检索结果-内蒙古大学图书馆

Characterization and Propagation of Historical and Projected Droughts in the Umatilla River Basin, Oregon, USA

Advances in Atmospheric Sciences 2024年第2期41卷 247-262,I0020-I0028页

作者： Sudip GAUTAM Alok SAMANTARAY Meghna BABBAR-SEBENS Meenu RAMADAS School of Civil and Construction Engineering Oregon State UniversityCorvallisOR 97331USA School of Infrastructure Indian Institute of TechnologyBhubaneswarOdisha 752050India

Climate change is expected to have long-term impacts on drought and wildfire risks in Oregon as summers continue to become warmer and drier. This paper investigates the projected changes in drought characteristics and drought propagation in the Umatilla River Basin in northeastern Oregon for mid-century(2030–2059) and late-century(2070–2099) climate scenarios. Drought characteristics for projected climates were determined using downscaled CMIP5 climate datasets from ten climate models and Soil and Water Assessment Tool to simulate effects on hydrologic processes. Short-term(three months) drought characteristics(frequency, duration, and severity) were analyzed using four drought indices, including the Standardized Precipitation Index(SPI-3), Standardized Precipitation-Evapotranspiration Index(SPEI-3), Standardized Streamflow Index(SSI-3), and the Standardized Soil Moisture Index(SSMI-3). Results indicate that short-term meteorological droughts are projected to become more prevalent, with up to a 20% increase in the frequency of SPI-3drought events. Short-term hydrological droughts are projected to become more frequent(average increase of 11% in frequency of SSI-3 drought events), more severe, and longer in duration(average increase of 8% for short-term droughts).Similarly, short-term agricultural droughts are projected to become more frequent(average increase of 28% in frequency of SSMI-3 drought events) but slightly shorter in duration(average decrease of 4%) in the future. Historically, drought propagation time from meteorological to hydrological drought is shorter than from meteorological to agricultural drought in most sub-basins. For the projected climate scenarios, the decrease in drought propagation time will likely stress the timing and capacity of water supply in the basin for irrigation and other uses.

关键词： Umatilla drought SPI SPEI SSI SSMI

来源：评论

学校读者我要写书评

暂无评论

Modeling uncertainty propagation in Eccentric Braced Frames using Endurance Time method and Radial Basis Function networks

引用

Frontiers of Structural and civil engineering 2025年第3期19卷 378-395页

作者： Mohsen MASOOMZADEH Mohammad Ch.BASIM Mohammad Reza CHENAGHLOU Amir H.GANDOMI Industrial Technical Center for Metal Construction Saint-Aubin 91190France Department of Civil and Urban Engineering National Institute of Applied Sciences of RennesRennes 35700France Faculty of Civil Engineering Sahand University of TechnologyTabriz 51335Iran Faculty of Engineering&IT University of Technology SydneyUltimoNSW 2007Australia University Research and Innovation Center Óbuda UniversityBudapest 1034Hungary

A robust analytical model of Eccentric Braced Frames (EBFs), as a well-known seismic resistance system, helps to comprehensive earthquake-induced risk assessment of buildings in different performance levels. Recently, the modeling parameters have been introduced to simulate the hysteretic behavior of shear links in EBFs with specific Coefficient of Variation associated with each parameter to consider the uncertainties. The main purpose of this paper is to assess the effect of these uncertainties in the seismic response of EBFs by combining different sources of aleatory and epistemic uncertainties while making a balance between the required computational effort and the accuracy of the responses. This assessment is carried out in multiple performance levels using Endurance Time (ET) method as an efficient Nonlinear Time History Analysis. To demonstrate the method, a 4-story EBF that considers behavioral parameters has been considered. First, a sensitivity analysis using One-Variable-At-a-Time procedure and the ET method has been utilized to sort the parameters with regard to their importance in seismic responses in two intensity levels. A sampling-based reliability method is first used to propagate the modeling uncertainties into the fragility curves of the structure. Radial Basis Function Networks are then utilized to estimate the structural responses, which makes it feasible to propagate the uncertainties with an affordable computational effort. The Design of Experiments technique is implemented to acquire the training data, reducing the required data. The results show that the mathematical relationships defined by Artificial Neural Networks and using the ET method can estimate the median Intensity Measures and shifts in dispersions with acceptable accuracy.

