检索结果-内蒙古大学图书馆

An experimental study on early age compression and shear strength properties of mixed clay soil

Arabian Journal of Geosciences 2024年第2期17卷 1-14页

作者： Abbas, Azhar Akbar, Muhammad Huali, Pan Zar, Ali Ramzan, Samar Hussain, Zahoor Department of Geotechnical Engineering Tongji University Shanghai China Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Sir Syed University of Engineering & Technology Karachi Pakistan Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin China Department of Civil Engineering University of Engineering and Technology Lahore Lahore Pakistan Zhengzhou University Zhengzhou China

Clay mixed soil is a combination of clay and soil components that may be used as the core of earth dams and the foundation for building and road construction. Up until now, significant research work has been carried out to design cement-based clay materials; however, only a couple of studies have been reported in the literature on earth-based materials. The methodology portion provides an overview of the different materials, tools, and protocols used during work to develop ways to earth-based materials and study their early age compression strength along with their shear strength. Finally, it summarizes all the results and the outcome of the experimental work done. The probability of producing an object using earth-based material was examined. Improvement in the compressive strength in the early age of strength by adding additives like bentonite and rice husk was assessed in this study. Three clayey soil samples were investigated. The undrained shear strength based on an unconfined compression test (UCT) over those samples was measured by varying the moisture content (MC). After performing all these tests, a relationship was developed between the UCT and vane shear test (VST) undrained shear strengths of the selected soil samples. Clay samples with different mix designs were investigated, and building components were printed out to check the early age shear strength development and printable properties of different mix designs. This study will lay the foundation for further research on different aspects relating to the emerging technology of 3D clay printing in Pakistan.

关键词：

来源：评论

学校读者我要写书评

暂无评论

The Deformation of C–S–H Gel and its Link with Length Change of Cement Pastes on Drying and Resaturation

SSRN

引用

SSRN 2023年

作者： Zhang, Xiaoyu Qiao, Jing Feng, Jingjing Xu, Shilang Zhou, Chunsheng Zeng, Qiang Key Lab of Structures Dynamic Behavior and Control Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China College of Water Conservancy and Civil Engineering Shandong Agricultural University Taian271018 China College of Civil Engineering and Architecture Zhejiang University Hangzhou310058 China

Drying shrinkage of cement pastes (CPs) facilitating superficial cracking deserves primary concern when handling durability performance. In order to further clarify shrinkage mechanism, the changes of mass, length and pore water allocation of two mature CPs were monitored principally through non-destructive low-field NMR relaxation technique. Experimental results revealed that, heat treatment under hot water slightly coarsens the pore structure of CPs through modifying the morphology of C-S-H gel, but reduces shrinkage during first drying remarkably. During drying at 80% RH, although both interlayer and gel pores are saturated, they loss their water progressively at reducing rates. At the expense of reducing interlayer space, the contraction of gel pores is partly and even entirely compensated. When drying at lower 43% RH, interlayer pores still saturated are compacted more significantly with reducing size and volume. The compaction of interlayer pores is at the micro-structural origin and dominates drying shrinkage of CPs. © 2023, The Authors. All rights reserved.

关键词： Drying

来源：评论

学校读者我要写书评

暂无评论

Reliability Assessment of Offshore structures Using Subset Simulation with Adaptive Standard Deviation for Mmh Algorithm with Two-Stage Delayed Rejection

SSRN

引用

SSRN 2023年

作者： Ma, Junming Lan, Chengming Guo, Anxin Li, Hui National Center for Materials Service Safety University of Science & Technology Beijing Beijing100083 China Research Institute of Urbanization and Urban Safety School of Civil and Resource Engineering University of Science & Technology Beijing Beijing100083 China Key Lab of Structures Dynamic Behavior and Control Ministry of Education School of Civil Engineering Harbin Institute of Technology Harbin150090 China

This paper explores modified strategies for MMH in the subset simulation for reliability assessment in ocean engineering. To improve the sampling efficiency in complex distributions comprising correlated or non-normal variables, this study proposes a modified approach involving a two-stage delayed rejection and an adaptive STD for the proposal distribution based on MMH. The acceptance rate of the candidate sample in two-stage delayed rejection approach is derived based on the reversibility condition of Markov chain to reduce the repeated samples. Additionally, the STD for all accepted samples is used as the STD for the proposal, which dominates the sampling scale and increases the acceptance rate. The Neal’s normal distribution, the Banana-shaped bivariate distribution, and the correlated joint distribution for wind and wave are adopted to study the sampling efficiency and ergodicity for MMHDR, AMMHDR, and AMMHDDR. Furthermore, three sampling algorithms are employed to generate conditional samples for estimating the probabilities of base shear failure and system failure in jacket platforms. The results indicate that the AMMHDDR can enhance the sampling efficiency, especially for complex distributions with correlated variables. Also, the AMMHDDR can be used in SS to improve the accuracy and reduce the variation when estimating failure probabilities of offshore structures. © 2023, The Authors. All rights reserved.

