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Quick Search     Advanced Search MODERN TUNNELLING TECHNOLOGY   2016 Vol.53 Issue.6 Published 2016-12-25 Article 1 Studies and Prospects of Train Vibration and Vibration Isolation Based on 2.5D Finite-Element Method DING Zhi LI Danwei WEI Xinjiang With the development of rail transit construction in recent years, the study of train vibration and vibra? tion isolation has produced a general concern in engineering. As the 2.5D FEM is efficient at analyzing complex dynamic problems, this paper sums up thoughts about the 2.5D FEM analysis application and the research status of train vibrations and vibration-isolation issues from the two aspects of elastic subsoil and saturated subsoil based on domestic and overseas investigations. Previous research has mostly focused on the elastic subsoil and railway trains;a few studies have focused on the saturated subsoil, subway trains and calculation method optimization, but only considered the effect of a single train on surroundings and buildings instead of the vibration response between adjacent trains. In light of the characteristics of dynamic problems concerning train operation, this paper discusses potential directions for research of and prospects for train vibrations and vibration isolation analysis by 2.5D FEM. 2016 Vol. 53 (6): 1-11 [Abstract] ( 1193 ) [HTML 1KB] [ PDF 4389KB] ( 2011 ) 12 A Defect Classification and Evaluation System for Existing Railway Tunnels LUO Jian-Chun- 1 Gao-Ju-Ru- 2 Based on foreign and domestic research, a“power exponent”based classification and evaluation system for defects of existing railway tunnels is presented so as to analyze tunnel defects and evaluate the health of existing railway tunnels, as well as to provide reasonable and economical renovation plans. With different power exponents,the system gives the values of influence (values of damage) on the tunnel structure by a single defect under different development stages, and obtains a classification for the single defect. In addition, a comprehensive evaluation of multiple factors is available by means of a power exponent calculation, which provides a basis for the tunnel defect classification and health status evaluation. Finally, it is verified that this is a scientific method by practical cases. 2016 Vol. 53 (6): 12-17 [Abstract] ( 1245 ) [HTML 1KB] [ PDF 672KB] ( 1960 ) 18 Management of Geological Information at the Tunnel Face Based on the Internet of Things and Cloud Computing LI Tao- 1, 2 Chou-Wen-Ge- 1, 2 Li- Bin- 2 Liu- Yi- 2 Aimed at the problems that exist for geological information management of the tunnel face and based on the internet of things and cloud computing, a big data platform for geological information management of the tunnel face was established to realize geological information management of tunnel face and meet the demands of data sharing and data mining. Field practice shows that this big data platform allows for data collection and processing as well as for storing geological information at the tunnel face and rapid online program processing and automatic report generation, thereby providing a brand-new technology platform for tunnel information construction. 2016 Vol. 53 (6): 18-24 [Abstract] ( 1200 ) [HTML 1KB] [ PDF 4046KB] ( 1832 ) 25 Study on Risk Assessment of Highway Tunnel Operational Safety LUO Yong- 1 Li-Yu-Wen- 2 Yuan-Jia-Wei- 1 Liu-Da-Gang- 1 Wang-Ming-Nian According to the characteristics of highway tunnel accidents, the subject tunnel was divided into three research sections. A comprehensive analysis of the various factors affecting the operational safety of highway tunnels was carried out, a hierarchical structure model of the three sections was set up, and relative weights of the factors influencing the evaluated objects were obtained by an analytical model. Finally, a multi- hierarchy comprehensive evaluation on the three sections was carried out by the fuzzy logic comprehensive judgment method, and a scientific and reasonable method for highway tunnel operational security risk assessment was developed. 2016 Vol. 53 (6): 25-30 [Abstract] ( 1214 ) [HTML 1KB] [ PDF 2359KB] ( 1857 ) 31 Tunnel Fire Dynamic Early-Warning, Evacuation and Rescue System and Its Application YAN Zhi-Guo- 1, 2 Tian- Ye- 1, 2 Zhu-He-Hua- 1, 2 Shi-Yong-Quan- 3 Yu-Li-Yang- 4 In this paper, by means of temperature data information collected by the FBG system, we establish a re? construction method for the source position, length of the inverse smoke-flow layer and cross section temperature distribution of a tunnel fire, which allows the reconstruction and visualization of fire behaviour in case of a tunnel fire and provides help for evacuation and rescue efforts in tunnels. Based on the tunnel fire dynamic early-warning,evacuation and rescue technology, we develop a tunnel fire dynamic early-warning, evacuation and rescue system that has been applied to the Dalianlu Tunnel. A site fire test is conducted to calibrate the key operation parameters of the system and verify its availability. 