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Triaxial creep damage characteristics of sandstone under high crustal stress and its constitutive model for engineering application
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作者 Dongxu Chen Laigui Wang +1 位作者 Pierre Darry Versaillot Chuang Sun 《Deep Underground Science and Engineering》 2023年第3期262-273,共12页
The creep characteristics of rock under high crustal stress are of important influence on the long‐term stability of deep rock engineering.To study the creep characteristics and engineering application of sandstone u... The creep characteristics of rock under high crustal stress are of important influence on the long‐term stability of deep rock engineering.To study the creep characteristics and engineering application of sandstone under high crustal stress,this study constructed nonlinear creep damage(NCD)constitutive mode based on the triaxial graded loading‒unloading creep test of sandstone in the Yuezhishan Tunnel.A numerical NCD constitutive model and a breakable lining(BL)model were developed based on FLAC3D and then applied to the stability analysis of the Yuezhishan Tunnel.Based on the creep test results of sandstone,a power function of creep rate and stress level was constructed,by which the long‐term strength was solved.The results show that the long‐term strength of the red sandstone based on the related function of the steady‐state creep rate and stress level is close to the measured stress value in engineering.The NCD model considering damage factors reflects the instantaneous and viscoelastic plasticity deformation characteristics of the red sandstone.The numerical NCD constitutive model and the BL model can reflect surrounding rock deformation characteristics and lining failure characteristics in practical engineering.The research results provide theoretical references for long‐term stability analysis of rock engineering and the deformation control of surrounding rock under high crustal stress. 展开更多
关键词 creep damage model high stress long‐term strength secondary development tunnel engineering
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Mechanism of high-preload support based on the NPR anchor cable in layered soft rock tunnels
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作者 SUI Qiru HE Manchao +3 位作者 SHI Mengfan TAO Zhigang ZHAO Feifei ZHANG Xiaoyu 《Journal of Mountain Science》 SCIE CSCD 2024年第4期1403-1418,共16页
The control of large deformation problems in layered soft rock tunnels needs to solve urgently.The roof problem is particularly severe among the deformation issues in tunnels.This study first analyzes the asymmetric d... The control of large deformation problems in layered soft rock tunnels needs to solve urgently.The roof problem is particularly severe among the deformation issues in tunnels.This study first analyzes the asymmetric deformation modes in layered soft rock tunnels with large deformations.Subsequently,we construct a mechanical model under ideal conditions for controlling the roof of layered soft rock tunnels through high preload with the support of NPR anchor cables.The prominent roles of long and short NPR anchor cables in the support system are also analyzed.The results indicate the significance of high preload in controlling the roof of layered soft rock tunnels.The short NPR anchor cables effectively improve the integrity of the stratified soft rock layers,while the long NPR anchor cables effectively mobilize the self-bearing capacity of deep-stable rock layers.Finally,the high-preload support method with NPR anchor cables is validated to have a good effect on controlling large deformations in layered soft rock tunnels through field monitoring data. 展开更多
关键词 Tunnel engineering Soft rock High-preload support NPR anchor cables
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Application Strategy of NDT Technology in Tunnel Engineering Quality Inspection
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作者 Duan Pu Zhifa Zeng Yuxiao Wu 《Journal of World Architecture》 2022年第6期35-39,共5页
Nondestructive testing(NDT)is an advanced and commonly used technique in tunnel engineering quality inspection.To achieve good application of nondestructive testing technology,its main application in tunnel engineerin... Nondestructive testing(NDT)is an advanced and commonly used technique in tunnel engineering quality inspection.To achieve good application of nondestructive testing technology,its main application in tunnel engineering quality inspection strategy is analyzed,including the significance of applying nondestructive testing technology in tunnel engineering quality inspection,the main nondestructive testing technology applied in tunnel engineering quality test analysis,and the analysis of nondestructive testing technology of tunnel engineering quality inspection strategy.The analyses in this paper are done in hopes of providing scientific reference for the utilization of NDT technology and the improvement of tunnel engineering quality. 展开更多
关键词 Tunnel engineering Nondestructive testing technology Significance of application
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Practice Research on Standardization of Undergraduate Graduation Design of Tunnel and Underground Engineering
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作者 Mingfeng Lei Weidong Wang +2 位作者 Chenghua Shi Chaojun Jia Chenjie Gong 《Journal of Educational Theory and Management》 2022年第1期46-50,共5页
