作者： Lin, Sen;Chou, Nengzhuo;Bao, Dingwen;Zhang, Genbao;Xiong, Chengwang;...

期刊： Computers & Structures,2023年276:106955 ISSN：0045-7949

通讯作者： Lin, Sen(senlin@hnu.edu.cn)

作者机构： [Chou, Nengzhuo; Lin, Sen] Hunan Univ, Coll Mech & Vehicle Engn, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Peoples R China.;[Xie, Yi Min; Bao, Dingwen] RMIT Univ, Ctr Innovat Struct & Mat, Sch Engn, GPO Box 2476, Melbourne 3001, Australia.;[Bao, Dingwen] RMIT Univ, Sch Architecture & Urban Design, GPO Box 2476, Melbourne 3001, Australia.;[Zhang, Genbao] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Hunan, Peoples R China.;[Xiong, Chengwang] Harbin Engn Univ, Coll Shipbuilding Engn, Harbin 150001, Peoples R China.

通讯机构： [Sen Lin] S;State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, College of Mechanical and Vehicle Engineering, Hunan University, Changsha 410082, China

关键词： Brain corals;Matter interchange;Topological optimization;Turbulent hydrodynamics

摘要： This paper presents a study of the morphogenesis of brain corals based on an experimental investigation and a topological optimization method. The resistance to matter interchange was employed to allocate the optimal space for the growth of polyp colonies from the perspective of topological optimization, where the optimized structures are those of natural brain corals. Computational fluid dynamics simulations revealed that these complicated structures can provide shelter to protect polyps from ocean currents. A reverse mold was prepared from silica gel and used to cast models from mixtures of cement and calcium carbonate, where the mixture ratio was determined based on compressive strength and biocompatibility. Based on an acid corrosion experiment, the matter interchange capability was verified. This study also proved that the many folds in the structure of brain corals contribute to the circulation of seawater, thus maintaining the concentration of nutrients and hindering the deposition of harmful substances. This paper establishes an innovative methodology for the creation of artificial brain corals, which is important for environmental restoration. © 2022 Elsevier Ltd

语种： 英文

作者： Zhang, Shusen;Zheng, Xia;Yin, Canbin;Ye, Yunpeng;Li, Xingong

期刊： Case Studies in Construction Materials,2023年18:e01739 ISSN：2214-5095

通讯作者： Li, Xingong(lxgwood2021@163.com)

作者机构： [Li, Xingong; Zhang, Shusen; Ye, Yunpeng; Zheng, Xia] Cent South Univ Forestry Technol, Coll Mat Sci & Engn, Changsha 410004, Peoples R China.;[Yin, Canbin] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.

通讯机构： [Xingong Li] C;College of Materials Science and Engineering, Central South University of Forestry,Technology, Changsha 410004, China

关键词： Rice straw;Silicate cement;Compatibility;Hydration;Inorganic composites

摘要： In order to study the feasibility of preparing cement particle board by compounding silicate and rice straw shavings, this paper explored their compatibility by detecting the heat of hydration of both by HPLC and characterized by FTIR, SEM and XRD. The results suggested that rice straw contained a certain amount of sugars soluble in water as well as organic carboxylic acids, having toxic effects on the hydration of silicate cement and could retard the hydration reaction of silicate cement. The addition of rice straw would inhibit the generation of crystals of hydration products in the early stage of silicate cement hydration, which makes it difficult for the C-S-H gel to build a dense spatial mesh, resulting in the poor compatibility of rice straw with silicate cement. The verification experiments exhibited that the static flexural strength of straw cement particleboard was far lower than the standard value of CB/T 24312–2009 cement particleboard, indicating that rice straw was unsuitable for direct apply for the preparation of rice straw silicate cement particleboard, and the compatibility regulation of rice straw and silicate cement was required. © 2022 The Authors

语种： 英文

作者： Liu, Jing;Lyu, Fei;Ding, Fa-Xing;Liu, Xue-Mei

期刊： Advanced Steel Construction,2022年18(3):658-669 ISSN：1816-112X

通讯作者： Lyu, Fei(lyufei@csu.edu.cn);Ding, Fa-Xing(dinfaxin@csu.edu.cn)

作者机构： [Liu, Jing] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.;[Lyu, Fei; Ding, Fa-Xing] Cent South Univ, Sch Civil Engn, Changsha 410075, Hunan, Peoples R China.;[Liu, Xue-Mei] Univ Melbourne, Dept Infrastruct Engn, Parkville, Vic 3010, Australia.

