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Quick Search     Advanced Search MODERN TUNNELLING TECHNOLOGY   2023 Vol.60 Issue.1 Published 2023-02-25 1 Carbon Emission Accounting and Research Progress Analysis of Traffic Tunnel Engineering GUO Chun1,2 GUO Yalin1,2 CHEN Zheng1,2 In response to the increasingly serious global warming problem, the Chinese government has put forward the "carbon emission peak and carbon neutrality" goals. The greenhouse gas emitted from the production activities of traffic tunnels is one of the main sources of carbon emissions in the field of civil engineering. The efficiency of energy conservation and emission reduction is the key to achieving the "carbon emission peak and carbon neutrality"goals in time and with good quality. The current research status of carbon emission calculation and analysis of traffic tunnels is summarized through statistical research on relevant documents in the past 10 years. The results show that the carbon emission research of tunnel life cycle at present is often carried out based on life cycle evaluation at home and abroad, and the emission coefficient method is selected for calculation. Most documents mainly focus on the calculation and emission reduction analysis of carbon emissions during the construction of highway tunnels and shield tunnels, and generally the carbon emissions during the construction of tunnels are divided into three phases: material production, material transportation and on-site construction. A comprehensive description of the research progress on the influencing factors and prediction formulas of carbon emissions from tunnel construction can provide a reference for future research. 2023 Vol. 60 (1): 1-10 [Abstract] ( 204 ) [HTML 1KB] [ PDF 2089KB] ( 683 ) 11 Present Status and Prospect of the Study on Key Technologies of Tunnel Ahead and Station (Shaft) Following Method WEI Gang1,2,3 LIN Zhiying1 WANG Xiao2,3 WEI Xinjiang2,3 The tunnel ahead and station (shaft) following method has the advantages of short construction period, small site area and slight influence on the surrounding environment. Based on the summary and review of 18 practical engineering cases of the construction with tunnel ahead and station (shaft) following method, the method is classified into two categories: tunnel ahead and station following method and tunnel ahead and shaft following method.The tunnel first and shaft following method can be classified into the one for construction without cross passage and the one for construction with cross passage. And the tunnel ahead and shaft following method for construction without cross passage can also be classified into the large-shaft and small-tunnel method and the small-shaft and largetunnel method according to the size of the tunnel and shaft. This paper summarizes the key technologies in the construction process with the tunnel ahead and station (shaft) following method, such as several forms of expanding subway station excavation, supporting form of foundation pit and segment breaking mode with tunnel first and station following method, draws a useful conclusion that the selection conditions of foundation pit support can be applied to the engineering practice with tunnel ahead and station (shaft) following method, looks forward to the future research direction of the tunnel ahead and station (shaft) following method in engineering application, numerical simulation,which provides reference for the promotion and application of tunnel ahead and station (shaft) following method in China. 2023 Vol. 60 (1): 11-22 [Abstract] ( 184 ) [HTML 1KB] [ PDF 3671KB] ( 562 ) 23 Research Progress of Subway Tunnel Passing Through Xi′an Ground Fracture and Application Prospect of "Shield Tunnelling before Expansion" Method LAI Hongpeng1 YAO Yi1 GAO Qiang2 KANG Zuo3 Xi′an ground fracture is a typical geological disaster in the loess area, which covers almost the whole ur? ban area. Its creep activity seriously endangers the safety of subway tunnels, which is a major technical problem in subway construction. Based on the ground fracture prevention and control experience of Xi′ an Metro for more than ten years, this paper systematically sorts out the distribution and activity characteristics of ground fractures, the hazards faced by the metro, the concept and measures of fortification, the fortification parameters, the operation of fortification structures, etc. It focuses on the analysis of the problems existing in the conventional construction method of "mined excavation + shield stepping", and puts forward a new construction technology of "shield tunnelling before expansion". The main conclusions are as follows: (1) The conventional construction method of metro passing through a ground fracture section involves a series of complex processes such as shaft and cross passage excavation, manual operation with CRD method, shield stepping, etc. The contradiction between the necessity of fortification and the complexity of existing construction technology seriously restricts the construction process of the Xi ′ an metro. (2) The construction process, problems to be solved and engineering application prospects of the new construction method of "shield tunnelling before expansion" are given. (3) The "shield tunnelling before expansion" method ensures the continuity of shield operation, avoids the launching and receiving in the shield tunnel, and then reduces the fortification section under the same fortification parameters through the optimization of structure and construction method,which is an important exploration and attempt to realize the convenient and low-cost ground fracture section of the subway tunnel. 