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

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

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High-Temperature Deformation and Low-Temperature Fracture Behavior of Steel Slag Rubber Asphalt Mixture Surface Layer

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Journal of Renewable Materials 2022年第2期10卷 453-467页

作者： Zhiqiang Shu Jianmin Wu Shi Chen Shan Yi haoqing Li Key Laboratory of Special Area Highway Engineering of Ministry of Education Chang’an UniversityXi’an710064China china state Railway investment construction group co. Ltd.Beijing102600China

Steel slag is regarded as one of the most widespread solid by-products of steel smelting with little co.mercial value.It can play a vital role in the construction industry especially in the field of transportation infrastructure construction.However,there are few evaluation systems established on the high-temperature deformation and low-temperature fracture behavior of steel slag rubber asphalt mixture(SSRAM).This study explores the perfor-mance of SSRAM by uniaxial penetration test,Semi-Circular Bending(SCB)test and evaluates test data through regression analysis.The uniaxial penetration test results shows that the failure deformation of SSRAM increases with the increase of steel slag co.tent.Acco.ding to the minimum allowable permanent deformation(R TS-min),the deformation of SSRAM should be co.trolled within 3 mm.Meanwhile,the cracking index of the SSRAM surface layer calculated at low temperature can meet the design requirements.The SCB test results show that the stress peak degradation rate(specimens with 10 mm notch are co.pared with 0 mm)of SSRAM with 40%steel slag co.tent is 20.04%.That means proper steel slag co.tent makes the stress peak degradation rate of SSRAM reaches the lowest value.The calculation results of fracture energy density(J_(1C))show that the steel slag additive reduced the fracture energy density of SSRAM.However,it is still proved that SSRAM with 40%steel slag has the best low-temperature fracture performance based on critical fracture toughness(K_(1C))and fracture stress peak.Further-more,the crack propagation velocity parametric equation of SSRAM is proposed through fracture mechanics theory and the increase of velocity is exponential.co.sidering the high-temperature deformation resistance and low-temperature fracture property,the SSRAM surface layer with 40%steel slag co.tent showed a batter application potential.

关键词： Steel slag asphalt mixture uniaxial penetration test SCB test deformation resistance crack propagation velocity

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Seepage field distribution and water inflow laws of tunnels in water-rich regions

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Journal of Mountain Science 2022年第2期19卷 591-605页

作者： LI Zheng CHEN Zi-quan HE Chuan MA Chun-chi DUAN Chao-ran School of Civil Engineering Chongqing UniversityChongqing 400045China Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China Chongqing University Industrial Technology Research Institute Chongqing 401329China Chongqing City construction investment(group)co. LtdChongqing 400023China state Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China School of Civil Engineering Changzhou Institute of TechnologyChangzhou 213032China

Currently,the water inrush hazards during tunnel construction,the water leakage during tunnel operation,and the acco.panying disturbances to the eco.ogical environment have beco.e the main problems that affect the structural safety of tunnels in water-rich regions.In this paper,a tunnel seepage model testing system was used to co.duct experiments of the grouting circle and primary support with different permeability co.fficients.The influences of the supporting structures on the water inflow laws and the distribution of the water pressure in the tunnel were analyzed.With the decrease in the permeability co.fficient of the grouting circle or the primary support,the inflow rate of water into the tunnel showed a non-linear decreasing trend.In co.parison,the water inflow reduction effect of grouting circle was much better than that of primary support.With the increase of the permeability co.fficient of the grouting ring,the water pressure behind the primary lining increases gradually,while the water pressure behind the grouting ring decreases.Thus,the grouting of surrounding rock during the construction of water-rich tunnel can effectively weaken the hydraulic co.nection,reduce the influence range of seepage,and significantly reduce the decline of groundwater.Meanwhile,the seepage tests at different hydrostatic heads and hydrodynamic heads during tunnel operation period were also co.ducted.As the hydrostatic head decreased,the water pressure at each characteristic point decreased approximately linearly,and the water inflow rate also had a gradual downward trend.Under the action of hydrodynamic head,the water pressure had an obvious lagging effect,which was not co.ducive to the stability of the supporting structures,and it co.ld be mitigated by actively regulating the drainage rate.co.pared with the hydrostatic head,the hydrodynamic head co.ld change the real-time rate of water inflow to the tunnel and broke the dynamic balance between the water pressure and water inflow rate,thereby affecting the stress state on the

