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Quick Search     Advanced Search MODERN TUNNELLING TECHNOLOGY   2022 Vol.59 Issue.1 Published 2022-02-25 1 On Stability Analysis and Classification of Surrounding Rocks in Rock Tunnels ZHENG Yingren1 ABI Erdi2 After 1975, the appearance of finite element numerical limit method and the application and development of computer technology have brought the elastic-plastic analytical calculation of engineering materials into a new era of numerical limit calculation. The new methods, namely, strength reduction method and load increment method,as well as the recently proposed ultimate strain method, are adopted in the rock tunnels studied in this paper. To solve the uncertainty of mechanical parameters of surrounding rock in rock tunnels and provide more scientific and reasonable mechanical parameters of surrounding rock, the surrounding rock classification must be made combining theory, investigation and experience. Taking the surrounding rock classification in rail transit tunnels as an example,the improvement of the classification level includes improving the strength index, mainly adopting the quantitative classification method, reasonably determining the basic index BQ value of rock mass quality, increasing the number of surrounding rock classifications, formulating the surrounding rock classification tables for the running tunnel and the station tunnel, and achieving the coordination and unification of qualitative and quantitative classification methods. Finally, the quantitative indexes of surrounding rock self-stability are determined, and the more scientific and reasonable physical and mechanical parameters of surrounding rocks are put forward through back calculation. 2022 Vol. 59 (1): 1-13 [Abstract] ( 603 ) [HTML 1KB] [ PDF 3297KB] ( 981 ) 14 Intelligent Construction of Shield Tunnels Based on Resilience Theory CHEN Xiangsheng1,2 YU Yiliang1,2 BAO Xiaohua1,2 CUI Hongzhi1,2 XIA Changqing1,2 Urban rail transit that is mainly based on shield tunnels has made rapid development during the period of the 13th Five-Year Plan, and shield tunnelling equipment has obtained fast progress in intelligent development.However, the tunnel structure design, structural element production and on-site segment assembly needs more innovations and breakthroughs in terms of intelligence. Faced with the strategic goal of building a resilient smart city, we also still have a series of problems needing urgent resolutions for shield tunnelling, such as limited knowledge and theory about the physical properties of new materials, the lack of target in the arrangement of sensors and poor monitoring perception, and the heavy reliance of tunnel segment assembly on manual labor, which produces large errors.The key to solving these problems lies in building an intelligent shield tunnel construction system based on the resilience theory. By using the resilience characteristics of materials and structures, and in combination with computer and other information technologies, a series of measures could be taken such as resilient design, intelligent percep? tion, intelligent production, and intelligent assembly, etc. to make the materials in tunnel structures intelligently perceivable, the structure accurately monitorable, the data twinned in real time, the information efficiently manageable,the production automatically manipulable, the process perceivable in ganzfeld, the model dynamically adjustable, and the segments intelligently assembled, thus finally achieving the goal of construction of shield tunnels in a resilient city 2022 Vol. 59 (1): 14-28 [Abstract] ( 809 ) [HTML 1KB] [ PDF 8417KB] ( 1118 ) 29 New Automatic Pouring and Vibrating Techniques for the Construction of Railway Tunnel Lining ZHANG Minqing1 JIA Dapeng1 WANG Shuishan2 GAO Cuncheng3 Defects caused by quality problems of railway tunnel lining, such as cavity behind lining, cracking, and spalling etc., could lead to great threats to the normal operation of the railway, and concrete pouring and vibration is the key to ensuring the quality of tunnel lining. Therefore, this paper develops a new automatic pouring and vibrating technique for tunnel lining construction with the objective to improve the quality of tunnel lining. The study shows that for the window-by-window pouring technique with automatic rotary concrete distributors it needs only 3 to 4 minutes per change of the pipe, showing the characteristics of simple structure, convenient operation, excellent effect, safety and reliability, which not only speeds up the tunnel lining construction progress but also ensures the quality of the tunnel lining; for the new plug-in vibration technique with automatic lifting and plug-in vibration for the sidewalls and automatic pneumatic plug-in vibration for the vault, it can effectively improve the effect of concrete vibration; for the pressurized reverse pouring technique with 60° inclined holes at the tunnel vault, compared with traditional vault pouring methods, it shows a significant reduction in the number of pipe blocking and the number of deformation of formworks at pouring openings, while the quality of concrete pouring is significantly improved. 2022 Vol. 59 (1): 29-34 [Abstract] ( 651 ) [HTML 1KB] [ PDF 2627KB] ( 988 ) 35 Study on New Structural Type of the Emergency Rescue Station of Mabaishan Tunnel in Qinling Mountains CHEN Shaohua Regarding the disaster prevention and rescue problems of high-speed railway tunnels in dangerous moun? tainous areas, a new type of emergency rescue station structure suitable for such tunnels is put forward based on actual conditions of Mabaishan Tunnel in Qinling Mountains. Using FDS software it simulates the smoke diffusion under longitudinal ventilation in a scenario of train fire in the tunnel, and determines the length parameter of the isolation area for emergency rescue station, which is not given in specifications. The results show that: (1) the new structural type of the emergency rescue station of Mabaishan Tunnel in Qinling Mountains should include evacuation area, isolation area and refuge area for rescue. (2) By FDS numerical simulation, the