2023 Vol. 60 (1): 23-33 [Abstract] ( 194 ) [HTML 1KB] [ PDF 4625KB] ( 482 ) 34 A Study on Geometric Design Parameters of Grille Sunshades in Highway Tunnels YU Li1,2 WANG Song1,2 LUO Xiang1,2 WANG Xiaoyong3 GUO Xiaohan1,2 DUAN Ruyu1,2 In order to improve the design parameters of the grille sunshade, vehicle tests are carried out in the tun? nel group section of the Ya′an-Kangding expressway with an eye tracker. The change rate of the driver′s pupil diameter and the driver′ s subjective comfort were used as evaluation indicators to verify the shading effect of the grille sunshade. On this basis, two types of grid sunshade models, annular and portal, are built with DIAlux software.The shading rate of grill sunshade under different portal directions and different grill spaces is calculated, and the influence of different parameters on the shading effect of the sunshade is explored. Based on the relationship between the driver′s pupil area at the tunnel portal and the ambient illumination, the illumination requirements for different positions in the sunshade at different design speeds are given. The research shows that the grille sunshade effectively improves the driver′ s visual comfort at the entrance and exit of the tunnel. There is no obvious difference in shading effect between circular and portal sunshades. Affected by the natural light and the dark environment in the tunnel, there is a drastic transition between light and dark within the range of 5~10 m at both ends of the sunshade. The illumination of the middle section of the sunshade is relatively stable, which can be used as the basis for calculating the shading rate of the grille sunshade. The portal orientation has a great influence on the shading effect,and the shading rate of the east-west portal orientation is 5%~10% higher than that of the north-south portal orientation. Linear reduction is not the best option for gradual light reduction in the sunshade. The value can be calculated according to the relationship between illuminance and speed and the distance from the portal or according to the field illuminance test results. 2023 Vol. 60 (1): 34-46 [Abstract] ( 221 ) [HTML 1KB] [ PDF 8268KB] ( 407 ) 47 Study on Application Standardization of Construction Information Model for Subway Stations WANG Ru LU Tongyang CHENG Kai In order to solve the problems of heavy workloads, low efficiency, insufficient application of model data and poor effect of optimizing the construction scheme in the construction process of subway stations, the research is carried out from the perspective of application standardization of subway station information model with the construction contractor as the main application subject and the construction process as the main application line. Firstly, the application standardization process of the construction information model for subway stations is defined, which provides a general method for the construction contractor to apply the information model and optimize the construction scheme in the subway station construction. Secondly, the standard component design with less specifications, multiple combinations and multiple station calls are carried out. The standard component library management system is designed based on the Revit platform, and its management function is realized by using the secondary development technology of Revit API and MySQL database. Finally, taking the Nanmen Station Project of Wuxi Metro Line S1 as an example, the standard component library is called to design the standard site layout scheme, verify the efficiency of the application standardization process and the standard component design and management, and improve the application quality of the construction information model. 2023 Vol. 60 (1): 47-55 [Abstract] ( 198 ) [HTML 1KB] [ PDF 5021KB] ( 348 ) 56 Research on the Automatic Identification Method for Rock Mass Fracture in Tunnel Face Based on Computer Vision Technology and Deep Learning LUO Hu1 Miller Mark1 ZHANG Rui2 FANG Yong1 In this paper, the fracture identification and feature extraction of tunnel face images are studied. Firstly, the data enhancement including various illumination processing measures is carried out on the tunnel face image set based on the characteristics of insufficient illumination and uneven light in the tunnel. Though recognizing the contour of the tunnel face by the Unet network, the average value of intersection over union and the average similarity are 91% and 93%. The morphological operation is used to make the edge of the tunnel face contour smooth and eliminate noise points. Then, the high-resolution tunnel face images are processed by splitting-splicing strategy, and the rock mass fractures are identified by DeepCrack network model transfer learning. The average value of intersection over union and average similarity are 61% and 75%. Further, the identification results are refined, skeletonized and analyzed in connected domains by using the Zhang-Suen algorithm and the 8 neighborhoods labeling algorithm. Finally, the pixel-level length and dip angle of each fracture is calculated by the control point marking and corrosion marking methods. 2023 Vol. 60 (1): 56-65 [Abstract] ( 201 ) [HTML 1KB] [ PDF 5005KB] ( 614 ) 66 Design and Development of the Shield Construction Assistant Decision-making System Based on the Knowledge Graph HU Min1,2 HU Xingchen1,2 SONG Yun3 QIANG Pei3 The literatures and case reports of shield construction are utilized to design a shield construction assistant decision-making system based on the knowledge graph for the purpose of guiding engineering and technical personnel to make shield construction decisions. On the basis that a standard lexicon of shield construction is created, the knowledge graph ontology architecture of shield construction is proposed. The Chinese word segmentation model method combining BiLSTM and rules is employed to semi-automatically extract engineering case knowledge derived from papers and special reports and construct the extensible shield construction knowledge graphs. On this basis, a recommended algorithm for shield construction decision making is designed and developed according to the subgraph similarity characteristics of knowledge graph node weights to offer solutions and reference schemes for actual problems encountered during shield tunnel construction and ensure successful construction. 2023 Vol. 60 (1): 66-75 [Abstract] ( 211 ) [HTML 1KB] [ PDF 3300KB] ( 403 ) 76 Research & Development and Application Analysis of Risk Ranking Management and Control Platform for Shield Construction of Urban Underground Works WANG Yesheng1,2 WU Yong1,2 ZHAO Liangyun3 LI Wei3 JIANG Yijie4 ZHAO Huan4 DING Zhi5,6 In order to effectively solve the problems of the high incidence of risk events and untimely early warning response in shield construction of urban underground works, based on the concept of risk ranking control and in combination with the research on the intelligent pre-alarm mechanism of shield tunneling parameters, a risk ranking control system platform for shield construction of urban underground works has been developed. The platform mainly includes a full-dimensional collection of shield tunneling equipment parameters and monitoring data, comprehensive information integration, GIS layer display, intelligent monitoring of shield tunneling parameters, intelligent collection of monitoring measurement data, risk prediction and early warning management, system management and other modules. It can realize the functions of intelligent early warning of shield tunneling data overrun, intelligent risk monitoring, dynamic management of construction risks and post-construction risk status control of formed tunnel structures. The development and application of the platform provide a reference example for effectively solving the current problems of difficult shield construction supervision and lagging risk response, as well as the construction of an information-based intelligent control platform for shield construction risks of various types of urban rail transit and large municipal projects in the current period. 