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Application of excavation compensation method for enhancing stability and efficiency in shallow large-span rock tunnels
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作者 BIAN Wen-hui YANG Jun +2 位作者 ZHU Chun WANG Ke-xue XU Dong-ming 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第9期3242-3263,共22页
Engineering shallow,large-span rock tunnels challenges deformation control and escalates construction costs.This study investigates the excavation compensation method(ECM)and its associated technologies to address the... Engineering shallow,large-span rock tunnels challenges deformation control and escalates construction costs.This study investigates the excavation compensation method(ECM)and its associated technologies to address these issues.Utilizing five key technologies,the ECM effectively modulates radial stress post-excavation,redistributes stress in the surrounding rock,and eliminates tensile stress at the excavation face.Pre-tensioning measures further enhance the rock’s residual strength,establishing a new stability equilibrium.Field tests corroborate the method’s effectiveness,demonstrating a crown settlement reduction of 3–8 mm,a nearly 50%decrease compared to conventional construction approaches.Additionally,material consumption and construction duration were reduced by approximately 30%–35%and 1.75 months per 100 m,respectively.Thus,the ECM represents a significant innovation in enhancing the stability and construction efficiency of large-span rock tunnels,marking a novel contribution to the engineering field. 展开更多
关键词 excavation compensation method rocky tunnels shallow spanning tunnels tunnel support field test
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Mechanism of high-preload support based on the NPR anchor cable in layered soft rock tunnels 被引量:1
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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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Semi-analytical solution for mechanical analysis of tunnels crossing strike-slip fault zone considering nonuniform fault displacement and uncertain fault plane position
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作者 YANG Heng-hong WANG Ming-nian +1 位作者 YU Li ZHANG Xiao 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2116-2136,共21页
The tunnel subjected to strike-slip fault dislocation exhibits severe and catastrophic damage.The existing analysis models frequently assume uniform fault displacement and fixed fault plane position.In contrast,post-e... The tunnel subjected to strike-slip fault dislocation exhibits severe and catastrophic damage.The existing analysis models frequently assume uniform fault displacement and fixed fault plane position.In contrast,post-earthquake observations indicate that the displacement near the fault zone is typically nonuniform,and the fault plane position is uncertain.In this study,we first established a series of improved governing equations to analyze the mechanical response of tunnels under strike-slip fault dislocation.The proposed methodology incorporated key factors such as nonuniform fault displacement and uncertain fault plane position into the governing equations,thereby significantly enhancing the applicability range and accuracy of the model.In contrast to previous analytical models,the maximum computational error has decreased from 57.1%to 1.1%.Subsequently,we conducted a rigorous validation of the proposed methodology by undertaking a comparative analysis with a 3D finite element numerical model,and the results from both approaches exhibited a high degree of qualitative and quantitative agreement with a maximum error of 9.9%.Finally,the proposed methodology was utilized to perform a parametric analysis to explore the effects of various parameters,such as fault displacement,fault zone width,fault zone strength,the ratio of maximum fault displacement of the hanging wall to the footwall,and fault plane position,on the response of tunnels subjected to strike-slip fault dislocation.The findings indicate a progressive increase in the peak internal forces of the tunnel with the rise in fault displacement and fault zone strength.Conversely,an augmentation in fault zone width is found to contribute to a decrease in the peak internal forces.For example,for a fault zone width of 10 m,the peak values of bending moment,shear force,and axial force are approximately 46.9%,102.4%,and 28.7% higher,respectively,compared to those observed for a fault zone width of 50 m.Furthermore,the position of the peak internal forces is influenced by variations in the ratio of maximum fault displacement of the hanging wall to footwall and the fault plane location,while the peak values of shear force and axial force always align with the fault plane.The maximum peak internal forces are observed when the footwall exclusively bears the entirety of the fault displacement,corresponding to a ratio of 0:1.The peak values of bending moment,shear force,and axial force for the ratio of 0:1 amount to approximately 123.8%,148.6%,and 111.1% of those for the ratio of 0.5:0.5,respectively. 展开更多
