资源类型

期刊论文 543

年份

2024 1

2023 35

2022 59

2021 46

2020 39

2019 48

2018 14

2017 20

2016 24

2015 14

2014 25

2013 34

2012 20

2011 25

2010 14

2009 28

2008 25

2007 22

2006 7

2005 6

展开 ︾

关键词

混凝土 17

DX桩 9

三峡工程 8

承载力 7

三峡升船机 4

容量 4

混凝土面板堆石坝 3

三点弯曲梁 2

升船机 2

实时监控 2

混凝土坝 2

混凝土浇筑 2

碾压混凝土坝 2

组合梁 2

5% 法 1

700 MW级水电机组 1

700 m跨径级别 1

ANSYS 1

D区 1

展开 ︾

检索范围:

排序: 展示方式:

surface cracking, anchor head profile, and anchor head size on cast-in headed anchors in geopolymer concrete

《结构与土木工程前沿(英文)》   页码 1163-1187 doi: 10.1007/s11709-023-0987-5

摘要: In this study, the concrete cone capacity, concrete cone angle, and load–displacement response of cast-in headed anchors in geopolymer concrete are explored using numerical analyses. The concrete damaged plasticity (CDP) model in ABAQUS is used to simulate the behavior of concrete substrates. The tensile behavior of anchors in geopolymer concrete is compared with that in normal concrete as well as that predicted by the linear fracture mechanics (LFM) and concrete capacity design (CCD) models. The results show that the capacity of the anchors in geopolymer concrete is 30%–40% lower than that in normal concrete. The results also indicate that the CCD model overestimates the capacity of the anchors in geopolymer concrete, whereas the LFM model provides a much more conservative prediction. The extent of the difference between the predictions by the numerical analysis and those of the above prediction models depends on the effective embedment depth of the anchor and the anchor head size. The influence of concrete surface cracking on the capacity of the anchor is shown to depend on the location of the crack and the effective embedment depth. The influence of the anchor head profile on the tensile capacity of the anchors is found to be insignificant.

关键词: cast-in anchor     concrete cone capacity     geopolymer concrete     head size     surface crack     anchor profile    

Experimental research on the creep behavior and bearing capacity of repeatedly prestressed concrete beam

SHAO Xudong, LI Lifeng, YANG Jianjun

《结构与土木工程前沿(英文)》 2007年 第1卷 第3期   页码 305-311 doi: 10.1007/s11709-007-0040-0

摘要: In the prestress tensioning process of medium or short span prestressed concrete beam bridges, there are always many serious problems, such as the camber of straight beam being too large, curved beam going crosswise, and columns of rigid beam bridge cracking, that can be commonly seen because of its greater additional stress in prestressing. To solve the above problems, a new concept of repeatedly prestressed bridge structure was innovatively proposed in this work. It was proved, through theoretical and experimental comparison between this new structure and the traditional prestressed structure, that the application of repeated prestressing technology can greatly improve the mechanical and deformational performance of the low height beam during construction and long-term use. Furthermore, a kind of computational formula to calculate creep strain and deformation due to repeated prestressing in terms of time was derived in this paper and the bearing capacity of this new structure has been tested. Finally, the work concludes that there is a bright application prospect for this new structure for medium and short span prestressed beam bridges to control deformations.

关键词: computational     cracking     technology     prestressed concrete     application prospect    

Analysis on shear capacity of prestressed concrete spatial connections

XUE Weichen, LIU Zhenyong, JIANG Dongsheng

《结构与土木工程前沿(英文)》 2008年 第2卷 第4期   页码 309-317 doi: 10.1007/s11709-008-0052-4

摘要: Based on experimental results of prestressed concrete spatial connections, nonlinear finite element models were established to analyze the shear capacity of spatial connections and parametric studies were performed using ANSYS. It is found that the shear capacity of spatial connection is influenced by joint hoop, beam prestress, column compressive load, and direction of resultant shear force. The parametric studies also indicate that the shear capacity of spatial connection under biaxial cyclic loading is lower than that of corresponding connections under plane loading. A design formula for calculating the shear capacity of spatial connections is proposed based on the parametric studies and verified by the available test results.