2023 Vol. 60 (1): 76-89 [Abstract] ( 194 ) [HTML 1KB] [ PDF 11812KB] ( 479 ) 90 Unsymmetrical Loading Evolution Law and Surrounding Rock Control for tunnels with Extremely High Geostress and Layered Surrounding Rock PU Song1 XIANG Long2 LIAO Hang1 YU Tao1 YAO Zhigang1 FANG Yong1 ZHU Muyuan1 Taking the gently inclined layered surrounding rock of the Grand Canyon Tunnel as the case, and adopt? ing the 3DEC discrete element analysis method and combining with the means of field monitoring, the evolution law of the surrounding rock unsymmetrical loading under the high geostress and different dip angles of rock stratum is deeply studied, the relationship between the unsymmetrical loading and the field support structure damage is revealed, and the optimal support parameters are proposed according to the influence of the bolt support parameters on the unsymmetrical loading control. The research shows that the deformation and failure of the support structure under the condition of high geostress and gently inclined rock stratum show obvious asymmetry. With the increase of the dip angle of rock stratum, the peak position of the maximum principal stress of the initial support shifts from the crown to the right shoulder, and the bending deformation of the anti-dip side is greater than the sliding deformation of the down dip side. With the increase of bolt length, the shear slip zone of surrounding rock, the initial support displacement and the maximum principal stress of the initial support gradually decrease. The optimal length of the bolt is about 3.5~4.5 m, the bolt is set along the vertical direction of bedding plane, and the unsymmetrical loading of the initial support structure is significantly improved. After the field optimization of support, the left and right shoulders are symmetrically deformed, the displacement is basically identical, and the unsymmetrical loading is significantly improved. 2023 Vol. 60 (1): 90-99 [Abstract] ( 216 ) [HTML 1KB] [ PDF 5061KB] ( 440 ) 100 Research on the Initial In-situ Stress Inversion Method Based on Disturbance Correction of Tunnel Excavation and Its Application YANG Yanchun This paper puts forward an initial in-situ stress inversion method based on numerical simulation, taking into account the tunnel excavation disturbance along a plate′s suture zone, and has applied the method in five typical tunnels along a railway line. The results show that the correction coefficients k and λ of the in-situ stress for a typical tunnel along this railway vary between 1.236~1.404 and 0.846~1.069, respectively, and the actual measured values of the in-situ stress are generally small. Also, the results indicate that horizontal principal stresses have a substantial impact on tunnel construction, and it is necessary to carry out the inversion of initial in-situ stress for the construction of similar projects. Furthermore, according to this inversion method, if taking into account the excavation disturbance, the error between the calculated and measured values of the in-situ stress is no more than 5%. 2023 Vol. 60 (1): 100-106 [Abstract] ( 207 ) [HTML 1KB] [ PDF 3426KB] ( 455 ) 107 Deformation Failure Process and Characteristics of Tunnels with Different Flatness Ratios under Horizontal Interbedding Conditions HONG Ming FAN Xiang YANG Xiaohua REN Xianda The test pieces of interbedded surrounding rock tunnel with different flatness ratios were prefabricated, to study the deformation and failure characteristics around the interbedded surrounding rock tunnel through tests, and numerical simulation was used to analyze and compare the distribution of stress and strain around the interbedded surrounding rock tunnel. Three different flatness ratios of 0.45 (test specimen S), 0.55 (test specimen M) and 0.65(test specimen L) were used respectively. The study shows that the overall failure mode of test specimen S is compression failure mode (TC mode), obvious compression and shear failure easily occurs at the arch waist, and a tension-shear composite crack is formed near the arch shoulder. Test specimen M was subjected to mixed failure (TX mode), in which obvious tensile failure at the arch crown easily occurred, and obvious compression-shear composite crack was formed at the arch shoulder. Test specimen L was subject to the hole failure (TH mode), in which obvious tensile failure easily occurred at the arch crown, and tension-shear composite crack was formed at the arch foot.Moreover, the distribution of stress and strain around the tunnel is significantly related to the compression failure characteristics of tunnels with different flatness ratios, and the difference of stress levels at the same location of the tunnel is the main reason for the different failure modes of the tunnels with three different flatness ratios. 2023 Vol. 60 (1): 107-118 [Abstract] ( 161 ) [HTML 1KB] [ PDF 8628KB] ( 369 ) 119 Study on Stability and Initial Support Optimization of Multi-tunnel Based on Bearing Characteristics YAO Zhixiong1,2,3 LIU Mengfei1 WU Bo4 LIU Yaoxing1 CHEN Ximao5 ZHENG Guowen5 LUO Zhiyi1 Based on a large-span four-tube small-clearance tunnel (the two-tube traffic tunnel in the middle is a two-way eight-lane tunnel) passing under an expressway in Fujian Province, this paper carries out an overall optimization study taking into consideration the bearing characteristics of each tube to achieve a more scientific design. By means of the strength reduction limit theory method, this paper evaluates the stability of each tube and explores the determination method and failure mode of multi-tunnel instability in combination with the deformation of surrounding rock, the development of the plastic zone of middle rock pillar and the failure process of the tube. Based on the concept of equal-strength design of each tube, the implicit relationship between the safety coefficient of each tube and the thickness of the initial support is fitted through a mathematical function model, and the support thickness is optimized through a genetic