关键词 strike-slip fault tunnel engineering semi-analytical solution fault zone width nonuniform fault displacement uncertain fault plane position
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Mechanical properties of steel mesh in anchor-mesh support for rocky tunnels
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作者 SUN Keguo JIA Jinglong +4 位作者 XU Weiping ZHANG Yu WANG Jinjin WANG Yichao LIU Yongkui 《Journal of Mountain Science》 SCIE CSCD 2024年第10期3487-3502,共16页
Underground geotechnical engineering encounters persistent challenges in ensuring the stability and safety of surrounding rock structures, particularly within rocky tunnels. Rock reinforcement techniques, including th... Underground geotechnical engineering encounters persistent challenges in ensuring the stability and safety of surrounding rock structures, particularly within rocky tunnels. Rock reinforcement techniques, including the use of steel mesh, are critical to achieving this goal. However, there exists a knowledge gap regarding the comprehensive understanding of the mechanical behavior and failure mechanisms exhibited by steel mesh under diverse loading conditions. This study thoroughly explored the steel mesh's performance throughout the entire loading-failure process, innovating with detailed analysis and modeling techniques. By integrating advanced numerical modeling with laboratory experiments, the study examines the influence of varying reinforcement levels and geometric parameters on the steel mesh strength and deformation characteristics. Sensitivity analysis, employing gray correlation theory, identifies the key factors affecting the mesh performance, while a BP (Backpropagation) neural network model predicts maximum vertical deformation with high accuracy. The findings underscore the critical role of steel diameter and mesh spacing in optimizing peak load capacity, displacement, and energy absorption, offering practical guidelines for design improvements. The use of a Bayesian Regularization (BR) algorithm further enhances the predictive accuracy compared to traditional methods. This research provides new insights into optimizing steel mesh design for underground applications, offering an innovative approach to enhancing structural safety in geotechnical projects. 展开更多
关键词 TUNNEL Steel mesh BP neural network Anchor-mesh support Rock reinforcement technique
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Study on Mechanism of Water Inrush of Karst Tunnels
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作者 WANG Qingsong ZHAI Jinying(Translated) 《Chinese Railways》 2023年第2期20-28,共9页
Water inrush,which is one of the challenging issues and hot topics in the tunneling industry,is very easy to occur during the construction of karst tunnels.The mechanism of water inrush of karst tunnels is discussed a... Water inrush,which is one of the challenging issues and hot topics in the tunneling industry,is very easy to occur during the construction of karst tunnels.The mechanism of water inrush of karst tunnels is discussed and analyzed in the paper:the water inrush of karst tunnels is generally divided into three steps,i.e.,the forming of the hazard source,the forming of the water inrush passage and the failure of the anti-inrush rock mass.The failure of the anti-inrush rock mass of karst tunnels are classified into 5 types,i.e.,the integral tensile-shear failure,the hydraulic fracturing,the infiltration induced sliding of the filling medium,the loss of key blocks and the comprehensive water inrush mode.The failure mechanism is studied on basis of typical cases and by means of numerical simulation or theoretical analysis.Conclusion is drawn that most of the water inrushes in actual tunneling are comprehensive water inrushes,which are the comprehensive results of the interrelation and interaction of various water inrush types,and that different types of water inrushes have related continuity and progressive evolution relationships under certain conditions. 展开更多
