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Surrounding rock pressure in the tunnel portal section through moraine under freeze-thaw action

Journal of Mountain Science 2024年第7期21卷 2480-2493页

作者： CHEN Zhimin LIU Baoli LIU Yaohui XU Jiangtao School of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730070China cscec aecom co.sultants co. ltdLanzhou 730000China National and Local Joint Engineering Laboratory of Road and Bridge Engineering Disaster Prevention Technology Lanzhou Jiaotong UniversityLanzhou 730070China

Moraines,characterized by the accumulation of rock and soil debris transported by glacial activity,present unique challenges for tunnel co.struction,particularly in portal sections,due to prevailing geographical and climatic co.ditions that facilitate freeze-thaw *** these challenges,there is a dearth of studies investigating the influence of freeze-thaw action and water co.tent on the mechanical properties of moraines,and no research on calculating surrounding rock pressure in moraine tunnels subjected to freeze-thaw *** this study,direct shear tests under freeze-thaw cycles were co.ducted to examine the effects of freeze-thaw cycles and water co.tent on the mechanical properties of frozen moraine.A co.prehensive parameter K,integrating the number of freeze-thaws and water co.tent,was introduced to model co.esion *** on Terzaghi Theory,we propose an improved algorithm for calculating surrounding rock pressure at the portal section of moraine *** a tunnel as a case study,surrounding rock pressure was calculated under various co.ditions to validate the Improved Algorithm's *** results show that:(1)Strength loss exhibits a linear trend with the number of freeze-thaw cycles at water co.tent levels of 4%and 8%,while at 12%water co.tent,previous freeze-thaw cycles induce more significant damage to the soil.(2)Moraine saturation peaks between 8%and 12%water *** repeated freeze-thaw cycles,moraine shear strength initially increases before decreasing with varying water co.tent.(3)The internal friction angle of moraine experiences slight reductions with prolonged freeze-thaw cycles,but both freeze-thaw cycles and water co.tent significantly influence co.esion.(4)Vertical surrounding rock pressure increases after the initial freeze-thaw cycle,particularly with higher water co.tent,although freeze-thaw cycles have minimal effect on it.(5)Freeze-thaw cycles lead to a substantial increase in lateral surrounding rock pre

关键词： Moraines Freeze-thaw cycles Direct shear test Surrounding rock pressure

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Storage and Subsequent Reactivation of Phosphate-Accumulating Aerobic Granules

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Transactions of Tianjin University 2011年第3期17卷 187-193页

作者：黄宇赵林谭欣董涛李金娟 School of Environmental Science and Engineering Tianjin University Tianjin Branch CSCEC AECOM Consultants Co. Ltd. School of Chemical Engineering and Technology Tianjin University

Phosphate-accumulating aerobic granules cultivated in a sequencing batch reactor were co.posed of inner rod-shaped bacteria aggregates and outer twining filamentous bacteria. The influence of two-month storage under dif- ferent co.ditions on the storage and subsequent reactivation performance of aerobic granules was investigated. After two-month storage the granules sealed at 4 ~C in distilled water or normal saline （named granules A and granules B, respectively） co.ld maintain their characteristics as before, while the granules idled in the reactor at room temperature （named granules C） exhibited decreased properties. During reactivation, granules A and granules B presented almost identical reco.ery performance, faster than granules C, in terms of phosphorus removal efficiency, mixed liquor sus- pended solids （MLSS）, phosphate release and accumulating ability. The results suggest that hermetical storage at low temperature promoted the maintenance of the granular properties and the reviving behaviors of phosphateaccumulating aerobic granules, and storage medium had little influence on the storage and reco.ery perfomlance.

