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Quick Search     Advanced Search MODERN TUNNELLING TECHNOLOGY   2022 Vol.59 Issue.5 Published 2022-10-25 1 Elastoplastic Anisotropic Damage Model of Carbonaceous Shale in Thermodynamic Framework ZHANG Qiang1 ZHENG Lifeng1 SONG Meng2 LI Mei2 JIA Chaojun3 Carbonaceous shale is a kind of brittle rock encountered in the construction of tunnel engineering, which has typical nonlinear anisotropy characteristics. It is significantly important to established suitable constitutive model to approach the complicated mechanical behavior of this kind of rock. In this paper, an elastoplastic anisotropic damage constitutive model was proposed within the framework of thermodynamic. The plastic hardening/softening response is described by an improved Mohr-Coulomb yield criterion and the plastic flow is controlled by a non-associated flow rule. An exponential function form of damage criterion accounting for the anisotropic damage evolution was adopted to describe the degradation of stiffness. Plastic deformation and anisotropic damage evolution were coupled through combing“two surfaces”plastic yield criterion and damage criterion. Conventional triaxial compression tests were conducted on carbonaceous shale to exam the efficiency of the model. The comparison between the predictive result and experimental data suggests that the proposed model is capable to reproduce the damage evolution at different stress conditions and non-linearly mechanical behavior under compression of carbonaceous shale. In addition,the coupling between plastic deformation and anisotropic damage evolution was well produced. The proposed model can be implemented into FEM/FDM software to provide the theoretical support for stability and safety analysis of tunnel surrounding rock. 2022 Vol. 59 (5): 1-9 [Abstract] ( 302 ) [HTML 1KB] [ PDF 3491KB] ( 731 ) 10 The Cross-section Deformation Prediction Method for Shield Tunnel Using Bayesian Network HUANG Zhongkai1 ZHANG Dongmei1 ZHOU Wending1 CHENG Yixin1 TONG Yue2 The cross-section deformation is one of the major factors affecting the service safety of the shield tunnel. However, the cross-section deformation prediction method with reasonable consideration on multi-source uncertainty is still lacking, and the influence of reinforcement corrosion is neglected. In this paper, the segment bending degradation model is built considering the corrosion effect, and then a cross-section deformation model is built using uniform rigidity ring method based on a Bayesian network .The monitoring data and Markov Chain Monte Carlo simulation method are used to update the model. The study shows that the model prediction after Bayesian updating is closer to the monitoring data, the model prediction in 2013 after updating is nearly the same as the monitoring data,and there has only 1.6% error between the model prediction in 2015 after updating and the monitoring data. In contrast, the prediction errors for 2013 and 2015 are 21.1% and 21.9% respectively. It is obvious that the model prediction of Bayesian network is revised after fusing the monitoring data, making it closer to the monitoring data and the model prediction accuracy is improved greatly. 2022 Vol. 59 (5): 10-17 [Abstract] ( 328 ) [HTML 1KB] [ PDF 2548KB] ( 657 ) 18 Distribution Law of Longitudinal Stress of the Shallow-covered Receiving Shield Tunnel YANG Zhenhua The overburden thickness is an important factor influencing the longitudinal stresses between the rings. The overburden thickness of shallow-covered receiving shield tunnel is small near the receiving end, which would lead to small longitudinal stresses. And so the water tightness of shield tunnel will be influenced. By establishing and solving the mathematical model, the distribution law of the longitudinal stresses is proposed. The difference between the longitudinal stresses distribution law of shallow-covered receiving tunnel and that of conventional receiving tunnel is discussed. Based on the longitudinal stresses distribution law of shallow-covered receiving tunnel, the structural measures and relevant design method which increase the longitudinal stresses are proposed. Taking a river-crossing tunnel under construction in Shanghai as the background, the practical application of the structural measures is discussed. The result shows that the longitudinal stress increases with the increase of the distance from the receiving end. At the shallow-covered receiving end the longitudinal stress is the smallest. The longitudinal pressure at the dividing point of variable overburden thickness area and constant overburden thickness area reaches about 70% of the limit value of longitudinal pressure. In the background project, the longitudinal pressure of the conventional receiving tunnel is about 1.21 times that of the shallow-covered receiving tunnel. Pre-tight? ened bolts can be set in the segments near the receiving end to increase the longitudinal stress. For the background project, pre-tightened bolts shall be set in about 24 ring segments near the receiving end. 2022 Vol. 59 (5): 18-26 [Abstract] ( 322 ) [HTML 1KB] [ PDF 2025KB] ( 557 ) 27 Research on Airport Tubing Settlement Caused by Shield Tunnelling in Curved Section PEI Luguang1 FU Helin2 YU Nenggen1 YU Gui2 HOU Weizhi1 The excavation process of the airport maglev shield tunnel will cause disturbance to the airport runway and underground tubeing, and in severe cases, it will affect the safe operation of the airport and cause significant economic losses. In order to reveal the deformation disturbance effect of the underground tubeing caused by the shield tunnel in the airport maglev curved section, the settlement deformation caused by the shield tunnel in the curved section passing through the underground tubing was studied based on theoretical calculation, numerical simulation and on-site monitoring. The results show that during the tunnel excavation process of the curved section, the lateral settlement trough of the underground tubing will deviate from the central axis of the tunnel. On the inner side of the curved tunnel where the curvature is small, the settlement of the underground tubing is significantly larger than that on the outside of the curved tunnel; the additional thrust t on the shield excavation surface, the shield friction f and the additional grouting pressure g cause the lateral distribution on the subsidence of the underground tubing to be in the shape of "U", and the significant influencing factors are the shield friction and the ground loss; the deformation results of the underground tubing under the three methods are similar, which verifies the theoretical calculation method. 