diffusion length of smoke along the downhill direction is 295 m without considering longitudinal ventilation, and the longest diffusion length of smoke along the downhill direction is 980 m with considering longitudinal ventilation. It is recommended to set the length of isolation area as 1 000 m. 2022 Vol. 59 (1): 35-41 [Abstract] ( 703 ) [HTML 1KB] [ PDF 2728KB] ( 707 ) 42 Research and Application of Key Construction Technologies for TBM-driven Tunnels under Extreme Complex Geological Conditions FENG Huanhuan1,2 HONG Kairong1,2 YANG Yandong2 YANG Luwei1 SI Jingzhao1 YOU Jinhu3 With successive construction commencement of the Gaoligongshan Tunnel of the Dali-Ruili Railway, the Qinling Tunnel of the Hanjiang-to-Weihe Water Diversion Project, and the Xianglushan Tunnel of the Central Yunnan Water Diversion Project, various TBM construction problems have become increasingly prominent, such as TBM jamming caused by water-rich, broken and extremely soft strata, and rockburst caused by extremely hard rock strata with high in-situ stress. Firstly, this paper compares and elaborates on the typical adverse geological conditions such as broken and soft rock, and extremely hard granite commonly encountered during the construction of TBM tunnels in China and their impacts on TBM boring. On the basis of summarizing and analyzing the tunnel collapse and TBM jamming cases, and their influencing factors during the construction of various projects such as the Liaoning northwest water supply project, the songhua river water diversion project, and the tao river water supply project, this paper conducts a systematic study on the key TBM boring technologies under extreme complex geological conditions, and the results show that: (1) the advance geological prediction technology is an important tool for TBM construction to cope with extreme complex geological conditions, but presently, it is not yet possible to accurately quantify and predict the geological conditions in the medium and long distance ahead of the tunnel face.Based on the analysis results of micro-seismic monitoring, corresponding countermeasures may be taken according to potential different rockburst levels such as minor, moderate and intense rockburst levels. For different soft and broken strata such as developed joints, carbonaceous slates, fault and broken zones, etc., targeted measures should be taken to prevent TBM jamming, while a suitable TBM machine release scheme can be chosen according to the length of the poor geological section. (2) Abnormal fluctuations of TBM boring parameters such as thrust, advancing speed, cutterhead rotation speed and torque are important indicators to characterize the geological conditions in front of the tunnel face. Before the TBM excavation, appropriate TBM boring parameters should be selected respectively according to the pre-estimated surrounding rock conditions such as full-face hard rocks or soft and fractured rocks. During the TBM boring process, the predicted geological conditions should be corrected timely, and corresponding control measures should be adjusted based on the abnormal changes of the boring parameters, thus ensuring that the TBM is in the best boring condition. (3) In view of the fact that it is difficult for the existing TBMs to adapt to the existing geological conditions, this paper carries out an analysis and discussion on the TBM modification technologies with the tunnels in the Tao river diversion and water supply project, the Hongyan river-to-shitou river water diversion project and the Hanjiang-to-weihe water diversion project as examples. Finally, it discusses the new problems that could arise in TBM tunnel construction under extreme complex geological conditions and future prospects of corresponding countermeasures. 2022 Vol. 59 (1): 42-54 [Abstract] ( 679 ) [HTML 1KB] [ PDF 3129KB] ( 1526 ) 55 General Construction Technology Scheme of Tianshan Shengli Tunnel on Urumqi-Yuli Expressway WANG Shuaishuai1 MAO Jinbo2 ZHANG Binbin2 Li Yalong2 ZHAO Honggang2 With a total length of about 22 km, Tianshan Shengli Tunnel on Urumqi-Yuli Expressway is currently the longest expressway tunnel under construction in the world. It adopts the construction scheme of "3 tunnels (2 D&B main tunnels and 1 TBM-driven middle pilot tunnel) + 4 shafts", which is characterized by great construction difficulty and high technical standard requirements. The tunnel construction is faced with technical challenges such as TBM passing through large fault fracture zones, long-distance construction ventilation in three tunnels, deep and large shaft construction and logistics organization in two-main tunnel construction assisted by middle pilot tunnel.In the parallel three-tunnel method design of Tianshan Shengli Tunnel, the TBM-driven middle pilot tunnel can not only play the role of advanced pilot tunnel, but also assist the construction of the two main tunnels and speed up the construction progress. For the middle pilot tunnel, the TBM excavation diameter is 8.4 m, and the initial support is designed as 100% force-bearing capacity in construction period, which can meet the requirements for two-way material transportation, ventilation and belt mucking in the pilot tunnel. Vault suspension scheme is adopted for the continuous belt conveyor, which can reduce the impact on the material flow organization in the cross passages. Multifunctional service vehicles (MSVs) independently developed by CCCC Group are used for the transportation of TBM materials and prefabricated inverted arch blocks, which can realize double-headed driving. TBM will pass through two large fault fracture zones F6 and F7. According to the stability of the surrounding rock at the tunnel face, the targeted treatment measures would be adopted. If necessary, the scheme of "steel segment + extruded concrete" shall be used for the initial support. In case of serious machine jamming or rock collapse, the heading expansion excavation method or bypass heading method shall be used. Tianshan Shengli Tunnel adopts phased forced ventilation option, and the ventilation mode is designed in stages with the change of tunnel construction