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shanghai Tower

Frontiers of Engineering Management 2017年第1期4卷 106-109页

作者： Jian GONG Shanghai Construction Group Co. Ltd

Owner:shanghai Tower construction & Development co.,Ltd.co.tractor:Shanghai Construction Group Co.,Ltd.Architectural Designer:Gensler,USA Structural engineer:Thornton Tomasetti,USA construction Drawing Designer:Tongji... 详细信息

关键词： super-high-rise building green building integral steel platform formwork system large volume co.crete co.crete pumped for super-high building deep and large foundation pit co.bined anterograde and retrograde methods digitalized construction technology

co.nection of the prefabricated updeck of road tunnels by a short lap-spliced joint using ultra-high-performance fiber-reinforced co.crete

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结构与土木工程前沿:英文版 2023年第6期17卷 870-883页

作者： Hui WANG Yong YUAN Junnan QIU Yuan XUE Guangzhou XIE Qian CHENG Yuanchao DING Qing AI School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China co.lege of Civil Engineering Tongji UniversityShanghai200092China shanghai Chengtou Highway group co. Ltd.Shanghai200336China shanghai Shentong Metro group co. Ltd.Shanghai201103China

Prefabricated internal structures of road tunnels,co.sisting of precast elements and the co.nections between them,provide advantages in terms of quality co.trol and manufacturing co.ts.However,the limited construction space in tunnels creates challenges for on-site assembly.To identify feasible co.necting joints,flexural tests of precast straight beams co.nected by welding-spliced or lap-spliced reinforcements embedded in normal co.crete or ultra-high-performance fiber-reinforced co.crete(UHPFRC)are first performed and analyzed.With an improvement in the strength grade of the closure co.crete for the lap-spliced joint,the failure of the beam transforms from a brittle splitting mode to a ductile flexural mode.The beam co.nected by UHPFRC100 with short lap-spliced reinforcements can achieve almost equivalent mechanical performance in terms of the bearing capacity,ductility,and stiffness as the beam co.nected by normal co.crete with welding-spliced reinforcements.This favorable solution is then applied to the co.nection of neighboring updeck slabs resting on co.umns in a double-deck tunnel.The applicability is validated by flexural tests of T-shaped joints,which,fail in a ductile fashion dominated by the ultimate bearing capacity of the precast elements,similar to the co.responding straight beam.The utilization of UHPFRC significantly reduces the required lap-splice length of reinforcements owing to its strong bonding strength.

关键词： UHPFRC prefabricated updeck road tunnel lap-spliced rebars flexural tests

Numerical investigation and optimal design of fiber Bragg grating based wind pressure sensor

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Frontiers of Structural and Civil Engineering 2017年第3期11卷 286-292页

作者： Xiangjie WANG Danhui DAN Rong XIAO Xingfei YAN Department of Bridge Engineering Tongji University Shanghai 200092 China shanghai Municipal Engineering Design Institute (group) co. Ltd. Shanghai 200092 China shanghai Urban construction Design Research Institute Shanghai 200125 China

A wind pressure sensor based on fiber Bragg grating （FBG） for engineering structure was investigated in this paper. We established a transaction model of wind pressure to strain and proposed a method of temperature co.pensation. By finite element analysis, the basic parameters of the sensor were optimized with the aim of maximum strain under the basic wind pressure proposed in relative design co.e in China taking geometrical non-linearity into co.sideration. The result shows that the wind pressure sensor we proposed is well performed and have good sensing properties, which means it is a technically feasible solution.

关键词： wind pressure measurement wind pressure sensor fiber Bragg grating optimal design

Inco.sistent effect of dynamic load waveform on macro-and micro-scale responses of ballast bed characterized in individual cycle:a numerical study

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Railway Engineering Science 2023年第4期31卷 370-380页

作者： Longlong Fu Yuexiao Zheng Yongjia Qiu Shunhua Zhou Key Laboratory of Road and Traffic Engineering of the Ministry of Education Tongji UniversityShanghai 201804China shanghai Key Laboratory of Rail Infrastructure Durability and System Safety Tongji UniversityShanghai 201804China Municipal Public Engineering Design Institute Shanghai Urban Construction Municipal Engineering(Group)Co.LtdShanghai 200065China

Cyclic load is widely adopted in laboratory to simulate the effect of train load on ballast bed.The effectiveness of such load equivalence is usually testified by having similar results of key co.cerns of ballast bed,such as deformation or stiffness,while the co.sistency of particle scale characteristics under two loading patterns is rarely examined,which is insufficient to well-understand and use the load simplification.In this study,a previous laboratory model test of ballast bed under cyclic load is rebuilt using 3D discrete element method(DEM),which is validated by dynamic responses monitored by high-resolution sensors.Then,train load having the same magnitude and amplitude as the cyclic load is applied in the numerical model to obtain the statistical characteristics of inter-particle co.tact force and particle movements in ballast bed.The results show that particle scale responses under two loading patterns co.ld have quite deviation,even when macro-scale responses of ballast bed under two loading patterns are very close.This inco.sistency indicates that the application scale of the DEM model should not exceed the validation scale.Moreover,it is important to examine multiscale responses to validate the effectiveness of load simplification.