关键词 karst tunnel water inrush MECHANISM numerical simulation failure mechanism
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Research progress and development trends of highway tunnels in China 被引量:69
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作者 Chuan He Bo Wang 《Journal of Modern Transportation》 2013年第4期209-223,共15页
The highway tunnel system in China has in recent years surpassed Europe, the United States, and other developed countries in terms of mileage, scale, complexity, and technical achievement. Much scientific research has... The highway tunnel system in China has in recent years surpassed Europe, the United States, and other developed countries in terms of mileage, scale, complexity, and technical achievement. Much scientific research has been conducted, and the results have greatly facilitated the rapid development of China's highway tunnel building capacity. This article presents the historical development of highway tunneling in China, according to specific charac- teristics based on construction and operation. It provides a systematic analysis of the major achievements and chal- lenges with respect to construction techniques, operation, monitoring, repair, and maintenance. Together with future trends of highway tunneling in China, suggestions have been made for further research, and development prospects have been identified with the for a Chinese-style highway aim of laying the foundation tunnel construction method and technical architecture. 展开更多
关键词 Highway tunnels Mining methods - Shieldtunneling Immersed tube tunnel Operation - MonitoringMaintenance PROGRESS
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Typical Underwater Tunnels in the Mainland of China and Related Tunneling Technologies 被引量:11
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作者 Kairong Hong 《Engineering》 SCIE EI 2017年第6期871-879,共9页
In the past decades, many underwater tunnels have been constructed in the mainland of China, and great progress has been made in related tunneling technologies. This paper presents the history and state of the art of ... In the past decades, many underwater tunnels have been constructed in the mainland of China, and great progress has been made in related tunneling technologies. This paper presents the history and state of the art of underwater tunnels in the mainland of China in terms of shield-bored tunnels, drill-and-blast tunnels, and immersed tunnels. Typical underwater tunnels of these types in the mainland of China are described, along with innovative technologies regarding comprehensive geological prediction, grouting-based consolidation, the design and construction of large cross-sectional tunnels with shallow cover in weak strata, cutting tool replacement under limited drainage and reduced pressure conditions, the detection and treatment of boulders, the construction of underwater tunnels in areas with high seismic intensity, and the treatment of serious sedimentation in a foundation channel of immersed tunnels. Some suggestions are made regarding the three potential great strait-crossing tunnels-the Qiongzhou Strait-Crossing Tunnel, Bohai Strait-Crossing Tunnel, and Taiwan Strait-Crossing Tunnel--and issues related to these great strait-crossing tunnels that need further study are proposed. 展开更多
关键词 Underwater tunnel Strait-crossing tunne Shield-bored tunnel Immersed tunnel Drill and blast
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Support pressure assessment for deep buried railway tunnels using BQ-index 被引量:6
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作者 WANG Ming-nian WANG Zhi-long +3 位作者 TONG Jian-jun ZHANG Xiao DONG Yu-cang LIU Da-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第1期247-263,共17页
Estimation of support pressure is extremely important to the support system design and the construction safety of tunnels.At present,there are many methods for the estimation of support pressure based on different roc... Estimation of support pressure is extremely important to the support system design and the construction safety of tunnels.At present,there are many methods for the estimation of support pressure based on different rock mass classification systems,such as Q system,GSI system and RMR system.However,various rock mass classification systems are based on different tunnel geologic conditions in various regions.Therefore,each rock mass classification system has a certain regionality.In China,the BQ-Inex(BQ system)has been widely used in