2022 Vol. 59 (5): 27-33 [Abstract] ( 274 ) [HTML 1KB] [ PDF 2379KB] ( 564 ) 34 Numerical Reconstruction of TBM Muck with Real Shape and Numerical Simulation of Muck Transfer Process DU Hongjin1 XIONG Hao2,3 ZHOU Hao1 ZENG Deqi4 The numbers of mucking chute, revolutions per minute (RPM) and muck shapes are important factors that affect the muck transfer ability and stability of TBM. In the research of TBM muck transportation, the muck is usually simplified as rigid spherical particles, thus ignoring the influence of the real shape of the particles on the transportation process. In order to simulate the real shapes of TBM muck in the numerical simulation, this paper used close-range photogrammetry, quantitative analysis of particle shapes to extract the particle shape characteristics of real muck. According to the characteristics of particle shape, the muck with real particle shape was reconstructed in three dimensions using particle reconstruction technology. Then, the reconstructed mucks were imported into the discrete element software program to generate a collection of real muck with irregular shapes. A TBM muck transfer model was constructed, and a three-dimensional simulation of TBM muck transfer process was conducted. Otherwise，the influence of RPM and the numbers of mucking chute on the muck transfer capacity of TBM was quantitatively analyzed through the proposed numerical simulation method. The research results have certain guiding significance for the design of the numbers of mucking chute of TBM in the actual project and the TBM operation of the muck transfer. 2022 Vol. 59 (5): 34-40 [Abstract] ( 274 ) [HTML 1KB] [ PDF 3389KB] ( 497 ) 41 Numerical Simulation Study on Loosened Zone of Surrounding Rock of Large-span Flat Caverns LEI Zhongdai1,2 KONG Xinli3 WANG Wenye3 YAN Zhiguo1,2 From the perspective of the expansion law of cavern loosen zone, FLAC 2D software was adopted to carry out the numerical simulation of four different flat caverns with different spans and buried depths. The full-face excavation method was selected to simulate the construction. And the loosened zone of surrounding rock was estimated by the ultimate tensile strain criterion. After that the corresponding expansion pattern of loosened zone was analyzed.The research result shows that: (1) The loosened zone of the four caverns are mainly distributed at the arch part of surrounding rock, and the sidewall is not loose. When the span increases to 68 m, the scale of loosen zone increases significantly. (2) With the increase of buried depth of caverns, the range of loosened zone firstly increases, then decreases and increases again. (3) The increase of span and degree of flattening leads to higher requirement of buried depth for the decreasing stage of loosened zone. Four different caverns have different optimum buried depths, which can provide reference for the design and construction of practical projects. 2022 Vol. 59 (5): 41-46 [Abstract] ( 280 ) [HTML 1KB] [ PDF 2675KB] ( 453 ) 47 Research on Mechanical and Deformation Characteristics of Large Diameter Shield Tunnels under Cyclic Loadings LI Chunlin1 ZHANG Xiwen2,3 LIU Guangsen2,3 LIU Junyan2,3 LIU Yan2,3 SUN Wenhao4 ZHANG Liangliang4 The cyclic vehicle loads on the shield tunnel during operation period always induce stress concentration and plastic strain accumulation, which lead to fatigue damage and cracking deformation of tunnel structures. Based on ABAQUS software and concrete plastic damage constitutive model (CDP), a numerical calculation model of double-deck shield tunnel was established, the internal force and deformation characteristics of tunnel structure and connecting bolts under different cyclic times were analyzed. The results show that (1) the internal force of tunnel segment and internal structure present periodic variation according to the cyclic vehicle loads. With the increase of loading frequency, the plastic strain zone of tunnel segment and internal structure increases, and the vertical displacement of internal structure increases. (2) The axial stress of connecting bolts also shows periodic variation, and the maximum axial stress appears in the middle of the connecting bolt. Under the cyclic load, the axial stress of the connecting bolt near the loading position is larger than that of the surrounding bolts. (3) Under the action of soil pressure and cyclic vehicle loads, stress concentration occurs at the bottom and waist of tunnel segments, where the plastic deformation accumulation is easy to occur at the stress concentration area. 2022 Vol. 59 (5): 47-53 [Abstract] ( 281 ) [HTML 1KB] [ PDF 4779KB] ( 504 ) 54 Mechanical Characteristics of Distributed Mortise-and-Tenon of Largediameter Shield Tunnels ZHAO Sensen ZHANG Dongmei HUANG Zhongkai To explore the shear resistance effect and failure mechanism of distributed mortise-and-tenon in the pro? cess of dislocation of large-diameter shield tunnel segments, a numerical model was established based on the Jihualu tunnel in Foshan. The laws of shear force-dislocation of circumferential joints under radial and tangential dislocation conditions were revealed. Furthermore, the mechanical characteristics, failure modes and shear bearing capacity of mortise-and-tenon with different sizes in different shear directions were analyzed. And a mechanical model calculating the radial shear bearing capacity of tenon was established. The distributed mortise-and-tenons can restrict lining dislocation, improve the shear resistance of circumferential joints, and inhibit further yielding of oblique bolt and further damage to the concrete. Compression damage of the root of the tenon is severe under radial dislocation condition, which causes the reduction of the shear bearing capacity. And the tenon tends to be sheared off when the height-thickness ratio k is less than 6. While tenon is damaged by local compression due to stress concentration under tangential condition. The calculation results of the mechanical model are consistent with the numerical simulation results, which can provide a reference for the design of the size of the distributed mortise-and-tenon. 