stage. The fans and air pipes used are imported ones, and a ventilation management team is set up to strengthen ventilation management and ensure ventilation quality. Highly mechanized construction is used for the two D&B main tunnels, the application of equipment such as three-arm rock drilling jumbo and wet shotcrete machine is promoted, so as to reduce the number of workers and labor intensity, and improve work efficiency. The deep shafts of Tianshan Shengli Tunnel are constructed by short-section excavation and lining mixed operation method, and the initial support is lined by formwork pouring concrete, so as to realize safe and rapid excavation. According to the research results, the construction technology scheme for Tianshan Shengli Tunnel can meet the needs of tunnel construction. The research results can be directly used to guide the construction of Tianshan Shengli Tunnel, and provide reference for the construction of extra long highway tunnels in high-altitude areas. 2022 Vol. 59 (1): 55-68 [Abstract] ( 866 ) [HTML 1KB] [ PDF 8727KB] ( 944 ) 69 Comprehensive Evaluation of the Intelligent Degree of the Mining Face Based on Grey Relational Analysis ZHANG Kexue1,2,3,4,5,6 YANG Haijiang1,2,5 HE Manchao3 SUN Jiandong1,2,5 LI Dong1,2,5 CHENG Zhiheng1,2,5 In order to further evaluate the intelligent degree of the coal mining face scientifically and reasonably, this paper constructs a gray relational analysis based comprehensive evaluation model for the intelligent degree of mining face by deeply analyzing the influencing factors on the intelligent degree of mining face, such as surrounding rock detection, mining equipment, production system, supporting production system, organization and management,etc. By quantifying and scoring factors affecting the intelligence degree of mining face, using the hierarchical analysis method to obtain the weights and determine the correlations, the intelligence degrees of mining face are classified into four levels: excellent, good, medium and poor. Using the comprehensive evaluation model to empirically verify the 802 working face of Shaanxi Huangling Mining Co., Ltd., the calculated correlation is 0.765 8, which indicates that the intelligent degree of 802 working face is excellent according to the rating criteria, and it is consistent with the actual situation. Therefore, the comprehensive evaluation model based on gray relational analysis can accurately and objectively evaluate the intelligent degree of the mining face. 2022 Vol. 59 (1): 69-79 [Abstract] ( 657 ) [HTML 1KB] [ PDF 1878KB] ( 898 ) 80 Intelligent Reconstruction of the Digital Model of Metro Shield Tunnels with Disordered Erected Segment Ring Structure ZHANG Chun ZHOU Yuxuan LI Dengpeng The management, health monitoring and maintenance of operational metro tunnels have been gradually becoming digital and intelligent. However, the lack of digital tunnel models often limits the application and development of intelligent maintenance and management systems for metro shield tunnel management and inspection organizations. This paper proposes an intelligent reconstruction method of the digital model of disordered erected segment ring structure in metro shield tunnels based on deep learning and machine vision, uses high-definition pictures of the inner surface of the tunnel lining obtained by inspection vehicles to intelligently identify and automatically classify the tunnel segment features (bolt holes), and then automatically infers the layout pattern of the tunnel segment rings according to the distribution characteristics of the bolt hole groups, thus achieving rapid reconstruction of the tunnel digital model by combining with the actual tunnel alignment. The application case in a certain metro tunnel shows that the proposed method is applicable to shield tunnels with irregularly and staggered erected segments, and can achieve the intelligent reconstruction of the digital model of the metro shield tunnel with 100% accuracy. 2022 Vol. 59 (1): 80-86 [Abstract] ( 618 ) [HTML 1KB] [ PDF 4084KB] ( 774 ) 87 3D Laser Scanning, Measurement and Processing Integrated Technology Solution and Application Practice in Tunnelling MIN Shiping1 PENG Dong2 HE Yuechuan1 ZHANG Tao3 The 3D laser scanning technology has been widely applied in tunnelling, but some problems are also in? creasingly prominent, such as the disconnection between the indoor and field work, excessive manual operation, and poor real-time feedback. Based on engineering practice, this paper proposes an integrated technical solution for 3D laser scanning, measurement and processing in tunnelling. Through collection of information in tunnel design model,calculation of the coordinate mileage, automatic filtering of point clouds, downsampling of point clouds and separation of ground objects, etc. it can extract feature values from point clouds and obtain a point cloud data model considering the scale, accuracy and efficiency. And results related to the quality and safety of tunnel projects can be obtained by comparing point clouds with the design data, and point clouds with point clouds. The integrated technical solution is applied in a railway tunnel project, showing that it could shorten the total time of indoor and field work to within 20 minutes with high automation, good accuracy, and good potentials for further promotion. 