2016 Vol. 53 (6): 31-35 [Abstract] ( 1235 ) [HTML 1KB] [ PDF 3092KB] ( 1952 ) 36 Analysis of Structural Disasters in Shield Tunnels and Measures and Suggestions for Waterproofing FENG Huan-Huan- 1, 2 Chang- Xiang- 2 The structural safety of shield tunnels is fundamental for urban rail transit. Therefore, tunnel disasters need to be controlled immediately whenever they occur, otherwise they will be a serious threat to the tunnel′s structure and operation. For this reason, prevention and control of structural disasters is the most important issue for a tunnel′s structural safety. Since there is an increasing number of tunnel defects occurring in the tunnels operated in Shanghai and Nanjing, this paper classifies the structural disasters into four categories based on a contrastive analysis of shield tunnel projects (i.e., longitudinal uneven settlement, convergence and deformation, water leakage and structure damage) and presents a detailed analysis and discussion of the occurrence mechanism of each disaster as well as treatment measures and suggestions. Additionally, it details the key technologies and processes commonly used in tunnel disaster prevention and control, such as steel fiber reinforced concrete and instant sealing with chemical grouts. Finally, it predicts the future development of shield tunnel structural disaster prevention and control in China in terms of concepts, systems, mechanism construction and technical breakthroughs. 2016 Vol. 53 (6): 36-43 [Abstract] ( 1060 ) [HTML 1KB] [ PDF 2575KB] ( 1858 ) 44 Study on the Labor Intensity Classification Standard for Critical Construction Procedures of High-Altitude Tunnels WU Qiu-Jun- 1, 2 Yu- Li- 1, 2 Xie-Wen-Qiang- 3 Li- Qi- 1, 2 Wang-Ming-Nian- 1, 2 During tunnel construction at high altitudes, construction crews often encounter an oxygen deficit and their labor intensity is different than when they are working in normal-altitude (plain area) tunnels. In this paper, using the Queershan tunnel as an engineering case, the labor intensity classification standard for tunnel construction procedures in a plain area is obtained according to the national physical labor intensity classification standards and actual research results. Based on the principle of alveolar ventilation, the correction coefficient of the average metabolic rate changing with altitude is obtained. Considering the correction coefficient of the average energy metabolic rate changing with altitude for physical labor, the labor intensity indexes and classifications of critical tunnel construction procedures under different altitudes and the labor intensity classification of critical construction procedures in the Queershan tunnel are calculated. By comparative analysis, it is found that the labor intensity classifica? tion of critical construction procedures in the Queershan tunnel is generally one level higher than the labor intensity of tunnel construction in plain areas (normal altitudes). 2016 Vol. 53 (6): 44-48 [Abstract] ( 1092 ) [HTML 1KB] [ PDF 782KB] ( 1922 ) 49 On the Constitutive Parameter Values of Collapsible Loess Based on the Duncan-Chang Model LIU Yin- Zhang-Zhi-Qiang- Zhao-Zi-Tong- Li- Xin Based on the Duncan-Chang Model, the stress-strain relation curves of collapsible loess with or without vertical joints were obtained through triaxial compression tests. The results show that under the same confining pressure, the stress-strain curves of collapsible loess with or without vertical joints are concentrated in a narrow range;the average value curve in the narrow band obtained by normalized processing can comprehensively reflect the loess physical and mechanical properties in practical engineering; and the stress-strain relation expression for loess with vertical joints and its relative parameters are given by an average value curve. A practical engineering model suitable for Q3 loess in the Panjianhe tunnel is established which lays a solid foundation for a follow-up study of collapsible loess. 