and mechanism analysis on static and dynamic mechanical properties of BFLAC at low temperatures 低温下 BFLAC 静态和动态力学性能的实验研究与机理分析

IF 3.8 2区工程技术

Cold Regions Science and Technology Pub Date : 2024-09-24 DOI: 10.1016/j.coldregions.2024.104333

{"title":"Experimental study and mechanism analysis on static and dynamic mechanical properties of BFLAC at low temperatures","authors":"","doi":"10.1016/j.coldregions.2024.104333","DOIUrl":"10.1016/j.coldregions.2024.104333","url":null,"abstract":"<div><div>This paper conducted comprehensive axial compressive and splitting-tensile tests to investigate the static and dynamic mechanical properties of basalt fibre reinforced lightweight-aggregate concrete (BFLAC) with fibre volume fractions <span><math><msub><mi>V</mi><mi>f</mi></msub></math></span> of 0.0∼0.3% at the temperatures ranging from 20 °C to −90 °C, with a special focus on the microscopic mechanism analysis and quantitative discussion of low-temperature enhancement effect, strain rate effect and fibre reinforcement effect. Test results show that the splitting-tensile strength, compressive strength, and elastic modulus of lightweight-aggregate concrete (LAC) perform an apparent low-temperature enhancement effect and this enhancement effect can be strengthened by the addition of basalt fibres. More basalt fibres reach the tensile failure strength and undergo rupture failure (Mode-2), resulting in the strain rate effect of BFLAC is slightly more significant than that of LAC; but the influence of low temperature on strain rate effect is mild. The incorporation of 0.3%<span><math><msub><mi>V</mi><mi>f</mi></msub></math></span> basalt fibres in LAC can bring at least a 20% increase in nominal strengths, showing an significant fibre reinforcement effect which can be enhanced (with maximum increase of 45.6%) as the temperature drops. Based on test results, the relationships between compressive and splitting-tensile strengths were discussed, and the empirical prediction formulas for predicting the static and dynamic mechanical properties of BFLAC at low temperatures were proposed. Research results of this paper can provide reference for mechanical performance calculation and engineering applications of BFLAC in the low-temperature environment.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of ice skeleton on the mechanical behavior of frozen soil under uniaxial compression 冰骨架对单轴压缩下冻土力学行为的影响

IF 3.8 2区工程技术

Cold Regions Science and Technology Pub Date : 2024-09-23 DOI: 10.1016/j.coldregions.2024.104327

{"title":"Influence of ice skeleton on the mechanical behavior of frozen soil under uniaxial compression","authors":"","doi":"10.1016/j.coldregions.2024.104327","DOIUrl":"10.1016/j.coldregions.2024.104327","url":null,"abstract":"<div><div>The formation of multi-layer horizontal ice lenses in frozen soil significantly alters its internal structure, leading to changes in its mechanical properties. To quantitatively analyze the effects of multi-layer ice lenses on mechanical properties, a series of freezing tests were conducted with frost-susceptible clay materials at varied freezing ratios. Then, the uniaxial compression tests were conducted to investigate the deformation and strength properties of frozen soil at different freezing ratios and temperatures. The experimental results indicate that the unique ice skeleton structure formed by horizontal ice lenses and inclined ice wedges can significantly improve the strength of the samples, leading to the peak stress and secant modulus <span><math><msub><mi>E</mi><mn>50</mn></msub></math></span> increase with the freezing ratio, and the presence of an ice skeleton makes the strength more sensitive to temperature changes. The frozen soil samples exhibit two failure modes (bulging failure and shearing failure), which significantly affect the mechanical parameters of the soil. Based on the test results, a frost heave-induced damage coefficient is introduced into the strain softening model to account for the initial stiffness reduction caused by microcracks generated during the ice skeleton growth. This modified model effectively predicts the stress-strain relationship of soils with varying ice skeleton structures. These findings have practical implications for predicting the properties of frozen soil constructed using artificial freezing methods.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the influence of early frost attack on the performance of cement mortar 研究早期冻害对水泥砂浆性能的影响

IF 3.8 2区工程技术

Cold Regions Science and Technology Pub Date : 2024-09-23 DOI: 10.1016/j.coldregions.2024.104329