2022 Vol. 59 (1): 87-94 [Abstract] ( 576 ) [HTML 1KB] [ PDF 2223KB] ( 1118 ) 95 Study on Mechanical Properties of Tunnel Lining Structure with Spray-applied Waterproofing Membrane JIANG Yajun1 HE Bin1 ZHAO Jumei1 LIU Jitai1 WANG Huqun2,3 In order to study the influence of spray-applied waterproofing membrane layer on the mechanical proper? ties of tunnel lining structure, a numerical calculation model of composite lining, spray-applied waterproofing lining and single-shell lining is established according to the mechanical parameters and interface parameters of waterproofing membrane measured by tests, and comparative analysis is made on the mechanical properties of the three types of lining structures. The research results show that: (1) compared with the composite lining, the stress of the secondary lining in the spray-applied waterproofing lining structure is significantly reduced, and the stress of the initial support has little change, but the displacement of both the initial support and the secondary lining increases;(2) in the spray-applied waterproofing lining structure, the whole section of the secondary lining is in the state of small eccentric compression, and the safety factor is greatly improved; (3) spray-applied waterproofing membrane layer can improve the cooperative force-bearing capacity of initial support and secondary lining, and improve the stress state of secondary lining, which is beneficial to improve the safety of secondary lining; and (4) with the increase of the cooperative force-bearing capacity of spray-applied waterproofing lining structure, the internal force of spray-applied waterproofing lining structure will be infinitely close to that of single-shell lining structure. 2022 Vol. 59 (1): 95-103 [Abstract] ( 712 ) [HTML 1KB] [ PDF 3714KB] ( 780 ) 104 Experimental Study on the Bonding Performances of Spray-applied Waterproofing Membrane in Tunnels with CSL Structure YANG Juan1,2,3 YANG Qixin2,3 QIU Pinming2,3 In view of the serious problem of water leakage in tunnels, this paper adopts a new spray-applied water? proofing membrane technology to establish a form of tunnel composite shell lining (CSL) structure with bonding properties to both outer and inner concrete layer, thus overcoming the drawbacks of the traditional supporting structure of concrete layer with waterproofing boards in terms of waterproofing performance. The bonding performance between the spray-applied waterproofing membrane and the outer and inner concrete layer is an important parameter in the CSL design and directly decides the waterproofing and supporting performance of the CSL. In view of this, this paper carries out a bonding performance test on the spray-applied waterproofing membrane for the tunnel CSL structure, studies the impacts of dry and wet states of the shotcrete surface, and the membrane thickness on the CSL bonding performance. The research results show that the interlayer bonding strength is inversely proportional to the square root of the membrane thickness; Under the premise of no flowing water on the shotcrete surface, the waterbearing shotcrete surface helps to improve the bonding strength of the waterproofing membrane to the shotcrete and gives full play to its bonding properties; With the increase of the water content, the bonding strength of the CSL structure shows a gradual increase. 2022 Vol. 59 (1): 104-110 [Abstract] ( 683 ) [HTML 1KB] [ PDF 2572KB] ( 760 ) 111 On Influence of the Shading Shed on the Driver′s Light-dark Adaptation at Tunnel Entrances and Exits BAO Yifan1,2 WANG Mingnian1,2 QIN Pengcheng1,2 CHEN Zhanwen1,2 HAN Changling3 In order to study the characteristics of driver′ s light-dark adaptation at tunnel entrance/exit sections and the influence of shading shed on the adaptation process, this paper is based on the Zijing tunnel (without shading shed) and Balangshan tunnel (with shading shed) to conduct real vehicle driving tests, in which the distribution law of light-dark adaptation and the buffering effect of the shading shed on the light-dark adaptation process at tunnel entrance/exit sections are analyzed by taking the driver′s pupil diameter and the variation rate of pupil diameter as evaluating indicators. The study results show that over 90% of the dark adaptation process and over 54.61% of the light adaptation process occur inside the tunnel; during the dark adaptation at the tunnel entrance section, the maximum pupil diameter change rate decreases by 4.84% when the time passing through the shading shed is 2 seconds and by 33.58% when the time passing through the shading shed is 5 seconds; during the light adaptation at the tunnel exit section, the maximum pupil diameter change rate decreases by 38.75% when the time passing through the shading shed is 2 seconds and by 49.97% when the time passing through the shading shed is 5 seconds. 2022 Vol. 59 (1): 111-117 [Abstract] ( 660 ) [HTML 1KB] [ PDF 3128KB] ( 827 ) 118 Study on Relationship between Labor Intensity and Oxygen Concentration in High-altitude Tunnel Construction CHEN Guizhou1,2 CHEN Zheng1,2 JU Guoquan3 WANG Huiwu3 GUO Chun1,2 In order to study the oxygen concentration issues in the case of workers working in high-altitude tunnels, riding tests were carried out to get the physiological indexes and the labor intensity indexes of test objects at the altitude of 590~4 000 m and oxygen concentration of 20.9%~29% under the riding loads of 0, 50 W, 75 W and 100 W.The analysis and research conclusions are as follows: (1) under the working conditions of the same altitude and the same labor intensity, increasing the ambient oxygen concentration can significantly reduce the labor intensity index;(2) there is no linear relationship between the decrease of labor intensity index and the increase of oxygen concentration. When the ambient oxygen concentration exceeds 25%, the decrease of labor intensity index is limited; (3) the relationship between the labor intensity index of construction workers and the altitude and oxygen concentration is fitted and obtained under the labor load of 100 W and the oxygen concentration of 20.9%~25%. 2022 Vol. 59 (1): 118-123 [Abstract] ( 632 ) [HTML 1KB] [ PDF 1828KB] ( 916 ) 124 Numerical Analysis on Ground Settlement Induced by Shield Tunnelling with Adjacent End Shaft Works WANG Ling1 ZHONG Jiuqiang2,3 ZHU Bitang2,3 Taking the construction of Yayuan Road Station of Nanchang Metro Line 2 as an example, this paper es? tablishes a numerical simulation model of double-line shield tunnelling starting from the end shaft based on the HSS (Hardening Soil model with Small Strain) constitutive model, and analyzes the ground settlement law under the interaction of foundation pit excavation and double-line shield tunnelling. The results show that: (1) ground reinforcing in the shield launching area can effectively reduce the ground settlement within the area, and the magnitude of ground settlement in the area is much smaller than that in the running tunnel section; (2) under the same buried depth condition, the maximum ground settlement value of previously excavated tunnel is higher than that of subsequently excavated tunnel, and the transverse ground settlement trough shows an asymmetric‘W’shape; (3) the ground settlement caused by the interaction of foundation pit excavation and shield tunnelling can be calculated by superposition of the settlement values induced by construction of the two works separately. 