the field of rock engineering ever since its development.Unfortunately,there is still no estimation method of support pressure with BQ-index as parameters.Based on the field test data from 54 tunnels in China,a new empirical method considering BQ-Inex,tunnel span and rock weight is proposed to estimate the support pressure using multiple nonlinear regression analysis methods.And then the significance and necessity of support pressure estimation method for the safety of tunnel construction in China is explained through the comparison and analysis with the existing internationally widely used support pressure estimation methods of RMR system,Q system and GSI system.Finally,the empirical method of estimating the support pressure based on BQ-index was applied to designing the support system in the China’s high-speed railway tunnel—Zhengwan high-speed railway and the rationality of this method has been verified through the data of field test. 展开更多
关键词 rock mass classification support pressure deep buried tunnel field test multiple nonlinear regression analysis BQ-Index
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An experimental study of the isolation performance of trenches on ground-borne vibration from underground tunnels 被引量:5
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作者 Yang Wenbo Shang Yingchao +4 位作者 Liu Dexiong Zou Tao Yan Qixiang Fang Yong He Chuan 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2020年第3期779-790,共12页
This paper presents a study of the isolation performance of trenches on train-induced ground-bore vibration from underground tunnels.A series of model tests was conducted to perform the study.Both train loads and sinu... This paper presents a study of the isolation performance of trenches on train-induced ground-bore vibration from underground tunnels.A series of model tests was conducted to perform the study.Both train loads and sinusoidal sweep loads were applied to the model tunnel invert by a shaker.The response of the soil at the surface of the ground was measured by accelerometers.Three types of isolation trenches,i.e.,an open trench,an expanded Polystyrene(EPS)-filled trench,and a Duxseal-filled trench,were modelled in the experiment.The results showed that the open trench and the EPS-filled trench increased the dynamic response of the surface soil in front of the trench,but the Duxseal-filled trench had little effect on the dynamic response of the soil on the surface in this area.Although all three types of isolation trenches reduced the response of the soil behind the trench,the open trench and the Duxseal-filled trench were clearly more effective.The test results also showed that,as the excitation frequency increased,the vibration isolation trench was more effective in the near field.The effects of the width,depth,and position of an open trench on isolation performance also were examined in the tests. 展开更多
关键词 FILLED UNDERGROUND GROUND
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Centrifuge modelling of ground-borne vibrations induced by railway traffic in underground tunnels 被引量:2
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作者 Yang Wenbo Qian Zhihao +4 位作者 Tu Jiulin Zhou Ziyang Yan Qixiang Fang Yong He Chuan 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2022年第2期517-528,共12页
Increased attention has been given to ground-borne vibrations induced by railway vehicles and to the effects of these vibrations as they propagate through the ground into nearby buildings.Various studies,mainly based ... Increased attention has been given to ground-borne vibrations induced by railway vehicles and to the effects of these vibrations as they propagate through the ground into nearby buildings.Various studies,mainly based on numerical methods as well as physical modelling,have been carried out to investigate this problem.To study the dynamic response of tunnels and the surrounding soil due to train-induced vibration loads,a centrifuge test was conducted with a small-scale model in 1 g and 50 g stress field environments.An aluminum tube was embedded in sand to model the underground tunnel.A small parallel pre-stressed actuator(PPA)was employed to apply vibration loads on the tunnel invert.The model responses were measured using accelerometers.Both time and frequency domain analyzes were performed.The test results demonstrated that electronic noise had a clear impact on the test results and should be eliminated.It also found that the dynamic response of both the tunnel and soil were affected by the stress field.Therefore,it is important to account for the stress field effects when assessing the ground-borne vibration from tunnels. 展开更多