{"title":"Study on the influence of early frost attack on the performance of cement mortar","authors":"","doi":"10.1016/j.coldregions.2024.104329","DOIUrl":"10.1016/j.coldregions.2024.104329","url":null,"abstract":"<div><div>The loss of strength and durability caused by early frost attack is the macro performance of internal microstructure deterioration. Understanding the influence mechanism of early frost attack at the micro level is necessary to avoid or minimize the early frost attack to macro performance. In this study, the influence of early frost attack on the strength, water sorptivity, chloride permeability, and microstructure of cement mortar was investigated. The fresh mortars were pre-cured for 10, 12, 14, and 16 h and then frozen at −10 °C for 7 days to simulate an early frost attack. After freezing, the standard curing (20 °C) was carried out until the testing. It is found that after standard curing of 28 days, the strength of early-frozen mortar can reach more than 95 % of the 28-day strength of unfrozen mortar. Interestingly, the sorptivity coefficient and total charge passed of early-frozen mortar are much higher than the level of unfrozen mortar, and the loss of resistance to water penetration and chloride ion penetration exceeds 20 %, indicating that early frost attack causes more severe damage to the durability than to the strength of mortar. Mercury intrusion porosimetry (MIP) results show that early frost attack can increase the pore volume of >50 nm and coarsen the pores within 10–50 nm. Correspondingly, key pore parameters (critical pore diameter, threshold pore diameter, and tortuosity) that affect the durability of mortar are also negatively affected. Energy dispersive spectroscopy (EDS) analysis also shows that after suffering early frost attack, the interfacial transition zone (ITZ) thickness of mortar is increased from 4 to 10 μm to 8–13 μm, and the probability of high Ca/Si ratios (4–10) in the ITZ is also increased. Finally, it is concluded that the coupling effect of pore structure coarsening and ITZ degradation leads to more severe durability loss.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142358539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on the freeze-thaw damage degree and its influence on the shear strength parameters of sandstones 冻融破坏程度及其对砂岩剪切强度参数影响的研究

IF 3.8 2区工程技术

Cold Regions Science and Technology Pub Date : 2024-09-23 DOI: 10.1016/j.coldregions.2024.104328

{"title":"Study on the freeze-thaw damage degree and its influence on the shear strength parameters of sandstones","authors":"","doi":"10.1016/j.coldregions.2024.104328","DOIUrl":"10.1016/j.coldregions.2024.104328","url":null,"abstract":"<div><div>The variations of shear strength parameters against the freeze-thaw cycles are not well understood in the previous study. This research mainly investigated the influence of freeze-thaw treatment on the shear strength parameters and their relationship with the freeze-thaw damage variable for sandstones. The fraction dimensions of sandstone surfaces and basic friction angles display an increasing trend under freeze-thaw cycles. It implies that the sandstone surface becomes rougher due to the freeze-thaw loss of cementation minerals and thus induces the increase in the basic friction angle. Another interesting finding is that although the cohesion of sandstone reduces, the internal friction angle also increases with increasing freeze-thaw cycles. Thus, the reduction in the shear strength under freeze-thaw actions should be attributed to the loss of cohesion. Moreover, the change of shear strength parameters is also related with the freeze-thaw damage degree. As the number of freeze-thaw cycles increases, the increase in porosity and reduction in P-wave velocity are much larger for the YY and YR sandstones with higher porosities, thus, they suffer much more serious freeze-thaw damage, and they have a much larger variation in shear strength parameters. The novel finding is that the growth in basic friction angle is positively correlated with the increase of freeze-thaw damage, and the internal friction angle exponentially increases with the increase of freeze-thaw damage. This study provides a much better understanding of the change of the shear strength parameters under freeze-thaw cycles.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Model test of in-situ remediation for heavy metal-contaminated clayey soil by artificial freezing and shaft washing 通过人工冻结和竖井冲洗对重金属污染粘性土壤进行原位修复的模型试验

IF 3.8 2区工程技术

Cold Regions Science and Technology Pub Date : 2024-09-23 DOI: 10.1016/j.coldregions.2024.104330