2016 Vol. 53 (6): 49-54 [Abstract] ( 1074 ) [HTML 1KB] [ PDF 1494KB] ( 1992 ) 55 Simplified Solution for Tunnelling-Induced Pile Foundation Deformation Based on the Kerr Foundation Model ZHANG Zhi-Guo- 1, 2 , 3 , 4 Lu-Ming-Hao- 2 Xu- Chen- 2 Gong-Jian-Fei- 3 Zhao-Qi-Hua- 4 The elastic subgrade reaction method based on the Winkler foundation model is widely used in the anal? ysis of laterally loaded piles. However, the shearing action in the foundation soil mass is neglected in this model. For this reason, the free-field soil mass displacements induced by tunnelling were calculated using the cylinder cavity contraction theory, which is more accurate than the Loganathan & Poulos (1998) solution. Then, based on the Kerr foundation model, which fully considers the shearing behaviors of the soil mass, the free-field soil displacement was applied to the pile foundation and a simplified solution for pile foundation deformation under the disturbance of passive displacements was established. The calculated results of the soil mass free-field displacements and pile deformations were compared with existing calculated results, 3D FEM numerical simulation results and measured data,and consistency was achieved with the cylinder cavity contraction theory proven to be more accurate. Finally, relative parameters of the Kerr foundation model, pile diameters, ground loss ratio and spacing of the pile and tunnel were analyzed. The results show that the thickness of the shear layer and pile diameter are inversely proportion to the pile′s lateral displacement; the ground spring parameter, ground loss ratio and spacing between the pile and tun? nel are proportional to the lateral displacement of the pile foundation; and when the thickness of the shear layer is zero, the foundation model degenerates into a Winkler foundation model, while the foundation spring parameters set as infinity means the foundation model degenerates into a Pasternak foundation model 2016 Vol. 53 (6): 55-66 [Abstract] ( 1304 ) [HTML 1KB] [ PDF 5355KB] ( 2035 ) 67 On Temperature Field Distribution and the Effects of Surrounding Rock Properties on Tunnels in Cold Regions SUN Ke-Guo- Xu-Yu-Ping- Chou-Wen-Ge- Zheng- Qiang Since freezing damage occasionally occurs in cold region tunnels, it is very important to study the tem? perature field distribution and effects of surrounding rock properties. Based on a highway tunnel in Liaoning province, theoretical analysis and numerical simulation were used to study the temperature field of cold region tunnels under the effects of thermal-fluid-solid coupling, the temperature field distribution along the longitudinal profile and cross section of tunnels was obtained and the influence of the initial ground temperature and thermal conductivity coefficient of surrounding rock on the temperature field in cold region tunnels was studied. Findings indicate that the higher the initial ground temperature, the smaller the thermal conductivity coefficient, and that it is better to solve the freezing problems in cold region tunnels under the influence of a negative temperature airflow. This paper provides reference and guidance for anti-freezing design in similar tunnels. 2016 Vol. 53 (6): 67-72 [Abstract] ( 1178 ) [HTML 1KB] [ PDF 2011KB] ( 1957 ) 73 Longitudinal Aseismic Analysis of Shield Tunnels in Inhomogeneous Ground WANG Wei- He- Chuan- Geng- Ping- Zhang- Jing- He- Yue As the longitudinal stiffness of shield tunnels is less than that of transverse sections, it is likely to suffer from seismic damage caused by excessive deformation, especially at places where the ground or the structure changes suddenly, and so the longitudinal aseismic study is worthy of attention. Based on the ground-structure mode, this paper uses a longitudinal equivalent stiffness model to simulate the longitudinal dynamic response of shield tunnels under different seismic actions and to verify the aseismic indicators of the longitudinal rotation angle, segment and joint bolt stress. The results show that: the areas with abrupt changes between hard and soft ground are the weakest parts of shield tunnels regarding the longitudinal aseismic design, and the areas where the internal forces of the tunnel structure increase obviously at the soft ground side are four times the areas covered by the tunnel external diameter; when the seismic wave spreads in a lateral direction, the longitudinal moment plays a control role, and when the seismic wave is input vertically, the higher axial force plays the control role; and the tunnel structure is in a more unfavorable condition with longitudinal seismic excitation as compared to lateral excitation under the same level of seismic action. 2016 Vol. 53 (6): 73-79 [Abstract] ( 1084 ) [HTML 1KB] [ PDF 2416KB] ( 2433 ) 80 Analysis of the Temperature Characteristics and Mechanical Behaviors of Tunnel Structures in Fires SHEN Yi As one of the main disasters threatening the safe operation of tunnels, fire can seriously damage or de? stroy tunnel lining structures. Spalling of a shield tunnel lining may occur due to fire, and the lining is prone to abrupt failure at the joints between segments. Meanwhile, the risk of collapse of tunnel lining structures due to fire is extremely high, thanks to low restraint of the ground around the shield tunnel. Through numerical calculations, we study the temperature characteristics and mechanical behaviors of shield tunnel lining structures under different heating curves and ground elastic restraints—including the temperature field, deformation and internal force distribution of the lining structure system and explore the effects of key factors like buried depth, spalling, staggered erection and segment layout variation on the compound structural system. 