通讯机构： [Lyu, F.; Ding, F.-X.] S;School of Civil Engineering, Hunan Province, China

关键词： Hysteretic behavior;Plastic energy consumption;Shear connection degree;Steel–concrete composite beam

摘要： The finite element (FE) software ABAQUS was used to establish a 3D FE model and perform a pseudo-static analysis of steel–concrete composite beams. With the validated model, the influences of several key parameters, including shear connection degree, force ratio, and transverse reinforcement ratio, on seismic behavior were investigated and discussed. In addition, the working performance of studs was analyzed. The FE analysis results show that the steel girder is the main energy dissipation component of the composite beam, and the energy dissipation of the steel girder is more than 80% of the total energy. The next is longitudinal reinforcement, followed by a concrete slab, the minimum proportion is the studs. Results show that the energy dissipation ratio of studs is less than 1% under the condition of the parameters. However, an increase in shear connection is beneficial to improve the energy dissipation of steel girders and rebars. Shear connection, force ratio, and steel girder width–thickness ratio are the major factors that influence bearing capacity and seismic behavior. Transverse reinforcement, section form, and st ud diameter are the secondary factors. Finally, a seismic design for composite beams was established. © 2022 by The Hong Kong Institute of Steel Construction. All rights reserved.

语种： 英文

作者： Li, Shanshan;Jiang, Changbo;Ma, Yuan;Long, Yuannan;Wu, Ruixuan;...

期刊： Atmosphere,2022年13(10):1735- ISSN：2073-4433

通讯作者： Jiang, Changbo(jiangchb@csust.edu.cn)

作者机构： [Long, Yuannan; Li, Donglin; Jiang, Changbo; Wu, Ruixuan; Ma, Yuan; Zhu, Qingxiong; Li, Shanshan; Ning, Zihao; Li, Chuannan] Changsha Univ Sci & Technol, Sch Hydraul Engn, Changsha 410114, Peoples R China.;[Li, Shanshan] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.;[Long, Yuannan; Li, Donglin; Jiang, Changbo; Wu, Ruixuan; Ma, Yuan; Zhu, Qingxiong; Ning, Zihao; Li, Chuannan] Key Lab Dongting Lake Aquat Ecoenvironm Control &, Changsha 410114, Peoples R China.

通讯机构： [Changbo Jiang] S;School of Hydraulic Engineering, Changsha University of Science & Technology, Changsha 410114, China<&wdkj&>Key Laboratory of Dongting Lake Aquatic Eco-Environmental Control and Restoration of Hunan Province, Changsha 410114, China<&wdkj&>Author to whom correspondence should be addressed.

关键词： GPM constellation satellites;IMERG V06;the Dongting Lake basin;satellite precipitation estimates;precision

摘要： Precipitation data from ground-based observatories in the Dongting Lake basin are often missing, resulting in large errors in surface precipitation data obtained by interpolation, which affects the accuracy of hydro-meteorological studies. Integrated Multisatellite Retrievals for Global Precipitation Measurement (IMERG) is the main high-resolution precipitation product, which is available to supplement measured missing data. To evaluate the applicability of this product in the Dongting Lake basin at multiple spatial and temporal scales, this paper analyzes daily, monthly, seasonal, annual, and extreme precipitation events of the three latest IMERG precipitation products (IPPs) (IMERG-F, IMERG-E, and IMERG-L) using eight statistical evaluation metrics. We find that the spatial and temporal performance of IMERG precipitation products varies over different time scales and topographic conditions. However, all three metrics (CC, RMSE, and RB) of the IMERG-F precipitation products outperform the IMERG-E and IMERG-L precipitation products for the same period. In the comparison of IMERG and TRMM (Tropical Rainfall Measuring Mission) precipitation products on monthly and seasonal scales, IMERG-F performed the best. IPPs can capture precipitation more accurately on seasonal scales and perform better in winter, indicating good detection of trace precipitation. Both high and low altitudes are not favorable for the satellite detection of extreme precipitation in both general and extreme precipitation events. Overall, the accuracy of IMERG-F with correction delay is slightly better than that of IMERG-E and IMERG-L without correction under near-real-time conditions, which is applicable in the Dongting Lake basin. However, the correction process also exacerbates overestimation of the precipitation extent.

语种： 英文

作者： Gong, B.B.

期刊： Advances in Transportation Studies,2022年2(Special Issue):133-144 ISSN：1824-5463

通讯作者： Gong, B.B.(24148408@qq.com)

作者机构： [Gong, B.B.] College of Civil Engineering, Hunan City University, YiYang;413000, China;Hunan Engineering Research Center of Structural Safety and Disaster Prevention for Urban Underground infrastructure, YiYang;[Gong, B.B.] 413000, China<&wdkj&>Hunan Engineering Research Center of Structural Safety and Disaster Prevention for Urban Underground infrastructure, YiYang;[Gong, B.B.] 413000, China

通讯机构： [Gong, B.B.] C;College of Civil Engineering, China

关键词： Grey gm(1,N) model;Improving random forest;Risk projection;Road traffic safety;Similarity measure

摘要： Traditional road safety prediction methods have low recall rate and poor prediction accuracy. This paper proposes a road traffic safety risk prediction method based on improved random forest. First, collect road traffic data, such as static data, traffic dynamic data, other traffic related data and accident data. Then, the abnormal road traffic data are identified based on chaos method, and the abnormal data are repaired with grey GM (1, n) model. Finally, the random forest algorithm is improved by optimizing the similarity measurement method and the optimal addition principle, and the improved random forest algorithm is used to predict the road traffic safety risk. The results show that the maximum recall rate of this method is 95%, and the prediction accuracy of road traffic safety risk is 93%. © 2022, Aracne Editrice. All rights reserved.

