Journal of Science and Technology in Civil Engineering (STCE) - HUCE最新文献_第4页

Utilization of artificial lightweight aggregate and unground rice husk ash as internal curing agents to modify performance of super-sulfated cement mortar 利用人造轻骨料和未磨稻壳灰作为内固化剂改性超硫酸盐水泥砂浆的性能

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2023-03-25 DOI: 10.31814/stce.nuce2023-17(1)-08

Vu-An Tran, Hoang-Anh Nguyen, Bui Le Anh Tuan, D. Vo

{"title":"Utilization of artificial lightweight aggregate and unground rice husk ash as internal curing agents to modify performance of super-sulfated cement mortar","authors":"Vu-An Tran, Hoang-Anh Nguyen, Bui Le Anh Tuan, D. Vo","doi":"10.31814/stce.nuce2023-17(1)-08","DOIUrl":"https://doi.org/10.31814/stce.nuce2023-17(1)-08","url":null,"abstract":"This study attempts to utilize cold-bonded fly ash based artificial lightweight aggregate (ALWA) and retrieved unground rice husk ash (URHA) as internal curing (IC) agents for improving performance of typical super-sulfaed cement (SSC) mortar fabricated with ternary mixture of 85% slag, 10% gypsum, and only 5% blended Portland cement (PCB). The ALWA partially replacing fine aggregate (FA) at four values of 25, 50, 75, and 100 vol.% was used. For evaluating impact of using hybrid addition of IC agents on performances of SSC mortars, the ALWA amount after being optimized was partially replaced by URHA at four levels of 25, 50, 75, and 100 vol.%. Experimental results showed that, ALWA partially replacing FA up to 50 vol.% led to the SSC mortars with remarkably increased workability and uncompromised impacts on the strengths and durability. Addition of URHA partially replacing ALWA significantly improved the fresh properties and flexural strength but it negatively impacted the durability performances of the resultant SSC mortars in terms of increased water absorption, decreased UPV, and increased drying shrinkage.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116679867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A study on the probabilistic safety assessment of the truss structure designed by the LRFD code 基于LRFD规范设计的桁架结构概率安全评估研究

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2023-03-25 DOI: 10.31814/stce.nuce2023-17(1)-09

N. Doan

{"title":"A study on the probabilistic safety assessment of the truss structure designed by the LRFD code","authors":"N. Doan","doi":"10.31814/stce.nuce2023-17(1)-09","DOIUrl":"https://doi.org/10.31814/stce.nuce2023-17(1)-09","url":null,"abstract":"The probabilistic analyses provide a more rational approach for the safety assessment of structures since they consider the uncertainties in the calculations. Consequently, the design specifications of engineering structures are gradually transformed from the allowable stress design to the reliability-based specifications such as load and resistance factors design (LRFD) or partial safety factor design. The partial safety factors and the load andresistance factors provided in the reliability-based design codes are successfully determined from probabilistic frameworks. However, these specifications are classified into semi-probabilistic-based codes because no probabilistic analysis is required in the design practice. Thus, the actual reliability index of the design solutions maynot be as close to the target value as expected. This study employs the fully probabilistic analysis as an additional analysis to examine the reliability index of an LRFD-based design of the truss structure. A planar truss,which is designed following the semi-probabilistic code, is thoroughly examined. Several feasible sections are first designed using the LRFD code. Then, the actual reliability indexes of truss structures are evaluated to check if they meet the target reliability index specified in the reliability-based design codes. The tension and compression members concerning the strength limit state and the maximum deflection presenting for service ability are investigated as representative performances. The results of the probabilistic analyses indicate thatthe reliability indexes for the strength limit state are higher than the target value stipulated in the LRFD code. Compared to the tension members, more redundancy in terms of reliability index is observed for compression elements, although they are both designed at the limit state. Moreover, the reliability index obtained for theserviceability limit state is strongly dependent on the component (i.e., floor or roof) where the truss is utilized.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123827054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Machine learning-based pedo transfer function for estimating the soil compression index 基于机器学习的pedo传递函数估算土壤压缩指数

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2023-03-25 DOI: 10.31814/stce.nuce2023-17(1)-06

Pham Nguyen Linh Khanh, Nguyen Huu Bao Ngan

{"title":"Machine learning-based pedo transfer function for estimating the soil compression index","authors":"Pham Nguyen Linh Khanh, Nguyen Huu Bao Ngan","doi":"10.31814/stce.nuce2023-17(1)-06","DOIUrl":"https://doi.org/10.31814/stce.nuce2023-17(1)-06","url":null,"abstract":"Soil compression index (Cc) plays a vital role in describing the settlement behaviors of geotechnical infrastructures. The conventional Oedometer test broadly used to determine Cc is time-consuming and expensive, which challenges incorporating the high spatial variability of Cc. Alternatively, this study utilized the pedo transfer function (PTF) concept to develop a predictive model on the extreme gradient boosting (XGB) framework for estimating Cc with high accuracy and low effort. The presented XGB-PTF implemented on the database is acquired from 40 boreholes in Ho Chi Minh city and its vicinity to learn and recognize the correlation patterns of Cc and the easily-obtainable soil parameters (i.e., grain size distribution, unit density, moisture content, Atterberg limits). Rigorous evaluation with standard regression metrics demonstrated the efficiency and excellent performance of the XGB-PTF (e.g., low root-mean-squared error of 0.089 and a high coefficient of determination of 0.903). Furthermore, the presented framework showed its superiority over the current empirical equations in estimating Cc by higher prediction accuracy and applicability to the broader range of soil types. Given efficiency, flexibility, and dynamics, the presented model is expected to be a versatile approach to quantizing and advancing the knowledge of soil characteristics over a regional area.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"2015 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127741966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