algorithm. The results show that the plastic zone of the surrounding rock develops and penetrates from near to far with the increase of the strength reduction coefficient, and there is room for optimization as the safety reserves of large-span vehicular and pedestrian tunnels are different. In combination with the stability and failure development process of each tube, three dominant failure modes of multi-tunnel system are summarized,i.e. through failure in the plastic zone of middle rock pillar, through failure in the plastic zone of arch springing and surface, and combined failure of the above two. The calculation results show that the thickness of the initial supports for pedestrian and vehicular tunnels can be reduced by 4~12 cm, and there is room for optimization ranging from 16.7% to 26.7%. The deformation and stress of the typical section in the optimized scheme and the original scheme are consistent with the measured values on site and are less than the specified values, and the structure is stable, indicating that the optimized support and surrounding rock can work well together, which verifies the rationality of the calculation method and optimization scheme. This optimization method, which comprehensively considers the bearing characteristics of each tube, the economy of supporting parameters and the overall stability of the multi-tunnel,better deals with the dialectical relationship between engineering safety and engineering cost, and is more scientific than the traditional engineering analogy method. 2023 Vol. 60 (1): 119-129 [Abstract] ( 208 ) [HTML 1KB] [ PDF 4612KB] ( 345 ) 130 Study on Transverse Seismic Performance of Double Lining of Large Diameter Shield Tunnel CAO Xiangpeng1,2 FENG Kun2 XUE Haoyun2 MAO Sheng1 YU Bo2,3 In order to find out the influence of double lining and different construction methods (composite and su? perimposed) of double lining on the lateral seismic performance of shield tunnel, the three-dimensional refinement model of the double lining of shield tunnel is established based on the Jintang Subsea Railway Tunnel of NingboZhoushan Railway, and the nonlinear performance of tunnel materials and contact is considered. The seismic performance is studied by the implicit dynamic time history method. The results of the study show that: (1) the greater the stiffness of the connection between the double lining and the segment, the smaller the tunnel deformation. (2) The composite lining has limited improvement in the circumferential seismic performance of the tunnel, and its deformation, damage and stress patterns are basically consistent with those of the single lining. (3) The superimposed lining can effectively improve the seismic performance of the tunnel and make full use of the mechanical properties of the materials, but it is necessary to focus on the damage to the tunnel. (4) It is recommended to adopt superimposed double lining for sections with high requirements on seismic fortification grade, and composite double lining for special sections with high requirements on waterproofing and fire protection. 2023 Vol. 60 (1): 130-139 [Abstract] ( 219 ) [HTML 1KB] [ PDF 4758KB] ( 429 ) 140 Analysis on Vibration Influence of the Construction of Short-distance Pile Foundation on Existing Shield Tunnels CHEN Fujiang1 DUAN Rongqian1 ZHANG Xin2 LIU Jingang3 SUN Cangqian1 LI Xiqian1 In order to analyze the dynamic response of the adjacent existing shield tunnel under the impact load during the construction of precast piles, relying on the tunnel project between the Nijiaqiao Station and the South Railway Station of Chengdu Rail Transit Line 18, the infinite element static-dynamic unified artificial boundary is introduced, and the "pile-soil-tunnel" 3D dynamic finite element-infinite element coupling model is constructed in combination with the actual engineering geological conditions for numerical tests. The results of geotechnical centrifuge tests are compared, and the validity of numerical model is verified. Based on this, the influence of different piling parameters on the vibration of adjacent existing tunnels is studied, and the limit value of tunnel peak vibration caused by piling construction of similar projects is proposed. The results show that: (1) The distribution of the maximum vibration velocity of the lining reflects the relative orientation of the vibration source and the tunnel. The most unfavorable vibration position of the tunnel affected by piling generally occurs on 1/4 arc or 1/2 arc near the pile side of the tunnel; (2) The vibration velocity increases with the increase of piling depth. When the pile driving depth exceeds the bottom of the tunnel, the influence of the increase of piling depth on the vibration of the tunnel is no longer significant; (3) When piling is carried out within the scope of the overlying soils pile above the tunnel, the influence of the horizontal spacing between piles and tunnels on the vibration of the tunnel is less than that of the piling depth. 2023 Vol. 60 (1): 140-148 [Abstract] ( 224 ) [HTML 1KB] [ PDF 2538KB] ( 378 ) 149 Influence Law and Analysis of Foundation Pit Stability in Water-bearing Karst Area SUN Keguo1 ZHEN Yingzhou1 WEI Yong1 XIAO Zhifei2 YANG Peng3 FANG Chunbin4 There are water-bearing karst areas in Guangzhou, Shenzhen and other cities. The groundwater is rich, and the development form is complex. It is easy to cause safety accidents such as water inflow and collapse during subway construction. Relying on a subway station project in Guangzhou, the site permeability coefficient is 6.32 m/d through the field pumping test, and the total water inflow of the foundation pit is predicted. Two process tests are carried out using numerical simulation, and the final state error of dewatering is 14.92% and 7.08%, respectively.The results are ideal. The influence rules of different forms of water-bearing karst caves on the stability of foundation pit are further studied, and the sensitivity analysis of various influencing factors is carried out based on the grey correlation theory. The groundwater level and the water pressure of the cave have a greater impact on the horizontal deformation of the envelop enclosure, with the sensitivity of 0.946 and 0.925 respectively. The spacing and water pressure of the cave have a great impact on the ground settlement, with sensitivity of 0.999 and 0.975 respectively.The spacing and diameter of the cave have great influence on the maximum tensile stress of the support structure and the pore water pressure of the foundation base. 2023 Vol. 60 (1): 149-158 [Abstract] ( 218 ) [HTML 1KB] [ PDF 