关键词： Eccentric Braced Frames uncertainty propagation behavioral parameters Endurance Time method correlation Latin hypercube sampling Artificial Neural Networks Radial Basis Function networks

来源：评论

学校读者我要写书评

暂无评论

MODELING OF SKELETON CURVES AND EVALUATION OF DEFORMATION CAPACITY OF EWECS COLUMNS

Journal of Structural and Construction Engineering

引用

Journal of Structural and construction engineering 2023年第803期88卷 153-160页

作者： Matsubara, Kosuke Enkhtuvshin, Serchinnyamgyal Matsui, Tomoya Taguchi, Takashi Dept. of Architecture and Civil Engineering Toyohashi University of Technology Japan Engineering Center YAHAGI CONSTRUCTION CO. LTD Japan

In this research, static loading test of engineering Wood Encased Concrete-Steel (EWECS) columns with different steel depth has been conducted. From the results, it was confirmed that deterioration in capacity during large deformation, and the concrete failed in shear. Flexural strength could be estimated by the generalized superposed strength theory and shear strength could be estimated by the simplified equation given in the Standard for Structural Calculation for Steel Reinforced Concrete Structures. In addition, an evaluation equation for stiffness reduction factor at yield point in the skeleton curve and ultimate deformation have been proposed based on test results. © 2023 Architectural Institute of Japan. All rights reserved.

关键词： Deterioration

来源：评论

学校读者我要写书评

暂无评论

Effects of TiO_(2)content on microstructure,thermal and mechanical properties of microwave sintered lunar regolith simulant

引用

Science China(Technological Sciences) 2025年第4期68卷 233-248页

作者： Zekai WANG Yan ZHOU Long XIAO Cheng ZHOU Lieyun DING National Center of Technology Innovation for Digital Construction School of Civil and Hydraulic EngineeringHuazhong University of Science and TechnologyWuhan430074China Planetary Science Institute China University of Geosciences(Wuhan)Wuhan430074China

Dense building components can be fabricated using lunar regolith simulants prepared via microwave *** this study,the microstructure and properties of such simulants containing high(14.72%),medium(6.71%),and low(1.7%)TiO_(2)contents prepared via microwave sintering at different temperatures(1030℃-1070℃)were *** sample sintered at 1060℃ with 14.72%TiO_(2)content exhibited the highest compressive strength of(125.2±22)*** was because high TiO_(2)content was more conducive to densification due to microwave *** influence of TiO_(2)content and sintering temperature on the strength of microwave-sintered samples was statistically analyzed,which revealed that sintering temperature was the main influencing factor(F value=187.3)and TiO_(2)content was the auxiliary influencing factor(F value=4.91).Using an enhanced multilayer perceptron model,a continuous surface diagram and prediction model were *** were then used to determine the influence of sintering temperature and TiO_(2)content on the compressive strength as well as to predict compressive strength with comparable *** study provides insights into microwave sintering of materials for future lunar construction.

关键词： lunar regolith simulant microwave sintering thermal property mechanical property modeling and prediction

来源：评论

学校读者我要写书评

暂无评论

Comparison of microwave- and thermal-assisted rock fragmentation methods at different temperatures and loading rates

引用

International Journal of Mining Science and technology 2024年第6期34卷 799-819页

作者： Wei Yao Shuai Wang Bangbiao Wu Ying Xu Kaiwen Xia State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation School of Civil EngineeringTianjin UniversityTianjin 300072China China Railway Design Corporation Tianjin 300308China Institute of Geosafety School of Engineering and TechnologyChina University of GeosciencesBeijing 100083China

Understanding the effects of microwave irradiation and thermal treatment on the dynamic compression and fragmentation properties of rocks is essential to quantify energy consumption in rock *** this study,Fangshan granite(FG)specimens were exposed to microwave irradiation and heat *** damage of FG specimens induced by these two methods was compared using X-ray CT scanning and ultrasonic wave *** temperatures of FG after microwave irradiation and thermal treatment were effectively evaluated using a newly proposed technique.A novelty method for precisely determining the geometric features of fragments is developed to estimate the fragmentation ***,the dynamic uniaxial compressive strength(UCS),the dynamic fragmentation characteristics,and the fragmentation energy of FG after these two pretreatment methods can be reasonably *** noticeable distinction of loading rate effect on the dynamic UCS of FG between these two pretreatment methods is first observed.A relationship is established between the dynamic UCS and the damage induced by microwave irradiation and heat ***,fragmentation energy fan analysis is introduced to accurately compare the fragmentation properties of FG after two pretreatment methods in dynamic compression tests.

