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Underground Space 2024年第2期15卷 188-202页

作者： Yong Fang Bin Zhuo Yubo Wang Hu Luo Junfeng Sun Yuxiang Yao Key Laboratory of Transportation tunnel engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China

Clogging is a major geohazards risk in mechanized tunnelling through cohesive *** clogging results from the high adhesion between the clay and *** on the water film theory and Reynolds fluid equation,the interfacial adhesion between metal and soil is simplified in this study as viscous hydrodynamic behavior between *** the influence of capillary force and the viscous force of water film at the interface between metal and soil,a theoretical calculation model of interfacial adhesion between metal and soil is *** influence of water film thickness and separation rate on the interfacial adhesion between metal and soil is qualitatively ***,the adhesion stress between the clay and the metal surface was tested with a pullout test and the influence of moisture content,pullout rates and types of clay minerals on the adhesion stress was ***,the calculation model of adhesion force was compared with the experimental *** calculation model of soil adhesion stress established in this paper can quantitatively describe the relationship between soil adhesion force and moisture content and can also qualitatively reveal the influence mechanism of soil moisture content on adhesion stress.

关键词： EPB clogging Adhesion stress Mechanics model Clays Mechanism analysis Experimental test

Soil conditioning of clay based on interface adhesion mechanism:Microscopic simulation and laboratory experiment

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Underground Space 2024年第5期18卷 239-255页

作者： Yong Fang Bin Zhuo Ruyue Zhang Yubo Wang Liupan Dou Yuxiang Yao Key Laboratory of Transportation tunnel engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China

Clogging frequently occurs in the cutter head,excavation chamber or screw conveyor when an earth pressure balance(EPB)shield machine is tunneling in soft or silty clay ground with high clay mineral *** this paper,montmorillonite,kaolinite,and illite were selected as research objects,and molecular dynamics simulation and laboratory experiment were *** the microscopic scale,dynamic contact behavior and interfacial mechanical behavior of the interface between clay minerals and water/surfactant solution was simulated and the interfacial adhesion and conditioning mechanism between clay minerals and water/surfactant solution was ***,sodium dodecyl benzene sulfonate surfactant was selected as the main composition of the soil ***,the adhesion stress before and after soil conditioning and the contact angles between clay minerals and water/surfactant solution were tested and analyzed at the macroscopic *** result shows that the contact angle between droplet and clay mineral surface is an important parameter to characterize soil *** simulation rules of the microscopic contact angle are consistent with the experiment ***,the adsorption energy between microscopic substances is dominated by electrostatic force,which can reflect the adhesion stress between macroscopic *** adhesion stress can be effectively decreased by adding the surfactant to the soil conditioner.

关键词： EPB clogging Clay minerals Microscopic simulation Mechanism analysis Laboratory experiment Adhesion stress

Comparative analysis between single-train passing and double-train intersection in a tunnel

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2024年第5期25卷 429-442页

作者： Jianming DU Qian FANG Xuan ZHANG Hualao WANG Bridge and tunnel Research Center Research Institute of Highway Ministry of TransportBeijing 100088China tunnel and Underground engineering Research Center of Ministry of Education Beijing Jiaotong UniversityBeijing 00044China

Aerodynamic pressure significantly impacts the scientific evaluation of tunnel service *** aerodynamic pressure of two trains running in a double-track tunnel is considerably more complicated than that of a single *** used the numerical method to investigate the difference in aerodynamic pressure between a single train and two trains running in a double-track ***,the numerical method was verified by comparing the results of numerical simulation and on-site ***,the characteristics of aerodynamic pressure were ***,the influence of various train-tunnel factors on the characteristics of aerodynamic pressure was *** results show that the aerodynamic pressure variation can be divided into stage I:irregular pressure fluctuations before the train tail leaves the tunnel exit,and stage II:periodic pressure declines after the train tail leaves the tunnel *** addition,the aerodynamic pressure simultaneously jumps positively or drops negatively for a single train or two trains running in double-track tunnel *** pressure amplitude in the two-train case is higher than that for a single *** maximum positive peak pressure difference(P_(STP))and maximum negative peak pressure difference(P_(STN))increase as train speed rises to the power from 2.256 to 2.930 in stage *** P_(STP) and P_(STN) first increase and then decrease with the increase of tunnel length in stage *** P_(STP) and P_(STN) increase as the blockage ratio rises to the power from 2.032 to 2.798 in stages I and II.