关键词 centrifuge test stress field frequency response function peak particle acceleration dynamic response
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Time-dependent squeezing deformation mechanism of tunnels in layered soft-rock stratum under high geo-stress 被引量:5
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作者 CHEN Zi-quan HE Chuan +1 位作者 WANG Jun MA Chun-chi 《Journal of Mountain Science》 SCIE CSCD 2021年第5期1371-1390,共20页
Large squeezing deformation of layered soft rock tunnel under high geo-stress has a significant time-dependent deformation behavior.In this paper,we studied the deformation mechanism during the construction period of ... Large squeezing deformation of layered soft rock tunnel under high geo-stress has a significant time-dependent deformation behavior.In this paper,we studied the deformation mechanism during the construction period of deep-buried softrock tunnel by means of a combination of field observations and a numerical method.First,a new classification criterion for large deformations based on the power exponent variation law between the deformation and the strength-stress ratio is proposed.Then,the initial damage tensor reflecting the bedding plane(joint)distribution and an equivalent damage evolution equation derived from the viscoplastic strain are introduced based on the geometric research method,i.e.,a new rheological damage model(RDL model)of layered soft rock is established consisting of elastic,viscous,viscoelastic,viscoplastic and plastic elements.A field test was conducted on the Maoxian tunnel in Sichuan province,southwestern China,which is in broken phyllite(layered soft rock)under high geo-stress.The tunnel has experienced large deformation due to serious squeezing pressure,thus we adopted double primary support method to overcome the supporting structure failure problems.The rheological parameters of phyllite in the Maoxian tunnel were recognized by using SA-PSO optimization,and the RDL model does a good job in describing the time-dependent deformation behavior of a layered soft-rock tunnel under high geo-stress.Thus,the RDL model was used to investigate the supporting effect and bearing mechanism of the double primary support method.Compared with the single primary support method,the surrounding rock pressure,secondary lining force,surrounding rock deformation,and the depth of the damage to the rock mass was reduced by 40%-60%after the double primary support method was used. 展开更多
关键词 Deformation mechanism Layered soft rock tunnel High geostress Large squeezing deformation Rheological damage model
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Seepage field distribution and water inflow laws of tunnels in water-rich regions 被引量:7
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作者 LI Zheng CHEN Zi-quan +2 位作者 HE Chuan MA Chun-chi DUAN Chao-ran 《Journal of Mountain Science》 SCIE CSCD 2022年第2期591-605,共15页
Currently,the water inrush hazards during tunnel construction,the water leakage during tunnel operation,and the accompanying disturbances to the ecological environment have become the main problems that affect the str... Currently,the water inrush hazards during tunnel construction,the water leakage during tunnel operation,and the accompanying disturbances to the ecological environment have become 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 conduct experiments of the grouting circle and primary support with different permeability coefficients.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 coefficient of the grouting circle or the primary support,the inflow rate of water into the tunnel showed a non-linear decreasing trend.In comparison,the water inflow reduction effect of grouting circle was much better than that of primary support.With the increase of the permeability coefficient 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 connection,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 conducted.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 conducive to the stability of the supporting structures,and it could be mitigated by actively regulating the drainage rate.Compared with the hydrostatic head,the hydrodynamic head could 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 supporting structures. 展开更多
关键词 Water-rich tunnel Seepage field distribution Water inflow law Construction period Operation period