2022 Vol. 59 (5): 54-62 [Abstract] ( 299 ) [HTML 1KB] [ PDF 4061KB] ( 578 ) 63 Mechanical Properties of Three-inclined Bolts in Longitudinal Joint of Large-diameter Shield Tunnel Segment CUI Qinglong1 LI Jin1 GAO Binyong2 XIONG Xinyue2 A three-dimensional refined finite element model was established, which was used to investigate the me? chanical properties of three-inclined bolts in longitudinal joint of large diameter shield tunnel segment under the effect of different axial pressures. The changes of the distribution of cracks, vertical displacement, joint opening, joint ′s rotation angle, and bending stiffness were revealed. The results show that the cracks including the compressive cracks, through tensile cracks at the inner edge of the hand hole and the bolt hole on the joint surface, and oblique cracks at the side appeared in the segment under the action of positive bending moment. Whereas the cracks including compressive micro cracks and tensile cracks appeared at the bolt hole of the joint surface under the action of negative bending moment. The appearance of two cracks running through the width direction corresponds to the inflection point of the three mechanical characteristics curves, which includes the vertical displacement of joint, the compressive strain of concrete, joint opening, and rotation angle. The curve changed from approximately linear to nonlinear with the increase of bending moment. The joint′ s rotation angle changed to a nonlinear change when the concrete was crushed. The increase of axial force could delay the occurrence of crack penetration. The change of bolt stress could be divided into three stages under the action of the bending moment of joint, i. e., linear growth stage, nonlinear growth stage, and yield stage. The rapid growth rate of bolt stress was affected by the bending moment and axial force. The bending stiffness of joint had no obvious change at first, and then decreased. The increasing axial force made the bending stiffness of joint larger. 2022 Vol. 59 (5): 63-71 [Abstract] ( 283 ) [HTML 1KB] [ PDF 5392KB] ( 488 ) 72 Study on the Influence of Different Degrees of Leakage on Long-term Settlement of Shield Tunnels LI Xiangyu1,2 LI Xinyuan3 LI Mingyu4 YANG Xiao5 HUANG Pei6 To address the increasingly prominent long-term settlement problem of shield tunnels in soft soil areas, the Shanghai Metro Line 2 project is used as the study case. Considering the coupling of soil consolidation and seepage, the long-term settlement pattern of tunnels in viscoelastic soil under different seepage conditions after construction disturbance is studied by using FLAC 3D numerical simulation method. And the influence patterns of different degrees of water seepage on the dissipation of excess pore pressure in the soil around the tunnel, pore pressure distribution,and long-term settlement of the tunnel and ground were comprehensively analyzed. It was found that when tunnel lining leakage occurs, the excess pore water pressure dissipates continuously with the growth of time, and the dissipation rate becomes gradually smaller with the distance to the tunnel from near to far. The larger the relative permeability coefficient, the stronger the permeability of the tunnel lining, and the more obvious the reduction of its pore pressure after the same time; tunnel settlement continues to increase with time, the larger the relative permeability coefficient, the greater the tunnel settlement at the same moment, and the greater the curvature of the ground settlement trough formed. 2022 Vol. 59 (5): 72-79 [Abstract] ( 276 ) [HTML 1KB] [ PDF 5634KB] ( 457 ) 80 Analysis of Construction Mechanical Behavior and Parameter Optimization for Subsequent Tunnel Tube of Double-arch Tunnel without Middle Drift LU Xiaogang1 GENG Jianyu1 PANG Lei1 FAN Jinhai1 LI Liangyong1 FANG Yabiao2,3 WANG Feng2,3 In order to study the construction mechanical behavior of the subsequent tunnel tube and the influence of the supporting time and spatial effect of double-arch tunnel without middle drift, based on the Huangjiaoping doublearch tunnel project of Yi-Jin Expressway, numerical simulation method is adopted, and the construction parameters such as excavation advance, bench length and different staggered distance of left and right faces of the subsequent tunnel are studied. The influence of these parameters on the displacement of surrounding rock, the mechanical characteristics of the initial support of the subsequent tunnel and the secondary lining of the advanced tunnel is further analyzed. The results show that with the increase of the excavation advance, the bench length and the staggered distance of left and right faces of the subsequent tunnel, the surrounding rock displacement, the principal stress of the initial support of the subsequent tunnel and the principal stress of the secondary lining of the advanced tunnel increase dramatically. Among them, the bench length and the staggered distance of left and right faces of the subsequent tunnel have significant effect on the principal stress of the initial support of the subsequent tunnel and the secondary lining of the advanced tunnel, and both shall be strictly controlled in actual construction. 