2016 Vol. 53 (6): 80-88 [Abstract] ( 1236 ) [HTML 1KB] [ PDF 3273KB] ( 2035 ) 89 Analysis of the Deformation and Mechanical Characteristics of the Surrounding Rock-Lining Structure of the Muzhailing Tunnel HUANG Ming-Li- 1 Zhao-Jian-Ming- 1 Tan-Zhong-Sheng- 1 Li-Yan-Zong- 2 With a maximum horizontal geostress of 27.16 MPa and a rock strength-stress ratio of 0.49, the Muzhail? ing tunnel at the ridge section of the Lanzhou-Chongqing Railway is under extremely high geostress. Focused on the problems of initial support deformation and secondary lining cracking during the construction of the Muzhailing tunnel, this paper analyzes the deformation and mechanical characteristics of the surrounding rock-lining structure by actual measurements and numerical simulation. Specifically, it addresses the effects of a stress relaxation zone by comparing changes to the lining′s stress concentration factors regarding a surrounding rock-lining structure with or without stress relaxation zones; examines the effects of the elasticity modulus Er on the stress relaxation zone, thickness La of the stress relaxation zone, lateral pressure coefficient and tunnel sectional form on the stress distribution of the surrounding rock-lining structure; and analyzes the causes of lining cracking for the Muzhailing tunnel at the ridge section. 2016 Vol. 53 (6): 89-99 [Abstract] ( 1043 ) [HTML 1KB] [ PDF 7533KB] ( 1464 ) 100 Research on Chloride Ion Erosion and Migration in Segment Joints of Undersea Shield Tunnels LIU Si-Jin- Sun- Qi- Feng- Kun- He- Chuan Since lining structure damage caused by chloride ion erosion increases with time for in-service subsea tunnels, an in-depth study of this process is necessary. Based on the migration mechanism of corrosive ions in a porous medium, we have set up a numerical model of chloride ion erosion and migration for segment joints by analyzing the coupling seepage and ion migration, with a focus on the erosion and migration law of chloride ions at segment joints under the long-term chloride salt erosion environment of the sea bottom. We conclude that pore water is the carrier of erosion and migration of chloride ions in concrete segments, which includes convection, molecular diffusion and mechanical dispersion. With a long in-service time, the chloride penetration depth increases from the outside surface of the segment joint to the interior, and external water pressure has a significant effect on the penetration velocity and depth of the affected segment, which means the higher the external water pressure, the deeper the penetration depth. An uneven distribution of chloride ion erosion occurs in the local area of the joints, where there is a higher chloride ion concentration with a shorter time to reach a critical concentration (than in areas farther away from the joints). Finally, a specific chloride migration curve trajectory exists near the joint surface due to different boundary conditions and the influence of discontinuities. 2016 Vol. 53 (6): 100-107 [Abstract] ( 1036 ) [HTML 1KB] [ PDF 2729KB] ( 1540 ) 108 Optimization of the Force Applied to Cutters and the Spacing of TBM Cutters ZHANG Zhi-Qiang- Zhang- Yang- Zhang- Biao- Zeng-Bo-Wen The TBM method has become the standard of tunnel construction by virtue of its safety, economy and speed. Studies on the cutter head and cutters are central to the TBM method in terms of both construction process and economic cost. A mechanical and numerical model of a cutter breaking rock was established by the PFC method, which determines the rock-breaking effect of cutters of different sizes in terms of the number of cracks as well as their width, depth and extending lengths. Appropriate cutter penetration and the corresponding optimal cutter spacing for different rock lithologies were obtained based on the multiple leaping characteristics of peak values of the relationship curve of cutter force and penetration as well as the through cracks between two cutters. The results provide a reference for the optimization of driving parameters of TBM tunnels with different lithologies. 