语种： 英文

作者： Ling, Tonghua;He, Wenchao;Liu, Xianjun;Zhang, Sheng;Huang, Fu;...

期刊： Geophysical Prospecting,2022年70(6):1052-1065 ISSN：0016-8025

通讯作者： He, Wenchao(hewenchao1224@stu.csust.edu.cn)

作者机构： [Ling, Tonghua; Liu, Xianjun; He, Wenchao; Huang, Fu; Hua, Fei] Changsha Univ Sci & Technol, Coll Civil Engn, Changsha 410114, Peoples R China.;[Zhang, Sheng] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.

通讯机构： [Wenchao He] C;College of Civil Engineering, Changsha University of Science and Technology, Changsha, 410114 China

关键词： Ground-penetrating radar;Finite difference methods;Numerical modelling;Signal processing;Wavelet

摘要： The Fisher–Yates random shuffling algorithm combined with the finite-difference time-domain method is proposed to construct a fine grid model for the forward simulation of ground-penetrating radar in mixed media. First, the finite-difference time-domain method was used to divide the coarse grid model into several fine grid models by conforming to the boundary conditions of different media, and the corresponding dielectric parameters were assigned to Yee cells in each fine grid model. Then, the Fisher–Yates random shuffling algorithm was used to randomly scramble all Yee cells with equal probability, and the array of scrambled Yee cells was recombined into a coarse grid model. Finally, the geoelectric model of mixed media was generated with the finite-difference time-domain method, and a ground-penetrating radar image excited by electromagnetic wave pulses was obtained. To explore the characteristic signals and dielectric properties of the ground-penetrating radar electromagnetic response in mixed media, image entropy theory was used to describe the ground-penetrating radar image, and waveform analysis and wavelet transform mode maximum methods were used to analyse the single-channel ground-penetrating radar signal of the mixed media. The results showed that the Fisher–Yates random shuffling–finite-difference time-domain method can be used to construct a valid and stable fine grid model for simulating ground-penetrating radar in mixed media. The model effectively inhibits electromagnetic attenuation and energy dissipation, and the wavelet transform mode maximum method explains the relative dielectric permittivity distribution of the mixed media. The findings of this study can be used as a theoretical basis for correcting radar parameters and interpreting images when ground-penetrating radar is applied to mixed media. © 2022 European Association of Geoscientists & Engineers.

语种： 英文

作者： Chen, C.;Zhu, S.;Zhang, G.;Morsy, A. M.;Zornberg, J. G.;...

期刊： Geosynthetics International,2022年29(3):241-253 ISSN：1072-6349

通讯作者： Zhang, G

作者机构： [Zhu, S.; Chen, C.; Huang, J.] Hunan Univ, Minist Educ, Key Lab Bldg Safety & Energy Efficiency, Changsha, Peoples R China.;[Zhu, S.; Chen, C.; Huang, J.] Hunan Univ, Coll Civil Engn, Changsha, Hunan, Peoples R China.;[Zhang, G.] Hunan City Univ, Coll Civil Engn, Yiyang, Hunan, Peoples R China.;[Morsy, A. M.] Loughborough Univ, Sch Architecture Bldg & Civil Engn, Loughborough, Leics, England.;[Morsy, A. M.] Cairo Univ, Dept Civil Engn, Giza 12613, Egypt.

通讯机构： [Zhang, G ] H;Hunan City Univ, Coll Civil Engn, Yiyang, Hunan, Peoples R China.

关键词： Geosynthetics;Glass fiber-reinforced polymer;Cemented soils;Interface creep behavior;Burgers model

摘要： This paper presents an experimental investigation and modeling of interface creep behavior of glass fiber-reinforced polymer (GRFP) tendons embedded in cemented soils. Rapid and creep pullout tests were carried out on GRFP tendons embedded in cemented soils using a specially developed pullout setup. Interface creep displacement responses for specimens with two different water-cement ratios were derived under various interface shear stress conditions. A modified Burgers model was developed to characterize the interface creep behavior by incorporating a time-dependent viscosity coefficient. This viscosity coefficient was calibrated using creep rate variation obtained experimentally. Regression fittings on a part of interface creep measurements were conducted to determine the value of the parameters of the interface creep model. Additional interface creep measurements were used to validate the applicability of the presented creep testing protocol and the effectiveness of the rheological modeling was validated. © 2021 Thomas Telford Ltd.

语种： 英文

作者： Zhang, Genbao;Chen, Changfu;Zhang, Yuhao;Zhao, Hongchao;Wang, Yufei;...

期刊： Geomechanics and Engineering,2022年28(6):599-611 ISSN：2005-307X

通讯作者： Wang, YF

作者机构： [Zhang, Genbao] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Hunan, Peoples R China.;[Wang, Yufei; Wang, YF] Chongqing Univ, Inst Smart City, Chongqing Univ Liyang, Zhenjiang 213300, Jiangsu, Peoples R China.;[Zhang, Genbao] Hunan Engn Res Ctr Struct Safety & Disaster Preve, Yiyang 413000, Hunan, Peoples R China.;[Chen, Changfu] Hunan Univ, Minist Educ, Key Lab Bldg Safety & Energy Efficiency, Changsha 410082, Hunan, Peoples R China.;[Chen, Changfu] Hunan Univ, Coll Civil Engn, Changsha 410082, Hunan, Peoples R China.