2022 Vol. 59 (5): 80-90 [Abstract] ( 275 ) [HTML 1KB] [ PDF 7509KB] ( 476 ) 91 Influence of Catchment Caused by Local Overbreak on the Mechanical Characteristics of Tunnel Support Structure AN Yonglin1 GUO Jindong1 ZHOU Jin1 HU Wei1 DONG Chenyang2 XIANG Hui2 DAI Ling2 The catchment caused by local overbreak of the tunnel increases the bearing burden of the supporting structure, and it is easy to cause groundwater leakage and cracking of support structure, thus influencing the construction safety. Based on it, in order to study the influence of catchment pressure on the deformation characteristics, stress characteristics, internal force changes and safety of tunnel support, the numerical model is established based on the tunnel excavation in the water-bearing section. The initial support of the tunnel is subjected to circumferential pressure to simulate the external water pressure. Five external water pressure conditions are set for comparative study, and the stress and displacement results of tunnel support at different positions in the same section are analyzed respectively. The results show that after the catchement of overbreak area occurs, the tunnel support structure will be displaced in the direction of the external water pressure due to the external water pressure distributed along the tunnel contour, and the main influence range is in the catchment area of the tunnel. Stress concentration occurs in the catchment area when catchment caused by overbreak occurs on the crown and shoulder of the tunnel.When the side wall is overbreakd, the maximum principal stress decreases and the minimum principal stress increases gradually. The external water pressure only affects the internal force of the catchment area. The increase of the external water pressure will increase the axial force and decrease the bending moment. In addition, when the catchment occurs at the crown, the crown bending moment gradually changes from negative bending moment to positive bending moment. The research results can provide technical reference for the deformation control of tunnel surrounding rock in water-bearing region and the reinforcement measures of supporting structure. 2022 Vol. 59 (5): 91-98 [Abstract] ( 234 ) [HTML 1KB] [ PDF 5508KB] ( 494 ) 99 Numerical Simulation Study on the Supporting Effect of Bolts in Interbedded Soft Rock Tunnel WANG Wei1，2 LI Xianmin1 SUN Xinhai1，2 Based on a tunnel project of Chongqing Expressway, the numerical calculation model of stratum structure method is established, and the effect of system bolts in deep buried grade Ⅳ interbedded soft rock tunnel is simulated and analyzed. Considering the influence factors of system anchor distribution range and bolt length, the bolts setting types of tunnel initial support structure are divided into six simulated calculation conditions. The characteristics of surrounding rock deformation and plastic zone, bolt axial force and initial support axial force of tunnel in different simulated calculation conditions were compared and analyzed, and the following conclusions were obtained: (1) The axial force of the system bolt is small, which has certain control effect on surrounding rock deformation, supporting structure stress and surrounding rock plastic zone development, but the support effect is not obvious; (2) The feetlock bolts set on the side wall of the tunnel has a large effect and the effect of controlling the horizontal convergence deformation of surrounding rock is obvious. Therefore, the quality of the feet-lock bolts must be guaranteed before canceling the system bolt; (3) For the tunnel project of grade Ⅳ soft rock with deep buried mudstone and sandstone interbedding, the system bolts in the tunnel of soft rock can be cancelled through the demonstration of scientific research test sections and engineering analogy checking to meet the technical safety conditions required by the codes;(4) The effect of system bolt in deep buried grade Ⅳ interbedded soft rock tunnel is not obvious, and canceling the application of system bolts can reduce the construction process, close the initial support in time, and facilitate the deformation control of tunnel structure. 2022 Vol. 59 (5): 99-107 [Abstract] ( 237 ) [HTML 1KB] [ PDF 6825KB] ( 517 ) 108 Optimization of Insulation Layer Thickness and Analysis of Lining Response under Thermal-mechanical Coupling in High Temperature Tunnels LIU Xingchen1, 2 HUANG Feng1, 2 ZHOU Yang1, 2 YANG Dong1, 2 HU Zheng3 As the main bearing structure, the thermal-mechanical coupling response law of tunnel lining is very im? portant in the study of thermal insulation lining of high temperature tunnels. Focused on the high temperature tunnel and based on the field temperature monitoring and material thermal parameter test data, the ANSYS thermalmechanical coupling analysis model is established around the characteristics of high temperature tunnel thermal insulation lining and the requirements of ventilation and cooling. The characteristics of ventilation and heat transfer in high temperature tunnel construction are revealed, the spray thickness of polyurethane insulation layer is optimized,and the thermal-mechanical coupling response law of secondary lining structure is discussed. It is concluded that the mechanical and thermophysical parameters of thermal conductive media in each layer of thermal insulation lining structure have significant temperature effect. The thermal conductivity of foamed polyurethane material increases nonlinearly with the increase of temperature, while the temperature effect of thermal conductivity of limestone and concrete is opposite. The uniaxial compressive strength and deformation modulus of the three media decreased with the increase of temperature, while the peak strain increased with the increase of temperature. The temperature effect of thermal conductivity, strain hardening characteristics and post-peak load retention of foamed polyurethane were related to the porous structure. In the construction ventilation environment, the temperature of tunnel surrounding rock and the radius of heat regulating ring decrease with time and gradually become stable. Under the action of thermal-mechanical coupling, the sensitive temperature point of the principal stress extreme value of the secondary lining structure and the critical temperature of the deviation of the principal stress extreme position are consistent with the safety threshold (50°C) of the secondary lining structure temperature. 