2016 Vol. 53 (6): 108-114 [Abstract] ( 1088 ) [HTML 1KB] [ PDF 3627KB] ( 1837 ) 115 Model Optimization and Computational Analysis of a Ventilation Network for Large Underground Petroleum Storage Caverns ZHANG Heng- Lin- Fang- Sun-Jian-Chun Usually it is necessary to use forced ventilation or a large number of ventilation shafts to solve construc? tion phase ventilation problems in large scale underground caverns. Since ventilation shafts are mostly set up in accordance with experience or site conditions, they are generally located at a relatively shallow depth in an oil storage cavern, resulting in a“disordered”ventilation network, leading to poor local ventilation. Shaft depth and the temperature difference between inside and outside have a great effect on the natural ventilation of the shaft. Taking the construction ventilation of the Jinzhou underground petroleum storage cavern as an example, this paper introduces a calculation method for gallery ventilation based on ventilation network theory in order to study the ventilation calculation and equipment configuration for three ventilation configurations in a cavern group. The results show that using the entrance of the construction adits (construction transport channels from the ground into the cavern) as a viable air outlet and forcing in fresh air with an axial flow fan at the shaft mouth results in an orderly circulation in the ventilation network. Using a shaft to exhaust air requires more than one fan operating at the same time, which means higher costs and, additionally, the natural ventilation effect of shafts is not sufficient in winter. When the shaft is connected to the cavern (i.e., the upper layer of the petroleum storage cavern is completed), it is possible to adopt forced ventilation supplemented by jet flow, or it may be necessary to use full jet flow if the ventilation distance is long. 2016 Vol. 53 (6): 115-122 [Abstract] ( 1112 ) [HTML 1KB] [ PDF 2248KB] ( 1941 ) 123 Analysis of the Optimal Anchoring Angle of Anchor Bolts (Cables) for Slope Reinforcement at Mountain Tunnel Portal Sections ZHOU Xiao-Jun- 1 Mao-Lu-Lu- 1 Jiang- Bo- 2 Zhou-Yue-Feng- 2 Zhu- Yong- 2 Yu- Yu- 2 The anchor bolt (cable) is commonly used in slope reinforcement, and the anchoring angle is a key pa? rameter of the design that affects both slope stability and engineering costs. In this paper, a calculation expression for the optimal angle of the anchor bolt (cable) used in a tunnel portal slope was proposed based on a comprehensive analysis of the effects of the anchoring angle on slope stability; the practicability of this calculation expression is verified by a project case. 2016 Vol. 53 (6): 123-128 [Abstract] ( 1249 ) [HTML 1KB] [ PDF 1974KB] ( 2045 ) 129 Design and Verification of a Model Test Box for Tunnel Seismic Response CHOU Wen-Ge- Duan-Dong-Ya- Li-Bing-Tian- Hu- Hui- Dai- Yong A structural dynamic test is an important research technique for evaluating structural seismic response mechanisms. The types of model boxes used to research the seismic response mechanisms of underground structures are mostly rigid, flexible and layered-shear, which have some defects and shortcomings. A new type of model box that is a coupling of static and dynamic modes and a new test method named the pseudo-static method are introduced in this paper and their effectiveness is validated by a dynamic test with a shaking table. A pseudo- static method is proposed to study the seismic response of tunnel structures. By comparing the results of the dynamic test and the pseudo-static test, it is determined that it is possible for the pseudo-static method to replace the dynamic test to some extent, which broadens both the testing method for this model box and the studying method for a model test of the seismic responses of tunnels. 2016 Vol. 53 (6): 129-136 [Abstract] ( 1186 ) [HTML 1KB] [ PDF 3045KB] ( 1945 ) 137 Study of the Dynamic Deformation Properties of Loess Under a Dynamic Load in the Lanzhou Metro WANG Qian- 1, 2, 3 Zhong-Xiu-Mei- 1, 3 Su-Yong-Qi- 3 Li- Na- 1, 3 Che-Gao-Feng- 1, 3 Wang-Li-Li- 1, 3 Dynamic triaxial tests of loess samples from the Lanzhou Subway Line 1 were performed under subwayincluded dynamic loadings with different dominant frequencies and a constant cyclic dynamic loading with the fre? quency of 1 Hz. With the comparison of test results, we analyze the dynamic stress-strain relation, dynamic shear modulus ratio and damping ratio characteristics of the loess under the effects of dynamic load and also study the accumulated deformation properties of loess under cyclic loading. The results show that vibration frequency has an obvious influence on the dynamic behaviors and cumulative plastic deformation of the loess—with an increasing vibration frequency, the dynamic stress required for achieving a certain stage of deformation increases significantly. With a smaller vibration frequency, the dynamic shear modulus ratio decreases more rapidly with an increase of the dynamic strain; with the same dynamic shear strain, the Gd/Gdmax is smallest while at a vibration frequency of 2.5 Hz,and it reaches maximum dynamic stress and Gd/Gdmax under the same dynamic strains. Moreover, the cumulative plastic deformation of the loess under dynamic loadings with different vibration frequencies could be split into three stages, which are: the rapidly-deforming stage, the slowly-deforming stage, and the fundamentally-stable stage. However, in the slowly-deforming stage and the fundamentally-stable stage, vibration times required to achieve a certain deformation will increase with the increase of the vibration frequency. Dynamic loadings from a subway with a vibration frequency between 0.4 Hz and 0.6 Hz have the most serious influence on the deformation of loess in Lanzhou. 