关键词： Normal distribution

来源：评论

学校读者我要写书评

暂无评论

A Two-Stage Mitigation Method for Optical Turbulence-Induced Errors in Vision-Based Structural Displacement Measurement

SSRN

引用

SSRN 2024年

作者： Zhang, Xiulin Zhou, Wensong Chen, Xize Wang, Yonghuan Wu, Qi Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters The Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Key Lab of Structures Dynamic Behavior and Control The Ministry of Education Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China Central Research Institute of Building and Construction Co. Ltd MCC Group Beijing100088 China

Vision-based structural displacement measurement techniques have been widely applied. However, the visual sensors used for remote monitoring of structures in high-temperature weather are easily affected by optical turbulence, which introduces errors in displacement measurement. Therefore, this paper proposes a two-stage optical turbulence-induced error alleviation method. In the first stage, the steerable pyramid method is used to decompose the monitoring video, and the phase of each position is independently temporal filtered at different spatial scales and directions to reconstruct the video. To further reduce errors with spatial randomness, a feature point matching method considering the weighted distance is used to track the displacement of multiple measurement points on the target structure in the reconstructed video, and the results are spatially filtered in the second stage. The effectiveness of the proposed method was verified through static and dynamic target experiments using a heater to simulate optical turbulence in the lab.ratory. © 2024, The Authors. All rights reserved.

关键词： Errors

来源：评论

学校读者我要写书评

暂无评论

Evaluating Progressive Collapse with Automatic Check Vba Programming and Identifying Optimal Performance Bracing of Systems

SSRN

引用

SSRN 2024年

作者： Bigonah, Mohammad Ali, Barham Haidar Rashed, Parya Li, Shuang Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters The Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China Faculty of Engineering Civil Engineering Department Tishk International University Erbil Iraq School of Civil Engineering Iran University of Science and Technology Narmak Tehran16765-163 Iran

Braced frames are among the most effective systems for resisting progressive collapse;however, determining the optimal bracing system remains a challenge. In this study, several bracing systems were evaluated using a flowchart that satisfied the regulations UFC (chapter 4). VBA programming tools were employed to facilitate the evaluation process. The utilization of the control process and automated VBA programming proved beneficial in the inspection of plastic hinges and ensuring compliance with UFC regulation. The behaviour of four types of braced frames, including concentrically and eccentrically braced frames (CBF and EBF), was investigated under three scenarios involving member removal. The results demonstrated that the inverted V-braced CBF and EBF systems exhibited superior performance by minimizing vertical displacement and redistributing forces on the remaining connected members. In this scenario, despite experiencing significant vertical displacement, lower global forces were observed in all beams and columns. However, the frame without any bracing system failed to meet the regulatory standards, as determined by the control flowchart. Conversely, the remaining structural systems performed exceptionally well. © 2024, The Authors. All rights reserved.

关键词： Compliance control

来源：评论

学校读者我要写书评

暂无评论

Study on Water Absorptivity and Frost Resistance Performance of Self-ignition Coal Gangue Autoclaved Aerated Concrete

Research Square

引用

Research Square 2021年

作者： Cong, Xinyu Tan, Yiqiu Lu, Shuang Wang, Zhaojia Huang, Tianyong School of Transportation Science and Engineering Harbin Institute of Technology Heilongjiang Harbin150090 China School of Civil Engineering Harbin Institute of Technology Harbin150090 China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education 9 Harbin Institute of Technology Harbin150090 China State Key Laboratory of Solid Waste Reuse for Building Materials Materials Academy of Science Research Beijing Building 11 Beijing100041 China

Self-ignition coal gangue (SCG) used as one of precursors to fabricate aerated autoclaved concrete (AAC). Aiming at studying water absorptivity and frost resistance performance of self-ignition coal gangue aerated autoclaved concrete (SCGAAC), three-period water absorbing tests and freezing-thawing tests were carried out and the corresponding results were recorded and analyzed. In order to modify the water absorptivity of SCGAAC, foam stabilizer was applied to adjust pore structure while calcium stearate was expected to change hydrophilic feature of CG. It was demonstrated that the compressive strength of SCGAAC containing foam stabilizer or calcium stearate declined at different levels, although the porosity became lower slightly. For water absorptivity, foam stabilizer failed to decrease the water content at any period and even increased water absorbing rates. Calcium stearate controlled water absorbing rate successfully but the ultimate water content hardly reduced. All of the SCGAAC samples exhibited intact appearance after 50 freezing-thawing cycles and showed excellent frost resistance performance. Three models were proposed to predict water absorptivity and frost resistance performance of SCGAAC and the corresponding prediction results matched test resulted ***: Self-ignition coal gangue;AAC;porosity;water absorptivity;frost resistance performance © 2021, CC BY.