2022 Vol. 59 (5): 108-117 [Abstract] ( 243 ) [HTML 1KB] [ PDF 6338KB] ( 418 ) 118 Research on Ventilation Flow Field in Multi-working Face Construction of Super-long Gas Tunnels LI Bing1 YE Aijun1 CUI Pengjie1 ZHAO Shulei2 GUO Chun2 Aiming at the problem of the ventilation flow field in multi-working face construction of the super long gas tunnel, taking Yangzong tunnel as the supporting project, the numerical simulation software FLUENT is used to analyze the ventilation flow field and gas migration law at the left and right tunnels, cross passages and parallel adit and verify it with the field measured data. The research results show that the ventilation flow field is in a stable state after 10 minutes of ventilation. The ventilation flow field of the right tunnel under the stable flow field is divided into the impingement jet zone, the vortex zone and the reflux zone. Since the air duct of the left tunnel is relatively far from the tunnel wall, the vortex zone will also be formed on the side near the wall of the air duct. During the construction, the air duct should be close to the tunnel wall; After stabilization, the wind speed of the left and right tunnels, cross passages and parallel adit is greater than 0.5 m/s, which meets the requirements of the tunnel site con? struction; At the initial stage of ventilation, the gas is mainly concentrated in the face area, and the gas concentration in the vault on the opposite side of the air duct at the face is significantly higher than that in other areas; The changing trend of gas concentration at the left and right tunnel face is first slowly rising and then suddenly falling. The change of gas concentration in the face area mainly depends on the gas concentration and emission intensity of the face. 2022 Vol. 59 (5): 118-124 [Abstract] ( 283 ) [HTML 1KB] [ PDF 3552KB] ( 464 ) 125 Study on Mechanical Characteristics of Super Large Section Riser Pipe by Vertical Jacking Method HAN Chao1 GAO Yimin2 ZHOU Guangjie1 ZHANG Lei1 LIU Xian2 In the construction process of the vertical jacking method, an important control factor for the structural safety is the opening size of the vertical method. The larger the ratio of the radius on the open riser compared to the original tunnel, the greater impact on the safety of the structure would happen after the opening. According to the background of the construction process of the super large section jacking riser opening in a water intake and drainage project, the dynamic construction process is transformed into a simulated working condition, and the structural stress characteristics of the super large section jacking riser are summarized by numerical simulation method. The research results show that: (1) There are two possible deformation trends of the structure during the construction process, one is the overall sinking trend of the structure under the jacking condition, and the other is the vertical duck egg deformation trend of the opening ring under the opening condition; (2) The axial force at the bottom of the opening ring is greatly reduced under the jacking condition. The maximum tensile force is 400 kN and the change trend of the open ring is greater than that of the closed ring. The internal force conditions of the unfilled and full water conditions are similar to the initial conditions; (3) The shear of the joint is mainly between the open ring and the closed ring. The maximum radial shear force reaches 30 kN/m under the jacking condition, and the inter-ring radial shear force reaches 60 kN/m under the opening condition; (4) The opening condition during the construction is the control condition; (5) Under the jacking condition and the opening condition, the checking design of the annular joint shall be carried out. Guide:  2022 Vol. 59 (5): 125-135 [Abstract] ( 279 ) [HTML 1KB] [ PDF 9168KB] ( 416 ) 136 Inverse Analysis and Optimization of SMW Pile Parameters Based on Orthogonal Numerical Test JU Haiyan1 LIU Xingxing1 ZHOU Yang2 WAN Ling3，4 LIU Yan1 The finite element analysis is used to establish a model to study the influence of foundation pit excava? tion on the horizontal deformation of adjacent tunnels. The influence of five factors on the deformation of adjacent tunnels is analyzed, including the insertion ratio of the SMW pile, the spacing of inserted steel, the type of inserted steel, the diameter of the cement-soil pile, and the pre-axial force of steel support. The orthogonal test visualizes the influence degree, and the design parameters of the SMW pile are optimized by the regression method. The results show that the change in the type of SMW retaining structure has little effect on the deformation of the adjacent tunnel. When the pile insertion ratio exceeds 2.0, the increase of the insertion depth of the retaining pile has little effect on the horizontal displacement of the tunnel. The diameter of the cement-soil pile has the most significant influence on the horizontal deformation of the adjacent tunnel, followed by the pre-axial force of the steel support. The influence of the spacing of the inserted steel in a pile should also be paid attention to. When the pile insertion ratio is between 1.0 and 2.5, it can be regarded as a non-major factor affecting the horizontal deformation of the adjacent tunnel;based on the orthogonal test, it is feasible to use the regression method to fit the regression equation to calculate the optimal parameter combination, and the obtained parameter combination is superior to the orthogonal test 2022 Vol. 59 (5): 136-143 [Abstract] ( 268 ) [HTML 1KB] [ PDF 2814KB] ( 412 ) 144 Study on the Structural Response of the Main Tunnel with Deep Cross Passages Built by the Mechanical Method ZHU Yaohong1 GAO Yimin2 LIU Xian2 The mechanical method for cross passages provides a new idea for the rapid connection of various under? ground structures. It is a construction method with strong feasibility and application prospect. In order to study the applicability of this construction method under deep buried conditions, a full-scale test on the segmental tunnel rings with opening using mechanical method under deep buried conditions has been carried out. The response characteristics of segments and joints are obtained, and the force transmission characteristics and failure process of tunnel structure under deep buried conditions are clarified. The following main conclusions are as followed: (1) Under the condition of deep burial, the change of the structural response in the tunnel opening ring is mainly concentrated in the dismantling condition, and the main structural response is concentrated on the cantilever end of the opening ring and top of the tunnel; (2) The changes of the inter-ring structural response of tunnel openings under buried conditions are mainly concentrated in the cutting and bracing conditions. Under the cutting condition, the