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Effect of geomembrane defects on the degradable contaminant transport through composite geomembrane cutoff walls: A novel transient model

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Journal of environmental Chemical engineering 2025年第5期13卷

作者： Chun-Hui Peng Xiang-Hong Ding Hong-Xin Chen Yong He Biao Luo School of Architecture and Civil Engineering Jinggangshan University Key Laboratory of Jiangxi Province for Agricultural Environmental Pollution Prevention and Control in red Soil Hilly Region Ji’an 343009 China School of Civil Engineering Central South University Changsha 410075 China Department of Geotechnical Engineering Tongji University Shanghai 200092 China Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring Central South University Ministry of Education Changsha 410083 China School of Civil Engineering Hunan University Changsha 410082 China

Composite geomembrane cutoff walls (CGCW) are among the most effective techniques for managing contaminated sites. Accurately predicting contaminant transport through CGCW is essential to the efficient remediation and management of contaminated sites. Previous prediction models have predominantly focused on contaminant diffusion in intact CGCW, with insufficient attention given to CGCW with geomembrane (GMB) defects. This study introduces fully transient models for contaminant transport in a CGCW-aquifer system, comprising an upstream slurry wall, a GMB with defects, a downstream slurry wall, and the adjacent aquifers. The model allows for three types of GMB defects, i.e., joint defects, bottom gaps, and GMB holes, and incorporates the contaminant advection-diffusion-adsorption-degradation process in the CGCW-aquifer system. Results indicate that existing CGCW models overlook the critical impact of GMB positioning on the containment performance of CGCW with GMB defects. The semi-infinite boundary assumption and the non-degradation assumption commonly adopted in previous models lead to, respectively, an underestimation and overestimation of contaminant plume concentrations in the downstream aquifer. Additionally, increasing the widths of joint defects, bottom gaps, and GMB holes significantly reduces the containment efficiency of CGCW, especially under conditions of high hydraulic head and low slurry wall permeability. To address this, an equivalent design curve for CGCW with GMB defects is proposed, offering engineers a practical reference for determining the required wall thickness.

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Application of Water Quality Index in the Evaluation of an Abandoned Mine Areas of Xunwu, China

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IOP Conference Series: Earth and environmental Science 2021年第1期668卷

作者： Shiyun Yin Zuwen Liu Shi Yang Yuan Lin Jiangxi Key Laboratory of Environmental Geotechnical and Engineering Disaster Control Ganzhou 341000 China Engineering Technology Research Center for Water Quality Safety Assurance of Ganjiang River Basin Jiangxi University of Science and Technology Ganzhou 341000 China

Within the display think about, an surrendered ion-type rare soil mine contains a tremendous affect on the encompassing water environment contamination in Xunwu, jiangxi Province, China. Since the usage of coordinates remediation innovation and extend in 2018, its natural quality has been enormously moved forward. In arrange to encourage assess the environmental remediation impact, a altered water quality index strategy (WQI) is proposed. Concurring to the grid method, 16 water quality examining focuses were set within the surrendered mine remediation extend, and 9 key assessment records such as NH4+-N and heavy metals were chosen for principal component analysis (PCA) and factor analysis (FA), in arrange to comprehensively assess the worldly and spatial changes of different contamination variables within the deserted mine environmental remediation range. The results uncovered that the water quality of the surface water has been slowly progressed, and the generally water quality has been getting superior, among which the water quality in August is clearly superior than that in July, and the progressed water quality index is successful for the classification of water quality and the assessment of the transient and spatial changes of water quality within the remediation of surrendered mines.

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Simplified Method and Influence Factors of Vibration Characteristics of Isolated Curved Girder Bridge

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Structural Durability & Health Monitoring 2018年第3期12卷 189-212页

作者： Tongfa Deng Junping Zhang Mahmoud Bayat Guangzhou University-Tamkang University Joint Research Center for Engineering Structure Disaster Preventioand Control Guangzhou UniversityGuangzhou510006China Jiangxi Provincial Key Laboratory of Environmental Geotechnical Engineering and Disaster Control Jiangxi University of Science and TechnologyGanzhouJiangxi341000China Guangdong Communication Polytechnic Guangzhou510170China Young Researchers and Elite Club Roudehen BranchIslamic Azad UniversityRoudehenIran