2016 Vol. 53 (6): 137-142 [Abstract] ( 1065 ) [HTML 1KB] [ PDF 1156KB] ( 1698 ) 143 Indoor Mechanical Experiment and Analytical Study of Frozen Interbedded Soil JIANG Ren-Chao- 1 Li- Jiang- 2 In order to evaluate the characteristics of frozen interbedded soil consisting of clay and sandy soil, in? door bending and shear experiments were carried out with a test specimen of frozen soil. Based on the bending experiments of compound beams, this paper shows the effects of preparation, location of the sand layer and the proportion of the sand layer thickness on the load, displacement, neutral axis movement, bending elastic modulus and deformation resistance. Bending and shear experiments of overlapping beams prove that the frozen interbedded soil beam may be regarded as a compound beam. Finally, an analytical method for the deformation of frozen interbedded soil is proposed, the results of which basically agree with the ones measured by an extensometer in bending experiments. 2016 Vol. 53 (6): 143-153 [Abstract] ( 1079 ) [HTML 1KB] [ PDF 5230KB] ( 2015 ) 154 Model Experiment and Numerical Simulation of Characteristics of Stress Disturbance Induced by Tunnel Excavation in a Soft Rock Mass XU Qian-Wei- 1 Cheng-Pan-Pan- 1 Zhu-He-Hua- 2 Ding-Wen-Qi- 2 Chen-Guo-Zhong- 3 Based on the Wuning-Ji′an highway tunnel projects, and taking soft and fractured rock masses as a research object, model experiments and numerical simulations were conducted to study the progressive failure mecha? nism and the stress development sequence of surrounding rock, with and without faults, above the tunnel crown, providing a reference for the prevention of collapse and the design of lining structures. Research results show that: 1)shear failure of the rock mass often occurs below the tunnel haunch after tunnel excavation due to highly concentrated stress; 2) in a tunnel with faults, the rock mass below the fault can be placed in a cantilevered state and is prone to tension and shear failure; 3) the influence zone caused by tunnel excavation is mainly located between two inclined planes starting from the arch springline with an angle of 45°+φ/2 to the horizontal plane—the collapsed rock mass only accounts for a small part of this affected area; 4) due to the existence of the fault, the radial stress in the rock mass above the tunnel crown is reduced after excavation, and the scope of such stress reduction is larger than if there is no fault; and 5) the tangential stress concentration of the rock mass above the tunnel crown gradually develops from the tunnel perimeter towards the outside, accompanied by rock cracking and collapse when there is no fault; the concentration of tangential stress occurs at a farther position from the crown when there is a fault. 2016 Vol. 53 (6): 154-164 [Abstract] ( 1193 ) [HTML 1KB] [ PDF 6544KB] ( 2086 ) 165 Study on the Construction Mechanical Behaviors of a Subway Station by PBA Method and Optimization of the Load-Structure Model YAN Qi-Xiang- 1 Xu-Ya-Jun- 1 Liu- Gang- 1, 2 He-Shou-Hai- 3 The requirements of underground subway station construction have become more complicated with the effects of, and requirements regarding, existing buildings and complex environments. The Pile-Beam-Arch (PBA) method is widely used in light of the advantages of safety and decreased impact on the environment under complex building conditions. However, the construction mechanical behavior of the PBA method is very complicated, and there are some differences between the internal forces predicted by traditional load-structure design models and the actual forces, which may result in inappropriate structure design if using the common load-structure model for a PBA subway station. Based on a station project of the Beijing metro, this paper carries out a model experimental study and numerical simulation for the mechanical behavior of the PBA method, which reveals internal force variations for the middle column, side pile and crown during the construction process, leading to a proposed modified load-structure model for mechanical analysis of the subway station by the PBA method. 