inter-ring structural response is a local structural response; in the load-holding stage of the dismantling condition, the interring structural response extends to the entire ring; (3) The failure process of the main tunnel structure under deep burial conditions can be divided into two stages. Before the brace is removed and after the steel sleeve is cut off, the cantilever effect occurs, and the bearing capacity between the fully-opened ring and the half-opened ring reaches the limit. In the load-holding stage of the dismantling condition, the fully-opened ring is damaged, and the load is transferred to the adjacent rings in turn through the transmission between rings; (4) In the final state, the fullyopened ring reaches the bearing capacity limit while the remaining rings are still in the elastic stage. The structure in the actual project is safer than that in the test, but special design and construction should be carried out on the opening ring and the ring joints near the opening position. 2022 Vol. 59 (5): 144-154 [Abstract] ( 251 ) [HTML 1KB] [ PDF 7182KB] ( 511 ) 154 Experimental Research on Mechanical Performance of Longitudinal Joint of Shield Tunnels with Quick Connectors XIAO Mingqing1, 2 XUE Guangqiao1, 2 ZHAO Mingying1, 2 The shield tunnel is composed of fabricated lining segments and connectors. Segment joint is the weak part of the mechanical performance of shield tunnel, and the form of joint has a great impact on the mechanical performance of the shield tunnel. At present, bolts are commonly used as connectors of shield tunnel in China, such as straight bolts and inclined bolts. There are few cases of fast connector research and application. This paper takes the longitudinal joint of shield tunnel with quick connector as the research object. Through the full-scale joint bending experiment, the bending stiffness and ultimate bearing capacity of the quick joint are studied, and the failure mode of the quick joint is found. The experimental results show that the quick joint has high bending stiffness and good mechanical performance. 2022 Vol. 59 (5): 154-162 [Abstract] ( 252 ) [HTML 1KB] [ PDF 6189KB] ( 419 ) 163 Full-scale Experimental Study on Mechanical Behavior of the Bundled Integrate Structure under the Unloading Condition of the Side BI Xiangli1 WANG Xiuzhi1 ZHANG Zhongjie2 PAN Weiqiang3 JIAO Bochang4 LIU Xian4 In order to study the structural mechanical properties and weak points of the bundled integrate structure, a full-scale test on the quarter structure had been conducted. The unloading condition of the side was studied by keeping the top load corresponding to 4 times of the design buried depth. The results showed that: (1)With the increase of the load difference between the upper and the side, the joint at the side was detached, the overall stiffness of the structure decreased by 87%, and the joint opening, structural deformation and prestressed tendon strain increased significantly. (2) After the side part was completely unloaded, the structure had obvious deformation, but it still had a certain bearing capacity. (3) In the whole process of the experiment, the structural stiffness first decreased, then increased and finally decreased substantially. The final stiffness was only 36% of the initial stiffness. 2022 Vol. 59 (5): 163-169 [Abstract] ( 272 ) [HTML 1KB] [ PDF 2887KB] ( 422 ) 170 Closed-loop Control Technology of Shield Thrust Hydro-cylinder Pressure Based on Target Total Thrust Vector ZHU Yeting1,2 GONG Wei1,2 QIN Yuan1,2 YUAN Xianghua1,2 WU Wenfei1,2 ZHANG Boya1,2 ZHU Yanfei1 To solve the problems of shield machine instability and excessive shield posture deviations caused by the lack of thrust force, a closed-loop control technology of the thrust cylinder pressures based on the target total thrust vector was proposed. Two thrust force vector calculation methods regarding to the shield driving with free partition technology of full-cylinders and the shield driving with self-compensation of missing thrust force were established,and the feasibility of both two methods were verified by constructing a large-scale model test platform, the testing results show that although affected by the performance of the proportional reducing valves during the two driving tests,oil pressure delays were found at the moment when the target pressures of the thrust cylinders changed, the measured pressures were controlled within ± 4% of the target values generally, and the total thrust force vector was maintained stable; the driving speed and shield postures were well controlled in the driving test with free partition of fullcylinders, while the acceleration phenomenon of the shield machine was discovered induced by the fixed flow output of the propulsion pump once part of hydro-cylinders were retracted, and sudden changes of the shield postures were caused at the same time by the response delay of the oil pressures and the uneven flow supply from the propulsion pump, both the driving speed and shield postures returned to the initial values after entering the full-cylinder thrust state; in the whole process of the driving test with self-compensation of missing thrust force, the shield driving speed and the shield posture deviations were controlled within ± 3 mm/min and -6 ~ +4 mm related to their respective ini? tial values 2022 Vol. 59 (5): 170-178 [Abstract] ( 275 ) [HTML 1KB] [ PDF 5538KB] ( 397 ) 179 Measurement and Calculation Method for Shield Tunnel Segment Dislocation Deformation Based on OFDR Technology MO Weiliang1 YANG Yubing1 LIN Yuexiang2,3 LU Mingjian1 A new type of optical frequency domain distributed optical fiber sensing technology (OFDR) was used to conduct laboratory model tests on the dislocation deformation of the tunnel segment under loading conditions, laying optical fibers at fixed points along the longitudinal direction, improving the existing quantitative calculation method of dislocation deformation, and the calculated value of the optical fiber strain was compared with the actual measurement of the percentile monitoring. At the same time, the influence of the fixed-point distance on the monitoring results was explored. The results of laboratory tests show that OFDR can accurately reflect the strain of the monitoring point and reveal the law of segment dislocation deformation. The improved calculation method can more accurately calculate the dislocation deformation of the tunnel segment, which is comparable to the monitoring value in actual projects. With the increase of the fixed-point distance, the dislocation deformation calculated by the optical fiber strain also increases. 