2022 Vol. 59 (1): 124-132 [Abstract] ( 534 ) [HTML 1KB] [ PDF 3465KB] ( 758 ) 133 Impact on and Prediction of Segment Opening of Shield Tunnels under Seismic Action YANG Chunshan1 Wei Lixin1 MO Haihong2 In order to explore the effect of seismic action on the segment opening of shield tunnels, by using numeri? cal analysis software, this paper analyzes the distribution law of segment opening under seismic action with different directions in a typical project. On the basis of the calculation results, this paper normalizes the segment opening indued by seismic acceleration and the seismic action with combined consideration to the existing calculation equations of segment opening, and puts forward the prediction method of the maximum segment opening under seismic action in tunnels with different depths. The study shows that seismic action has a significant impact on the opening of circumferential segment joints, with the maximum opening of the segments increasing by 16% and the average opening increasing by 27% at least; in areas with a seismic intensity of less 8 degrees, the anti-seismic reinforcement scope of the shield tunnel segments is mainly at 3-5 rings in the vicinity of the working shaft under static and dynamic loads; in high seismic intensity areas with a seismic intensity of 8 degrees and above, the anti-seismic reinforcement of the circumferential joints along the tunnel axis should be carried out. The comparison with the numerical calculation results shows that the proposed calculation method of the maximum segment opening under seismic action is reasonable to a certain extent. 2022 Vol. 59 (1): 133-140 [Abstract] ( 655 ) [HTML 1KB] [ PDF 3363KB] ( 731 ) 141 Analysis of Mechanical Performance of Operational Shield Tunnels under Different Ovality Deformations DING Xiaobin HAN Donglin Improper construction of underground structures could have a huge impact on the structure of adjacent existing metro shield tunnels. Based on a large deformation case occurring in an existing operational metro shield tunnel caused by the under-passing construction of a certain Guangzhou metro tunnel section, this paper analyzes the mechanical conditions of the segment structure under different ovality deformations of the existing tunnel structure caused by ground loss. Based on measured engineering data, and using the three-dimensional finite element analysis software, this paper studies the quantitative relationship between the ovality of the segment ring and the stress state of the structure, and analyzes the plastic deformation of the structure and its development trend, considering detailed structures such as the bolt holes at the segment joints. The results show that the maximum principal stress value and the maximum shear stress value of the structure increase with the rise in the ovality of the shield tunnel segment ring, and the maximum shear stress of the shield tunnel structure shows a linear relationship with the degree of ovality; the maximum principal stress of the shield tunnel structure varies more significantly with the degree of ovality, showing a non-linear relationship. 2022 Vol. 59 (1): 141-148 [Abstract] ( 545 ) [HTML 1KB] [ PDF 5729KB] ( 672 ) 149 Study on the Water Inrush Mechanism in Tunnelling with Karst Conduits Based on Nonlinear Seepage Model CHEN Zhongda1 LIN Zhi2 CHEN Xiang2 YANG Hongyun2 LU Yuanen3 ZHAO Yixin2 Water inrush in tunnels with karst conduits is a complex nonlinear seepage problem with multi-field cou? pling and may cause sudden disasters. In order to reveal the occurrence mechanism of water inrush in tunnels with karst conduits, this paper conducts a multi-field coupling analysis under the conditions of different water pressures in karst caves, different filling media in karst conduits and different karst conduit widths and lengths on the basis of the coupling mechanism of multiple physical fields, and draws the following conclusions: (1) water inrush disasters under the failure mode of karst conduits in tunnels are different depending on the difference in the permeabilities of the filling media; (2) the speed of the fluid flowing out of water-rich karst caves is low, but increases gradually after it flows through the karst conduits, and peaks when it enters the tunnel; (3) main factors affecting the water inrush process include: water pressure in water-rich karst cave, type of filling medium in karst conduit or fault fracture zone, width of karst conduit, and distance between tunnel and water source, of which the width of karst conduit and type of filling medium in karst conduit have a greater influence on water inrush than the other factors. 2022 Vol. 59 (1): 149-155 [Abstract] ( 603 ) [HTML 1KB] [ PDF 2328KB] ( 1021 ) 156 Study on State Parameter Control of Intake Air in Utility Tunnels Based on BB-MOPSO SHI Youzhi1 HONG Jiaoli2 LIN Shuzhi3 XU Jianning4 In order to explore the control method of the intake air state in utility tunnels when the outside fresh air humidity is too high, taking the ventilation works of a utility tunnel section in Pingtan comprehensive experimental area as the research background, this paper proposes the control method of intake air state parameters for ventilation and dehumidification in utility tunnels under normal and accident conditions, by means of the effective ventilation and dehumidification duration prediction model, the evolutionary multi-objective algorithm (EMOA), and in combination with the ventilation control requirements. The results show that the intake air state parameter controller can be adjusted freely according to the different requirements of decision makers for ventilation fan working duration and dehumidifier working temperature and moisture content, and the optimized appropriate control objectives can be achieved, which is conducive to the real-time decision-making of the intake air state parameter control for ventilation and dehumidification in utility tunnels. 