Graduation project(thesis)is an important practice part in undergraduate education,which forms an organic whole with theoretical teaching link,and it is the continuation,deepening and examination of the theoretical te... Graduation project(thesis)is an important practice part in undergraduate education,which forms an organic whole with theoretical teaching link,and it is the continuation,deepening and examination of the theoretical teaching part.This paper focuses on the constitution that the lack of quality standards for undergraduate graduation design,resulting in different depth and breadth standards;the graduation design materials are scattered and lack of standardization,which leads to the lack of systematic reference materials for students,taking the tunnel and underground engineering major as an example,this paper carries out the practice research on the standardization of the graduation design of tunnel and underground engineering through investigation and combining the teaching resources accumulated in the past decades.Through the study of practice,the content of undergraduate graduation design of tunnel and underground engineering is standardized,the breadth and depth of graduation design is defined,and the“Guide for undergraduate graduation design of tunnel and underground engineering”is organized and compiled,which can provide reference for the standardization and guidance of undergraduate graduation design of tunnel and underground engineering. 展开更多
关键词 Tunnel and underground engineering Undergraduate graduation project Design guidelines
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Viscoplastic solutions of time-dependent deformation for tunnels in swelling rock mass considering stress release
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作者 Gengyun Liu Youliang Chen +1 位作者 HyonChol Rim Rafig Azzam 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第8期2053-2071,共19页
Excavation and control of tunneling responses in swelling soft-rock tunnels of Sichuan-Tibet railway under seepage conditions were studied.For this,a fractional viscoplastic(FVP)model for swelling soft rocks was estab... Excavation and control of tunneling responses in swelling soft-rock tunnels of Sichuan-Tibet railway under seepage conditions were studied.For this,a fractional viscoplastic(FVP)model for swelling soft rocks was established by introducing Abel dashpot and unsteady viscosity coefficient,considering additional swelling deformation and damage of rock caused by humidity effect.In view of the FVP model,the viscoplastic deformation solutions for rock mass surrounding tunnel under seepage conditions were derived and long-term mechanical responses of swelling rocks upon tunnel excavation were analyzed.Next,a stress release coefficient considering seepage and creep was proposed,based on which control responses considering stress release and failure mechanism of stress release measures were analyzed.The results showed that:(i)The one-dimensional(1D)FVP model has a good application for swelling rock and the three-dimensional(3D)FVP model could well describe the whole creep process of rock mass despite a much higher creep attenuation rate in the first stage of creep;and(ii)An appropriate stress release and deformation of surrounding rocks could effectively reduce the supporting resistance.However,upon a large stress release,the radius of plastic region could increase significantly,and the strength of the surrounding rock mass decreases greatly.The proposed solution could provide a theoretical framework for capturing the excavation and support responses for tunneling in swelling rock mass in consideration of time effect. 展开更多
关键词 Sichuan-tibet railway Viscoplastic deformation Stress release Fractional model tunneling engineering
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Excavation compensation theory and supplementary technology system for large deformation disasters 被引量:4
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作者 Manchao He Qiru Sui Zhigang Tao 《Deep Underground Science and Engineering》 2023年第2期105-128,共24页
Given the challenges in managing large deformation disasters in energy engineering,traffic tunnel engineering,and slope engineering,the excavation compensation theory has been proposed for large deformation disasters ... Given the challenges in managing large deformation disasters in energy engineering,traffic tunnel engineering,and slope engineering,the excavation compensation theory has been proposed for large deformation disasters and the supplementary technology system is developed accordingly.This theory is based on the concept that“all destructive behaviors in tunnel engineering originate from excavation.”This paper summarizes the development of the excavation compensation theory in five aspects:the“theory,”“equipment,”“technology,”the design method with large deformation mechanics,and engineering applications.First,the calculation method for compensation force has been developed based on this theory,and a comprehensive large deformation disaster control theory system is formed.Second,a negative Poisson's ratio anchor cable with high preload,large deformation,and super energy absorption characteristics has been independently developed and applied to large deformation disaster control.An intelligent tunnel monitoring and early warning cloud platform system are established for remote monitoring and early warning system of Newton force in landslide geological hazards.Third,the double gradient advance grouting technology,the two-dimensional blasting technology,and the integrated Newton force monitoring--early warning--control technology are developed for different engineering environments.Finally,some applications of this theory in China's energy,traffic tunnels,landslide,and other field projects have been analyzed,which successfully demonstrates the capability of this theory in large deformation disaster control. 展开更多