通讯机构： [Wang, YF ] C;Chongqing Univ, Inst Smart City, Chongqing Univ Liyang, Zhenjiang 213300, Jiangsu, Peoples R China.

关键词： back propagation neural network;cemented soil;element pullout test;glass fibre reinforced polymer reinforcement;interface bond strength;machine learning;particle swarm optimisation

摘要： Tendon reinforced cemented soil is applied extensively in foundation stabilisation and improvement, especially in areas with soft clay. To solve the deterioration problem led by steel corrosion, the glass fiber-reinforced polymer (GFRP) tendon is introduced to substitute the traditional steel tendon. The interface bond strength between the cemented soil matrix and GFRP tendon demonstrates the outstanding mechanical property of this composite. However, the lack of research between the influence factors and bond strength hinders the application. To evaluate these factors, back propagation neural network (BPNN) is applied to predict the relationship between them and bond strength. Since adjusting BPNN parameters is time-consuming and laborious, the particle swarm optimisation (PSO) algorithm is proposed. This study evaluated the influence of water content, cement content, curing time, and slip distance on the bond performance of GFRP tendon-reinforced cemented soils (GTRCS). The results showed that the ultimate and residual bond strengths were both in positive proportion to cement content and negative to water content. The sample cured for 28 days with 30% water content and 50% cement content had the largest ultimate strength (3879.40 kPa). The PSO-BPNN model was tuned with 3 neurons in the input layer, 10 in the hidden layer, and 1 in the output layer. It showed outstanding performance on a large database comprising 405 testing results. Its higher correlation coefficient (0.908) and lower root-mean-square error (239.11 kPa) were obtained compared to multiple linear regression (MLR) and logistic regression (LR). In addition, a sensitivity analysis was applied to acquire the ranking of the input variables. The results illustrated that the cement content performed the strongest influence on bond strength, followed by the water content and slip displacement. © 2022 Techno-Press, Ltd.

语种： 英文

作者： Zhu, Shimin;Chen, Changfu;Zhang, Genbao;Du, Cheng

期刊： Canadian Geotechnical Journal,2022年59(9):1587-1601 ISSN：0008-3674

通讯作者： Chen, Changfu(cfchen@hnu.edu.cn)

作者机构： [Du, Cheng; Zhu, Shimin; Chen, Changfu] Hunan Univ, Key Lab Bldg Safety & Energy Efficiency, Minist Educ, Changsha 410082, Hunan, Peoples R China.;[Du, Cheng; Zhu, Shimin; Chen, Changfu] Hunan Univ, Coll Civil Engn, Changsha 410082, Hunan, Peoples R China.;[Zhang, Genbao] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Hunan, Peoples R China.

通讯机构： [Chen, C.] K;Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan, China

关键词： anchoring force loss;load transfer;prestressed ground anchor;relaxation

摘要： Anchoring force loss is critically concerned for the in-service performance of prestressed ground anchors. This time-dependent loss of pretension exerted at the anchor head is caused primarily by stress relaxation, which integrally manifests the rheological properties of the anchor and the geomaterial in which the anchor is embedded. A load-transfer modeling framework was established to derive the time-dependent anchoring force response. The modeling parameters were directly calibrated via element-scale pullout stress relaxation test using a specially developed setup. The applicability and effectiveness of this analytical modeling framework were verified via large-scale laboratory model tests and in situ tests of prestressed an-chors. The predictions derived using the presented modeling framework were in good agreement with measurements in both laboratory model tests and in situ tests, particularly for evolutions of anchoring force over time. Sensitivity evaluation of the model parameters was performed to study their respective impact on the anchoring force loss response. This work can provide insights into the understanding of the anchoring force loss behavior of prestressed ground anchors and facilitate their design practice for in-service performance. © 2022 The Author(s).

语种： 英文

作者： 刘哲锋;郑潇;王玉奎

期刊： 工程力学,2021年38(12):125-136 ISSN：1000-4750

通讯作者： Zheng, Xiao(874871915@qq.com)

作者机构： [刘哲锋; 郑潇] School of Civil Engineering and Architecture, Changsha University of Science & Technology, Changsha;410004, China;[王玉奎] School of Civil Engineering and Architecture, Hunan City University, Yiyang;413049, China;[刘哲锋; 郑潇] 410004, China

通讯机构： [Zheng, X.] S;School of Civil Engineering and Architecture, China

关键词： 钢筋混凝土构件;地震作用;变幅加载;滞回阶段;耗能能力衰变;受弯破坏

摘要： 为了优化地震作用下研究钢筋混凝土构件损伤量化的理论流程,建立合理的耗能能力计算方法,基于初始滞回阶段RC构件耗能能力衰变规律,在研究了同类型试件相等加载位移在不同滞回阶段D-n曲线形态特征的基础上,提出了后续滞回阶段耗能能力衰变模型。通过对不同滞回阶段的衰减指数进行拟合分析,提出了耗能能力计算方法中特征参数A、B、x_(0)、y_(0)的修正公式,且优化后的计算方法较优化前,其准确性和稳定性均有所提高。对于从PEER数据库选取的80个受弯破坏试件耗能估算而言,该方法同样表现出较好的准确性和适用性。