关键词: available     direction     nonlinear     capacity     compressive    

Novel empirical model for predicting residual flexural capacity of corroded steel reinforced concrete

Zhao-Hui LU, Hong-Jun WANG, Fulin QU, Yan-Gang ZHAO, Peiran LI, Wengui LI

《结构与土木工程前沿(英文)》 2020年 第14卷 第4期   页码 888-906 doi: 10.1007/s11709-020-0637-0

摘要: In this study, a total of 177 flexural experimental tests of corroded reinforced concrete (CRC) beams were collected from the published literature. The database of flexural capacity of CRC beam was established by using unified and standardized experimental data. Through this database, the effects of various parameters on the flexural capacity of CRC beams were discussed, including beam width, the effective height of beam section, ratio of strength between longitudinal reinforcement and concrete, concrete compressive strength, and longitudinal reinforcement corrosion ratio. The results indicate that the corrosion of longitudinal reinforcement has the greatest effect on the residual flexural capacity of CRC beams, while other parameters have much less effect. In addition, six available empirical models for calculating the residual flexural strength of CRC beams were also collected and compared with each other based on the established database. It indicates that though five of six existing empirical models underestimate the flexural capacity of CRC beams, there is one model overestimating the flexural capacity. Finally, a newly developed empirical model is proposed to provide accurate and effective predictions in a large range of corrosion ratio for safety assessment of flexural failure of CRC beams confirmed by the comparisons.

关键词: CRC beams     flexural capacity     steel corrosion     database     empirical models    

Instantaneous deflection of light-weight concrete slabs

Behnam VAKHSHOURI, Shami NEJADI

《结构与土木工程前沿(英文)》 2017年 第11卷 第4期   页码 412-423 doi: 10.1007/s11709-017-0416-8

摘要: Construction loading before the age of 28 d can have the most significant effects on the slabs, especially for multi-story structures. The changing properties of the young concrete complicate the prediction of serviceability design requirements also. An experimental investigation is performed on four simply supported Light-Weight Concrete (LWC) one-way slabs subjected to immediate loading at 14 d. Effects of aggregate type, loading levels and cracking moment together with the influences of ultimate moment capacity and service moment on the instantaneous deflection of slabs are studied. Comparison of the obtained results with predictions of existing models in the literature shows considerable differences between the recorded and estimated instantaneous deflection of LWC slabs. Based on sensitivity analysis of the effective parameters, a new equation is proposed and verified to predict the instantaneous deflection of LWC slabs subjected to loading at the age of 14 d.

关键词: instantaneous deflection     light-weight concrete     expanded polystyrene     effective moment of inertia     cracking moment     moment capacity     service moment    

Liquefaction prediction using support vector machine model based on cone penetration data

Pijush SAMUI

《结构与土木工程前沿(英文)》 2013年 第7卷 第1期   页码 72-82 doi: 10.1007/s11709-013-0185-y

摘要: A support vector machine (SVM) model has been developed for the prediction of liquefaction susceptibility as a classification problem, which is an imperative task in earthquake engineering. This paper examines the potential of SVM model in prediction of liquefaction using actual field cone penetration test (CPT) data from the 1999 Chi-Chi, Taiwan earthquake. The SVM, a novel learning machine based on statistical theory, uses structural risk minimization (SRM) induction principle to minimize the error. Using cone resistance ( ) and cyclic stress ratio ( ), model has been developed for prediction of liquefaction using SVM. Further an attempt has been made to simplify the model, requiring only two parameters ( and maximum horizontal acceleration ), for prediction of liquefaction. Further, developed SVM model has been applied to different case histories available globally and the results obtained confirm the capability of SVM model. For Chi-Chi earthquake, the model predicts with accuracy of 100%, and in the case of global data, SVM model predicts with accuracy of 89%. The effect of capacity factor ( ) on number of support vector and model accuracy has also been investigated. The study shows that SVM can be used as a practical tool for prediction of liquefaction potential, based on field CPT data.