关键词 energy engineering excavation compensation large deformation NPR anchor cable slope engineering traffic tunnel engineering
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Extraction and imaging of indicator elements for non-destructive,in-situ,fast identification of adverse geology in tunnels
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作者 Fumin Liu Peng Lin +2 位作者 Zhenhao Xu Ruiqi Shao Tao Han 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第12期1437-1449,共13页
The lag in quantitative methods and detection techniques for geologic information has resulted in time-consuming and human-experienced geologic analysis in tunnels.Geochemical indicators of rocks can be used to identi... The lag in quantitative methods and detection techniques for geologic information has resulted in time-consuming and human-experienced geologic analysis in tunnels.Geochemical indicators of rocks can be used to identify adverse geology and to explain the intrinsic causes of damage to normal rocks.This study proposes a method to identify adverse geology by extracting and imaging the indicator elements.The mapping relationship between rock components and geologic bodies is quickly determined by indicator element extraction based on factor analysis,and then the data are gridded for image output.The location and size of the target adverse geology are visually identified through the distribution images of the indicator elements,thus reducing data dimensions and analysis time.A non-destructive,in-situ and fast element detection technique in tunnels was adopted to speed up the process of geology identification.The accuracy of the detection was validated by comparing field and laboratory test results.This study further confirms and refines the previous research,and the results provide references for geological,mining and underground projects. 展开更多
关键词 Adverse geology identification Indicator elements Rock geochemistry Tunnel engineering Geological analysis
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Shaking table test and cumulative deformation evaluation analysis of a tunnel across the hauling sliding surface
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作者 Lifang Pai Honggang Wu Xu Wang 《Deep Underground Science and Engineering》 2023年第4期371-393,共23页
To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical ca... To explore the cumulative deformation effect of the dynamic response of a tunnel crossing the hauling sliding surface under earthquakes,the shaking table test was conducted in this study.Combined with the numerical calculations,this study proposed magnification of the Arias intensity(MIa)to characterize the overall local deformation damage of the tunnel lining in terms of the deformation characteristics,frequency domain,and energy.Using the time‐domain analysis method,the plastic effect coefficient(PEC)was proposed to characterize the degree of plastic deformation,and the applicability of the seismic cumulative failure effect(SCFE)was discussed.The results show that the low‐frequency component(f1 and f2≤10 Hz)and the high‐frequency component(f3 and f4>10 Hz)acceleration mainly cause global and local deformation of the tunnel lining.The local deformation caused by the high‐frequency wave has an important effect on the seismic damage of the lining.The physical meaning of PEC is more clearly defined than that of the residual strain,and the SCFE of the tunnel lining can also be defined.The SCFE of the tunnel lining includes the elastic deformation effect stage(<0.15g),the elastic–plastic deformation effect stage(0.15g–0.30g),and the plastic deformation effect stage(0.30g–0.40g).This study can provide valuable theoretical and technical support for the construction of traffic tunnels in high‐intensity earthquake areas. 展开更多
关键词 magnification of Arias intensity plastic effect coefficient seismic action seismic cumulative failure effect shaking table test tunnel engineering
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Tunnel Support Structure System and Its Synergy
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作者 Xingxing Wang Wenke Zhao Senyang Wu 《Journal of World Architecture》 2023年第4期11-16,共6页
The tunnel support system is composed of lining,bolt,and steel frame.It is of great significance to effectively control the deformation of the surrounding rock of the tunnel,make full use of the characteristics of dif... The tunnel support system is composed of lining,bolt,and steel frame.It is of great significance to effectively control the deformation of the surrounding rock of the tunnel,make full use of the characteristics of different support methods,and formulate an economical and effective support plan to ensure the safe operation of the tunnel structure.This paper clarifies the synergistic relationship between the support structure and the surrounding rock based on their fundamental characteristics and functions.Various support structures and components are also discussed in this paper.Additionally,the paper presents an optimized design of the tunnel support structure system. 展开更多