语种： 中文

作者： Chaozhuang Xi;Minghong Zheng;Ling He;Haodong Xia

期刊： 地球化学学报(英文),2021年40(5):739-751 ISSN：2096-0956

通讯作者： Zheng, Minghong(115969534@qq.com)

作者机构： [Chaozhuang Xi] School of Civil Engineering, Hunan City University, Yiyang;Hunan;413000, China;Hunan Engineering Research Center of Structural Safety and Disaster Prevention for Urban Underground Infrastructure, Yiyang;[Minghong Zheng] Non-Ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou, Guiyang

通讯机构： [Minghong Zheng] N;Non-Ferrous Metals and Nuclear Industry Geological Exploration Bureau of Guizhou, Guiyang, China

关键词： Abra cu-ag-pb-au polymetallic deposit;Australia;Pb–H-O isotope;Re-os isotope

摘要： The Abra deposit, a large lead-silver-copper–gold polymetallic deposit in Western Australia, is located at the eastern of the metallogenic belt of the Jillawarra basin in the Bangemall basin. The 4th to the 6th rock section of the Irrigully Group of Edmund Series are the principal ore-host strata, composed mainly of sandstone and fine sandstone. The orebody in Abra can be classified into two types as upper layer-like lead-silver and lower veins or netvein copper–gold. The metal minerals are mainly galena, chalcopyrite, and pyrite, while the gangue minerals are mainly quartz, dolomite, and barite. Both Re-Os isotopic age of the pyrite (1329.5 ± 98 Ma) with the initial (187Os/188Os) = 5.0 ± 3.8 and Pb isotopic compositions (206Pb/204Pb = 15.914–15.967, 207Pb/204Pb = 15.425–15.454, 208Pb/204Pb = 35.584–35.667) suggests that the metal minerals were sourced from the wall-rocks. δDV-SMOW values of quartz range from -35‰ to -17‰ whereas δ18OV-SMOW value range from 12‰ to 16‰ which indicates that the ore-forming fluids of Abra were medium–low temperature and medium–low salinity, and were mainly metamorphic water and secondary atmospheric precipitation. When the medium–low temperature ore-forming fluids are mixed with oxidizing reducing fluids carrying a large number of metal substances, a large number of ore-forming substances will be precipitated when the physical and chemical conditions change, thus it can be considered that the Abra deposit is a medium–low temperature hydrothermal polymetallic deposit. © 2021, The Author(s).

语种： 英文

作者： Peng, Xirong;Sui, Yunkang*

期刊： Engineering Optimization,2021年53(1):32-48 ISSN：0305-215X

通讯作者： Sui, Yunkang

作者机构： [Peng, Xirong] Hunan City Univ, Sch Civil Engn, Yiyang, Peoples R China.;[Sui, Yunkang] Beijing Univ Technol, Numer Simulat Ctr Engn, Beijing, Peoples R China.

通讯机构： [Sui, Yunkang] B;Beijing Univ Technol, Numer Simulat Ctr Engn, Beijing, Peoples R China.

关键词： Continuum structures;topology optimization;fail-safe

摘要： The topology optimization of continuum structures is investigated to obtain an optimized topology satisfying the fail-safe design principle with suitable redundancy components. An optimization model with a nonlinear objective and linear constraints is established by defining the reciprocal topology variable as design variables and linearly approximating the structural performance. The model is solved by a dual sequential quadratic programming (DSQP) algorithm. Topology optimization with displacement constraints is used as an example. The presented optimization model and solution approach offers the following advantages. (1) A volume constraint, which makes determining reasonable values difficult, need not be specified. (2) Weighted coefficients, which combine multiple compliances under different load cases into a combined compliance, need not be specified as well. (3) The presented optimization model is a type of single-objective programming and thus avoids the challenges in the min-max model. (4) The proposed method shows a strong capability of finding optimum solutions. © 2019 Informa UK Limited, trading as Taylor & Francis Group.

语种： 英文

作者： Chen, C.;Mao, F.;Zhang, G.*;Huang, J.;Zornberg, J. G.;...

期刊： Geosynthetics International,2021年28(5):541-557 ISSN：1072-6349

通讯作者： Zhang, G.

作者机构： [Mao, F.; Chen, C.] Hunan Univ, Key Lab Bldg Safety & Energy Efficiency, Minist Educ, Changsha, Peoples R China.;[Mao, F.; Chen, C.] Hunan Univ, Coll Civil Engn, Changsha, Hunan, Peoples R China.;[Zhang, G.] Hunan City Univ, Coll Civil Engn, Yiyang, Hunan, Peoples R China.;[Huang, J.] Univ Texas San Antonio, Dept Civil & Environm Engn, San Antonio, TX USA.;[Zornberg, J. G.] Univ Texas Austin, Dept Civil Architectural & Environm Engn, Austin, TX 78712 USA.