4778KB] ( 430 ) 159 Study on Multiple Air-Opening Ventilation Characteristics and Pollutant Control for the Tunnel with Decentralized Exhaust under Jet Pressurization LI Bao1,2 WU Kaijie2,3 XIONG Jing1 SHEN Hang1 WENG Jiajun2,3 WU Ke2,3,4 In order to reveal the influence of the sudden change of tunnel pressure caused by air intake/exhaust of the top exhaust outlet on the multiple air opening ventilation characteristics of the tunnel with decentralized exhaust,the computational fluid dynamics method was used to simulate the air intake and exhaust laws of grouped top exhaust outlets under the action of jet pressurization. The results show that air exhaust/intake of the top exhaust outlet will cause a sudden increase/decrease of the local pressure in the tunnel, and the ventilation characteristics of multiple top exhaust outlets in the tunnel with decentralized exhaust are affected together by jet pressurization, resistance along the way and sudden pressure change caused by the ventilation at the air opening. The interval between air openings is an important factor that affects the air volume change of multiple air openings. For the exhaust type air opening, when the interval between air openings is small, the sudden pressure increase generated by the exhaust at the upstream air opening will exceed the loss along the way between air openings, and the air exhaust volume at the downstream air opening will increase along the way due to the rise of the static pressure. When the interval between air openings is large, the sudden increase of pressure will not be enough to overcome the loss along the way between air openings, and the exhaust air volume of downstream air openings will decrease along the way, or even change into air intake; For the intake type air opening, the air intake volume of the air opening will increase along the way under the superposition of the sudden pressure drop caused by the air intake and the loss along the tunnel. Compared with starting methods of other fans, the fan is started to be in the staggered position relative to the air opening group,which is a more efficient ventilation control method for the tunnel with decentralized exhaust, and it can minimize the extreme concentration of pollutants in the tunnel. 2023 Vol. 60 (1): 159-167 [Abstract] ( 191 ) [HTML 1KB] [ PDF 3895KB] ( 352 ) 168 Experimental Study on the Law of Heat Transfer of Tube Structure of the Steel-concrete-steel Immersed Tube Tunnel JIANG Shuping1,2 LI Jing1 ZHANG Dandan1 CAO Peng2 To understand the fire resistance of steel-concrete-steel composite structure and further provide the ba? sis for its structural design and fire protection, the multifunctional large refractory-lined test furnace which is independently developed was used for the fire resistance test of local full-sized elements in different fire protection schemes to research the law of heat transfer of the tube structure of steel-concrete-steel immersed tube tunnel at high temperature caused by a fire. The results show that fireproof plates can greatly protect the tube structure in a fire, and if no fireproof plates are used for protection, obvious voids in concrete will appear in the vertical position of elements; the temperature value at each measuring point on the unexposed surface of a fireproof plate regularly varies with the hearth temperatures, but they do not completely synchronize, and the temperature changes in the measuring point on the unexposed surface of a fireproof plate lag behind those of the hearth; the depth of temperature influence on the tube structure at high temperature caused by a fire reaches about 550 mm from the upper surface of bottom plate, and the height of heat transfer of the concrete section is about 400 mm. 2023 Vol. 60 (1): 168-178 [Abstract] ( 206 ) [HTML 1KB] [ PDF 7219KB] ( 377 ) 179 Experimental Study on Influence Factors of Rock Breaking with High-pressure Premixed Abrasive Water Jet in Hard Rock Tunnel Boring Machine WEN Yongliang YANG Xingya HE Fei WANG Heng LU Yiqiang The application of the rock breaking technique with premixed abrasive water jet to the hard rock tunnel boring machine (TBM) is expected to solve the problems of low efficiency and high cost of traditional rock breaking with the disc cutter when high strength rock is tunneled during tunnel construction. However, rock breaking with the premixed abrasive water jet is affected by many factors and the system is complex, and its application in TBM rock breaking and tunnelling field is not mature enough. By making use of the comparative research method and the rockbreaking experimental device with high-pressure water and sand, the comparative tests are performed for fixed sprinkler at fixed time and mobile sprinkler at a constant speed, to study the influence of different hydrostatic pressure, injection distances and moving state of the sprinkler on the average consumption of abrasive, the depth and the width of the rock-breaking pit. For the rock-breaking width, these factors are sorted by their influence: moving state, injection distance and hydrostatic pressure. For the depth of rock breaking, these factors are sorted by their influence:movingstate,hydrostatic pressure and injection distance. By exploring the best rock breaking parameters of the premixed abrasive water jet technique, a basis is provided for the research of TBM-based new rock breaking techniques. 2023 Vol. 60 (1): 179-185 [Abstract] ( 196 ) [HTML 1KB] [ PDF 3092KB] ( 353 ) 186 Full-scale Experimental Study on Mechanical and Deformation Properties of Initial Support Structure of Horseshoe Tunnel WANG Yawei ZHAO Xiuwang ZHU Yi GUO Jianglong In view of the initial support structure of the horseshoe tunnel, the bearing capacity and deformation per? formance of the steel arch and shotcrete initial support structure are analyzed by using full-scale tests and monitoring the internal force, structural surface strain and deformation of the structure by embedding sensors. The results show that: (1) In the elastic phase, the bending moment and axial force on each section of the support structure are symmetrical about the neutral axis of the structure, and the corresponding radial displacement amplitude is small.