关键词： Porosity

来源：评论

学校读者我要写书评

暂无评论

Static and Fatigue Performances of Clip Anchoring System For Frp Rod Used in Cable

SSRN

引用

SSRN 2024年

作者： Xian, Guijun Niu, Yanzhao Tian, Jingwei Li, Chenggao Yue, Qingrui Guo, Rui Key Lab of Structures Dynamic Behavior and Control Harbin Institute of Technology Ministry of Education Heilongjiang Harbin150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China School of Civil Engineering Harbin Institute of Technology Heilongjiang Harbin150090 China Research Institute of Urbanization and Urban Safety School of Civil and Resource Engineering University of Science and Technology Beijing Beijing China

To obtain the static and fatigue performances and provide the design parameters of FRP rod for the application in cable structures. In the present paper, the design and preparation method of steel clip anchor, steel clip anchor with aluminum sleeve and adhesive interlayer are presented. The effect of taper difference, preload and anchor type on static and fatigue performances is studied by tensile and fatigue test, and the optimal design and application parameters of anchor are obtained. The results show that the peak shear stress of the rod at the front end of anchor can be reduced effectively by setting 0.1 ° taper difference, and the bearing capacity of anchor is increased by 5.3%-40.7% compared with 0 ° and 0.2 ° taper difference. The slippage of anchor can be reduced effectively with the increase of preload, which improves the critical slippage load of anchor. In addition, the stress concentration of rod inside the anchor can be reduced with the added of low modulus adhesive layer between steel clip and rod, which reduces the sensitivity of tensile performances to taper difference and delays the fatigue damage accumulation process of rod inside the anchor, the anchoring efficiency and fatigue resistance increases by 10.9% and 61.4% compared with steel clip anchor, respectively. © 2024, The Authors. All rights reserved.

关键词： Fatigue testing

来源：评论

学校读者我要写书评

暂无评论

Effects of cooking oil on the shrinkage-reducing of high-strength concrete

Results in Materials

引用

Results in Materials 2024年 23卷

作者： Huo, Yanlin Dong, Xinhong Gao, Yang Xu, Xiaodong Zeng, Liang Wu, Yuanchao Zhao, Yunhui Yang, Yingzi Su, Qunshan Huang, Jinguang Lu, Dong School of Civil Engineering Harbin Institute of Technology Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology Harbin Institute of Technology Postdoctor Workstation Henan D.R. Construction Group Research and Development Center Henan Qingshui Construction Technology Co. Ltd.

Autogenous shrinkage is a serious problem for high-strength concrete, which may lead to early-age cracking. Shrinkage-reducing agents are typically used to mitigate the autogenous shrinkage of concrete. However, some negative effects, such as unstable workability and the reduction of compressive strength, will be caused. In this study, emulsified or plain cooking oil is used as a shrinkage-reducing agent in low water-binder ratio concrete. Deformational behaviours of concrete with cooking oil and normal commercially availab.e shrinkage-reducing agent are investigated. Experimental results show that the utilization of cooking oil could significantly reduce the autogenous shrinkage of high-strength concrete due to the reduction of surface tension. Additionally, emulsified cooking oil is better than normal shrinkage-reducing agents and plain cooking oil in many aspects of the concrete. Micro-structure of the concrete with different shrinkage-reducing agents is also observed. Emulsified cooking oil is considered a promising admixture for the mitigation of autogenous shrinkage of high-strength concrete. © 2024 The Authors

关键词： Autogenous shrinkage Cooking oil High strength concrete Shrinkage reducing agent

来源：评论

学校读者我要写书评

暂无评论

dynamic Responses and Cumulative Damage of Coastal Bridges Subjected to Extreme Sequential Earthquake-Tsunamis