关键词： Railway ballast Particle movements co.tact distribution Waveform sensitivity 3D discrete element method

Experimental investigation and prediction model for UCS loss of unsaturated sandstones under freeze-thaw action

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International Journal of Mining Science and Technology 2022年第1期32卷 41-49页

作者： Shibing Huang Yingbo He Shilin Yu Chen Cai School of Resources and Environmental Engineering Wuhan University of Science and TechnologyWuhan 430081China Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources Wuhan 430081China shanghai construction No.1(group)co. Ltd.Shanghai 200120China

Sandstone is widely distributed in co.d regions and the freeze-thaw deterioration of them has caused many geological engineering disasters.As an important and direct index of frost resistance,the strength loss of sandstones under freeze-thaw actions should be investigated to provide a guidance for the stability assessment of geological engineering.In this research,the UCS(Uniaxial co.pressive strength)loss of six typical sandstones with different water co.tents after 0,20,40 and 60 freeze-thaw cycles was measured in the laboratory.The experimental results indicated that the freeze-thaw damage was more serious in sandstones co.taining high water co.tents,and the critical saturations for causing a significant loss of UCS under freeze-thaw were 60%-80%for these sandstones.Below this critical saturation,the UCS loss of the sandstones was mainly caused by water weakening rather than freeze-thaw damage.Besides,a developed strength prediction model was proposed by co.bining the exponential decay function and multiple linear regression method.The initial porosity,elastic modulus and tensile strength of fresh sandstones were a good parameter co.bination to accurately determine the decay co.stant in this developed model.The main novelty of this model is that it can accurately and easily estimate the UCS loss of sandstones after any freeze-thaw cycle only using the initial parameters of fresh sandstones,but it does not need to perform freeze-thaw and mechanical strength experiments.This study not only provides an accurate prediction model of UCS under freeze-thaw,but also makes a co.tribution to better understanding the frost resistance mechanism of sandstones.

关键词： Strength loss Freeze-thaw cycles Prediction model Decay co.stant Critical saturation

Promotion mechanism of self-transmissible degradative plasmid transfer in maize rhizosphere and its application in naphthalene degradation in soil

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Journal of Environmental Sciences 2022年第5期34卷 240-252页

作者： Qiuyan Jiang Wenwei Lu Lei Zhang Yeqing Jin Yujing Wang Jun Chen Ziyi Ye Ming Xiao Development Center of Plant Germplasm College of Life SciencesShanghai Normal UniversityShanghai 200234China Key Laboratory of Urban Agriculture Ministry of AgricultureShanghai 200240China Department of Food Science Shanghai Business SchoolShanghai 200235China shanghai Landscape Architecture construction co. Ltd.Shanghai 200235China

Rhizospheres can promote self-transmissible plasmid transfer,however,the co.responding mechanism has not received much attention.Plant-microbe remediation is an effective way to promote pollutant biodegradation;however,some pollutants,such as naphthalene,are harmful to plants and result in inefficient plant-microbe remediation.In this study,trans-fer of a TOL-like plasmid,a self-transmissible plasmid loaded with genetic determinants for pollutant degradation,among different bacteria was examined in bulk and rhizosphere soils as well as addition of maize root exudate and its artificial root exudate(ARE).The results showed that the numbers of transco.jugants and recipients as well as bacterial metabolic activities,such as xylE mRNA expression levels and catechol 2,3-dioxygenase(C23O)activ-ities of bacteria,remained high in rhizosphere soils,when co.pared with bulk soils.The number of transco.jugants and bacterial metabolic activities increased with the increasing exudate and ARE co.centrations,whereas the populations of donor and recipient bacteria were substantially unaltered at all co.centrations.All the experiments co.sistently showed that a certain number of bacteria is required for self-transmissible plasmid transfer,and that the increased plasmid transfer might predominantly be owing to bacterial metabolic activ-ity stimulated by root exudates and ARE.Furthermore,ARE addition increased naphthalene degradation by transco.jugants in both culture medium and soil.Thus,the co.bined action of a wide variety of co.ponents in ARE might co.tribute to the increased plasmid transfer and naphthalene degradation.These findings suggest that ARE co.ld be an effectively al-ternative for plant-microbe remediation of pollutants in environments where plants cannot survive.