2022 Vol. 59 (5): 179-187 [Abstract] ( 270 ) [HTML 1KB] [ PDF 6215KB] ( 566 ) 188 Study on Dynamic Lighting Effect of Vehicle Lights in Road Tunnels DAI Kailai1,2 WANG Feng1,2 ZHU Lei1,2 ZENG Yanhua1,2 Vehicle lighting test was carried out and three-dimensional simulation was used to study and analyze the lighting effect in the tunnel under the three different conditions of vehicle lights, tunnel luminaries, as well as the combination of vehicle lights and luminaries. The results show that the luminance decreases significantly in the distance from vehicle lights, the longitudinal effective illumination range of vehicle lights is 20 m and the transverse effective illumination range is 3.75 m. When the vehicle is located in the right lane, the maximum luminance at centerline of right lane under luminaries used in this paper is 1.6 cd·m-2,while the maximum luminance under vehicle lights is 5.6 cd·m-2. The luminance at centerline of right lane under the combined effect of vehicle lights and luminaries reaches to the maximum value of 7.1 cd·m-2. The maximum luminance at centerline of right lane under the combined effect of vehicle lights and luminaries increase by more than 300% compared to luminaries lighting, and 27% compared to vehicle lighting. 2022 Vol. 59 (5): 188-194 [Abstract] ( 235 ) [HTML 1KB] [ PDF 3083KB] ( 424 ) 195 Research on the Waterproof Performance of Segment Rubber Gasket Considering the Groove Boundary and Paste Quality HE Chuangbo1,2,3 XU Chao 1,2,3 YANG Zhao1,2,3 LIU Pengfei 1,2,3 ZHENG Jiajia4 GAO Ruchao1,2,3 Aiming at the structure of the bottom flat and comb-shaped rubber gaskets, finite element software was used to establish a three-dimensional calculation model, to carry out research on the impact of gasket grooves and paste quality on the waterproof performance of gaskets, to explore the weak points of gaskets in waterproofing, and to carry out physical modeling test for verification. The research results show that: (1) During the compression process of the rubber gasket, it is easy to deform into the gap between the segments on both sides, which reduces the actual area in the groove and reduces the waterproof ability of the gasket. (2) When the bottom comb-shaped gasket is pasted and fixed, the contact surface between the gaskets is the weak point of waterproofing of the joint; when it is not pasted, the contact stress between the gaskets is reduced by 25.8% compared with that of pasting and fixing, and the weakest waterproof point is the contact surface between the bottom of the gasket and the groove. (3) When the flat gasket is not pasted, the structure in the compression process is relatively stable, and the quality of the pasting has little effect on the waterproof of the gasket. 2022 Vol. 59 (5): 195-201 [Abstract] ( 322 ) [HTML 1KB] [ PDF 2870KB] ( 427 ) 202 Research on Thermal Properties and Mechanical Behaviors of Large Shield Tunnel in Fire ZHANG Tingrui Due to the closed space, tunnel fires have the characteristics of rapid temperature rise, long duration, uneven temperature distribution and so on. It is very easy to cause thermal damage to the tunnel lining, resulting in significant attenuation of structural mechanical properties, which seriously affects the safety and reliability of tunnel operation. In order to solve this problem, a three-dimensional finite element model is established based on a large diameter shield tunnel project, and the temperature field distribution, structural deformation and internal force under different fire scenarios are studied.The study concluded that: (1) Under the influence of thermal boundary conditions, the distribution of temperature field in tunnel appears obvious partition phenomenon in fire; (2) The deformation mode of the lining ring in fire is determined by load effect and thermal expansion effect, and the two factors are affected by fire scale and fire time; (3) In the area affected by the fire source, the stress on both sides of each seg? ment is large, and the inner rebar makes a great contribution to the mechanical performance of structure. However,with the development of fire, the stress distribution of segments and rebars changes significantly. 2022 Vol. 59 (5): 202-211 [Abstract] ( 271 ) [HTML 1KB] [ PDF 7075KB] ( 475 ) 212 Stability Evaluation for the Lining Structures of Tunnels with Large Corrosion Areas in Sulfate Environment DUAN Lian1 LI Yongheng2 WU Jianghang1 The stability evaluation for tunnel lining structure in service is the key basis for maintenance and rein? forcement. As for the HTG tunnel project, this paper established a load-structure method based calculation model of tunnel lining with large areas of corrosion, and in terms of corrosion depth and scope, the stress conditions and safety coefficient distribution characteristics of tunnel lining structure were calculated and analyzed under different working conditions. The results show that after occurring large areas of corrosion in the tunnel lining, the change of axial force of lining structure is small, the change of internal force of structure is mainly reflected in the change of bending moment of lining, which leads to the increase of eccentricity of lining element. The tunnel side wall and arch foot belong to the dangerous area of corrosion. When the tunnel lining at those parts has a large area of corrosion, the number of dangerous sections of the tunnel lining is larger, and the overall stability of the tunnel lining structure is in danger. On this basis, the tunnel lining is divided into a series structure system composed of five subsystems, and a calculation method is proposed for evaluating the safety level of the corroded tunnel lining structure based on cross section safety probability. It was applied to the HTG tunnel project, the safety probability and safe level were obtained with respect to the sulfate corrosion conditions in different tunnel lining positions. It can provide a basis for the maintenance and reinforcement of tunnel lining. 