关键词： Railway tunnel Aerodynamic effect Pressure characteristic Train speed tunnel length Blockage ratio

Quasi-three-dimensional hydrodynamics of the corona region of laser irradiation of a slab

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Chinese Physics B 2024年第8期33卷 351-360页

作者：董晓梅关本金李英骏 State Key Laboratory for tunnel engineering China University of Mining and TechnologyBeijing 100083China

This paper introduces and establishes a quasi-three-dimensional physical model of the interaction between a laser and a slab *** contrast to previous one-dimensional analytical models,this paper innovatively fits the real laser conditions based on an isothermal,homogeneous expansion similarity solution of the ideal hydrodynamic *** this simple model,the evolution law and analytical formulae for key parameters(e.g.,temperature,density and scale length)in the corona region under certain conditions are *** analytical solutions agree well with the relevant results of computational hydrodynamics *** constant laser irradiation,the analytical solutions provide a meaningful power-law scaling *** model provides a set of mathematical and physical tools that give theoretical support for adjusting parameters in experiments.

关键词： plasma self-similarity method fluid dynamics calculations

Novel wreck salvaging method using curved rectangular pipe basing method:A case study of"Yangtze River EstuaryⅡ"ancient shipwreck salvage project

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Underground Space 2024年第5期18卷 97-113页

作者： Qianwei Zhuang Guofang Gong Dongrong Zhou Chi Zhang Xin Huang Xiaodong Zhu Weihao Yuan Deng Li School of Mechanical engineering Zhejiang UniversityHangzhou 310030China Shanghai tunnel engineering Co.Ltd. Shanghai 200137China Department of Geotechnical engineering College of Civil EngineeringTongji UniversityShanghai 200092China College of Civil engineering and Architecture Xinjiang UniversityUrumqi 830047China Shanghai Salvage company Shanghai 200090China

Shipwreck salvage is a risky,time-consuming,and expensive *** there are many sunken ships along coastlines and in the open seas,the salvage process of a sunken ship has rarely been *** integrated salvage of the"Yangtze River EstuaryⅡ"shipwreck used a novel method with 22 closely locked curved rectangular pipes to form a watertight base that wrapped the shipwreck *** basing was lifted out of the water using a powerful crane situated on an engineering *** the first time,the tunneling method was used in a shipwreck salvage project,significantly reducing the disturbance to the shipwreck and its stowage,thereby preserving the original state and integrity of the shipwreck to the greatest *** this study,the basic concepts of the salvage method and process are *** to critical issues in the new salvage method are provided,including jacking force prediction and major considerations for the structural design of the salvage *** design of the salvage system and salvage process of the"Yangtze River EstuaryⅡ"shipwreck are *** monitored jacking force,pipe deformation,and observed water-tightness verified that the proposed method was effective and *** possible application scenarios for the proposed method are presented at the end.

关键词： Pipe jacking Shipwreck salvage Yangtze River EstuaryⅡ Structural design

Testing method of rock structural plane using digital drilling

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Journal of Rock Mechanics and Geotechnical engineering 2024年第7期16卷 2563-2578页

作者： Qi Wang Yuncai Wang Bei Jiang Hongke Gao Fenglin Ma Dahu Zhai Songlin Cai State Key Laboratory for tunnel engineering China University of Mining and Technology(Beijing)Beijing100083China