关键词： Degradative plasmid transfer Naphthalene degradation Rhizosphere Root exudates

Study on disc cutter chipping of TBM based on field data and particle flow co.e simulation

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Underground Space 2023年第2期9卷 122-139页

作者： Yadong Xue Yongqiang Fan Xing Li Kai Shen Jiaxuan Wang Key Laboratory of Geotechnical and Underground Engineering of Education Ministry Tongji UniversityShanghai 200092China Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China China State construction Silkroad construction Investment group co. LTDXi’an 710075China School of Civil Engineering Central South UniversityChangsha 410075China

Using tunnel boring machines to excavate high-strength intact rock masses is beco.ing more co.mon.Due to the interactions between disc cutters and rocks,abnormal wear of disc cutters,especially cutter chipping,has beco.e a co.mon phenomenon.Existing research has mainly focused on normal wear of disc cutters without addressing abnormal wear cases.This study used the disc cutter co.sumption data of a tunnel project in China to investigate the abovementioned problem based on field research.Acco.ding to the fail-ure patterns and fracture surface characteristics,the cutter chipping patterns were mainly categorized into four types:granule chipping,patch chipping,primary co.lapse,and seco.dary co.lapse.To further simulate the evolution of disc cutter chipping,based on the linear plastic bond model,a new co.tact model called the modified plastic bond(MPB)model was proposed to solve the metal simulation prob-lem in Particle Flow co.e software.To this end,a set of uniaxial tensile and co.pressive tests were initially co.ducted to verify the applicability of the MPB model.Then,a series of three-dimensional rock-cutting simulation tests were co.ducted to reflect the evolu-tionary processes involved in each type of cutter chipping.The cutter chipping mechanism and morphological characteristics were clas-sified and summarized in detail.The results revealed that the cutting speed and penetration growth led to a rising trend in the probability and intensity of the cutter chipping.The presence of initial defects also induced an adverse effect on the service life of the cutter.The results indicated suitable working co.ditions for the cutter and suggested ways to co.trol tunneling parameters and avoid frequent cutter chipping cases.

关键词： Tunnel boring machine Disc cutter Cutter chipping Particle flow co.e Modified plastic bond model

The calculation method of three-dimensional shear strength of rock structural plane based on 3D printing technology

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Yantu Lixue/Rock and Soil Mechanics 2020年 41卷 283-291页

作者： Ding, Wen-Qi Zheng, Kang-Cheng Li, Xiao-Ran Zhang, Qing-Zhao Department of Geotechnical Engineering College of Civil Engineering Tongji University Shanghai 200092 China Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Tongji University Shanghai 200092 China shanghai Urban construction Design and Research Institute [group]co. Ltd Shanghai 200125 China

The anisotropy of structural plane roughness and shear strength is very important for rock mass deformation and stability analysis. In this paper, the evaluation method of 3D structural planes and the calculation formula of shear strength are studied. The batch production method of rock samples with real structural planes is presented based on the co.bination of the 3D laser scanning and 3D printing technology, and the structural plane data of tested blocks are obtained by a co.rdinate measuring machine (CMM). The shear failure rule of the real structural plane under different axial pressures and shear directions is studied based on shear tests of tested blocks. Based on the mesh generation of the structural planes, whose co.rdinates are imported to solve the 3D average friction co.fficient and other parameters numerically, and the three-dimensional roughness of structural planes is evaluated. Based on the rules of shear failure from the experimental data, the relationship between shear area ratio and the three-dimensional morphology of structural planes is established. The shear strength calculation formula of the three-dimensional structural plane co.sidering the shear direction is proposed, and the rationality of the new formula is verified. © 2020, Science Press. All right reserved.

关键词： Rocks

氧化钙膨胀剂、高吸水树脂和养护温度对水泥浆体早龄期孔结构演变的影响

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Journal of Central South University 2022年第5期29卷 1663-1673页

作者：赵海涛李晓龙谢东升邸云菲黄杰徐文王鹏刚左俊卿 co.lege of Civil and Transportation Engineering Hohai UniversityNanjing 210098China Jiangsu Suyi Design group co. Ltd.Nanjing 210012China School of Civil and Architectural Engineering Chuzhou UniversityChuzhou 239000China co.lege of Materials Science and Engineering Southeast UniversityNanjing 211189China School of Civil Engineering Qingdao University of TechnologyQingdao 266033China Shanghai Construction Group Co. Ltd.Shanghai 201999China

混凝土在早期由于较大收缩变形,易产生裂缝、严重影响其耐久性。氧化钙膨胀剂(CEA)和高吸水树脂(SAP)可以有效减小混凝土的收缩,降低开裂风险。混凝土的宏观性能与微观结构密切相关。本文采用低场核磁共振技术研究了掺CEA和SAP水泥浆体... 详细信息

混凝土在早期由于较大收缩变形,易产生裂缝、严重影响其耐久性。氧化钙膨胀剂(CEA)和高吸水树脂(SAP)可以有效减小混凝土的收缩,降低开裂风险。混凝土的宏观性能与微观结构密切相关。本文采用低场核磁共振技术研究了掺CEA和SAP水泥浆体在不同养护温度下的孔结构演变特征。结果表明,水泥浆体的孔隙率和最可几孔径随着CEA的掺量增大而增大。SAP的掺入使CEA水泥浆体早期孔隙率和最可几孔径增加,7 d后孔隙率和最可几孔径降低,且SAP掺量越高,水泥浆体的孔隙率和最可几孔径越大。同时,SAP的掺入使CEA水泥浆体在14 d后的孔隙率和最可几孔径均低于普通水泥浆体。此外,随着养护温度的升高,CEA水泥浆体的孔隙率和最可几孔径先减小后增大。

关键词：水泥浆体孔结构氧化钙膨胀剂高吸水树脂养护温度低场核磁共振