2022 Vol. 59 (1): 156-163 [Abstract] ( 556 ) [HTML 1KB] [ PDF 2791KB] ( 690 ) 164 Model Test Study on‘Lost’Deformation and Corresponding Control Measures in Soft Rock Tunnels with Extremely High Ground Stress CHEN Zhimin1,2 LI Jiangpeng1 XUE Zhiwen3 In order to study the laws of core rock deformation and‘lost’rock deformation in soft rock tunnels with high ground stress, the deformations of core rocks in front of the working face and surrounding rocks are monitored by model test method, and the tunnel excavation process is simulated in detail under different high ground stress levels and working conditions with/without lining. The results show that: (1) the ground stress plays a key role in determining the installation time of soft rock tunnel support; (2) the advance deformation within 0.5D in front of the face accounts for about 2/3 of the total advance deformation; (3) the‘lost’deformation behind the tunnel face has a great impact on the monitoring and measurement. With a certain high ground stress, there is a power function relationship between the‘lost’deformation and the distance from the tunnel face. With the high ground stress greater than 20 MPa,it has little impact on the‘lost’deformation; (4) in order to effectively control the advance deformation in soft rock tunnels with high ground stress, it is necessary to reinforce the core rock mass within 0.5D in front of the tunnel face. For the core rock mass within 0.5D~1D in front of the tunnel face, the reinforcement depends on the actual situation. 2022 Vol. 59 (1): 164-175 [Abstract] ( 665 ) [HTML 1KB] [ PDF 6680KB] ( 662 ) 176 A Model Test Study on the Dewatering in the Construction of Ultra-deep Shafts in Deep and Thick Sand and Pebble Strata WANG Fei Foundation pit dewatering in water-rich sand and pebble strata is always a huge challenge in engineering industry. As for the ultra-deep shaft dewatering in strongly permeable deep and thick sand and pebble strata in Lan?zhou, this paper conducts theoretical calculations and model tests, develops an effective model test system, prepares materials similar to sand and pebble soils, and carries out a focused study on the impact of grouting reinforcement at the foundation pit base on pit dewatering. The results of the study show that: (1) the Yellow River has an important influence on the pit dewatering, with a steep and steep dewatering funnel curve on the side close to the Yellow River and a gentle dewatering funnel curve on the side far away from the Yellow River; (2) the grouting at the foundation base reduces the hydraulic gradient, improves the safety of pit construction, and can effectively reduce the amount of water pumped in the pit, but has a limited effect on the amount of water pumped outside the pit; (3) there is an optimal value of permeability coefficient in the foundation base reinforcement area, and for this project, it is recommended to use 1×10-6 m/s as the target permeability coefficient in the reinforcement area. 2022 Vol. 59 (1): 176-182 [Abstract] ( 651 ) [HTML 1KB] [ PDF 3124KB] ( 803 ) 183 Analysis on Ground Surface Deformation and Influence of Construction Parameters Caused by Two Different Shield Machines in Double-tube Tunnelling DING Zhi1,2 FENG Conglie1,2 QIU Shuo1 LU Zhao3 FAN Juncong4 Based on a shield-driven running tunnel project of Hangzhou Metro Line 2, this paper carries out field measuring of the ground surface deformation caused by two different shield machines in double-tube tunnelling in soft soil areas, obtains the laws of the surface deformation caused by shield-driven double-tube tunnelling and verifies the applicability of the modified Peck formula to double-tube tunnelling. The results show that in soft soil areas the impacts on ground surface deformation caused by different shield construction parameters in the previously and subsequently excavated tunnels are different, while the surface deformation changes sharply before and after the shield machine passing through the cutting face, and a rebound phenomenon occurs when the shield tail passes through the cutting face due to the influence of the grouting; The cutterhead torque of the shield machine in soft soil areas can be composed of five calculation factors, and the calculation results are in good agreement with the measured values. The larger the opening rate of the shield cutterhead is, the larger the average torque value will be, the higher the percentage of large ground loss rate will be, and the larger the maximum ground surface settlement will be; The ratio of cutterhead torque T to mucking volume per ring Q is used as the control parameter for analyzing the ground surface settlement, and a certain positive correlation between the ratio and the surface settlement value is determined, the smaller the cutterhead opening rate is, the more accurate the fitting results will be. 2022 Vol. 59 (1): 183-194 [Abstract] ( 624 ) [HTML 1KB] [ PDF 4362KB] ( 706 ) 195 Analysis on Gas Characteristics of the Sichuan Red-bed Section of ChengduGuiyang Railway and Suggestion on Division of Gas Working Areas in the Survey Stage SUN Yi Combining with the borehole gas concentration tests for the Sichuan red-bed section of the Chengdu-Gui? yang Railway, this paper analyzes its correlation with the stratum chronology geological structure, and tunnel depth on the basis of data statistics, and puts forward the suggestion to qualitatively and quantitatively divide gas working areas. The results show that the correlation between the tunnel gas concentration and the stratum chronology is not significant in the Sichuan red-bed section of the Chengdu-Guiyang Railway (except coal-bearing strata); geological structure plays a controlling role in gas transport and accumulation; and the positive correlation between the gas concentration and the tunnel depth is significant. According to the above conclusions, it could qualitatively divide the gas working areas according to the geological structure and mapping information collected during the survey stage, and quantitatively divide the gas working areas according to the gas concentration test results. The final categorization of gas working areas can be determined by combining the qualitative and quantitative results. 