SSRN

引用

SSRN 2024年

作者： Zhu, Deming Dong, You Feng, Ruiwei Li, Yaohan Zhai, Changhai Department of Civil and Environmental Engineering The Hong Kong Polytechnic University Hong Kong Research Institute for Sustainable Urban Development The Hong Kong Polytechnic University Hong Kong Department of Construction and Quality Management Hong Kong Metropolitan University Hong Kong Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education Harbin Institute of Technology Harbin150090 China Key Lab of Smart Prevention and Mitigation of Civil Engineering Disaster The Ministry of Industry and Information Technology Harbin Institute of Technology Harbin150090 China

Coastal bridges, as vital components of transportation networks, are vulnerable to damage from successive earthquake-tsunami (EQ-TS) events in rapidly developing coastal hazard-prone cities. Understanding how these bridges perform under the combined effects of earthquakes and tsunamis is crucial. Though studies have investigated coastal buildings facing these hazards, there is limited research on bridges experiencing extreme EQ-TS events, especially on the generation of load sequences, dynamic structural responses, and cumulative damage assessment. To overcome these limitations, this study aims to thoroughly examine the dynamic behavior of reinforced concrete coastal bridges subjected to successive EQ-TS hazards. To generate practical sequential EQ-TS loads, records of the 2011 Tohoku earthquake and resulting tsunami heights, which are calculated based on the earthquake magnitude and epicentral distance, are utilized for analyses. The tsunami wave load time series for each earthquake record is created using a high-fidelity computational fluid dynamics model. Nonlinear time-history analyses are then performed for the bridge model in OpenSees under the synthetic EQ-TS sequences, quantifying structural responses and cumulative damage. Moreover, the comparative results of structural performance under single and successive hazard scenarios are presented and discussed. Results indicate that successive EQ-TS hazards not only induce much larger structural responses as compared to a single EQ hazard, but also produce considerable residual displacements for both bearings and decks. The wave height is more appropriate than the peak ground acceleration as an individual intensity measure for predicting the cumulative damage of bridges under cascading EQ-TS hazards. Relying solely on peak responses for assessing the dynamic performance of piers under successive EQ-TS sequences may underestimate the actual damage. © 2024, The Authors. All rights reserved.

关键词： Earthquakes

来源：评论

学校读者我要写书评

暂无评论

Hysteretic phase transition sequence in 0.67Pb(Mg1/3Nb2/3)O3−0.33PbTiO3 single crystal driven by electric field and temperature

引用

Physical Review B 2015年第18期91卷 184105-184105页

作者： Limei Zheng Xiaoyan Lu Hengshan Shang Zengzhe Xi Ruixue Wang Junjun Wang Peng Zheng Wenwu Cao Condensed Matter Science and Technology Institute Harbin Institute of Technology Harbin 150080 China Key Lab of Structures Dynamic Behavior and Control of the Ministry of Education School of Civil Engineering Harbin Institute of Technology Harbin 150001 China Shaanxi Key Laboratory of Photoelectric Functional Materials and Devices School of Materials and Chemical Engineering Xi'an Technological University Xi'an 710032 China College of Electronics and Information Hangzhou Dianzi University Hangzhou 310018 China Department of Mathematics and Materials Research Institute Pennsylvania State University University Park Pennsylvania 16802 USA

Domain pattern variations with temperature were studied by polarizing light microscopy for the morphotropic phase boundary composition 0.67Pb(Mg1/3Nb2/3)O3−0.33PbTiO3 (PMN-0.33PT) single crystal. At room temperature, the monoclinic MA phase is the dominant phase in the unpoled crystal, which coexists with a small fraction of the tetragonal (T) phase. The orientation of spontaneous polarization was calculated to be ∼4.8∘ away from the pseudocubic 〈111〉C in the {001}C plane family. Under an electric field of 6 kV/cm along [011]C, a single domain orthorhombic (O) phase was induced but partially switched back to MA a few hours after the removal of the E field. It was found that the temperature induced phase transition sequence of the [011]C poled PMN-0.33PT single crystal is strongly hysteretic. On heating, the phase transition sequence is as follows: coexistence of O phase and MA→rhombohedral→monoclinicMC→cubic(C). On cooling, the phase transition sequence is given by C→T→MA. The complete set of dielectric, piezoelectric, and elastic constants for the [011]C poled PMN-0.33PT single crystal was measured, which showed the strong feature of the single domain O phase with high shear (d15=2321pC/N,d24=1941pC/N) and low longitudinal piezoelectric coefficients (d33=165pC/N).

关键词： SINGLE crystals ELECTRIC fields TEMPERATURE POLARIZATION (Electricity) PIEZOELECTRIC devices

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：