The isolated curved girder bridge's vibration characteristics play a major part in the seismic responses of structures and anti-seismic properties.A clear analytic relationship between design parameters and the system's vibration characteristics could be established by its simplified dynamic analysis model,making it convenient for providing a reference to the optimization of design and safety analysis.A double-mass six-degree-of-freedom model for curved girder bridges with isolation bearings installed at the top of the bridge piers is built and a simplified analysis method for the vibration characteristics of the system is *** with the Matlab programming,the influences of radius of curvature,central angle,bridge deck width and damping ratio of the isolation layer and circular frequency of the isolation layer of isolated curved girder bridges on the pseudo-undamped natural circular frequency(called pseudo-frequency for short)and system damping ratio are systematically analyzed,and the sensitivity of vibration characteristics of isolated curved girder bridges is *** results show that the vibration characteristics of isolated curved girder bridges can be reflected well with this simplified model and calculation *** pseudo-frequency of curved girder and system damping ratios increases with the increase of the isolation *** third-order vibration characteristic is more sensitive to the parameters of a curved girder,and the first-order vibration characteristic is sensitive to both central angle and radius of curvature to some extent while insensitive to the width of the bridge ***,the second-order vibration characteristic is not sensitive to the parameters of a curved girder.

关键词： Seismic isolation curved girder bridge vibration characteristics sensitivity analysis simplified analysis method

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Enhancing rice production sustainability and resilience via reactivating small water bodies for irrigation and drainage (vol 14, 3794, 2023)

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NATURE COMMUNICATIONS 2023年第1期14卷 1-11页

作者： Li, Sisi Zhuang, Yanhua Liu, Hongbin Wang, Zhen Zhang, Fulin Lv, Mingquan Zhai, Limei Fan, Xianpeng Niu, Shiwei Chen, Jingrui Xu, Changxu Wang, Na Ruan, Shuhe Shen, Wangzheng Mi, Menghan Wu, Shengjun Du, Yun Zhang, Liang Hubei Provincial Engineering Research Center of Non-Point Source Pollution Control Innovation Academy for Precision Measurement Science and Technology Chinese Academy of Sciences Wuhan 430077 PR China Key Laboratory for Environment and Disaster Monitoring and Evaluation of Hubei Wuhan 430077 PR China University of Chinese Academy of Sciences Beijing 100049 PR China Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 PR China State Environmental Protection Key Laboratory of Soil Health and Green Remediation Huazhong Agricultural University Wuhan 430070 PR China Interdisciplinary Research Center for Territorial Spatial Governance and Green Development Huazhong Agricultural University Wuhan 430070 PR China Institute of Plant Protection Soil and Fertilizer Sciences Hubei Academy of Agricultural Sciences Wuhan 430064 PR China Chongqing Institute of Green and Intelligent Technology Chinese Academy of Sciences Chongqing 400714 PR China Liaoning Academy of Agricultural Sciences Shenyang 110161 PR China Institute of Soil & Fertilizer and Resources & Environment Jiangxi Academy of Agricultural Sciences Nanchang 330200 PR China

Rice farming threatens freshwater resources, while also being increasingly vulnerable to drought due to climate change. Rice farming needs to become more sustainable and resilient to climate change by improving irrigation drainage systems. Small water bodies, used to store drainage water and supply irrigation in traditional rice farming systems have gradually been abandoned in recent decades. This has resulted in a higher water footprint (WF) associated with rice farming due to increased freshwater usage and wastewater release, also leaving rice production more vulnerable to extreme weather events. Here, we propose how protecting and reactivating small water bodies for rice irrigation and drainage can decrease rice production WF in China by 30%, save 9% of China’s freshwater consumption, increase irrigation self-sufficiency from 3% to 31%, and alleviate yield loss in dry years by 2–3%. These findings show that redesigning rice irrigation drainage systems can help meet water scarcity challenges posed by climate change.

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Optimal speed of a moving load for damage detection in bridges 7

Optimal speed of a moving load for damage detection in bridg...

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7th Asia-Pacific Workshop on Structural Health Monitoring, APWSHM 2018

作者： Zhu, X. Cao, M.S. Liu, J.Q. Deng, T.F. Xu, W. Department of Engineering Mechanics Hohai University Nanjing China College of Water Conservancy and Civil Engineering Shandong Agricultural University Taian China Jiangxi Provincial Key Laboratory of Environmental Geotechnical Engineering and Disaster Control Ganzhou China