2022 Vol. 59 (1): 195-199 [Abstract] ( 628 ) [HTML 1KB] [ PDF 1080KB] ( 843 ) 200 Excavation Technology of Shield Tunnels with Ultra-small Spacing in Complex Environment SUN Qingtian1 WANG Xinyu2 YANG Zhuangzhi1 As for the shield construction in shallow-buried tunnels with ultra-small spacing, taking the double-line shield tunnel construction of the western bid section of the Tel Aviv Red Line light rail project as the engineering background, this paper conducts a systematic study on various aspects such as tunnel reinforcement construction,shield driving control, monitoring control and emergency management, etc. The results show that reinforcement construction is crucial in the shield tunnelling with small spacing, which can effectively reduce the tunnel construction risks; for the shield construction in unreinforced tunnels with small spacing, the earth pressure should be kept steady with strengthened fine control; the volume of mucking should also be strictly controlled with good soil conditioning, and the ground loss rate should be curbed under 0.3%; injection of bentonite or clay shock to the outside of the shield shell can effectively reduce the displacement of the adjacent tunnel; the backfill grouting volume and quality should be controlled with consideration to the real-time monitoring data; and during the tunnel construction process, adjacent existing buildings should be monitored with strengthened vigor. 2022 Vol. 59 (1): 200-206 [Abstract] ( 577 ) [HTML 1KB] [ PDF 3352KB] ( 844 ) 207 Anti-seismic Effect of Fiber-reinforced Concrete Lining at Tunnel Portals in High-intensity Seismic Areas CUI Guangyao1 JIANG Mengxin1 WANG Mingsheng2 In order to improve the safety of tunnel portal lining structure during earthquake, taking the portal section of a highway tunnel as the research background, it carries out comparative analysis with the finite element analysis software ABAQUS on the anti-seismic effects of steel fiber reinforced concrete (SFRC), steel-basalt hybrid fiber reinforced concrete (SBHFRC) and plain concrete as secondary lining structure materials. The results show that: (1)compared with plain concrete lining, under the condition of the same fiber volume content, the maximum and minimum principal stress peaks and shear stress peaks of SFRC secondary lining are increased by 34.27%, 23.56% and 23.54% respectively, while those of SBHFRC secondary lining are increased by 3.90%, 3.37% and 3.32% respectively; (2) the equivalent displacements of SFRC and SBHFRC secondary lining structures are reduced by 8.08% and 2.36% respectively; and (3) the average safety factors of monitoring points on the monitoring sections of SFRC and SBHFRC secondary lining structures are increased by 38.73% and 50.04% respectively. 2022 Vol. 59 (1): 207-213 [Abstract] ( 596 ) [HTML 1KB] [ PDF 3437KB] ( 732 ) 214 Numerical Analysis on the Effect of Strike-slip Fault Dislocation on the Structural Safety of Railway Tunnels TANG Langzhou1,2 YU Li1,2 WANG Yusuo1,2 WANG Zhuhong1,2 WANG Mingnian1,2 Many active faults, especially strike-slip faults, exist along the Sichuan-Tibet Railway, and it is easy for strike-slip fault dislocations to make a tunnel that passes through an active fault zone suffer serious structure damages. Taking a railway tunnel that passes a fault zone as the engineering background, this paper adopts the finite-difference numerical simulation to evaluate the safety of the tunnel structure by analyzing the displacement, stress and strain of the tunnel structure under different strike-slip fault dislocations. The research shows that: with strike-slip fault dislocation, the larger the dislocation is, the greater the displacement of the tunnel structure will be except longitudinal displacement, and the greatest impact the strike-slip fault dislocation will have on the tunnel structure in the fault area and the hanging wall area; after the strike-slip fault dislocation is larger than 0.6 m, the stress on the tunnel structure is less affected by the dislocation; After the strike-slip fault dislocation is greater than 0.6 m, the tunnel structure starts to be damaged, and the damage rage increases with the increase of the dislocation. 2022 Vol. 59 (1): 214-224 [Abstract] ( 660 ) [HTML 1KB] [ PDF 4322KB] ( 702 ) 225 Causes and Treatment Measures of Sudden Segment Damage Failures in a Shield Tunnel under Construction HE Leiming1 DENG Feifan2，3 JIA Peng2，3 The shield construction method has been widely used in the construction of urban rail transit tunnels in China, and the problem of failures in shield tunnel segments has also been attracting increasing attention. This paper draws a development map of the segment damage failures based on the sudden segment damage event in a shield tunnel under construction, analyzes the relevant documentation and test data, clarifies the cause mechanism of the failures, formulates and implements corresponding treatment measures. The analysis results show that extensive cavities behind the segment lining would lead to the insufficient constraint on the tunnel structure by the surrounding rocks, and further cause the bending-torsion failure similar to the compression rod structure when the formed tunnel is subject to the action of the thrust and torque of the shield machine, the buoyancy of the synchronous injection grouts, as well as the soil and water pressure and torque of the cutterhead, which is the main cause of the segment damage failure; The monitored tunnel deformation data show that the two-stage treatment measure of "backfill grouting + repair of damaged parts" could achieve good results. In the process of shield driving, the quality of synchronous grouting should be strictly managed to prevent the shield tunnel segment cracking and fracturing failures induced by deviation from the tunnel axis . 