关键词 Tunnel engineering Support structure system SYNERGY Support structure design
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New technologies for high-risk tunnel construction in GuiyangGuangzhou high-speed railway 被引量:2
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作者 Yubao Zhao Shougen Chen +1 位作者 Xinrong Tan Ma Hui 《Journal of Modern Transportation》 2013年第4期258-265,共8页
Based on the construction of high risk tunnels in Guiguang-Guangzhou high-speed railway, several new technologies were developed for high-risk tunnel con- struction. First, an integrated advanced geological predic- ti... Based on the construction of high risk tunnels in Guiguang-Guangzhou high-speed railway, several new technologies were developed for high-risk tunnel con- struction. First, an integrated advanced geological predic- tion was developed for tunneling in karst area. Then, a new system of ventilation by involving the dedusting technol- ogy was proposed and used in the field, which received a good air quality. Finally, a method to minimize the dis- tance between the working face and the invert installation was proposed by optimizing the invert installation and adopting the micro bench method. Applying the method to the project obtained an excellent result. The achievement obtained for this study would be able to provide a valuable reference to similar projects in the future. 展开更多
关键词 tunneling engineering High-speed railway New technologies High-risk tunnel
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Compensation excavation method control for large deformation disaster of mountain soft rock tunnel 被引量:12
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作者 Manchao He Qiru Sui +2 位作者 Mengnan Li Zhijiao Wang Zhigang Tao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2022年第5期951-963,共13页
In recent years,the mine tunneling method and the new Austrian tunneling method have been considered the main theories of tunneling approaches in China.It is difficult for the traditional technique to overcome the lar... In recent years,the mine tunneling method and the new Austrian tunneling method have been considered the main theories of tunneling approaches in China.It is difficult for the traditional technique to overcome the large deformation problems imposed by complex geological conditions of mountain soft rock tunneling.Hence,the compensation excavation method has been proposed to solve this issue under the consideration that all damage in tunneling originates from the excavation.It uses supportive strategies to counteract the excavation effects successfully.This paper provides an overview of the fundamental ideas of the compensation excavation method,methodologies,and field applications.The scientific validity and feasibility of the compensation excavation method were investigated through the practical engineering study of the Muzhailing and Changning tunnels. 展开更多
关键词 Tunnel engineering Excavation method Soft rock Large deformation Compensation excavation method
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Model test on support scheme for carbonaceous slate tunnel in high geostress zone at high depth 被引量:5
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作者 TAO Zhi-gang REN Shu-lin +3 位作者 LI Gan XU Hao-tian LUO Sen-lin HE Man-chao 《Journal of Mountain Science》 SCIE CSCD 2021年第3期764-778,共15页
The Muzhailing extra-long highway tunnel and corresponding inclined shafts in Lanzhou,Gansu Province,China passes through structurally complex carbonaceous slate that is under high ground stress.Rationally-designed an... The Muzhailing extra-long highway tunnel and corresponding inclined shafts in Lanzhou,Gansu Province,China passes through structurally complex carbonaceous slate that is under high ground stress.Rationally-designed and effective support is of high importance for achieving safe and efficient tunnel construction.The No.2 inclined shaft of Muzhailing Tunnel was taken as the engineering background prototype,for which,a similar model test was conducted to evaluate the effect of highly pretightened constant resistance(NPR,Negative Poisson’s Ratio)anchor cable support provision to the geologically complex carbonaceous slate at different depths.Two schemes were proposed during testing:one scheme was without support and the second was with asymmetric support from highly pre-tightened constant resistance anchor cable.Digital speckle displacement analysis system and micro-groundstress sensors were employed to measure the deformation and shear stress distribution of the tunnel.The results demonstrated that through the second support scheme,the deformation of the surrounding rock could be effectively ameliorated,while this support scheme was applied on the project site of the No.2 inclined shaft,to explore the rationality of the scheme through field engineering tests.On-site monitoring indicated that the deformation of the surrounding rock was within the reasonable design range and the problem of severe tunnel deformation was effectively controlled.The research methods and related conclusions can be used as a reference for the treatment of large deformation problems in deep-buried soft rock tunnels. 展开更多
关键词 Tunnel engineering Support design Carbonaceous slate Similar simulation NPR anchor cable
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Protection against water or mud inrush in tunnels by grouting:A review 被引量:32