ISBN: (纸本)9783000603594

Damage like crack can occur in bridge decks during long-time service, and detecting damage is crucial to ensure the safety of bridges. Damage can cause singularity in deflections of bridges;by extracting such singularity, damage can be indicated and located. Moving loads are commonly employed to generate flexural deflections of bridges, and such deflections can be obtained by sensors along bridges. Speeds of moving loads are of great effect on the efficiency of damage detection in bridges. Addressing this problem, this study formulates the closed-form solution of bridge deflections under moving loads with any given speed based on Euler-Bernoulli beam theory, relying on which the singularity spectrum with variables of load speed and deflection location is established after processed by wavelet transform. Then, optimal speed of a moving load is obtained by investigating the effect of moving load speeds on efficiency of damage detection in bridges. Moreover, sensitivity of optimal speeds to damage location and extent is also studied. The proposed method to determine the optimal speed of a moving load can be applied to a real scenario of damage detection in a bridge. © APWSHM 2018. All rights reserved.

关键词： Wavelet transforms

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Experimental study on secondary consolidation characteristics of Kunming peat soil

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IOP Conference Series: Earth and environmental Science 2021年第1期787卷

作者： Xin-Ming Li Ying-Jie Fu Cheng Chen Song Yin School of Civil Engineering and Architecture Zhong-Yuan University of Technology Zhengzhou 450007 China Research Center of Environmental Geotechnical Engineering and Underground Engineering Disaster Control Engineering of Henan Province Zhengzhou 450007 China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China

A series of conventional consolidation tests and 60 d creep consolidation tests were carried out on undisturbed peat soil samples taken from Kunming for the consolidation and secondary consolidation characteristics. The variation rule and formation mechanism of secondary consolidation parameters were analyzed in detail. Test results show that the e - lgt curves of Kunming peat soil under different consolidation pressures show an inverse S-shape, the ratio of secondary consolidation deformation to total deformation is 32.8%. With the increase of consolidation pressure p, the Cα value of peat soil and general soft clay first increase rapidly to the peak value and then decrease gradually. However, different from general soft clay, the peak value of Cα value of peat soil is higher which appears at the consolidation pressure of 200kPa (preconsolidation pressure of 67kPa). It is believed that this is related to the high content of organic matter and the abundant micropores in the organic matter. The Cα/Cc value of Kunming peat soil is 0.052, which conforms to the 'Cα/Cc compression rule'. According to the soil classification standard based on the coefficient of secondary compressibility, Kunming peat soil belongs to high secondary compressibility soil.

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Singular component in modal Teager-Kaiser energy for characterizing incipient delaminations in composite laminates 7

Singular component in modal Teager-Kaiser energy for charact...

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7th Asia-Pacific Workshop on Structural Health Monitoring, APWSHM 2018

作者： Xu, W. Cao, M.S. Liu, J.Q. Deng, T.F. Liu, T.W. Zhu, X. Department of Engineering Mechanics Hohai University Nanjing China College of Water Conservancy and Civil Engineering Shandong Agricultural University Taian China Jiangxi Provincial Key Laboratory of Environmental Geotechnical Engineering and Disaster Control Ganzhou China

ISBN: (纸本)9783000603594

Delamination is a common type of local defect occurring during manufacturing and operating processes of composite laminates. Incipient delaminations can accumulate and develop, and gradually weaken the integrity and safety of composite laminates. Hence, identifying incipient delamination at the early stage is of significance. Modal Teager-Kaiser energy is formulated from a mode shape using the Teager- Kaiser energy operator, which contains damage features of local defects. In this study, modal Teager- Kaiser energy of plate-type structures is decomposed into components by singular value decomposition. Among the energy components, the singular component can be found where singularity peak appears in the defect region. In turn, the singular component can be utilized to characterize the presence and location of the delamination. Experimental results show that the singular component in modal Teager- Kaiser energy is capable of characterizing the presence and location of the incipient delamination in the composite laminate. The proposed method can be also applied to identify local defects in other platetype structures. © APWSHM 2018. All rights reserved.

关键词： Singular value decomposition

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Comparison and Analysis of Effects of Different Types of Isolation Bearings for ACurved Bridge

Comparison and Analysis of Effects of Different Types of Iso...