The rock mass consists of rock blocks and structural planes,which can reduce its integrity and ***,accurately obtaining the characteristics of the rock mass structural plane is a prerequisite for evaluating stability and designing supports in underground ***,there are no effective testing methods for the characteristic parameters of the rock mass structural plane in underground *** paper presents the digital drilling technology as a new testing method of rock mass structural *** rock specimens with cracks of varying widths and angles were used to simulate the rock mass structural planes,and the multifunctional rock mass digital drilling test system was employed to carry out the digital drilling *** analysis focuses on the variation laws of drilling parameters,such as drilling pressure and drilling torque,affected by the characteristics of prefabricated cracks,and clarifies the degradation mechanism of rock equivalent compressive ***,an identification model for the characteristic parameters of rock mass structural planes during drilling is *** test results indicate that the average difference of the characteristics of prefabricated cracks identified by the equivalent compressive strength is 2.45°and 0.82 mm,*** identification model while drilling is verified to be correct due to the high identification *** on this,a method for testing the characteristic parameters of the surrounding rock structural plane while drilling is *** research offers a theoretical and methodological foundation for precise in situ identification of structural planes of the surrounding rock in underground engineering.

关键词： Structural planes in the rock mass Digital drilling Drilling parameters Equivalent compressive strength Testing method

Influence of secondary lining thickness on mechanical behaviours of double-layer lining in large-diameter shield tunnels

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Underground Space 2024年第5期18卷 130-150页

作者： Shimin Wang Xuhu He Xiaoyu Peng Ya Wang Zhengxin Li Zihan Song Key Laboratory of Transportation tunnel engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China School of Civil engineering Southwest Jiaotong UniversityChengdu 610031China

In large-diameter shield tunnels,applying the double-layer lining structure can improve the load-bearing properties and maintain the stability of segmental *** secondary lining thickness is a key parameter in the design of a double lining structure,which is worth being *** on an actual large-diameter shield tunnel,loading model tests are carried out to investigate the effect of the secondary lining thickness on the mechanical behaviours of the double lining *** test results show that within the range of secondary lining thicknesses discussed,the load-bearing limit of the double-layer lining increases with growing secondary lining *** a passive support,the secondary lining acts as an auxiliary load-bearing structure by contacting the *** changes in secondary lining thickness have a significant effect on the contact state between the segment and secondary lining,with both the contact pressure level and the contact area between the two *** double-layer lining structures in large-diameter shield tunnels,it is proposed that the stiffness of the secondary lining needs to be matched to the stiffness of the segment,as this allows them to have a coordinated deformation and a good joint load-bearing effect.

关键词： Large-diameter shield tunnels Double-layer lining structure Secondary lining thickness Stiffness matching Similar model test

Development of multi-functional anchorage support dynamic-static coupling performance test system and its application

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International Journal of Mining Science and Technology 2024年第3期34卷 339-349页

作者： Qi Wang Shuo Xu Bei Jiang Chong Zhang Zhe Sun Jingxuan Liu Cailin Jiao State Key Laboratory for tunnel engineering China University of Mining&Technology-BeijingBeijing 100083China Research Center of Geotechnical and Structural engineering Shandong UniversityJinan 250061China

In underground engineering with complex conditions,the bolt(cable)anchorage support system is in an environment where static and dynamic stresses coexist,under the action of geological conditions such as high stresses and strong disturbances and construction conditions such as the application of high *** is essential to study the support components performance under dynamic-static coupling *** on this,a multi-functional anchorage support dynamic-static coupling performance test system(MAC system)is developed,which can achieve 7 types of testing functions,including single component performance,anchored net performance,anchored rock performance and so *** bolt and cable mechanical tests are conducted by MAC system under different prestress *** results showed that compared to the non-prestress condition,the impact resistance performance of prestressed bolts(cables)is significantly *** the prestress range of 50–160 k N,the maximum reduction rate of impact energy resisted by different types of bolts is 53.9%–61.5%compared to non-prestress *** the prestress range of 150–300 k N,the impact energy resisted by high-strength cable is reduced by76.8%–84.6%compared to non-prestress *** MAC system achieves dynamic-static coupling performance test,which provide an effective means for the design of anchorage support system.