关键词： Fangshan granite Dynamic experiments Microwave irradiation Thermal treatment Loading rate Fragmentation

来源：评论

学校读者我要写书评

暂无评论

Numerical investigation on the responses of existing single piles due to adjacent twin tunneling considering the lagging distance

引用

Underground Space 2023年第4期11卷 171-188页

作者： Chana Phutthananon Somkiat Lertkultanon Pornkasem Jongpradist Ochok Duangsano Suched Likitlersuang Pitthaya Jamsawang Construction Innovations and Future Infrastructures Research Center Department of Civil EngineeringFaculty of EngineeringKing Mongkut’s University of Technology ThonburiBangkok 10140Thailand Geotechnical and Foundation Engineering Co. LtdBangkok 10230Thailand Centre of Excellence in Geotechnical and Geoenvironmental Engineering Department of Civil EngineeringFaculty of EngineeringChulalongkorn UniversityBangkok 10330Thailand Soil Engineering Research Center Department of Civil EngineeringKing Mongkut’s University of Technology North BangkokBangkok 10800Thailand

This paper presents an assessment of the influence of the lagging distance between two horizontal tunnel faces of the side-by-side twin tunnels on the responses of the adjacent existing single pile by a series of three-dimensional numerical *** different relative positions between the pile tip and the tunnel are considered to cover the short and long pile *** responses of the existing pile in terms of pile head settlement,axial force,lateral movement and bending moment are considered and *** numerical results indicate that the lagging distance between twin tunnel faces significantly affects not only the soil movements but also the responses of the existing single *** critical case that produces unsatisfactory pile responses due to twin tunneling is when the lagging distance between the second tunnel and the preceding tunnel equals to the shield *** is recommended that the lagging distance be not less than three times of shield length when the two tunnels need to be concurrently excavated.

关键词： Twin tunnels Tunnel lagging distance Existing pile Finite element analysis Pile responses

来源：评论

学校读者我要写书评

暂无评论

Development and verification of real-time hybrid simulation with deep learning-based nonlinear numerical substructure

引用

Earthquake engineering and Structural Dynamics 2024年第6期53卷 2141-2161页

作者： Chen, Pei-Ching Hsu, Shang-Chi Ma, Chung-Chun Department of Civil and Construction Engineering National Taiwan University of Science and Technology Taipei Taiwan National Center for Research on Earthquake Engineering National Applied Research Laboratories Taipei Taiwan

Real-time hybrid simulation (RTHS) provides an effective approach for assessing structural responses under dynamic excitation. However, performing RTHS with a complex nonlinear numerical substructure is challenging, as computations must be completed within predefined time steps. In this study, a RTHS framework which contains a rate-dependent experimental substructure and a nonlinear numerical substructure has been proposed and verified. An OpenSees model was constructed to simulate a three-story, one-bay steel building with viscous dampers at each floor and was used to generate the training dataset through a large number of nonlinear time-history analyses. A Recursive Long Short–Term Memory (LSTM) neural network model was trained to predict the nonlinear structural responses using ground acceleration and time-delayed damper force located at the first story. Hence, the Recursive-LSTM model served as a surrogate model for the numerical substructure, implicitly incorporating delay compensation for the experimental substructure. After the training was completed, offline testing was performed to realize the stability of the RTHS framework. Then, online RTHS with a virtual damper taken as the experimental substructure was conducted to further confirm the feasibility and accuracy. Afterwards, a nonlinear rotary fluid viscous damper (RFVD) was fabricated as the actual experimental substructure, whose dynamic response was not considered in training the Recursive-LSTM model. Finally, RTHS with the RFVD was completed successfully and stably, demonstrating the capability of a well-trained Recursive-LSTM model to serve as a nonlinear numerical substructure incorporating constant delay compensation for RTHS. The potential of the proposed RTHS framework is worth further studies in the future. © 2024 John Wiley & Sons Ltd.