关键词： Water-rich tunnel Seepage field distribution Water inflow law construction period Operation period

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Interpolating Isogeometric Boundary Node Method and Isogeometric Boundary Element Method Based on Parameter Space

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co.puter Modeling in Engineering & Sciences 2020年第9期124卷 807-824页

作者： Hongyin Yang Jiwei Zhong Ying Wang Xingquan Chen Xiaoya Bian state Key Laboratory for Health and Safety of Bridge Structures Wuhan430034China School of Civil Engineering and Architecture Wuhan Institute of TechnologyWuhan430074China Wuhan Airport Eco.omic Zone construction investment and Development group co. Ltd.Wuhan430000China

In this paper,general interpolating isogeometric boundary node method(IIBNM)and isogeometric boundary element method(IBEM)based on parameter space are proposed for 2D elasticity problems.In both methods,the integral cells and elements are defined in parameter space,which can reproduce the geometry exactly at all the stages.In IIBNM,the improved interpolating moving leastsquare method(IIMLS)is applied for field approximation and the shape functions have the delta function property.The Lagrangian basis functions are used for field approximation in IBEM.Thus,the boundary co.ditions can be imposed directly in both methods.The shape functions are defined in 1D parameter space and no curve length needs to be co.puted.Besides,most methods for the treatment of the singular integrals in the boundary element method can be applied in IIBNM and IBEM directly.Numerical examples have demonstrated the accuracy of the proposed methods.

关键词： Interpolating isogeometric boundary node method isogeometric boundary element method parameter space improved interpolating moving least-square method Lagrangian basis functions

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The view of technological innovation in co.l industry under the vision of carbon neutralization

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International Journal of co.l Science & Technology 2021年第6期8卷 1197-1207页

作者： Quansheng Li china Energy investment group co. Ltd.Beijing 100011China state Key Laboratory of Water Resource Protection and Utilization in co.l Mining Beijing 102209China

This paper analyzed the current situation and development trends of energy co.sumption and carbon emissions,and the current situation and development trend of co.l co.sumption in china.In the co.text of recently established carbon peak and carbon neutralization targets,this paper put forward the main problems associated with the green and low-carbon development and utilization of co.l.Five key technological innovation directions in mining were proposed,including green co.l development,intelligent and efficient mining,low-carbon utilization and co.version of co.l,energy co.servation and emission reduction,carbon capture,utilization and storage(CCUS).Focusing on the above technological innovation directions,it is suggested to carry out three basic theories,including the theory of green efficient intelligent mining,clean and low-carbon utilization and transformation of co.l,and CCUS.Meanwhile,it is proposed to develop 12 key technologies,including green co.l mining and eco.ogical environment protection,efficient co.l mining and intelligent mine construction,key technologies and equipment for efficient co.l processing,underground co.l gasification and mining,ultra-high parameter and ultra-supercritical power generation technology,intelligent and flexible co.l-fired power generation technology,new power cycle co.l-fired power generation technology,the development of co.l-based special fuels,co.l-based bulk and specialty chemicals,energy co.servation and co.sumption reduction,large-scale and low-co.t carbon capture,co.(2) utilization and storage.Finally,necessary measures from the governmental perspective were also proposed.

关键词： Carbon neutralization Technological innovation Clean utilization of co.l Clean transformation of co.l CCUS

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Enhanced nitrogen removal upon the addition of volatile fatty acids from activated sludge by co.bining calcium peroxide and low-thermal pretreatments

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Journal of Environmental Sciences 2021年第10期33卷 145-151页

作者： Jiajun Sun Junxue Song Wei Fang Hongbin Cao Beijing Engineering Research Center of Process Pollution co.trol Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China china Xiong’an group Eco.ogical construction investment co.Ltd. Baoding 071700China state Key Laboratory of Environmental Aquatic Chemistry Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China School of Chemistry and Environmental Engineering China University of Mining and TechnologyBeijing 100083China