关键词: earthquake     cone penetration test     liquefaction     support vector machine (SVM)     prediction    

Stress-strain relationship of concrete in freeze-thaw environment

ZOU Chaoying, ZHAO Juan, LIANG Feng

《结构与土木工程前沿(英文)》 2008年 第2卷 第2期   页码 184-188 doi: 10.1007/s11709-008-0029-3

摘要: Adopting the ASTM C666 quick freeze-thaw method, freeze-thaw tests with the number of freeze-thaw cycles being 0, 100, 150, 200, 250, and 300, were carried out on eighteen concrete prism specimens, the frost-resistant level of which, reaches D300 grade. The internal micro-structures of these specimens were observed by means of scanning electron microscopy (SEM) in order to detect damages caused by the freeze-thaw action. Afterwards these frozen-thawed specimens were tested on monotonic axial load; stress-strain testing curves after the freeze-thaw action were obtained. The testing results show that with the increasing time of freeze-thaw cycles, both the internal micro-structures and the basic mechanical parameters, including the ultimate bearing capacity, the Poisson ratio and the modulus of elasticity, degenerate in various degrees. Finally, stress-strain theoretical curvilinear equations and correlated parameters relating to the loss of relative dynamic modulus of elasticity were proposed. These results provide great reference for further research on the behavior and the calculation model of concrete structures in a freeze-thaw environment.

关键词: stress-strain theoretical     freeze-thaw     capacity     reference     eighteen concrete    

Impingement of hollow cone spray on hot porous medium

ZHAO Zhiguo, XIE Maozhao

《能源前沿(英文)》 2008年 第2卷 第3期   页码 273-278 doi: 10.1007/s11708-008-0048-8

摘要: To have a good understanding of the formation of homogenous mixture in a porous medium engine, the interaction between hollow cone spray and hot porous medium was studied numerically by using an improved version of KIVA-3V code. The improved KIVA-3V code is incorporated with an impingement model, heat transfer model and linearized instability sheet atomization (LISA) model to simulate the hollow cone spray. The reasonability of the impingement model and heat transfer model was validated. With a simple model to describe the structure of the porous medium, the interaction between hollow cone spray and hot porous medium was simulated under different ambient pressures and spray cone angles. Computational results show that the fuel spray could be divided into smaller ones, which provides conditions for the quick evaporation of fuel droplets and the mixing of fuel vapor with air. Differences in ambient pressure and spray cone angle affect the distribution of droplets in the porous medium.

关键词: improved version     simple     impingement     atomization     hollow    

Enhanced empirical models for predicting the drift capacity of less ductile RC columns with flexural,

Mohammad Reza AZADI KAKAVAND, Reza ALLAHVIRDIZADEH

《结构与土木工程前沿(英文)》 2019年 第13卷 第5期   页码 1251-1270 doi: 10.1007/s11709-019-0554-2

摘要: Capacity of components subjected to earthquake actions is still a widely interesting research topic. Hence, developing precise tools for predicting drift capacities of reinforced concrete (RC) columns is of great interest. RC columns are not only frequently constructed, but also their composite behavior makes the capacity prediction a task faced with many uncertainties. In the current article, novel empirical approaches are presented for predicting flexural, shear and axial failure modes in RC columns. To this aim, an extensive experimental database was created by collecting outcomes of previously conducted experimental tests since 1964, which are available in the literature. It serves as the basis for deriving the equations for predicting the drift capacity of RC columns by different regression analyses (both linear with different orders and nonlinear). Furthermore, fragility curves are determined for comparing the obtained results with the experimental results and with previously proposed models, like the ones of ASCE/SEI 41-13. It is demonstrated that the proposed equations predict drift capacities, which are in better agreement with experimental results than those computed by previously published models. In addition, the reliability of the proposed equations is higher from a probabilistic point of view.

关键词: flexural-shear-axial failure     drift capacity     reinforced concrete columns     statistical analysis     fragility curves    

of undercut on the lower bound stability of vertical rock escarpment using finite element and power cone

《结构与土木工程前沿(英文)》 doi: 10.1007/s11709-023-0035-5

摘要: Correction to: Effect of undercut on the lower bound stability of vertical rock escarpment using finite element and power cone programming

关键词: finite element power     stability rock escarpment    

钢纤维混凝土厚承台承载力影响因素分析

孙成访,谷倩,陈习子,彭少民

《中国工程科学》 2003年 第5卷 第6期   页码 79-83

摘要:

在完成30个缩尺模型为1∶5的二桩混凝土和钢纤维混凝土承台试件的试验研究中,通过改变混凝土强度、钢纤维体积率、承台有效厚度、配筋量及配筋方式,观察和记录了不同条件下桩承台裂缝的开展与分布,承台底部中点挠度、侧边混凝土应变和底部受拉钢筋应变,并系统地分析了影响钢纤维混凝土二桩厚承台极限承载力的主要因素。分析结果为进一步研究钢纤维混凝土二桩承台的抗冲切、抗剪及配筋计算提供了试验基础,并为《钢纤维混凝土结构技术规程》的修订提供了背景材料。

关键词: 钢纤维     纤维增强混凝土     桩基厚承台     承载力     影响因素    

Axial compression behavior of CFRP-confined rectangular concrete-filled stainless steel tube stub column

《结构与土木工程前沿(英文)》 2021年 第15卷 第5期   页码 1144-1159 doi: 10.1007/s11709-021-0762-4

摘要: The mechanical properties of CFRP-confined rectangular concrete-filled stainless steel tube (CFSST) stub columns under axial compression were experimentally studied. A total of 28 specimens (7 groups) were fabricated for the axial compression test to study the influences of length-to-width ratio, CFRP constraint coefficient, and the thickness of stainless steel tube on the axial compression behavior. The specimen failure modes, the stress development of stainless steel tube and CFRP wrap, and the load–strain ratio curves in the loading process were obtained. Meanwhile, the relationship between axial and transverse deformations of each specimen was analyzed through the typical relative load−strain ratio curves. A bearing capacity prediction method was proposed based on the twin-shear strength theory, combining the limit equilibrium state of the CFRP-confined CFSST stub column under axial compression. The prediction method was calibrated by the test data in this study and other literature. The results show that the prediction method is of high accuracy.

关键词: CFRP     rectangular CFSST stub column     bearing capacity     limit equilibrium state     twin-shear strength theory    

Experimental research on self-stressing and self-compacting concrete filled steel tube columns subjected

Chengkui HUANG, Zuoqing SHANG, Peng ZHANG,

《结构与土木工程前沿(英文)》 2009年 第3卷 第4期   页码 455-461 doi: 10.1007/s11709-009-0058-6

摘要: A total of fifteen self-stressing and self-compacting concrete (SSC) filled steel tube columns and three common self-compacting concrete filled steel tube (CFST) columns are tested under eccentric compression load to analyze the effect of initial self-stress on the compression behavior of CFSTs. The results show that the elastic working range of the columns is lengthened because of initial self-stress and it slightly decreases with the increase of load eccentricity ratio and slenderness ratio. Because of the initial self-stress, the concrete core is always under compression in three directions, so the compactness is enhanced and the ultimate bearing capacity obviously increases; but the initial self-stress hardly affects the failure mode of the columns.

关键词: increase     capacity     failure     CFSTs     CFST    

of undercut on the lower bound stability of vertical rock escarpment using finite element and power cone

Shuvankar DAS; Debarghya CHAKRABORTY

《结构与土木工程前沿(英文)》 2022年 第16卷 第8期   页码 1040-1055 doi: 10.1007/s11709-022-0841-1

摘要: In the present study, the stability of a vertical rock escarpment is determined by considering the influence of undercut. Lower bound finite element limit analysis in association with Power Cone Programming (PCP) is applied to incorporate the failure of rock mass with the help of the Generalized Hoek-Brown yield criterion. The change in stability due to the presence of undercut is expressed in terms of a non-dimensional stability number (σci/γH). The variations of the magnitude of σci/γH are presented as design charts by considering the different magnitudes of undercut offset (H/vu and wu/vu) from the vertical edge and different magnitudes of Hoek-Brown rock mass strength parameters (Geological Strength Index (GSI), rock parameter (mi,), Disturbance factor (D)). The obtained results indicate that undercut can cause a severe stability problem in rock mass having poor strength. With the help of regression analysis of the computed results, a simplified design equation is proposed for obtaining σci/γH. By performing sensitivity analysis for an undisturbed vertical rock escarpment, we have found that the undercut height ratio (H/vu) is the most sensitive parameter followed by GSI, undercut shape ratio (wu/vu), and mi. The developed design equation as well as design charts can be useful for practicing engineers to determine the stability of the vertical rock escarpment in the presence of undercut. Failure patterns are also presented to understand type of failure and extent of plastic state during collapse.