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作者 Shucai Li Rentai Liu +1 位作者 Qingsong Zhang Xiao Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2016年第5期753-766,共14页
Grouting is a major method used to prevent water and mud inrush in tunnels and underground engineering. In this paper, the current situation of control and prevention of water and mud inrush is summarized and recent a... Grouting is a major method used to prevent water and mud inrush in tunnels and underground engineering. In this paper, the current situation of control and prevention of water and mud inrush is summarized and recent advances in relevant theories, grout/equipment, and critical techniques are introduced. The time-variant equations of grout viscosity at different volumetric ratios were obtained based on the constitutive relation of typical fast curing grouts. A large-scale dynamic grouting model testing system (4000 mm × 2000 mm × 5 mm) was developed, and the diffusions of cement and fast curing grouts in dynamic water grouting were investigated. The results reveal that the diffusions of cement grouts and fast curing grouts are U-shaped and asymmetric elliptical, respectively. A multi-parameter real-time monitoring system (&#981; = 1.5 m, h = 1.2 m) was developed for the grouting process to study the diffusion and reinforcement mechanism of grouting in water-rich faulted zone. A high early strength cream-type reinforcing/plugging grout, a high permeability nano-scale silica gel grout, and a high-expansion filling grout were proposed for the control of water hazards in weak water-rich faulted zone rocks, water inrush in karst passages, and micro-crack water inrush, respectively. Complement technologies and equipment for industrial applications were also proposed. Additionally, a novel full-life periodic dynamic water grouting with the critical grouting borehole as the core was proposed. The key techniques for the control of water inrush in water-rich faulted zone, jointed fissures and karst passages, and micro-crack water inrush were developed. 展开更多
关键词 Tunnel engineering Water or mud inrushModel testsGrouting theoryGrouting control techniques
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Updating the models and uncertainty of mechanical parameters for rock tunnels using Bayesian inference 被引量:2
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作者 Hongbo Zhao Bingrui Chen +2 位作者 Shaojun Li Zhen Li Changxing Zhu 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第5期224-236,共13页
Rock mechanical parameters and their uncertainties are critical to rock stability analysis,engineering design,and safe construction in rock mechanics and engineering.The back analysis is widely adopted in rock enginee... Rock mechanical parameters and their uncertainties are critical to rock stability analysis,engineering design,and safe construction in rock mechanics and engineering.The back analysis is widely adopted in rock engineering to determine the mechanical parameters of the surrounding rock mass,but this does not consider the uncertainty.This problem is addressed here by the proposed approach by developing a system of Bayesian inferences for updating mechanical parameters and their statistical properties using monitored field data,then integrating the monitored data,prior knowledge of geotechnical parameters,and a mechanical model of a rock tunnel using Markov chain Monte Carlo(MCMC)simulation.The proposed approach is illustrated by a circular tunnel with an analytical solution,which was then applied to an experimental tunnel in Goupitan Hydropower Station,China.The mechanical properties and strength parameters of the surrounding rock mass were modeled as random variables.The displacement was predicted with the aid of the parameters updated by Bayesian inferences and agreed closely with monitored displacements.It indicates that Bayesian inferences combined the monitored data into the tunnel model to update its parameters dynamically.Further study indicated that the performance of Bayesian inferences is improved greatly by regularly supplementing field monitoring data.Bayesian inference is a significant and new approach for determining the mechanical parameters of the surrounding rock mass in a tunnel model and contributes to safe construction in rock engineering. 展开更多
关键词 Rock tunnel engineering Back analysis Bayesian inference Uncertainty analysis Markov chain Monte Carlo simulation
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Prevention and treatment technologies of railway tunnel water inrush and mud gushing in China 被引量:17
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作者 Yong Zhao Pengfei Li Siming Tian 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2013年第6期468-477,共10页