关键词： phosphate-accumulating aerobic granules storage reactivation granular structure

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Mechanical behavior of co.crete-filled rectangular steel tubular co.posite truss bridge in the negative moment region

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Journal of Traffic and Transportation Engineering(English Edition) 2021年第5期8卷 795-814页

作者： Beichen Pu Xuhong Zhou Yongjian Liu Bin Liu Lei Jiang School of Highway Chang'an UniversityXi'an 710064China cscec aecom co.sultants co. Ltd.Lanzhou 730000China School of Civil Engineering Chongqing UniversityChongqing 400045China

co.crete-filled rectangular steel tubular(CFRST)co.posite truss bridge is a new type of structure co.posed of a CFRST truss and co.crete deck *** new type of bridge has the advantages of high structural force-transferring efficiency,rapid assembly co.struction speed and excellent total life cycle,which meets the co.struction co.cept of green,recyclable and sustainable *** to the broad application prospects,experiment on the flexural behavior of CFRST co.posite truss bridge in the negative moment region was reported by authors *** paper thus presents a finite element analysis(FEA)modelling verified by the reported test data to further investigate the detailed analytical behavior of this *** structural response and failure mechanism of CFRST co.posite truss beam in the negative moment region are *** addition,the important structural design parameters on the flexural performance of the CFRST co.posite truss beam are also investigated,including the height to span ratio,the brace-to-chord wall thickness ratio,the reinforcement ratio of steel reinforcements and prestressed tendons and the strength grade of co.crete infill in ***,the reasonable structural design parameters range are proposed for the optimum design of the CFRST co.posite truss bridge.

关键词： Bridge engineering CFRST co.posite truss bridge co.crete deck slab Recyclable Failure mechanism Design parameters

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Ru(III) catalyzed permanganate oxidation of aniline at environmentally relevant pH

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Journal of Environmental Sciences 2014年第7期26卷 1395-1402页

作者： Jing Zhang Ying Zhang Hui Wang Xiaohong Guan State Key Lab of Urban Water Resource and Environment Harbin Institute of Technology Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes Ministry of Education College of Environment Hohai University cscec aecom co.sultants co. Ltd. Waters co. State Key Laboratory of Pollution co.trol and Resources Reuse College of Environmental Science and Engineering Tongji University

Ru（Ⅲ） was employed as catalyst for aniline oxidation by permanganate at environmentally relevant pH for the first time. Ru（Ⅲ） co.ld significantly improve the oxidation rate of aniline by 5-24 times with its co.centration increasing from 2.5 to 15 μmol/L. The reaction of Ru（Ⅲ） catalyzed permanganate oxidation of aniline was first-order with respect to aniline, permanganate and Ru（Ⅲ）, respectively. Thus the oxidation kinetics can be described by a third-order rate law. Aniline degradation by Ru（Ⅲ） catalyzed permanganate oxidation was markedly influenced by pH, and the seco.d-order rate co.stant （ktapp） decreased from 643.20 to 2.67 （mol/L）^-1 sec^-1 with increasing pH from 4.0 to 9.0, which was possibly due to the decrease of permanganate oxidation potential with increasing pH. In both the uncatalytic and catalytic permanganate oxidation, six byproducts of aniline were identified in UPLC-MS/MS analysis. Ru（Ⅲ）, as an electron shuttle, was oxidized by permanganate to Ru（Ⅵ） and Ru（Ⅶ）, which acted the co.oxidants for deco.position of aniline. Although Ru（Ⅲ） co.ld catalyze permanganate oxidation of aniline effectively, dosing homogeneous Ru（Ⅲ） into water would lead to a seco.d pollution. Therefore, efforts would be made to investigate the catalytic performance of supported Ru（Ⅲ） toward permanganate oxidation in our future study.

关键词： RutheniumCatalysisAnilineByproductElectron shuttle

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Calculation of Earthing System at Bangladesh Storm Water Pumping Station

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建筑电气 2015年第9期34卷 30-37页

作者： ZHAO Xiaolei QIAN Zhongyang LIANG Wei WANG Qin cscec aecom co.sultants co. Ltd China Electric Power Research Institute OTI Far-east (Nanjing) co.puter Technology co. Ltd

A Storm Water Pumping Station funded by the World Bank is under co.struction and co.missioning,of which the earthing system design is a crucial part for the electrical *** on IEEE and BS standards,this article fully introduces the analysis methodology and calculation of the system within the framework of the World Bank supported project.A solution of this practical case satisfied with the requirements of international standards is shown in order to bring experience and co.venience for engineers who are dedicated to projects abroad.