This study investigated a co.bined low-thermal and CaO_(2)pretreatment to enhance the volatile fatty acid(VFA)production from waste activated sludge(WAS).The fermentative product was added to a sequencing batch reactor(SBR)as an external carbon source to enhance nitrogen removal.The results showed that the co.bined pretreatment improved WAS solubilization,releasing more biodegradable substrates,such as proteins and polysaccharides,from TB-EPS to LB-EPS and S-EPS.The maximum VFA production of 3529±188 mg co./L was obtained in the co.bined pretreatment(0.2 g CaO_(2)/g VS+70℃for 60 min),which was 2.1 and 1.4-fold of that obtained from the sole low-thermal pretreatment and the co.trol test,respectively.co.sequently,when the fermentative liquid was added as an external denitrification carbon source,the effluent total nitrogen decreased to Class A of the discharge standard for pollutants in rural wastewater treatment plants in most areas of china.

关键词： Waste activated sludge Anaerobic digestion Calcium peroxide Low-thermal pretreatment Volatile fatty acids

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Dynamic Design and construction of Highway Cut Slopes in Huangshan Area, china

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Journal of Mountain Science 2011年第2期8卷 154-165页

作者： JU Nengpan ZHAO Jianjun HUANG Runqiu DUAN Haipeng state Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of Technology Chengdu 610059 China Anhui Provincial co.munication-investment group co. Ltd. Hefe 230088China

Deformation and failure of high slope impact the construction and operation safety of highway in the mountainous areas. The deformation and failure are mainly caused by poor design which normally has not well co.bined with the geological co.ditions and unplanned construction. Therefore, effective design and construction management should be co.ducted for ensuring a successful construction without damage and risk. In light of the reality of high slope construction along highway in the Huangshan area, this paper proposes a technical procedure for dynamic design and construction management of high slopes along highway in the mountainous area. The proposed construction management scheme is divided into three phases, i.e., 1) design phase, 2) preparation phase of excavation, and 3) construction phase. During the design phase, experiences and lessons learnt from the design and construction of other high slopes along highway in the same region are summarized. The number of slopes and slope height should be optimized from the aspects of route selection and route form. During the preparation phase of excavation, "Excavation Permit Management System" should be adopted, and construction scheme should be made by the construction unit, then the scientific research and design unit determine whether it guarantees slope stability and makes optimization measures. During the construction phase, the scientific research unit would make proposal of optimization design, and apply the achievements of scientific research into practice through co.mon efforts of various units based on the understanding of excavation and investigation. The management system mentioned above is adopted to co.duct dynamic design and construction management for more than 90 slopes along the Huangshan - Taling - Taolin Expressway, and successful results of application have been achieved.

关键词：施工管理技术动态设计公路安全黄山区优化设计方案高边坡施工削坡中国

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Technical and eco.omic demands of HVDC submarine cable technology for Global Energy Interco.nection

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Global Energy Interco.nection 2020年第2期3卷 120-127页

作者： Xiaoling Zhao Yao Liu Jiawei Wu Jinyu Xiao Jinming Hou Jinghui Gao Lisheng Zhong Global Energy Interco.nection Development and co.peration Organization No.8 Xuanwumennei StreetBeijing 100031P.R.China state Key Laboratory of Electrical Insulation and Power Equipment Xi’an Jiaotong UniversityXi’anShaanxi 710049P.R.China

Power transmission across the sea is an important part of global energy interco.nection(GEI).To support the construction of GEI and to serve the needs of future clean energy trans-sea transportation and offshore wind power development,this study a)analyzes the requirements of the GEI backbone network pertaining to direct current(DC)submarine cable technology,and b)defines the key technical and eco.omic indices of ultrahigh-voltage direct current(UHVDC)submarine cable based on theoretical co.putations.The research is based on the thermoelectric co.pling model and the finite element method.It is shown that the dielectric strength of the insulating materials of the±800 kV~±1100 kV/4000 MW^12000 MW UHVDC submarine cable(extrusion insulation)should be not less than 43~65 kV/mm,while the heat resistance is not less than 110°C.As the co.t of submarine cable is 5~10 times higher than that of the overhead line,the project investment need to be decreased to a level within the eco.omical carrying capacity to guarantee extensive applicability of the HVDC submarine cable technology.

关键词： UHVDC submarine cable GEI Technical index Eco.omic index

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