2022 Vol. 59 (1): 225-231 [Abstract] ( 633 ) [HTML 1KB] [ PDF 4690KB] ( 922 ) 232 Study on the Law of Separation Defects of Monolithic Track Bed in Shield Tunnels HE Jian1 PENG Yuekai1 LIANG Xiao2,3 QI Taiyue2,3 The separation defects of monolithic track bed in shield tunnels have seriously affected the safety of sub? way operation. In order to study the law of separation defects of monolithic track bed, taking an operating subway line in China as the engineering background, it establishes a numerical model of monolithic track bed-segmentgrouting layer. The research results show that: (1) when the train wheel set acts on one side of the track bed near the expansion joint, it will cause larger separation deformation of the track bed, which is the most unfavorable position;(2) the separation amount caused by train load under vibration is much greater than that under static load, and there is a functional relationship between the two separations; (3) the location of the expansion joint is the area where separation is most likely to occur. The separation first occurs at the edges of both sides of the expansion joint, and with the increase of the action time of the dynamic load of train, the separation area extends to 1.5 m of the expansion joint; and (4) both the grouting layer stiffness and the contact surface bond strength are important factors affecting the separation amount, and increasing the stiffness of the grouting layer and the bond strength of the track bed-segment contact surface can effectively reduce the separation amount. 2022 Vol. 59 (1): 232-240 [Abstract] ( 609 ) [HTML 1KB] [ PDF 4266KB] ( 680 ) 241 Instrument Selection and Coil Arrangement for Train-borne Transient Electromagnetic Method Detecting Water-bearing Anomalies in Short Distance LI Zongyang1 Qi Taiyue1 QIN Shaojie1 QIAN Wangping2 The percentage of groundwater-related defects in operating high-speed railway tunnels has been increas? ing with an urgent need for fast and accurate defect detection technologies. The use of train-borne transient electromagnetic method (TEM) to detect water-bearing anomalies within 5 to 10 meters behind the lining of operating tunnels is a new technical practice. In view of the uniqueness of water-bearing anomalies in tunnels, this paper first adopts the numerical simulation method to study the electromagnetic features of different types of water-bearing anomalies, then carries out numerical simulations for the distribution of water-bearing anomalies, and finally conducts physical model tests for the electromagnetic response of coils missing from the numerical simulations. In the tests, the feasibility of existing instruments for detecting water-bearing anomalies in short distance is verified by comparing different TEM instruments, as well as the effectiveness of the close-distance train-borne TEM detection system when the anomalous position changes. 2022 Vol. 59 (1): 241-248 [Abstract] ( 519 ) [HTML 1KB] [ PDF 3151KB] ( 675 ) 249 Experimental Study on the Property Change of CMC-Modified Seawater Slurry and Filter Cake Formation in Sand Strata LIU Laicang1,2 XIA Pengju3 LV Huanjie1,2 WANG Yunzhi1,2 LI Pengfei1,2 MIN Fanlu1,2 In order to investigate the impact of sodium carboxymethyl cellulose (CMC) on the properties of seawater slurry and filter cake forming effect when a slurry shield drives through sand strata in the seabed, this paper prepares seawater slurry with different CMC dosages to analyze variation of properties of the slurry, such as water bleeding rate, viscosity and Zeta potential etc., and conducts tests on the slurry infiltration and filter cake formation. The results show that the viscosity of the slurry after the addition of CMC gradually increases compared with that of the seawater slurry, the 2 h water bleeding rate decreases significantly, the bound water content in the formed filter cake gradually increases, and the permeability coefficient of the filter cake decreases to 4.03×10-8 cm/s. The content of fine particles less than 75 μm in the modified seawater slurry increases significantly, and after resting for 24 hours the upper part of the slurry shows turbidity while the lower part still has serious precipitation. When the CMC dosing reaches 0.16%, the 2 h bleeding rate of the modified seawater slurry is less than 10%, and the permeation flow rate of the formed filter cake is less than 0.01 m3/m2, which can ensure the short-term stability of the slurry and form a dense filter cake. 2022 Vol. 59 (1): 249-255 [Abstract] ( 608 ) [HTML 1KB] [ PDF 2535KB] ( 960 ) 256 Study on Corrosion Resistance of Grouting Materials for Subsea Tunnels and Its Engineering Application JIAO Lei Seawater is highly corrosive, and it is very easy to cause erosion and destruction of tunnel lining structure through the weak area of surrounding rocks. In order to ensure the durability of the supporting structure, the mix proportion of corrosion-resistant grouting materials with ordinary Portland cement as the base material is designed by means of adjusting the content of water reducer, accelerator and high molecular polymer, and the corrosion-resistant index test and field grouting effect test are carried out on grouting materials with different mix proportions. The indoor test results show that the strength corrosion coefficient of the grouting material sample (water-cement ratio:0.65~1.0) after 360 d soaking in seawater is greater than 0.80, with good volume stability. In order to accelerate the erosion rate, the test sample is soaked in saturated MgSO4 solution, and the strength corrosion coefficient of the grouting material sample (water-cement ratio: 0.65) after 360 d soaking is greater than 0.80, and still with good volume stability. The strength of set grouts is tested through field grouting test. The test results show that the average point load strength of set grouts after 180 d soaking in saturated MgSO4 solution is 0.931 kN, which is 5.5% lower than the average strength 0.984 kN of non-soaked samples, further verifying the corrosion resistance of grouting materials. 2022 Vol. 59 (1): 256-262 [Abstract] ( 576 ) [HTML 1KB] [ PDF 2163KB] ( 719 )

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