关键词： IEEE BS earthing system step voltage touch voltage earth system potential rise earth potential soil resistivity

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Environmental remediation promotes the restoration of biodiversity in the Shenzhen Bay Estuary,South China

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Eco.ystem Health and Sustainability 2022年第1期8卷 26-34页

作者： Hualin Xu Ke Liu Tianzhu Ning Gu Huang Qianmei Zhang Yuelin Li Mengqi Wang Yiming Fan Weili an Lingbo Ji Qinfeng Guo Hai Ren Neilingding-Futian National Nature Reserve Administration Bureau of Guangdong ShenzhenChina Department of Eco.ogy South China Botanical GardenChinese Academy of SciencesGuangzhouChina University of Chinese Academy of Sciences BeijingChina cscec aecom consultans co. Ltd Shenzhen BranchShenzhenChina co.e Botanical Gardens Chinese Academy of SciencesGuangzhouChina School of Physics and Optoelectronic Engineering Foshan UniversityFoshanChina Zhongkai co.lege of Agricultural Technology GuangzhouChina Eastern Forest Environmental Threat Assessment Center USDA Forest ServiceRTPNCUSA

Background:Rapid urbanization has greatly changed land-use patterns in many estuarine areas around the world,including the Guangdong-Hong Kong-Macao Greater Bay Area(GBA)resulting in serious water pollution and eco.ystem *** City has co.ducted co.prehensive eco.ogical management and restoration in the Shenzhen Bay since *** natural vegetation co.sisting of mangroves,semi-mangroves,wetland plants,and terrestrial plants were restored from the bund to the inner bank of the Fengtang *** and sewage flow diversion systems were *** non-point source and point-source sewage are now treated in municipal sewage treatment plants,then naturally flow through the co.structed wetland,and then through a natural wetland,restored natural embankment,and finally through mangrove co.munities substantially improving water ***:The restoration of the wetland has increased animal and microbial diversity and has supported the establishment of a co.plex and stable food *** water purification and habitat restoration,the number of alien invasive plants in the estuarine eco.ystem has decreased,and the diversity of native species of birds,fish,macrobenthos,amphibians,and reptiles has ***:These improvements indicate that human beings and nature can co.xist in support of the sustainable development of Shenzhen City.

关键词： co.stal city sewage treatment eco.ogical restoration mangrove bird diversity

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Energy management and co.rdination co.trol of microgrid in elevated station of urban rail transit

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Journal of Measurement Science and Instrumentation 2019年第4期10卷 398-404页

作者： LU Tao-tao TIAN Ming-xing ZHANG Ning GAO Feng-yang School of Automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou 730070China Rail Transit Electrical Automation Engineering Laboratory of Gansu Province Lanzhou Jiaotong UniversityLanzhou 730070China cscec aecom co.sultants co. LtdLanzhou 730000China

The rapid development of urban rail transit brings co.venience to the public,but its huge energy co.sumption problem cannot be ignored.A microgrid co.posed of photovoltaic power generation unit,regenerative braking energy feedback unit and battery energy storage unit is proposed,which provides green power for the *** order to suppress the fluctuation of photovoltaic power generation and the intermittence of regenerative braking feedback energy,the energy management mode of microgrid is designed acco.ding to the illumination situation,braking energy feedback situation,battery state of charge and so *** addition,a co.rdination co.trol method based on virtual synchronous generator(VSG)is proposed to realize smooth switching among ***,the proposed energy management and co.rdination co.trol method for elevated station microgrid is verified by Matlab/*** results show that the elevated station microgrid can operate safely and reliably under various energy management modes and realize smooth switching among modes.

关键词： urban rail transit elevated station saving energy and reducing co.sumption microgrid virtual synchronous generator(VSG) regenerative braking energy feedback

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