2016 Vol. 53 (6): 165-173 [Abstract] ( 1191 ) [HTML 1KB] [ PDF 4975KB] ( 1893 ) 174 Experimental Field Study on the Structural Behaviors of the Linings of Quasi-Rectangular Shield Tunnels WANG Dong-Fang- 1 Zhang-Wei-Xi- 2 Dong-Zi-Bo- 1 Liu- Xian- 2 Zhu-Yao-Hong- 1 With the development of subway shield technology, the quasi- rectangular shield tunnel is gradually coming to prominence. Since the effect of construction loads on the shield tunnel′s structure cannot be ignored, a field experiment regarding a lining′s structural behavior under the construction load was carried out to evaluate the mechanical effect of simultaneous grouting on the structural behavior of the lining, using the quasi- rectangular shield tunnel in Ningbo as an engineering model. Studies show that the area affected by grouting pressures is generally concentrated in a location approximately three segment rings away from the shield tail. Because of the grouting effect, the load on the lining structure during construction is higher than that in the final state, and the load distribution trends to be asymmetrical and the measured grouting pressure affected area is larger than shown by the design model. 2016 Vol. 53 (6): 174-181 [Abstract] ( 1114 ) [HTML 1KB] [ PDF 3873KB] ( 1747 ) 182 Test of Thixotropic Slurry Properties and Study of Resistance-Reducing Technology for Pipe Jacking Tunnel Construction WANG Ming-Sheng- 1 Liu-Da-Gang- 2, 3 Based on the Hongzhuanlu jacking pipe tunnel project underneath Zhongzhou Avenue in Zhengzhou City, we studied the influence of changing contents of materials—including bentonite, CMC, soda ash and PHP—on the properties of a thixotropic slurry, then determined its mix proportions. Furthermore, we also studied the technologies of slurry preparation, grouting equipment selection, grouting parameter design, the arrangement of grouting holes, synchronous grouting and secondary grouting and surface waxing of tunnel elements per the situation of field construction. The theoretical calculation and field testing showed that after applying resistance reducing technologies the values of the maximum jacking force and the average friction resistance coefficient for the vehicle tunnel tube with a large cross section is reduced by 56.3% and 62.3%, respectively, and 56.7% and 60.9% for the non-vehicle tunnel tube with a small cross section, which indicates that these technologies are effective 2016 Vol. 53 (6): 182-189 [Abstract] ( 1170 ) [HTML 1KB] [ PDF 2685KB] ( 2300 ) 190 Experimental Study on Joint Waterproofing Gasket Patterns for Deep Sewage Tunnels Excavated by Shield Machines WU Wei-Feng- 1, 2 Ding-Wen-Qi- 1, 2 Wei-Li-Xin- 3 Yang-Guang-Hua- 4 There is no precedent regarding the construction of large deep sewage tunnels in China and there are many related technical problems. Generally, these tunnels are more than 40 m deep and have to withstand high water pressure. Usually they use dual-sealed gaskets, but a large assembling force is detrimental due to the size limit of the shield machines; additionally, there are challenges regarding water tightness since the gaskets are not thick enough or big enough compared with those used in common domestic underwater tunnels. It is particularly important to use a waterproofing test to ensure the elastic gasket is capable of a long-term and stable performance while resisting high pressure. For the Guangzhou Donghaoyong deep sewage tunnel project, the gasket and concrete test specimens were produced according to the actual engineering size. Several waterproofing performance tests were conducted using a three-dimensional loading system. The tests compared the waterproofing joints with different openings and misalignments, and verified the feasibility of the gasket scheme for deep sewage shield tunnels. 2016 Vol. 53 (6): 190-195 [Abstract] ( 1205 ) [HTML 1KB] [ PDF 1820KB] ( 2201 ) 196 S/P Value-Based Optical Performance Study of Light-Storing and Reflective Side Wall Applied Material for Auxiliary Energy-Saving Lighting in Tunnels LIANG Bo- 1, 2 Cui-Lu-Lu- 1, 2 Chen- Wei- 1 Li-Yan-Jun- 1 This paper describes the development status of light-storing and reflective material, including perfor? mance and spectrum experiments aimed at optimizing the energy consumption and operational safety of highway tunnels. The authors systematically analyze the effect of tunnel light-storing and reflective materials used for auxiliary energy-saving lighting based on the concept of mesopic vision using a calculation method with a spectrum S/P value. The results show that: 1) the measured diffuse reflectance of light-storing and reflective material is about 80%,and the percentage of electric energy savings can reach about 15% with this material when used in tunnels; 2) due to the unique material composition of the light-storing and reflective material, its reflecting function significantly improves the spectral distribution of LED lamps and car headlights, and also increases the S/P value of the original light source; 3) the changing rules of S/P value accord with the theoretical cognition on light and color response of human eyes under mesopic vision, and it is an effective and reasonable evaluation method relative to the tunnel′s re? flective spectrum. 