通讯机构： [Zhang, G.] H;Hunan City Univ, Coll Civil Engn, Yiyang, Hunan, Peoples R China.

关键词： Geosynthetics;surrogate modeling;post-construction settlement;cost optimization;Geogrid-Reinforced Pile-Supported Foundation

摘要： Cost optimization of Geogrid-Reinforced Pile-Supported Foundation (GRPSF) requires the minimum construction cost among all design alternatives within both ultimate limit state (ULS) and serviceability limit state (SLS) criteria. Usually, the optimization is conducted by selecting a limited number of design alternatives based on experience and then comparing them, which often does not lead to the real optimal design. This paper presents a novel optimization framework to systematically determine the design parameters to achieve the minimum construction cost for GRPSF, considering both ULS and SLS constraints that are relevant to post-construction performance and constructability. This framework is a hybrid of surrogate modeling and Finite Element Method (FEM) to calculate the post-construction settlement of GRPSF and search for the optimal design. Genetic Algorithm improved Black Hole Algorithm (BH-GA) was developed to determine the optimal values of design variables, including pile length and spacing, pile cap geometry, and geogrid layers and layout. The proposed approach can quickly identify the optimal design by exhausting all possible combinations of design parameters. Two well-documented case histories of GRPSF were redesigned using this framework, which validated its applicability and effectiveness in optimizing the design of GRPSF. © 2021 Thomas Telford Ltd.

语种： 英文

作者： Sun, Junbo;Lin, Sen;Zhang, Genbao;Sun, Yuantian;Zhang, Junfei;...

期刊： Construction and Building Materials,2021年281:122606 ISSN：0950-0618

通讯作者： Zhang, Genbao(gbzhang@hnu.edu.cn)

作者机构： [Wang, Xiangyu; Sun, Junbo] Curtin Univ, Australasian Joint Res Ctr Bldg Informat Modellin, Bentley, WA 6102, Australia.;[Lin, Sen] Hunan Univ, Coll Mech & Vehicle Engn, Changsha 410082, Hunan, Peoples R China.;[Zhang, Genbao] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Hunan, Peoples R China.;[Sun, Yuantian] China Univ Min & Technol, Sch Mines, Xuzhou 221116, Jiangsu, Peoples R China.;[Zhang, Junfei] Univ Western Australia, Sch Civil Environm & Min Engn, Crawley, WA 6009, Australia.

通讯机构： [Genbao Zhang] C;College of Civil Engineering, Hunan City University, Yiyang 413000, Hunan, China

关键词： Graphite;Slag;Compressive behavior;Flexural behavior;Conductive composite;Cementitious composite

摘要： Electrically conductive cementitious composites (ECCCs) have become a significant research interest in structural health monitoring. The use of graphite in ECCCs can significantly improve their electrical performance, however, with unsatisfactory friction resistance because of the graphite's smooth microsurfaces. Slag can be incorporated with graphites into ECCCs to achieve good performance in both of mechanical resistance and electrical conductivity. This study investigated the impact of graphite and slag on the electrical and mechanical behaviors of ECCCs. Two hundred and eighty ECCC specimens were prepared with two different types of slags and with various conductivity ingredient fractions and curing times. The specimens were tested for compressive strength, flexural strength, and electrical resistance. It was concluded the 4% graphite content in ECCCs can significantly enhance electrical conductivity with moderate decrease in compressive and flexural strengths. Slags were found to improve both electrical conductivity and mechanical properties of ECCCs. The best results could be obtained with optimized contents of steel slag, blast furnace slag, and graphite. Finally, the microstructural mechanisms of the ECCC specimens were analyzed using scanning electron microscope (SEM) for graphite and slag. Variable sensitivity analysis was performed to allow for optimization of ingredient contents. (C) 2021 Elsevier Ltd. All rights reserved.

语种： 英文

作者： Zhou, Yanming;Liu, Xinxi;Deng, Zongwei;Gao, Qian-Feng

期刊： Advances in Materials Science and Engineering,2021年2021 ISSN：1687-8434

通讯作者： Deng, Zongwei(dengzongwei@hncu.edu.cn)

作者机构： [Zhou, Yanming; Liu, Xinxi] Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Peoples R China.;[Deng, Zongwei] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Peoples R China.;[Gao, Qian-Feng] Changsha Univ Sci & Technol, Sch Traff & Transportat Engn, Changsha 410114, Peoples R China.

通讯机构： [Deng, Z.] C;College of Civil Engineering, China

摘要： The objective of this study is to examine the performance of the shallow reinforced concrete foundation of a large-scale wind turbine under the influence of environmental loads. A 2 MW horizontal-axis onshore wind turbine supported by a shallow concrete foundation was considered. The foundation stresses, foundation settlements, and static and dynamic contact pressures at various positions of the shallow foundation were monitored from the construction phase to the operation phase in the field. Numerical simulations were also performed to further analyze the behavior of the wind turbine foundation in different cases. The results demonstrate that the responses of the reinforced concrete foundation, i.e., foundation stresses, contact pressures, and foundation settlements, were variables closely related to the wind direction and wind speed. The distribution of foundation stresses suggested that a reasonable design of steel reinforcement cages around the foundation steel ring is important. The dynamic contact pressure of the foundation could reach 5 kPa, so the influence of dynamic wind loads on the foundation response could not be always neglected, particularly for the foundations seated on weak soils. The foundation settlement during the operation phase could be characterized by the logistic model, but its distribution was uneven due to the presence of eccentric upper weight and wind load. The findings would provide guidance for the foundation design of onshore wind turbines in hilly areas. © 2021 Yanming Zhou et al.