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A practical approach for seismic risk assessment of underground structures:A case study of Iranian subway tunnels
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作者 Arsham Moayedifar Hamid Reza Nejati +1 位作者 Amin Nazerigivi Mohammad Khosrotash 《Earthquake Science》 2019年第2期64-71,共8页
Active geological and young faulted zones have made Iran's territory one of the most seismological active areas in the world according to recent historical earthquakes.Some of the deadliest earthquakes such as Gil... Active geological and young faulted zones have made Iran's territory one of the most seismological active areas in the world according to recent historical earthquakes.Some of the deadliest earthquakes such as Gilan 1990 and Kermanshah 2018 caused tens of thousands fatalities.If such violent earthquakes affect strategical structures of a country,indirect losses would be more concerning than direct losses.Nowadays there is no doubt about the vital role of tunnels and underground structures in urban areas.These facilities serve as nonstop functional structures for human transportation,water and sewage systems and underground pedestrian ways.Any external hazard subjected to underground spaces,such as earthquake could directly affect passenger's lives and significantly decrease whole system reliability of public transportation.Commonly two earthquake levels of intensities,Maximum Design Earthquake(MDE)and Operating Design Earthquake(ODE)were used in seismic design of underground structures.However,uncertain nature of earthquakes in terms of frequency content,duration of strong ground motion,and level of intensity indicate that only the two levels of earthquake(ODE and MDE)cannot cover the all range of possible seismic responses of structures during a probable earthquake.It is important to evaluate the behavior of tunnel under a wide range of earthquake intensities.For this purpose,a practical risk-based approach which is obtained using the total probability rule was used.This study illustrates a framework for evaluation seismic stability of tunnels.Urban railway tunnels of Tehran,Shiraz,Ahwaz,Mashhad,Isfahan and Tabriz were considered as study cases.Nominal value of seismic risk for three main damage states,including minor,moderate and major were calculated. 展开更多
关键词 seismic response FRAGILITY risk assessment under-ground structures urban tunnel
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Influence of secondary lining thickness on mechanical behaviours of double-layer lining in large-diameter shield tunnels
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作者 Shimin Wang Xuhu He +3 位作者 Xiaoyu Peng Ya Wang Zhengxin Li Zihan 《Underground Space》 SCIE EI CSCD 2024年第5期130-150,共21页
In large-diameter shield tunnels,applying the double-layer lining structure can improve the load-bearing properties and maintain the stability of segmental lining.The secondary lining thickness is a key parameter in t... In large-diameter shield tunnels,applying the double-layer lining structure can improve the load-bearing properties and maintain the stability of segmental lining.The secondary lining thickness is a key parameter in the design of a double lining structure,which is worth being explored.Based 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 structure.The 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 thickness.As a passive support,the secondary lining acts as an auxiliary load-bearing structure by contacting the segment.And 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 varying.For 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. 展开更多
关键词 Large-diameter shield tunnels Double-layer lining structure Secondary lining thickness Stiffness matching Similar model test
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Technical innovation in the “Beishan No. 1” hard rock tunnel boring machine for high-gradient spiral tunnels 被引量:1
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作者 Ju WANG Mengxue QI +1 位作者 Bin LONG Hongsu MA 《Frontiers of Engineering Management》 CSCD 2024年第1期175-179,共5页