2016 Vol. 53 (6): 196-201 [Abstract] ( 1064 ) [HTML 1KB] [ PDF 1421KB] ( 1841 ) 202 Partitioning of Adjacent Influence Zones and Construction Control Measures for Metro Tunnels Passing under Existing Railways ZHENG Yu-Chao- 1 Cai-Jia-Liang- 1 Yuan- Zhu- 2 Yang-Tian-Chun With large-scale construction of urban rail transit projects, many running tunnels will be constructed be? neath existing railways, affecting the operation of these existing railways. Based on a running tunnel of the Yataidajie- Weihuanggong section on the Chuangchun light rail line 4, which passes under several existing railways at Changchun Railway Station, the interaction between vertical track deviation and subgrade settlement is studied using an empirical formula prediction and numerical simulation. A multivariate nonlinear regression method is proposed based on a single-factor analysis, and the partition criteria for adjacent influence zones is obtained based on vertical track deviation and subgrade settlement. It is proven that the controlling criteria based on vertical track deviation is stricter than other criteria, and corresponding construction classification parameters are set up regarding different influence zones. Finally, a dynamic construction adjustment method is put forward to ensure that running tunnel excavation under existing railways is done safely and efficiently. 2016 Vol. 53 (6): 202-209 [Abstract] ( 1112 ) [HTML 1KB] [ PDF 3213KB] ( 1989 ) 210 Analysis and Considerations of an Express Railway Tunnel Lining Failure by Seasonal Karst Conduct Flow WANG Gang- 1 Wang-Li-Chuan- 2, 3 Chou-Wen-Ge- 1 Gong- Lun- 1 Wu- Jian- 4 It is very common for railway tunnel linings to have some undiscovered quality defects due to various un? favorable factors in the construction process, which may threaten operational safety and transportation order; can cause accidents; and may result in property loss and shut down train operations. In this paper, using a crushing failure at a thin sidewall lining due to seasonal karst conduct flow as an example, we analyze water pressures that the tunnel lining bears related to the design lining thickness and insufficient sidewall lining thickness. Results show that the tunnel lining cannot bear the peak pressure that might be produced by a seasonal karst conduct flow although the lining design meets relative requirements; however, water pressure is reduced because the local sidewall is crushed due to insufficient thickness, possibly avoiding the risk of a larger and entire failure of the lining structure. Regarding a tunnel with seasonal karst conduct flow, it is necessary to take corresponding measures to fully mitigate or eliminate risks caused by seasonal high water pressure. Furthermore, the paper reviews problems concerning design alternatives for this project. 2016 Vol. 53 (6): 210-218 [Abstract] ( 1255 ) [HTML 1KB] [ PDF 5080KB] ( 1953 ) 219 Field Jacking Test of Steel Tubes with Flange Slabs in a Layer of Sand ZHAO Wen- 1 Jia-Peng-Jiao- 1 Li-Shen-Gang- 1 Yu-Hua-Liang- 1 Xia-Yun-Peng- 2 Liu- Heng The STS (Steel Tube Slab) curtain method, which consists of a load supporting structure formed by the coupling of steel tubes with concrete, flange slabs and bolts, is a new construction method used in the construction of super-shallow subway stations. Based on a subway station in Shenyang, this paper studies the construction difficulties and rectification techniques in the jacking construction of a steel tube with flange slabs, and presents relevant solutions and control measures, thereby providing a reference for the popularization of the STS curtain method. 2016 Vol. 53 (6): 219-226 [Abstract] ( 1098 ) [HTML 1KB] [ PDF 3983KB] ( 2051 ) 227 Discussion of the Large Deformation Mechanism and Control Measures for a Soft Rock Tunnel under High Ground Stress: A Case Study of the Muzhailing Tunnel 吕Xian-Fu- 1 Zhao-Zhan-Qun- 2 Wei-Xing-Xing- 2 Large deformation of tunnels in soft rock is a common and major engineering geological hazard that se? verely hampers construction progress and safety. In this paper, using the Muzhailing tunnel on the newly-built Lanzhou–Chongqing railway as an example, the large deformation mechanism of soft rock tunnels is analyzed from the aspects of lithology, underground water, geological structure, ground stress and construction technology, and the failure characteristics of large surrounding rock deformation in the Muzhailing tunnel and corresponding measures are elucidated. 2016 Vol. 53 (6): 227-231 [Abstract] ( 1314 ) [HTML 1KB] [ PDF 1203KB] ( 1623 )

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