2022 Vol. 59 (5): 212-220 [Abstract] ( 290 ) [HTML 1KB] [ PDF 4315KB] ( 392 ) 221 Study on Water Inrush Mechanism and Control Measures for Water Bearing Carbonaceous Phyllite Tunnels ZHANG Jianfeng1 ZHENG Xiaoyue2 YU Guoliang1 SHI Chenghua2 Serious water inrush event occurred when the small mileage section of No. 4 inclined shaft of Ganzhuang tunnel on Yuxi-Mohan Railway passed through the water-rich carbonaceous phyllite layered stratum, and the surrounding rock was weak, water-rich, broken and changed frequently. Through the site investigation on water environment and ground conditions, combined with the features of water inrush disaster and evolutionary regularity of cavity,the catastrophic mechanism of water inrush in tunnels is illustrated from three stages: energy storage, energy release and triggering due to construction disturbance. It is pointed out that the failure mechanisms of water inrush include bending failure, shear failure and infiltration failure. The prevention and control process as well as the specific control measures against water inrush in water-rich carbonaceous phyllite tunnel are put forward, and the determination method of tunnel risk section and the control method of water inrush are clarified, including reinforcement measures such as the pre-grouting, the dense rows of pipe-roof and local advanced grouting. The field application shows that the water inrush disaster in the tunnel has been controlled, indicating that the water inrush prevention and control measures can effectively control the impact of water inrush in surrounding rock and ensure the safety and stability of the tunnel structure. 2022 Vol. 59 (5): 221-227 [Abstract] ( 257 ) [HTML 1KB] [ PDF 2437KB] ( 387 ) 228 Overall Design and Key Technologies of Nanjing Jianning West Road Rivercrossing Tunnel Project WEI Longhai1 WANG Miao2 WU Shuyuan1 Nanjing Jianning West Road is located in the city′s core area, and the cross-river section adopts a twinbore six-lane large-diameter shield tunnel.The paper expounds the control factors and construction conditions of the project, and introduces the overall design scheme of the tunnel from the aspects of plane, longitudinal section and cross section. By using theoretical analysis, numerical methods and engineering analogy,the key technologies of design and construction for shield tunnelling through the anti-slip group piles of the Changjiang dyke, the long distance crossing through the mixed stratum of soft and hard rock, the shallow covering of fine sand and the tunnelling close to the existing structures are systematically studied, and the optimized final design option is proposed so that the overall function and safety of construction and operation can be best achieved. 2022 Vol. 59 (5): 228-236 [Abstract] ( 295 ) [HTML 1KB] [ PDF 4211KB] ( 649 ) 237 Study on Deformation Control Technology for Unsymmetrically Loaded Tunnels in Bedding Strata under High Geo-stress YU Guoliang1 LOU Yili2,3 WU Guopeng1 SHI Chenghua2,3 ZHENG Keyue2,3 During the construction of Ganzhuang Tunnel on the China/Kunming-Laos/Vientiane Railway, large de? formation occurred due to high geo-stress and unsymmetrical load in bedding strata, which resulted in the cracking of tunnel primary support, block dropping and clearance invasion. Aiming at the large deformation of Ganzhuang tunnel, based on the three bench excavation method, a modified short bench construction control technology is proposed, and the block discrete element software 3DEC is used to carry out numerical simulation of tunnel excavation under different bench heights and lengths. The results show that the bench parameters have a significant effect on the deformation of the unsymmetrically loaded tunnel in bedding strata. When the height of the middle bench decreases from 4 m to 2 m, the tunnel deformation convergence decreases rapidly; When the length of the middle bench is less than 15 m, the deformation convergence of the tunnel decreases gradually with the increase of the length of the middle bench. When the middle bench length is greater than 15 m, the tunnel deformation convergence tends to be stable, and the tunnel deformation convergence is about 21 cm. The height of the middle bench in the bedding unsymmetrical loading section of Ganzhuang tunnel should be set at about 2 m, and the length of the middle bench should be controlled at more than 15 m. Field monitoring data show that this construction control technology has achieved good deformation control effect in Ganzhuang tunnel. 2022 Vol. 59 (5): 237-245 [Abstract] ( 268 ) [HTML 1KB] [ PDF 3841KB] ( 491 ) 246 Comparative Study on Reinforcement Schemes for Shield Tunnel Under-crossing Railway Bridge with Isolated Shallow Foundation in Water-rich Sand Stratum OUYANG Hongzhi1 ZHU Dinggui2 AN Bin3 SHI Chenghua2 In order to ensure the construction safety of shield tunnel undercrossing isolated shallow foundation rail? way bridge in water-rich sand stratum, taking Nanchang Metro Line 4 undercrossing Qingshan Road overpass of Bei?jing-Kowloon Railway as the engineering background, the reinforcement measures of stratum grouting and cast-inplace raft foundation frame culvert are put forward by means of construction method comparison, numerical analysis and field monitoring. The law of track settlement is analyzed, and the effectiveness of reinforcement measures is verified. The results show that it is reasonable and effective to use stratum grouting and cast-in-place raft foundation frame culvert to reinforce the railway bridge and realize the control of track settlement before shield tunnelling. Compared with the condition without any reinforcement measures, the maximum value of track settlement is reduced by 83.53%, which is 1.88 mm. The field monitoring results show that the maximum settlement of the track is 1.45 mm after stratum grouting and cast-in-place raft foundation frame culvert reinforcement, which verifies the correctness of the numerical analysis results and the effectiveness of the reinforcement measures, and ensures the normal operation of the Beijing-Kowloon Railway. 2022 Vol. 59 (5): 246- [Abstract] ( 257 ) [HTML 1KB] [ PDF 3392KB] ( 527 )

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