An enhanced single damage identification in beams using natural frequency shifts and analytic modal curvatures 利用固有频移和解析模态曲率增强梁的单一损伤识别

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2023-03-24 DOI: 10.31814/stce.nuce2023-17(1)-01

Duc-Tuan Ta, T. Le, Micheal Burman

{"title":"An enhanced single damage identification in beams using natural frequency shifts and analytic modal curvatures","authors":"Duc-Tuan Ta, T. Le, Micheal Burman","doi":"10.31814/stce.nuce2023-17(1)-01","DOIUrl":"https://doi.org/10.31814/stce.nuce2023-17(1)-01","url":null,"abstract":"This article presents an improved procedure for detecting single damage in beam-like structures. Many damage detection methods are based on the analysis of beam natural frequency shifts in damaged and intact states and its analytical modal curvatures. They identify the damage by constructing curves of damage coefficients along the beam and visually determining the point of their mutual intersection. However, for some cases, the absence of an unambiguous point of intersection of these curves or the low accuracy of its localization makes it difficultto use these methods. To accurately determine the mutual intersection of damage coefficient curves, this work proposes to use a subset of modes without one having its curvature close to zero at the site of the alleged damage. This approach greatly simplifies the determination of the point of intersection of the curves of damagecoefficients. An enhanced procedure for the numerical determination of this intersection point is also proposed,rather than the visual one used in existing methods. The effectiveness of the proposed technique was confirmedby numerical simulation followed by experimental verification.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128188515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Evaluating the performance of the RANS turbulence models for simulating wave propagation over a submerged breakwater using openfoam 利用开放泡沫模拟水下防波堤波浪传播的RANS湍流模型的性能评价

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2023-03-24 DOI: 10.31814/stce.nuce2023-17(1)-07

Luong Cao Linh, M. C. Tri

引用次数: 0

Grain boundary strengthening of microstructure phases in SS400 structural steel weld zone SS400结构钢焊缝区显微组织相的晶界强化

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2023-03-24 DOI: 10.31814/stce.nuce2023-17(1)-03

Nguyễn Ngọc Vinh, Duong Hong Quan

{"title":"Grain boundary strengthening of microstructure phases in SS400 structural steel weld zone","authors":"Nguyễn Ngọc Vinh, Duong Hong Quan","doi":"10.31814/stce.nuce2023-17(1)-03","DOIUrl":"https://doi.org/10.31814/stce.nuce2023-17(1)-03","url":null,"abstract":"Grain boundary strengthening is a method of strengthening materials by changing their average crystalize (grain) size, exhibiting the basic relationship between yield stress and the grain size of the materials. This methodology is based on the observation of grain boundaries that are insurmountable borders for dislocationsand the number of dislocations located within a grain. Applying this methodology to the structural steel weld zone, the mechanical properties of each microstructural phase can be evaluated through the values of grain diameter. For structural steel weld zones, there are not many methods to directly determine the mechanicalproperties of microstructural phases. Thus, in this study, a methodology was created to evaluate the values of the yield stress of materials based on the grain boundary strengthening equation. This method was constructedby observing the average grain size and determining the mechanical properties of three microstructural phasesin the weld zone (i.e. based metal, heat-affected zone, and weld metal). The results from this study provide aneasy way for engineers, architects, and scientists to evaluate the values of mechanical properties of based metal, heat-affected zone, and weld metal in the SS400 structural steel weld zone.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133223562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Compressibility characteristics of clays in the Red River Delta 红河三角洲粘土的压缩性特征

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2023-03-24 DOI: 10.31814/stce.nuce2023-17(1)-04