关键词： Long short-term memory

来源：评论

学校读者我要写书评

暂无评论

Factors influencing contractors’ low-carbon construction behaviors in China: a LDA-DEMATEL-ISM approach

引用

Environmental Science and Pollution Research 2024年第36期31卷 49040-49058页

作者： Wang, Zhihai Wang, Wentao Li, Dezhi Wang, Yang Yu, Lugang Zhou, Shenghua Zhou, Huan Jiangsu Zhongjiang Digital Construction Technology Company Limited Nanjing210008 China Department of Construction and Real Estate School of Civil Engineering Southeast University Nanjing210018 China

Contractors’ low-carbon construction behaviors (CLCB) are pivotal in advancing decarbonization during the construction phase. However, there exists a notable gap in the comprehensive exploration of the multifaceted factors and mechanisms influencing CLCB. Therefore, this study aims to systematically identify the factors influencing CLCB in China, examine the interrelationships among these factors, and pinpoint the key determinants. Based on topic modeling of Latent Dirichlet Allocation (LDA), influencing factors are identified firstly from the pertinent literature. Subsequently, the causality degree and centrality degree between these factors are assessed by the Decision-Making Trial and Evaluation Laboratory (DEMATEL), followed by the establishment of a hierarchical structure using the Interpretive Structural Modeling (ISM) method, culminating in the identification of pivotal factors. Findings reveal that (1) 21 influential factors influencing CLCB are identified. (2) "Incentive policies for relevant stakeholders" and "Low-carbon regulation and supervision" emerge as key influences. (3) CLCB should be guided by policy and subjective awareness, fortified by market and management support, underpinned by technology, and directly driven by economic considerations. This research furnishes valuable insights for promoting low-carbon development during the construction phase, thereby assisting the construction sector in achieving carbon peak and carbon neutrality. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

关键词： Contractors

来源：评论

学校读者我要写书评

暂无评论

On-site Visual construction Management System Based on the Integration of SLAM-based AR and BIM on a Handheld Device

引用

KSCE Journal of civil engineering 2023年第11期27卷 4688-4707页

作者： Hsieh, Chang-Cheng Chen, Hung-Ming Wang, Sheng-Kai Dept. of Civil & Construction Engineering National Taiwan University of Science and Technology Taipei106 Taiwan

Recently, Simultaneous Localization and Mapping (SLAM) has been integrated into the development of AR systems. Using conventional SLAM adoption method to overlay a building information model (BIM) onto the image of a real scene on handheld device in a construction site will result in poor model overlaying accuracy owing to the relatively unique environment and monotonous texture of such environment. This paper proposes an adoption method of SLAM suitable for construction environment to improve positioning accuracy for the fitting of BIMs for the AR presentation. In addition, a AR system to visualize construction progress on-site is developed. It allows site personnel to input on-site work progress through an AR device, then compares the originally planned construction progress with the actual on-site progress, and presents BIM components using different colors in the AR mode to show whether work progress on each component is ahead or behind schedule intuitively. © 2023, Korean Society of civil Engineers.

关键词： Augmented reality

来源：评论

学校读者我要写书评

暂无评论

Microbial self-healing of cracks in cement-based materials and its influencing factors

引用

Frontiers of Structural and civil engineering 2023年第11期17卷 1630-1642页

作者： Xiaoniu YU Qiyong ZHANG Xuan ZHANG Mian LUO Jiangsu Key Laboratory of Construction Materials Southeast UniversityNanjing 211189China College of Engineering and Technology Southwest UniversityChongqing 400715China School of Civil Engineering and Architecture Jiangsu University of Science and TechnologyZhenjiang 212114China College of Civil Science and Engineering Yangzhou UniversityYangzhou 225127China

Cement-based materials are brittle and crack easily under natural *** can reduce service life because the transport of harmful substances can cause corrosion damage to the *** review discusses the feasibility of using microbial self-healing agents for crack *** and spherical carriers can be used to load microbial self-healing agents and protect microbes,which prolongs the self-healing *** area self-healing ratio,permeability,mechanical strength,precipitation depth method,numerical modeling,and ultrasonic method can be employed to identify the self-healing effect of ***,the self-healing mechanism is systematically *** results showed that microbial self-healing agents can repair cracks in cement-based materials in underground projects and dam *** difficulties and future development of self-healing cracks were analyzed.A microbial selfhealing agent was embedded in the cement-based material,which automatically repaired the developing *** the development of intelligent building materials,self-healing cracks have become the focus of attention.

关键词： cement-based materials cracks microbial self-healing agent mechanism intelligent building materials

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：