1 Project overview The“Beishan No.1”,the world’s first-ever hard rock Tunnel Boring Machine(TBM)tailored for high-gradient spiral tunnels,constitutes a pivotal element within the Beishan Underground Research Labora... 1 Project overview The“Beishan No.1”,the world’s first-ever hard rock Tunnel Boring Machine(TBM)tailored for high-gradient spiral tunnels,constitutes a pivotal element within the Beishan Underground Research Laboratory(URL)initiative in China.Beishan URL,the first URL for geological disposal of high level radioactive waste(HLW)in China,is a national key construction project listed in the“13th Five-Year Plan”.In 2019,subsequent to receiving approval from the China Atomic Energy Authority,the Beijing Research Institute of Uranium Geology(BRIUG),serving as the project’s owner,initiated its construction.This underground facility,categorized as a“third generation”URL for HLW disposal,i.e.,area-specific URL,was located in Beishan,Jiuquan City,Gansu Province,China,following more than three decades of rigorous research on site selection. 展开更多
关键词 tunnel boring machine extremely hard rock continuous small-radius curves high gradient equipment technology INNOVATION
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Novel numerical model to simulate water seepage through segmental gasketed joints of underwater shield tunnels considering the superimposed seepage squeezing effect
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作者 Qixiang Yan Haojia Zhong +3 位作者 Chuan Zhang Zechang Zhao Yanxin Wen Ping Wang 《Underground Space》 SCIE EI CSCD 2023年第6期104-120,共17页
The water leakage through segmental joint gaskets has become a major concern that adversely affects the normal serviceability of underwater shield tunnels throughout the construction and operational periods.Therefore,... The water leakage through segmental joint gaskets has become a major concern that adversely affects the normal serviceability of underwater shield tunnels throughout the construction and operational periods.Therefore,it is of great significance to investigate the sealing performances of the joint gaskets,which directly helps evaluate the waterproof capacity of underwater shield tunnels.To date,the numerical modeling plays an irreplaceable role in the analysis on the waterproof capacity of the joint gaskets.Nevertheless,conventional methods tend to ignore the self-sealing effect induced by the water seepage pressurization,thus failing to reveal the progressive evolution of the water infiltration process through the joint gasket.To remedy this defect,this paper proposed a novel numerical model to simulate the penetration process of the sealing gasket based on the Python language-enabled secondary programming in the ABAQUS software,which could fully consider the superimposed seepage squeezing effect.Based on the proposed model,the waterproof failure process and the dynamic contact stress of the gasket’s water seepage path subject to excessive hydraulic pressure were thoroughly investigated.Moreover,indoor tests on the waterproof capacity of the gasket were also performed to validate the proposed model.It is found that the numerical results from the developed model are consistent with the experimental results.This research will contribute to better understanding of the gaskets’hydraulic penetration process and more accurate prediction of the maximum waterproof capacity in underwater shield tunnels. 展开更多
关键词 Underwater shield tunnel Hydraulic pressure Gasketed joint Water leakage Sealing performance Finite element method
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Drilling-based measuring method for the c-φ parameter of rock and its field application 被引量:3
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作者 Bei Jiang Fenglin Ma +5 位作者 Qi Wang Hongke Gao Dahu Zhai Yusong Deng Chuanjie Xu Liangdi Yao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期65-76,共12页
The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(R... The technology of drilling tests makes it possible to obtain the strength parameter of rock accurately in situ. In this paper, a new rock cutting analysis model that considers the influence of the rock crushing zone(RCZ) is built. The formula for an ultimate cutting force is established based on the limit equilibrium principle. The relationship between digital drilling parameters(DDP) and the c-φ parameter(DDP-cφ formula, where c refers to the cohesion and φ refers to the internal friction angle) is derived, and the response of drilling parameters and cutting ratio to the strength parameters is analyzed. The drillingbased measuring method for the c-φ parameter of rock is constructed. The laboratory verification test is then completed, and the difference in results between the drilling test and the compression test is less than 6%. On this basis, in-situ rock drilling tests in a traffic tunnel and a coal mine roadway are carried out, and the strength parameters of the surrounding rock are effectively tested. The average difference ratio of the results is less than 11%, which verifies the effectiveness of the proposed method for obtaining the strength parameters based on digital drilling. This study provides methodological support for field testing of rock strength parameters. 展开更多