关键词: undercut     vertical escarpment     stability     Hoek-Brown yield criterion     PCP    

Impacts of cone-structured interface and aperiodicity on nanoscale thermal transport in Si/Ge superlattices

Pengfei JI, Yiming RONG, Yuwen ZHANG, Yong TANG

《能源前沿(英文)》 2018年 第12卷 第1期   页码 137-142 doi: 10.1007/s11708-018-0532-8

摘要: Si/Ge superlattices are promising thermoelectric materials to convert thermal energy into electric power. The nanoscale thermal transport in Si/Ge superlattices is investigated via molecular dynamics (MD) simulation in this short communication. The impact of Si and Ge interface on the cross-plane thermal conductivity reduction in the Si/Ge superlattices is studied by designing cone-structured interface and aperiodicity between the Si and Ge layers. The temperature difference between the left and right sides of the Si/Ge superlattices is set up for nonequilibrium MD simulation. The spatial distribution of temperature is recorded to examine whether the steady-state has been reached. As a crucial factor to quantify thermal transport, the temporal evolution of heat flux flowing through Si/Ge superlattices is calculated. Compared with the even interface, the cone-structured interface contributes remarkable resistance to the thermal transport, whereas the aperiodic arrangement of Si and Ge layers with unequal thicknesses has a marginal influence on the reduction of effective thermal conductivity. The interface with divergent cone-structure shows the most excellent performance of all the simulated cases, which brings a 33% reduction of the average thermal conductivity to the other Si/Ge superlattices with even, convergent cone-structured interfaces and aperiodic arrangements. The design of divergent cone-structured interface sheds promising light on enhancing the thermoelectric efficiency of Si/Ge based materials.

关键词: thermoelectric material     thermal transport     Si/Gesuperlattics     molecular dynamics (MD)    

标题 作者 时间 类型 操作

surface cracking, anchor head profile, and anchor head size on cast-in headed anchors in geopolymer concrete

期刊论文

Experimental research on the creep behavior and bearing capacity of repeatedly prestressed concrete beam

SHAO Xudong, LI Lifeng, YANG Jianjun

期刊论文

Analysis on shear capacity of prestressed concrete spatial connections

XUE Weichen, LIU Zhenyong, JIANG Dongsheng

期刊论文

Novel empirical model for predicting residual flexural capacity of corroded steel reinforced concrete

Zhao-Hui LU, Hong-Jun WANG, Fulin QU, Yan-Gang ZHAO, Peiran LI, Wengui LI

期刊论文

Instantaneous deflection of light-weight concrete slabs

Behnam VAKHSHOURI, Shami NEJADI

期刊论文

Liquefaction prediction using support vector machine model based on cone penetration data

Pijush SAMUI

期刊论文

Stress-strain relationship of concrete in freeze-thaw environment

ZOU Chaoying, ZHAO Juan, LIANG Feng

期刊论文

Impingement of hollow cone spray on hot porous medium

ZHAO Zhiguo, XIE Maozhao

期刊论文

Enhanced empirical models for predicting the drift capacity of less ductile RC columns with flexural,

Mohammad Reza AZADI KAKAVAND, Reza ALLAHVIRDIZADEH

期刊论文

of undercut on the lower bound stability of vertical rock escarpment using finite element and power cone

期刊论文

钢纤维混凝土厚承台承载力影响因素分析

孙成访,谷倩,陈习子,彭少民

期刊论文

Axial compression behavior of CFRP-confined rectangular concrete-filled stainless steel tube stub column

期刊论文

Experimental research on self-stressing and self-compacting concrete filled steel tube columns subjected

Chengkui HUANG, Zuoqing SHANG, Peng ZHANG,

期刊论文

of undercut on the lower bound stability of vertical rock escarpment using finite element and power cone

Shuvankar DAS; Debarghya CHAKRABORTY

期刊论文

Impacts of cone-structured interface and aperiodicity on nanoscale thermal transport in Si/Ge superlattices

Pengfei JI, Yiming RONG, Yuwen ZHANG, Yong TANG

期刊论文