{"title":"Model test of in-situ remediation for heavy metal-contaminated clayey soil by artificial freezing and shaft washing","authors":"","doi":"10.1016/j.coldregions.2024.104330","DOIUrl":"10.1016/j.coldregions.2024.104330","url":null,"abstract":"<div><div>The low permeability of clayey soil and the pressure of liquid extraction and injection tend to form preferential flow paths in the soil, diminishing the remediation efficiency of shaft washing. Therefore, a new in-situ repair method combining artificial freezing and shaft washing is proposed. Using Pb and Cd contaminated clayey soil as the research object, in-situ model tests of different eluent types, concentrations, and suction modes were conducted to investigate the removal rate of heavy metals and the distribution of temperature and water field. The results demonstrated that the artificial freezing method can effectively induce the water (eluent) migration from the unfrozen zone to the freezing front. Besides, it effectively resolved the issue of poor washing efficiency caused by preferential flow between the extraction and injection wells during the extraction process. After five freeze-thaw cycles, the removal rate of Pb and Cd reached 46.16 % and 59.04 %, respectively. The combination of artificial freezing and plastic drainage plate technology merges artificial freezing and shaft washing methods to achieve the remediation of heavy metal-contaminated soil, providing a reference for the in-situ remediation of heavy metal-contaminated clayey soil.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of ice-covered catenary on dynamic interactions of pantograph-catenary system and limited speed of trains 冰封导管对受电弓-导管系统动态相互作用和列车限速的影响

IF 3.8 2区工程技术

Cold Regions Science and Technology Pub Date : 2024-09-23 DOI: 10.1016/j.coldregions.2024.104331

{"title":"Effect of ice-covered catenary on dynamic interactions of pantograph-catenary system and limited speed of trains","authors":"","doi":"10.1016/j.coldregions.2024.104331","DOIUrl":"10.1016/j.coldregions.2024.104331","url":null,"abstract":"<div><div>As part of the pantograph-catenary system, a catenary covered with ice can affect the current collected by pantograph sliding, posing a threat to the normal operation of the train. At the icing conditions, the speed reduction method is usually adopted in practical engineering to ensure the stable energy transfer quality of the pantograph-catenary system, while its reduction ranges remain unclear. To aim at providing speed recommendations for safe train operation under various ice conditions in practical engineering, the model of the ice-covered pantograph-catenary system is established in this work and the effect of ice covering on both the static characteristics of the catenary and the dynamic interaction of the system are investigated. The results indicate ice increases the stiffness and sag of the contact wire, resulting in a significant increase in elastic inhomogeneity across the span of the contact wire. As ice thickness and train speed increase, there is an increase in the vibration amplitude of support point and an increase in the fluctuation range of the contact force. It is suggested that the operational speeds of trains should be less than 350 km/h, 330 km/h, 280 km/h, and 260 km/h, corresponding to the ice thicknesses of 4 mm, 8 mm, 12 mm, and 16 mm, respectively.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Long-Term One-Dimensional Compression Tests and Fractional Creep Model of Compacted Snow 压实雪的长期一维压缩试验和分数蠕变模型

IF 3.8 2区工程技术

Cold Regions Science and Technology Pub Date : 2024-09-21 DOI: 10.1016/j.coldregions.2024.104326

{"title":"Long-Term One-Dimensional Compression Tests and Fractional Creep Model of Compacted Snow","authors":"","doi":"10.1016/j.coldregions.2024.104326","DOIUrl":"10.1016/j.coldregions.2024.104326","url":null,"abstract":"<div><div>Compacted snow is a primary construction material in polar regions and experiences persistent deformation during loading, which considerably affects the safety of snow structures. This study conducts a series of one-dimensional compression tests to investigate the effect of initial densities and stress levels on the long-term deformation of compacted snow samples over 90 days. The compression curve of compacted snow can be divided into three stages: instantaneous, primary, and secondary compressions. Instantaneous compression occurs at pressurization; primary compression occurs within 10 to 40 min of loading; secondary compression occurs when snow remains unstable for 90 days. Secondary compression is the main cause of long-term deformation of the samples and the secondary compression coefficient tends to decrease with a higher initial density and lower normal pressure. A fractional creep model is developed to describe the experimental data and a good agreement was obtained. The proposed model adopts the fractional deviation approach to modify the classic Burgers model, and the density-dependent parameters are calibrated using the experimental data. The proposed model is verified as a useful tool in describing the creep behavior of snow, and the results of this study contribute to the safe operation of building structures on snow foundations.</div></div>","PeriodicalId":10522,"journal":{"name":"Cold Regions Science and Technology","volume":null,"pages":null},"PeriodicalIF":3.8,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142420577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0