(2) In the plastic phase, with the increase of the applied load, the bending moment and axial force of the support structure increase rapidly. The support structure presents a deformation state of "convex arch bottom and concave arch waist", and is approximately symmetrical about the neutral axis. (3) The support structure finally failed at the right arch shoulder section steel connection. The concrete and section steel at the failure location were in a large range of peeling state, and the exposed section steel bulge was bent and damaged. The ultimate bearing capacity of the structure was about 1.32 times of the design load. 2023 Vol. 60 (1): 186-194 [Abstract] ( 180 ) [HTML 1KB] [ PDF 5767KB] ( 357 ) 195 Experimental Study on the Adsorption Law of Anionic Surfactants in Shield Soil CAO Yazhou1 WU Zhixiong1 LI Yannan1 HU Liming1 WANG Rui1 ZHANG Xuan2 XIAO Ying2 This paper studies the adsorption and desorption behaviors of anionic surfactant sodium dodecyl sulfate (SDS) on the surface of soil particles in different particle size ranges, analyzes the adsorption and desorption patterns of surfactants in shield soil, measures the changes of zeta potential of soil particles, and investigates the feasibility of rapid determination of SDS adsorption by zeta potential. The results show that the unit equilibrium adsorption capacity of SDS is larger on soil particles with smaller size. The equilibrium adsorption capacity increases with the increase of SDS concentration and the adsorption isotherm is linear when the SDS concentration of the surfactant is less than its critical micellar concentration. The equilibrium adsorption capacity decreases with increasing SDS concentration when the concentration is greater than the critical micelle concentration. The smaller the particle size of the residue, the less effective the SDS desorption. The larger the adsorption capacity of SDS, the lower the desorption rate. It is feasible to determine the surface SDS equilibrium adsorption capacity of soil particles with particle size less than 0.075 mm by measuring their zeta potential. 2023 Vol. 60 (1): 195-201 [Abstract] ( 201 ) [HTML 1KB] [ PDF 1527KB] ( 418 ) 202 Classification Method of Monitoring Level in Railway Tunnel Construction Phase and Its Application LU Junfu1 ZHANG Hongxin1 PEI Qifan2 The instrumentation and monitoring in the construction phase of railway tunnels is an important means to ensure the informatization construction. At present, the instrumentation and monitoring items and contents of the tunnel are mainly determined by the qualitative determination of the surrounding rock level. No unified quantitative evaluation system has been established. Based on the risk analysis theory and the risk probability index & risk consequence index faced by tunnel, the monitoring level and classification method of railway tunnel construction phase are established. We take the unascertained measurement theory as the risk probability index evaluation method, select eight impact indexes, such as rock weathering degree, rock quality index and uniaxial saturated compressive strength, and construct the index measurement function. Also, we combine the improved analytic hierarchy process to weight each evaluation index, determine the risk probability index according to the confidence identification criteria, and calculate the monitoring level index quantitatively to determine the monitoring level and corresponding monitoring content. Taking Xiaocaoba Tunnel of Chongqing-Kunming Railway as an example, the monitoring level of the three mileage sections of the tunnel during construction phase is divided. The evaluation results show that the monitoring level of DK344+200~DK344+220 section is C. 2023 Vol. 60 (1): 202-208 [Abstract] ( 223 ) [HTML 1KB] [ PDF 1161KB] ( 526 ) 209 Research on the Effect of Foundation Reinforcement of Small-radius Shield Tunnels in Soft Soil Stratum Crossing under High-speed Rail under Construction CAO Xiaoping1 WEI Zhikai1 LU Hongqiang2 MOU Jing2 FU Xiaolin2 LI Zhichao2 Taking as a research case the shield tunnel of Line 5 of the Fuzhou Metro crossing under the Fuzhou-Xia? men High-speed Railway (under construction), the on-site monitoring data were used to analyze the full process of Crossing construction according to the characteristics of the small-diameter curved shield tunnel in a soft soil stratum crossing under the high-fill subgrade of high-speed rail, so as to research the effect of foundation reinforcement of such projects and the law of construction deformation. The results show that if prestressed concrete pipe piles are used for foundation reinforcement of this project and construction conditions are not available in the metro shield construction at a later stage, the pile-slab structure should be constructed for foundation treatment; after the pileslab structure is used for reinforcement in the soft soil area, the maximum ground settlement is 5.6 mm in the measured data, accounting for 18.67% of the ground settlement control value, which is in the controllable range; after foundation reinforcement is conducted in advance, only slight settlement occurs in different positions of the subgrade in case of undercrossing construction of the shield tunnel, indicating that the reinforcement of pile-slab structure has a very good effect on controlling crossing construction deformation; as the subgrade filling height increases,the soil pressure value of each layer shows an overall increase, and the rate of change in the soil pressure of each layer shows the "bimodal curve" and the soil pressure value in the middle of the subgrade is higher than that close to both sides; before the shield tunnel crosses under the high-speed rail, the change in the axial force of concrete support of the pile-slab structure is roughly split into 4 stages: "linear growth - transition - regrowth - stability", and after the shield tunnel crosses, the axial force of concrete support slightly increases and gradually becomes stable at a later stage. It can be seen from the analysis of monitoring data that the reinforcement effect of pile-slab structure is significant. 