语种： 英文

作者： Chen, Changfu;Zhu, Shimin;Zhang, Genbao;Mao, Fengshan;Cai, Huan

期刊： Computers and Geotechnics,2021年132:103969 ISSN：0266-352X

通讯作者： Zhu, Shimin(smzhu@hnu.edu.cn)

作者机构： [Zhu, Shimin; Mao, Fengshan; Chen, Changfu; Cai, Huan] Hunan Univ, Minist Educ, Key Lab Bldg Safety & Energy Efficiency, Changsha 410082, Hunan, Peoples R China.;[Zhu, Shimin; Mao, Fengshan; Chen, Changfu; Cai, Huan] Hunan Univ, Coll Civil Engn, Changsha 410082, Hunan, Peoples R China.;[Zhang, Genbao] Hunan City Univ, Coll Civil Engn, Yiyang 413000, Hunan, Peoples R China.

通讯机构： [Shimin Zhu] K;Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education, Hunan University, Changsha 410082, PR China<&wdkj&>College of Civil Engineering, Hunan University, Changsha, Hunan 410082, PR China

关键词： Grouted anchors;Laterite;Load transfer behavior;Merchant model;Time effect

摘要： The load transfer behavior of grouted anchors is time-dependent under long-term (creep) load. This study aims at investigating the time-dependent behavior of grouted anchors in laterite by both physical model test and theoretical simulation. A laboratory creep pullout model test of full-length-bond grouted anchor in laterite was carried out using a special developed apparatus. The creep pullout load–displacement response at anchor head and time history curves of axial strain were tested and presented. The creep behavior on the grout - soil interface was simulated using Merchant rheological model in theoretical simulation. By comparing the experimental data with predictions, the applicability of the proposed theoretical method was validated, and the time-dependent load transfer behavior of grouted anchors was discussed. The impacts of five model parameters on the time-dependent pullout response were further analyzed by parametric studies. It revealed that the tensile force distribution tends to be linear, and the shear stress distribution towards uniformity as time elapsed. Additionally, the time-dependent load transfer behavior for grouted anchors is influenced by the above parameters in various levels. This work provides insights into understandings of time-dependent behavior, and facilitates the service life design practice for grouted anchors embedded in laterite. © 2021 Elsevier Ltd

语种： 英文

作者： Yang, Yiming;Peng, Jianxin*;Liu, Xinhua;Cai, Steve C. S.;Zhang, Jianren

期刊： Engineering Structures,2021年228:111486 ISSN：0141-0296

通讯作者： Peng, Jianxin

作者机构： [Yang, Yiming] Hunan City Univ, Sch Civil Engn, Yiyang 413000, Hunan, Peoples R China.;[Peng, Jianxin; Yang, Yiming; Zhang, Jianren; Liu, Xinhua] Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.;[Cai, Steve C. S.] Louisiana State Univ, Dept Civil & Environm Engn, Baton Rouge, LA 70803 USA.

通讯机构： [Peng, Jianxin] C;Changsha Univ Sci & Technol, Sch Civil Engn, Changsha 410114, Hunan, Peoples R China.

关键词： Box-girder;Corrosion;Prestress tensioning technique;Uncertainty;Web cracking

摘要： Reasonable assessment of web cracking probability is essential to ensure the service performance of corroded prestressed concrete (PC) bridges. In this paper, a time-dependent prediction model of effective prestress for different prestress tensioning techniques and a corrosion propagation model are established. Meanwhile, an assessment approach of web cracking probability considering both aleatory and epistemic uncertainties is proposed. The case analysis results show that the doubled-tensioned prestress technique is obviously more effective in decreasing the web cracking probability than the traditional prestress tensioning technique. The existing probabilistic method that only considers the aleatory uncertainty may greatly underestimate the probability of web cracking. In comparison, the fastest time to reach the threshold value of web cracking probability when considering the epistemic uncertainty is over 11% earlier than that of using the existing methods. Additionally, the epistemic uncertainty of the chloride diffusion coefficient among the selected corrosion parameters has a most significant impact on the probability of web cracking. Therefore, the epistemic uncertainty of corrosion parameters, especially for the chloride diffusion coefficient, should be minimized as much as possible in this assessment process. © 2020 Elsevier Ltd

语种： 英文

作者： Hu, Zhangqi;Wu, Yusheng;Zhang, Miao;Lv, Weirong

期刊： Journal of Engineering Science and Technology Review,2020年13(5):82-89 ISSN：1791-9320

通讯作者： Hu, Zhangqi(huzhangqi0413@163.com)