Water inrush and mud gushing are one of the biggest hazards in tunnel construction. Unfavorable geological sections can be observed in almost all railway tunnels under construction or to be constructed, and vary in ex... Water inrush and mud gushing are one of the biggest hazards in tunnel construction. Unfavorable geological sections can be observed in almost all railway tunnels under construction or to be constructed, and vary in extent. Furthermore, due to the different heights of mountains and the lengths of tunnels, the locations of the unfavorable geological sections cannot be fully determined before construction, which increases the risk of water inrush and mud gushing. Based on numerous cases of water inrush and mud gushing in railway tunnels, the paper tries to classify water inrush and mud gushing in railway tunnels in view of the conditions of the surrounding rocks and meteorological factors associated with tunnel excavation. In addition, the causes of water inrush and mud gushing in combination of macroand micromechanisms are summarized, and site-specifc treatment method is put forward. The treatment methods include choosing a method of advance geological forecast according to risk degrees of different sections in the tunnel, determining the items of predictions, and choosing the appropriate methods, i.e. draining-oriented method, blocking-oriented method or draining-and-blocking method. The treatment technologies of railway water inrush and mud gushing are also summarized, including energy relief and pressure relief technology, advance grouting technology, and advance jet grouting technology associated with their key technical features and applicable conditions. The results in terms of treatment methods can provide reference to the prevention and treatment of tunnel water inrush and mud gushing. 展开更多
关键词 Tunnel engineering Unfavorable geological regions Water inrush and mud gushing Pressure relief technology Advance grouting technology Advance jet grouting
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Approximate analytical solution for seepage field of drained tunnel in vertically stratified phreatic aquifer 被引量:1
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作者 MENG Wei HE Chuan +5 位作者 WU Fang-yin YANG Wen-bo KOU Hao ZHOU Zi-han GUO De-ping MENG Hai-long 《Journal of Mountain Science》 SCIE CSCD 2022年第5期1437-1455,共19页
To explore the water table and water inflow after tunnel excavation in a vertically stratified phreatic aquifer,approximate analytical solutions for the steady-state water table and water inflow of a drained tunnel in... To explore the water table and water inflow after tunnel excavation in a vertically stratified phreatic aquifer,approximate analytical solutions for the steady-state water table and water inflow of a drained tunnel in a vertically stratified phreatic aquifer were obtained based on the Dupuit assumptions and the integral method.By comparing the approximate analytical solutions with numerical solutions,it was found that the relative error of the approximate analytical solution for the water table elevation is less than 10%,and the relative error of the approximate analytical solution for the water inflow is approximately 25%.The sources of the above errors are as follows:(1)At the lateral boundary of water replenishment,the water surface should be tangent to the horizontal line,but the water surface for the approximate analytical solutions has a gradient.(2)At the vertical boundaries near the tunnel,the total head is variable,but the total head for the approximate analytical solutions is assumed to be constant.(3)The Dupuit assumptions are applied in the flow domain near the tunnel.Although the relative errors of the approximate analytical solutions for the water table elevation and water inflow are evident,the lowered water table is reflected in the approximate analytical solutions. 展开更多
关键词 Dupuit assumptions Water table Water inflow Tunnel engineering Equipotential line Integral method
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Geomechanics model test and numerical simulation of 2G-NPR bolt support effect in an active fault tunnel 被引量:1
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作者 REN Shu-lin HE Man-chao +2 位作者 LIN Wei-jun ZHANG Teng-wu TAO Zhi-gang 《Journal of Mountain Science》 SCIE CSCD 2022年第9期2729-2741,共13页
Active faults are a common adverse geological phenomenon that can occur during tunnel excavation and has a very negative impact on the construction and operation of the tunnel.In this paper,the grade IV rock surroundi... Active faults are a common adverse geological phenomenon that can occur during tunnel excavation and has a very negative impact on the construction and operation of the tunnel.In this paper,the grade IV rock surrounding the cross-fault tunnel with poor geological conditions has been chosen for the study.The support capacity of 2^(nd) Generation-Negative Poisson’s Ratio(2G-NPR)bolt in an active fault tunnel has been carried out on the basis of relevant results obtained from the geomechanical model test and numerical investigations of failure model for existing unsupported fault tunnel.The investigation shows that surrounding rock of the tunnel is prone to shear deformation and crack formation along the fault,as a result,the rock mass on the upper part of the fault slips as a whole.Furthermore,small-scale deformation and loss of blocks are observed around the tunnel;however,the 2G-NPR bolt support is found to be helpful in keeping the overall tunnel intact without any damage and instability.Due to the blocking effect of fault,the stress of the surrounding rock on the upper and lower parts of the fault is significantly different,and the stress at the left shoulder of the tunnel is greater than that at the right shoulder.The asymmetrical arrangement of 2G-NPR bolts can effectively control the asymmetric deformation and instability of the surrounding rock.The present numerical scheme is in good agreement with the model test results,and can reasonably reflect the stress and displacement characteristics of the surrounding rock of the tunnel.In comparison to unsupported and ordinary PR(Poisson’s Ratio)bolt support,2G-NPR bolt can effectively limit the fault slip and control the stability of the surrounding rock of the fault tunnel.The research findings may serve as a guideline for the use of 2G-NPR bolts in fault tunnel support engineering. 展开更多