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International Conference on Smart City and Systems engineering (ICSCSE)

作者： Lei Chen Tongfa Deng Shuai Li Kaikai Zhang Jiangxi Provincial Key Laboratory of Environmental Geotechnical Engineering and Disaster Control Jiangxi University of Science and technology Ganzhou Jiangxi China

ISBN: (纸本)9781728113678;9781728113661

Since there are many types of isolation bearings, it is hard for designers to grasp the seismic isolation effects of different types of isolation bearings, so this paper discussed the seismic reduction and isolation effects of several common types of seismic isolation devices, and exampled by a curved bridge, it built a dynamic analysis model by use of the finite element analysis program Midas civil, carried out time-procedure analysis of different types of seismic isolation devices, compared it with the seismic response of a bridge structure not using a seismic isolation device model, and analyzed the seismic isolation effects of different types of isolation bearings. The results indicate that the FVD (Fluid Viscous Damper) can control the displacement and internal force of structure very well, but its effect of isolation is related to the earthquake waves input; the LRB (Lead Rubber Bearing) produces a significant effect of isolation, but its effect of isolation has something to do with the earthquake waves input; the FPS (Friction Pendulum Systems) has an ordinary effect of isolation, and its performance is unstable and even aggravated sometimes; the PRB (Pot Rubber Bearing) produces the worst effect of isolation, and it is inapplicable to the bridge structure discussed in this paper.

关键词： Bridges Earthquakes Damping Structural beams Force Rubber Seismic waves

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Analysis of Seismic Responses of Continuous Rigid Frame Bridge Under Influences of Topographic Effect and Incident Angles

Analysis of Seismic Responses of Continuous Rigid Frame Brid...

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International Conference on Smart City and Systems engineering (ICSCSE)

作者： Tongfa Deng Qianyong Chang Shuai Li Meikai Xia Jiangxi Provincial Key Laboratory of Environmental Geotechnical Engineering and Disaster Control Jiangxi University of Science and technology Ganzhou Jiangxi China

ISBN: (纸本)9781728113678;9781728113661

In order to study seismic responses of high-pier continuous rigid frame bridge under seismic waves of oblique incidence and under Topographic effect, this paper built a finite element model of 6-span continuous rigid frame bridge in concave valley terrain by use of the finite element software ABAQUS, and analyzed the seismic responses of a bridge under the circumstances of seismic waves of different incident angles, different bridge pier sizes and different stiffness by use of that model. The results indicate that the internal forces of structure change with the change in the incident angles of seismic wave; due to the existence of local topography, the local internal forces of bridge structure magnify; when piers have an identical cross-section area, a solid pier can more effectively reduce the pier stress, compared with a hollow pier; in the case of an identical cross-section size and identical longitudinal stiffness, a hollow pier can more effectively reduce the pier stress; the larger the number of straining beams that a pier has is, the larger the stiffness is, and the worse it is for the seismic resistance of bridge.

关键词： Bridges Employee welfare Seismic waves Force Earthquakes Vibrations Shearing

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Author Correction: Enhancing rice production sustainability and resilience via reactivating small water bodies for irrigation and drainage

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Nature communications 2023年第1期14卷 4529页

作者： Sisi Li Yanhua Zhuang Hongbin Liu Zhen Wang Fulin Zhang Mingquan Lv Limei Zhai Xianpeng Fan Shiwei Niu Jingrui Chen Changxu Xu Na Wang Shuhe Ruan Wangzheng Shen Menghan Mi Shengjun Wu Yun Du Liang Zhang Hubei Provincial Engineering Research Center of Non-Point Source Pollution Control Innovation Academy for Precision Measurement Science and Technology Chinese Academy of Sciences Wuhan 430077 PR China. Key Laboratory for Environment and Disaster Monitoring and Evaluation of Hubei Wuhan 430077 PR China. University of Chinese Academy of Sciences Beijing 100049 PR China. Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 PR China. State Environmental Protection Key Laboratory of Soil Health and Green Remediation Huazhong Agricultural University Wuhan 430070 PR China. Interdisciplinary Research Center for Territorial Spatial Governance and Green Development Huazhong Agricultural University Wuhan 430070 PR China. Institute of Plant Protection Soil and Fertilizer Sciences Hubei Academy of Agricultural Sciences Wuhan 430064 PR China. Chongqing Institute of Green and Intelligent Technology Chinese Academy of Sciences Chongqing 400714 PR China. Liaoning Academy of Agricultural Sciences Shenyang 110161 PR China. Institute of Soil & Fertilizer and Resources & Environment Jiangxi Academy of Agricultural Sciences Nanchang 330200 PR China. Hubei Provincial Engineering Research Center of Non-Point Source Pollution Control Innovation Academy for Precision Measurement Science and Technology Chinese Academy of Sciences Wuhan 430077 PR China. lzhang@***. Key Laboratory for Environment and Disaster Monitoring and Evaluation of Hubei Wuhan 430077 PR China. lzhang@***. University of Chinese Academy of Sciences Beijing 100049 PR China. lzhang@***.

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