2023 Vol. 60 (1): 209-218 [Abstract] ( 196 ) [HTML 1KB] [ PDF 5914KB] ( 342 ) 219 Mechanism and Effect Analysis of Surface Deep-hole Sleeve Valve Pipe Grouting Reinforcement in Deep-buried Water-bearing Loess Tunnel ZHANG Minqing1 ZHANG Huyuan2 XIE Juntai3 Loess is characterized by "low strength, large deformation, small self-supporting capacity and poor engi? neering properties", and is particularly sensitive to water. Once it meets water, the strength will be significantly reduced, and the engineering properties will deteriorate sharply. Therefore, the construction of the water-bearing loess tunnel is extremely difficult and the safety risk is extremely high. The Shangge Village tunnel on Yinchuan-Xi ′ an High-speed Railway passes through the water-bearing loess stratum, with a buried depth of 102 m. During the conStruction, no obvious dewatering effect can be achieved through the dewatering test, and the surrounding rock of the tunnel is deformed greatly and the progress is slow. In view of this, an experimental study on grouting of surface deep-hole rigid sleeve valve pipe is carried out. The results show that: (1) the grouting of the surface deep-hole sleeve valve pipe can effectively strengthen the stratum and improve its self-stability. The reinforcement mechanism is mainly the filling and water-blocking effect of grouting on vertical primary joints and the spatial skeleton effect of grout stones. (2) After grouting, the accumulated settlement of the tunnel vault is obviously reduced, the deformation rate is reduced, the invert closure time is advanced, and the tunnel excavation progress can reach 60 ~ 80 m/month.The construction schedule has been improved by more than three times compared to that of the ungrouted case. (3)Through grouting, the bearing capacity of the loess stratum at the tunnel base can be increased by more than 3times, thus ensuring the long-term operation safety of high-speed railway tunnels. 2023 Vol. 60 (1): 219-224 [Abstract] ( 193 ) [HTML 1KB] [ PDF 2760KB] ( 449 ) 225 Research on Key Technologies for Tunnelling in Faulted Fracture Zones by Slurry Balance Shields with Super Larg LIU Zhi1 ZHONG Changping2 Based on a tunnel project in Shenzhen, this study is to investigate the construction technologies for slurry balance shields with super-large diameter through faulted fracture zones. The study analyzes the engineering characteristics and challenges of slurry balance shields with super-large diameter through faulted fracture zone, with a focus on the causes of different problems, such as clogging discharge, caking and serious tool wear during the boring process of the slurry balance shield, and investigates the key technologies for slurry balance shields through faulted fracture zones. To address the problems of clogging discharge and caking, the study optimizes the design of the cutter head structure during the selection phase of the shield machine, and adopts targeted measures, such as large grating plus crushing system with double crushers to discharge slags, small circulation mode with air-cushioned direct discharge at the host section, to improve the slag carrying capacity and conveying capacity of the slurry and reduce the risk of clogging discharge and caking. In view of the serious problem of tool wear, this study puts forward the tool management guideline of strengthening monitoring over the tool conditions, "inspecting upon warning and replacing a tool with any damage", and eliminating "working with problems", with the objectives to ensure the reliability and accuracy of tool condition monitoring and improve the life of tools. Finally, this paper summarizes the construction principles of "early prevention with control and comprehensive management of problems" through field practice, and adopts the supportive pneumatic tunnelling mode to cross the faulted fracture zone. Through the study and analysis of the construction process, this study deduces the recommended values of shield tunnelling parameters and slurry parameters and different targeted solutions 2023 Vol. 60 (1): 225-232 [Abstract] ( 226 ) [HTML 1KB] [ PDF 3988KB] ( 533 ) 233 Construction Scheme and Application Analysis of Synchronous Construction of Subway Shield Tunnels and Freezing Reinforcement for Cross Passages CHEN Jingang GUO Qiang ZHOU Hailong HUAI Wenbao DONG Xiaoqi Taking the east extension project of Beijing Metro Line 7 as a project case, in order to ensure the sched? ule of the opening and operation of the line, the mechanical and electrical installation and decoration of stations,construction of shield tunnels and freezing for cross passages had to be carried out simultaneously. Based on this,during construction, the construction schedule, site conditions (ground surface and interior of stations and tunnels),freezing effect and cost were comprehensively considered, the construction technical scheme that two cross passages share one freezing station was proposed, that is, the freezing station was located in the middle of two cross passages of the tunnel that has achieved breakthrough. By means of optimizing the selection of freezing station units, layout of freezing pipeline, tunnel segment pre-reinforcement support system and other technical measures, synchronous construction of shield tunnels and freezing reinforcement was achieved. According to monitoring and data analysis of the construction process, the development law of the freezing wall and the conditions for the safe excavation of the passages were summarized, and countermeasures for the problems were proposed, such as rise of the cooling water temperature on the site and the ambient temperature. The results show that the construction scheme and relevant technical measures are safe, effective and feasible. 2023 Vol. 60 (1): 233-240 [Abstract] ( 188 ) [HTML 1KB] [ PDF 7859KB] ( 444 ) 241 Construction Technology for the Shallow Twin-tube Six-lane Multi-arch Tunnel without Middle Drift under Large Unsymmetrical Loading WANG Mingjiang1 CI Xinhang2 CHEN Junwu3 ZHU Changjiang1 YANG Feng2 The Jinshan Tunnel of the Chuxiong (Guangtong)-Dali Expressway Expansion Project of Yunnan Nation? al Expressway Network of G56 is a six-lane multi-arch tunnel without middle drift. The tunnel passes laterally through the steep slope with a broken rock stratum. The whole tunnel is of shallow-buried large unsymmetrical loading terrain, and the lower part of the side is close to the existing expressway and township road. The unsymmetrical loading of the portal section at the entrance of the tunnel is particularly serious, and there is a large range of sections with negative burial depth. In order to smoothly carry out the entrance construction of Jinshan Tunnel and avoid the influence of mountain disturbance on the operation of existing highways, a comprehensive technical scheme is put forward from the aspects of tunnel structure, mountain reinforcement and excavation construction: (1) The buried depth section of the tunnel portal is provided with pile cap + thin-walled ear wall structure to provide an external vertical foundation and lateral support to resist the unsymmetrical loading of the mountain. (2) The reinforcement of the upper anchor cable and the lower steel pipe pile enhances the lateral stability of the portal slope; (3) The tunnel portal is constructed by half-open cover cut method to reduce the disturbance of surrounding rocks. The successful implementation of the entrance scheme of Jinshan Tunnel on site not only creates good conditions for the smooth opening of the whole line as planned but also accumulates engineering experience for the construction of the portal section of the large-span multi-arch tunnel without middle drift under large unsymmetrical loading. 