关键词 Digital drilling Rock crushing zone c-u parameter Measurement method Field application
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走滑断层黏滑作用下隧道纵向及横断面分区破坏机理 被引量:1
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作者 杨恒洪 王明年 +3 位作者 罗勋 于丽 张霄 唐浪洲 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第1期250-271,共22页
黏滑作用下走滑断层将出现永久性的错动位移,当隧道与此类断层相交时将发生严重破坏,并且具有明显的分区特征。为了揭示隧道纵向和横断面的分区破坏机理,为穿越活动断裂带隧道抗震设计提供支撑,本文首先通过震害实例调研总结得到隧道的... 黏滑作用下走滑断层将出现永久性的错动位移,当隧道与此类断层相交时将发生严重破坏,并且具有明显的分区特征。为了揭示隧道纵向和横断面的分区破坏机理,为穿越活动断裂带隧道抗震设计提供支撑,本文首先通过震害实例调研总结得到隧道的三种破坏模式,即环向裂缝、斜向裂缝和纵向裂缝。给出并讨论了断层类型、交角、错动量和隧道刚度等关键影响因素。结果表明:1)断层类型是影响隧道力学响应和安全性的最显著因素,而倾角影响很小;2)受左旋走滑断层黏滑作用的隧道沿纵向可分为弯曲-压缩-剪切(L-BCS)区和弯曲-压缩(L-BC)区,而受右旋走滑断层黏滑作用的隧道可分为弯曲-拉伸-剪切(L-BTS)区和弯曲-拉伸(L-BT)区;3)L-BCS区和L-BTS区的范围为1.4D~1.7D(D为隧道直径),而L-BC区和L-BT区范围随关键影响因素变化而变化;4)隧道横断面可分为偏心受压(C-EC)区和偏心受拉(C-ET)区,分别发生偏心受压破坏或偏心受拉破坏。C-EC区和C-ET区的范围约为距断层面5D;5)穿越左旋走滑断层隧道的C-EC区包括上盘左拱腰、下盘右拱腰、拱顶和仰拱,C-ET区包括下盘左拱腰和上盘右拱腰。穿越右旋走滑断层隧道的横断面分区分布与左旋对称。 展开更多
关键词 走滑断层 黏滑 隧道工程 分区破坏机理 力学响应
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深部多形式应用交岔点围岩失稳机理及能量演化研究 被引量:1
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作者 武毅艺 何满潮 +2 位作者 李辉 高玉兵 谢生荣 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第3期890-911,共22页
随着采矿进入深部地层,具有长服务年限的各类巷道交岔点围岩发生强烈破坏,需要明晰深部环境下交岔点围岩失效机理,以针对性地指导修复和补强作业。通过对多地矿井交岔点维护情况的调研,全面总结了连接型、交岔型、分岔型和旋岔型(环三角... 随着采矿进入深部地层,具有长服务年限的各类巷道交岔点围岩发生强烈破坏,需要明晰深部环境下交岔点围岩失效机理,以针对性地指导修复和补强作业。通过对多地矿井交岔点维护情况的调研,全面总结了连接型、交岔型、分岔型和旋岔型(环三角柱)四类16种交岔点类型,提出了三类交岔点的典型应用形式:单一大型交岔点、嵌套式两交岔点组和环三角岩柱式交岔点群。将现场交岔点的破坏情况分为围岩局部破坏、三角岩柱破坏和整体性破坏的三种级别,从灾害的诱因和来源上,提出了外部环境因素、自身结构属性和人为设计隐患的三类13种致灾因素,并详述了各种致灾因素的致灾路径。建立了三类典型应用形式下交岔点的精细化模型,对数值软件进行二次开发,引入了畸变能密度指标进行围岩的能量分析。研究表明,交岔点围岩的畸变能峰值在三角区岩柱内,增高系数在2.5左右。最大断面处围岩畸变能同样发生积聚,增高系数在1.5左右。因此,提出了交岔点的修复需以强化三角岩柱和大断面处围岩为重点,并对深井交岔点的修复提出了以三角岩柱和大断面段补强为主的针对性方案。本研究为深部交岔点的破坏因素分析、数值模拟指标引入和修复支护提供了参考。 展开更多
关键词 巷道交岔点 围岩失稳 应用形式 精细化模型 畸变能密度
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A novel method for simulating nuclear explosion with chemical explosion to form an approximate plane wave: Field test and numerical simulation 被引量:1
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作者 Wei Ming Xiaojie Yang +3 位作者 Yadong Mao Xiang Wang Manchao He Zhigang Tao 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2137-2153,共17页
A nuclear explosion in the rock mass medium can produce strong shock waves,seismic shocks,and other destructive effects,which can cause extreme damage to the underground protection infrastructures.With the increase in... A nuclear explosion in the rock mass medium can produce strong shock waves,seismic shocks,and other destructive effects,which can cause extreme damage to the underground protection infrastructures.With the increase in nuclear explosion power,underground protection engineering enabled by explosion-proof impact theory and technology ushered in a new challenge.This paper proposes to simulate nuclear explosion tests with on-site chemical explosion tests in the form of multi-hole explosions.First,the mechanism of using multi-hole simultaneous blasting to simulate a nuclear explosion to generate approximate plane waves was analyzed.The plane pressure curve at the vault of the underground protective tunnel under the action of the multi-hole simultaneous blasting was then obtained using the impact test in the rock mass at the site.According to the peak pressure at the vault plane,it was divided into three regions:the stress superposition region,the superposition region after surface reflection,and the approximate plane stress wave zone.A numerical simulation approach was developed using PFC and FLAC to study the peak particle velocity in the surrounding rock of the underground protective cave under the action of multi-hole blasting.The time-history curves of pressure and peak pressure partition obtained by the on-site multi-hole simultaneous blasting test and numerical simulation were compared and analyzed,to verify the correctness and rationality of the formation of an approximate plane wave in the simulated nuclear explosion.This comparison and analysis also provided a theoretical foundation and some research ideas for the ensuing study on the impact of a nuclear explosion. 展开更多
关键词 Approximate plane wave Multi-hole simultaneous blasting Chemical explosion Nuclear explosion Pressure sensor inclusion
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