关键词 Tunnel engineering Fault 2G-NPR bolt Geomechanics model test Numerical simulation
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Investigation of Sulfate Attack Resistance of Shotcrete under Dry-wet Cycles 被引量:1
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作者 王家滨 牛荻涛 +1 位作者 MA Rui ZHANG Yongli 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2016年第6期1329-1335,共7页
In order to research the sulfate attack resistance of shotcrete, the sulfate attack of shotcrete in the presence and absence of steel fiber was experimentally studied by using dry-wet cycle method. Meanwhile, compared... In order to research the sulfate attack resistance of shotcrete, the sulfate attack of shotcrete in the presence and absence of steel fiber was experimentally studied by using dry-wet cycle method. Meanwhile, compared with ordinary concrete by the same mixture, the difference of sulfate attack resistance of shotcrete was studied. The experimental results showed that, with dry-wet cycles increasing, the changes of loss rate of relative dynamic elastic modulus and mass loss rate of specimens included three stages: initial descent stage, stable stage, and rapid descent stage, respectively. However, the changes of mechanical properties first increased and then decreased. Furthermore, the corrosion products of shotcrete after sulfate attack were observed by using the method of XRD, thermal analysis, and SEM, respectively, and the failure mode of shotcrete turned from ettringite destruction to ettringite-gypsum comprehensive failure. Meanwhile, the contents of ettringite and gypsum increased with increasing dry-wet cycle. Simultaneously, the stratified powders drilled from shotcrete under 150's dry-wet cycle were analyzed for the mineral phase composition and thermal analysis. With the drywet cycle increasing, the content of ettringite first increased and then decreased and tended to stable. However, the determination of gypsum decreased gradually and even to 0 when the depth was more than 12 mm. 展开更多
关键词 tunnel engineering durability shotcrete sulfate attack dry-wet cycles
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A construction strategy for a tunnel with big deformation 被引量:1
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作者 Liang Chen Shougen Chen Xinrong Tan 《Journal of Modern Transportation》 2013年第2期86-94,共9页
By integrating literature reviews, site observa- tion, field monitoring, theoretical analysis, summarization, etc., a construction strategy was proposed and verified for tunneling with big deformation in this paper. T... By integrating literature reviews, site observa- tion, field monitoring, theoretical analysis, summarization, etc., a construction strategy was proposed and verified for tunneling with big deformation in this paper. The tunnel was in phyllite, shotcrete cracks and steel arch distortion were observed, and a big deformation with a maximum of 2.0 m was monitored during the initial stage of the construction. Through carefully examining the site observation and laboratory test results, a construction principle was established for the tunneling on the basic concept of maintaining the rock strength/stiffness and keeping the rock dry, by providing confinement pressure to the rock, reducing the rock exposure time, keeping water out of the tunnel, etc. To achieve the construction principle, a set of specific construction measures with 11 items was further proposed and applied to the construction. To check the effectiveness of the construction measures, field monitoring was carried out, which showed that the rock deformation was well controlled and the tunnel became stable. An allowable deformation was then determined using the Fenner formulae and the monitored data in order to guide further construction, which received a good result. From this study, it can be concluded that providing quick strong initial support and reserving core soil at the working faceare extremely important to control the rock deformation and keep the tunnel stable. 展开更多
关键词 Tunnel engineering Big deformation Construction strategy
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Analysis of Non-destructive Testing and Disease Diagnosis Technology of Tunnel Projects
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作者 Yike Wei Lingfeng Yu 《Journal of World Architecture》 2021年第1期8-10,共3页
Engineering incidents caused by the quality of tunnel construction and geological diseases occur from time to time,which not only causes many problems in engineering geophysical prospecting,but also provided a broad s... Engineering incidents caused by the quality of tunnel construction and geological diseases occur from time to time,which not only causes many problems in engineering geophysical prospecting,but also provided a broad space for the application and development of engineering geophysical prospecting technology.Non-destructive testing technology has made great progress.Combining the diagnosis and treatment of tunnel diseases,the ground penetrating radar non-destructive detection technology is discussed. 展开更多
关键词 Tunnel engineering Non-destructive testing Disease diagnosis
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