2023 Vol. 60 (1): 241-248 [Abstract] ( 185 ) [HTML 1KB] [ PDF 4329KB] ( 544 ) 249 Research on Key Technologies and Management of Gas Tunnel Construction in Non-coal Measure Strata YANG Yi Gas tunnels in non-coal measure strata are essentially different from those in coal measure strata in terms of the gas source, reservoir and release. There are many studies on the construction and gas monitoring technology for gas tunnels in coal measure strata at home and abroad, and most of the gas tunnels in non-coal measure strata are managed through the technology for gas tunnels in coal measure strata, with few specific studies. Based on the construction cases of two different types of non-coal measure strata gas tunnels, namely the Xiaojialiang Tunnel of the New Lanzhou-Chongqing Railway and the Huangcao Tunnel of the New Chongqing-Huaihua Second Line, this paper deeply analyzes the gas features of connected gas tunnels in non-coal measure strata and gas tunnels in shale gas formation , and puts forward the key gas management technology mainly based on gas forecasting and ventilation dilution and discharge, and combining manual and automatic monitoring. The field engineering practice shows that construction safety is guaranteed, the investment and construction period is controlled, and good results are achieved, which provides reference experience for the safety management and control of gas tunnels in non-coal measure strata. 2023 Vol. 60 (1): 249-255 [Abstract] ( 203 ) [HTML 1KB] [ PDF 2149KB] ( 551 ) 256 Study on the Self-propelling Function of Sleeve-type Screw-driven Tunnel Boring Machine for Excavating Rescue Channel in Loose Rock and Soil LU Qingguo1 MA Shaojun2 YAO Wenjie3 ZHANG Peng2 It is the primary task of emergency rescue to quickly, efficiently and timely excavate the rescue channel to the place where people are trapped (buried) in the loose rock and soil medium with geological disasters such as landslides or debris flow, tunnel collapse and earthquakes. This paper introduces a new type of tunneling technology and equipment that relies on the rotation of multiple long helices mounted parallel to the periphery of the cylindrical tunnel boring machine to drive the entire boring machine to traverse and excavate independently in the loose rock and soil, analyzes the structure of the tunnel boring machine and the self-propelling mechanism, and deduces the conditions for the self-propelling of the sleeve-type screw-driven tunnel boring machine. Based on the reasonable values of the parameters of helical tooth height, tooth root pitch and tooth profile angle obtained by laboratory tests,the first test prototype of the sleeve-type screw-driven tunnel boring machine has been developed. In the field test,the prototype autonomously moves forward for a distance of 10 m in the loose soil, which proves the feasibility of using the screw-driven principle to autonomously move forward to excavate the rescue channel in loose rock and soil media, and provides safe and rapid construction technology and equipment for the construction of rescue channel to rescue trapped people in similar disasters and accidents. 2023 Vol. 60 (1): 256-261 [Abstract] ( 192 ) [HTML 1KB] [ PDF 1681KB] ( 351 ) 262 Experimental Study on the Muck Improvement of Earth Pressure Balance Shield Tunnelling in Water-bearing Composite Stratum HUANG Fengyuan1 ZHANG Kangjian2 CHEN Dengkai1 ZHANG Zhiqiang2 JIA Bin1 In view of the water-bearing composite stratum of Nanchang Metro Line 4, a muck improvement test has been conducted on saturated gravelly sand and moderately weathered argillaceous siltstone, and the appropriate modifier is selected and the performance test of the modifier is carried out. Based on the slump test, permeability test and direct shear test, the reasonable addition ratio of the modifier for saturated gravel sand and moderately weathered argillaceous siltstone are determined. The indoor muck test results are applied to the on-site muck improvement to verify the rationality of the indoor muck improvement test. The results show that the performance of the modifier meets the engineering requirements when the concentration of foam agent solution is 3% and the bentonite slurry ratio is 1∶8. For saturated gravelly sand muck, the proper addition method of modifier is that the ratio of foam to bentonite slurry is 4∶1, and the addition ratio is 5%~7%. For moderately weathered argillaceous siltstone, the proper addition method of modifier is that the ratio of foam to bentonite slurry is 1∶4, the addition ratio is 10.8%~12.6%, or the addition ratio of full bentonite slurry is 9.9%~12%. 2023 Vol. 60 (1): 262-269 [Abstract] ( 191 ) [HTML 1KB] [ PDF 3707KB] ( 464 ) 270 Study on the Preparation and Performance of Red Mud-based Grouting Reinforcement Materials ZHANG Ning1,2 WANG Mengya2,3 WANG Chuan1,2 LI Zhaofeng2,3 MA Chuanyi1,2 In order to meet the needs of grouting reinforcement and treatment in karst collapse areas, solid wastes such as red mud and steel slags are selected to prepare high-performance red mud-based grouting reinforcement materials and to establish methods for regulating properties such as setting time, mechanical strength and swellability. The test results show that the change in cement content has the greatest influence on the 7 d compressive strength of stones. The 7 d compressive strength of red mud-based grouting reinforcement materials shows a trend of increasing first and then decreasing with the increase of cement content. When the single factor acts, the strength is the highest when the cement content is 15%. Combined with the influence of single factors on the final setting time of grout and the 7 d mechanical strength of stones, it can be determined that the red mud-based grouting reinforcement materials have the best performance and excellent fluidity when the cement content is 15%, the steel slag content is 15% and the activator content is 12%. Considering the final setting time and mechanical strength of red mudbased grouting reinforcement materials, it is determined that the optimal mixing amount of each kind of expansive agent is 6% of UEA expansive agent, 6% of CSA expansive agent and 0.2% of the plastic expansive agent. 2023 Vol. 60 (1): 270-280 [Abstract] ( 198 ) [HTML 1KB] [ PDF 4575KB] ( 513 )

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