关键词： Anchorage support system Development of test system Dynamic-static coupling test Combined stress

Mechanical response of a tunnel subjected to strike-slip faulting processes,based on a multi-scale modeling method

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Frontiers of Structural and Civil engineering 2024年第8期18卷 1281-1295页

作者： Guoguo LIU Ping GENG Tianqiang WANG Xiangyu GUO Jiaxiang WANG Ti DING Key Laboratory of Transportation tunnel engineering Ministry of EducationChengdu 610031China College of Civil engineering Huaqiao UniversityXiamen 361021China China Railway Design Corporation Tianjin 300308China

The stick-slip action of strike-slip faults poses a significant threat to the safety and stability of underground *** this study,the north-east area of the Longmenshan fault,Sichuan,provides the geological background;the rheological characteristics of the crustal lithosphere and the nonlinear interactions between plates are described by Burger’s viscoelastic constitutive model and the friction constitutive model,respectively.A large-scale global numerical model for plate squeezing analysis is established,and the seemingly periodic stick-slip action of faults at different crust depths is *** a second model at a smaller scale,a local finite element model(sub-model),the time history of displacement at a ground level location on the Longmenshan fault plane in a stick-slip action is considered as the displacement *** integration of these models,creating a multi-scale modeling method,is used to evaluate the crack propagation and mechanical response of a tunnel subjected to strike-slip *** determinations of the recurrence interval of stick-slip action and the cracking characteristics of the tunnel are in substantial agreement with the previous field investigation and experimental results,validating the multi-scale modeling *** can be concluded that,regardless of stratum stiffness,initial cracks first occur at the inverted arch of the tunnel in the footwall,on the squeezed side under strike-slip *** smaller the stratum stiffness is,the smaller the included angle between the crack expansion and longitudinal direction of the tunnel,and the more extensive the crack expansion *** the tunnel in a high stiffness stratum,both shear and bending failures occur on the lining under strike-slip faulting,while for that in the low stiffness stratum,only bending failure occurs on the lining.

关键词： stick-slip action plate squeezing analysis multi-scale modeling method lining cracking mechanical response

Natural rubber latex as a potential additive for water-based drilling fluids

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Petroleum Science 2024年第4期21卷 2677-2687页

作者： Jun Yang Guan-Cheng Jiang Jing-Tian Yi Yin-Bo He Li-Li Yang Teng-Fei Dong Guo-Shuai Wang College of Petroleum engineering China University of Petroleum (Beijing) National engineering Research Center of Oil & Gas Drilling and Completion Technology Changqing Drilling General company CNPC Chuanqing Drilling Engineering Company Limited

The environmental hazards and "carbon footprint" of oil and gas drilling can be significantly reduced by replacing traditional petroleum-based chemical additives with natural materials derived from plants and animals. This paper explored for the first time the interaction mechanism between natural rubber latex(NRL) and bentonite suspensions(BTs) through a series of characterization experiments, as well as the potential applications in water-based drilling fluids(WBDF). The gel viscoelasticity experiments showed that NRL could decrease the consistency coefficient(k) and flow index(n) of BTs, and enhance the shear thinning performance of BTs as pseudo-plastic fluids. In addition, 0.5 w/v% NRL not only increased the critical yield stress and strengthened the structural strength between the bentonite particles, but also facilitated the compatibility of pressure loss and flow efficiency. The evaluation of colloidal stability and WBDF performance indicated that NRL particles could promote the hydration and charge stability on the surface of BTs particles, and optimize the particle size distribution and flow resistance of WBDF under the "intercalation-exfoliation-encapsulation" synergistic interaction. Moreover, NRL can improve the rheological properties of WBDF at high temperatures(<150.C), and form a dense blocking layer by bridging and sealing the pores and cracks of the filter cake, which ultimately reduces the permeability of the cake and the filtration loss of WBDF.

关键词： Natural materials Water-based drilling fluids Natural rubber latex Bentonite suspensions Filtration loss