作者机构： [Hu, Zhangqi; Wu, Yusheng; Zhang, Miao] College of Civil Engineering, Hunan City University, Yiyang, China;[Lv, Weirong] College of Civil Engineering, Hunan University of Science and Technology, Xiangtan, China

摘要： Stiffness reduction coefficient of coupling beams (κ) can reflect the stiffness degradation degree at yield and significantly affect the seismic response and the internal force distribution. However, existing calculation methods do not consider the influencing factors comprehensively and have a limited application scope. To effectively predict the stiffness reduction coefficient of conventionally reinforced concrete coupling beams (CCBs), a simplified analysis model was established, and analysis and parameter modification were also implemented. Then, an equation with comprehensive consideration, wide application, and high accuracy was proposed. The proposed equation was verified by comparison with existing test data and calculation methods, and parametric analysis was performed to investigate the independent factors, including the span–depth ratio, longitudinal reinforcement ratio, stirrup ratio and concrete compressive strength. Results show that the independent factors are related to each other, and the span–depth ratio has the greatest influence on the stiffness reduction coefficient of CCBs. Furthermore, κ significantly increases with the longitudinal reinforcement ratio when the coupling beam has a large span–depth ratio, but the stirrup ratio has a bigger role when the span-depth ratio is small. Finally, on the basis of the analysis results, suggestions are made to improve the stiffness reduction coefficient of CCBs. The study results provide a reference for the design and optimization of shear wall and core tube structures. © 2020 School of Science, IHU. All rights reserved.

语种： 英文

作者： Cheng, Yanhui;He, Dongliang

期刊： Geotechnical and Geological Engineering,2020年38(4):4361-4368 ISSN：0960-3182

通讯作者： He, Dongliang(hedongliang14@126.com)

作者机构： [Cheng, Yanhui; He, Dongliang] School of Civil Engineering, Hunan City University, Yiyang;Hunan;413000, China;[Cheng, Yanhui; He, Dongliang] Hunan;[Cheng, Yanhui; He, Dongliang] 413000, China

通讯机构： [Dongliang He] S;School of Civil Engineering, Hunan City University, Yiyang, China

关键词： Correlation coefficient;Monte-Carlo;Reliability index;Spatial variability

摘要： The traditional safety factor method cannot consider the uncertainty in the slope system, and the reliability theory based on probability and statistics can more objectively evaluate the degree of influence on the slope, which has become a trend of slope stability evaluation. In this paper, the spatial variability of soil strength parameters cohesion c, internal friction angle φ is considered to build a stochastic variable model, the Monte Carlo method is adopted to study the effect of reliability index β for two parameters. The results shows that, the soil parameters c, have a significant impact on the reliability index β, however, φ is more sensitive in the calculation process which have a greater impact on the calculation of the safety factor and reliability index. The steeper slope has less reliability index. For high variability of the steep slope, a reliable indicator of φ variability is no longer sensitive. In actual engineering, the correlation of soil parameters c and is often not considered, so the reliable index calculated in this case is smaller than the actual one. © 2020, Springer Nature Switzerland AG.

语种： 英文

作者： Cao, Guohui*;Zhang, Wang;Hu, Jiaxing;Peng, Xirong

期刊： Canadian Journal of Civil Engineering,2020年47(7):856-864 ISSN：0315-1468

通讯作者： Cao, Guohui

作者机构： [Peng, Xirong; Cao, Guohui] Hunan City Univ, Coll Civil Engn, 518 Yingbin East RD, Yiyang 413000, Hunan, Peoples R China.;[Zhang, Wang] Changsha Univ Sci & Technol, Sch Civil Engn, 960,2nd Sect,Wanjiali South RD, Changsha 410114, Hunan, Peoples R China.;[Hu, Jiaxing] Hunan Univ, Coll Civil Engn, Lushan South RD, Changsha 410082, Hunan, Peoples R China.

通讯机构： [Cao, Guohui] H;Hunan City Univ, Coll Civil Engn, 518 Yingbin East RD, Yiyang 413000, Hunan, Peoples R China.

关键词： natural environment;prestressed concrete (PC);continuous box girders;long-term mechanical performance;reaction distribution;environnement naturel;béton précontraint (BP);poutres-caissons continues;performance mécanique à long terme;répartition des réactions

摘要： A long-term load test performed for 470 days on two two-span prestressed concrete (PC) continuous box girders is reported in this paper. Load types were selected as the test variates, and structural responses such as support reactions, deflections, and concrete strains were monitored. Simultaneously, affiliated experiments such as material strength, creep, and shrinkage tests were conducted to investigate the time-dependent performances of the materials. Data obtained from these tests showed that deflections, strains, and support reactions develop rapidly in the beginning and stabilize afterward; the reactions of mid-and end-supports decline and rise over time, respectively. Time-dependent patterns of deflections and support reactions were analyzed on the basis of an effective modulus method, and a practical calculation method for long-term deflections considering reaction redistributions was proposed. The effects of the service environment on the performance of PC girders were evaluated through an incremental analysis method. © 2020, Canadian Science Publishing. All rights reserved.

语种： 英文