Nguyen Tien Dung, P.S. Khin

{"title":"Compressibility characteristics of clays in the Red River Delta","authors":"Nguyen Tien Dung, P.S. Khin","doi":"10.31814/stce.nuce2023-17(1)-04","DOIUrl":"https://doi.org/10.31814/stce.nuce2023-17(1)-04","url":null,"abstract":"The Red River Delta (RRD) is the second largest delta in Vietnam and is a significant economic zone in the country, encompassing important cities and economic zones. Geologically, the delta consists of clay layers distributed all over its area, which strongly impact the foundation designs of the infrastructure system (e.g., highways, industrial parks, harbors). However, up to date, there were no comprehensive studies on the compressibility characteristics of the clays in the delta. This study presents a primary study on some compressibility characteristics of clays in the whole delta with an emphasis on the use of CPTu data in the interpretation. For this, high-quality field and laboratory test results obtained from four research test sites and eight project sites were analyzed to depict the characteristics. The results indicate that the clays in the delta are typically soft to medium stiff and normally consolidated to slightly overconsolidated, which represent typical characteristics of young Holocene deposits. The compression index (Cc) of the clays was found to have good correlations with natural water content (Wn) or in-situ void ratio (e0). The ratio of radial coefficient of consolidation from a consolidation test with a central drain (CD) to the vertical coefficient of consolidation from the standard consolidation test (i.e., cr,CD/cv) from the 4 research test sites is on average 2.76 (log t method) and 2.32 (root t method) and these average ratios are found typical for deltaic soil deposits. The correlations for the remolded samples indicate that the drainage type has a strong influence to the induced coefficients of homogeneously remolded soils. Results from this study help geotechnical engineers have a general view on the compressibility characteristics of the clays in the delta, which in turn helps secure optimal foundation design solutions.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126605889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Effects of the size polydispersity and friction coefficient on the compressive strength of wet granular materials 粒径多分散性和摩擦系数对湿式颗粒材料抗压强度的影响

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2023-02-09 DOI: 10.31814/stce.nuce2023-17(1)-05

Vo Thanh Trung, N. Kien

{"title":"Effects of the size polydispersity and friction coefficient on the compressive strength of wet granular materials","authors":"Vo Thanh Trung, N. Kien","doi":"10.31814/stce.nuce2023-17(1)-05","DOIUrl":"https://doi.org/10.31814/stce.nuce2023-17(1)-05","url":null,"abstract":"We numerically study the effects of the size polydispersity and the friction coefficient on the compressive strength of wet granules under a diametrical compression test by using discrete element simulations. The nu-merical method is coupled with the capillary cohesion law which is enhanced by the cohesive forces between grains in the pendular regime. The wet granules are composed of primary spherical particles whose size poly-dispersity is varied from1 to 10 and the friction coefficient between grains is varied from0.1 to 1.0. By applying a constant compression velocity on the top plate in quasi-static regime, the granule is deformed but does not abruptly rupture due to the cohesive effects between grains and the rearrangement of primary particles. This no abrupt rupture is characterized by the appearance of the peak compressive stress in a long vertical strain before the onset failure of the granule. The compressive strength of the granule increases with increasing the friction coefficient for all cases of the size polydispersity but seemly declines for low values of the size polydispersity and almost level-off for high-size polydispersity with the friction coefficient larger than 0.5.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"225 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132538883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Probabilistic evaluation of the axis distance’s influence on the flexural strength deterioration of reinforced concrete beams under ISO 834 fire ISO 834火灾下轴距对钢筋混凝土梁抗弯强度衰减影响的概率评估

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2023-02-09 DOI: 10.31814/stce.nuce2023-17(1)-02

Nguyen Truong Thang, Dang Viet Hung

{"title":"Probabilistic evaluation of the axis distance’s influence on the flexural strength deterioration of reinforced concrete beams under ISO 834 fire","authors":"Nguyen Truong Thang, Dang Viet Hung","doi":"10.31814/stce.nuce2023-17(1)-02","DOIUrl":"https://doi.org/10.31814/stce.nuce2023-17(1)-02","url":null,"abstract":"The distance from the nearest concrete exposed surface to the centroidal axis of main longitudinal steel re-inforcing bars, so-called axis distance, plays a critical role in ensuring the safety of reinforced concrete (RC) structures under fire, as it helps the rebars not being directly exposed to heating in a fire incident. However, a large axis distance value could reduce the effective height as well as the beam’s flexural strength at ambient condition. In order to determine the appropriate values of axis distance, this article developes a data-driven method for predicting the flexural strength deterioration (FSD) of RC beams under ISO 834 standard fire based on the material and geometrical inputs. This method consists of two main stages: (i) Establishing a theoretical/experimental database by collecting experimental data from the literature; and (ii) Engineering a probabilis-tic model based on the Bayesian Neural Network. The results obtained show that the proposed approach is a practical tool that is capable of performing quick and reasonably accurate analysis such as degradation curves of FSD against exposure time. In addition, the uncertainty related to the prediction results is also evaluated, providing useful information for structural fire engineers to achieve conservative designs.","PeriodicalId":387908,"journal":{"name":"Journal of Science and Technology in Civil Engineering (STCE) - HUCE","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116424815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

The influence of PVA content on the flexural behavior of engineered cementitious composite using local materials PVA含量对局部材料工程胶凝复合材料抗弯性能的影响

Journal of Science and Technology in Civil Engineering (STCE) - HUCE Pub Date : 2022-04-29 DOI: 10.31814/stce.huce(nuce)2022-16(2)-05

N. Thắng, Nguyen Cong Thang, N. Tuan, P. S. Dong, V. Tham, T. M. Tu

引用次数: 1