[an error occurred while processing this directive]

Home | About Journal |  Editorial Board |   |  Instruction |  Subscription |  Advertisement |   |  Download |  中文  Office Online   Search     Adv Search

·Online Submission ·Manuscript Tracking ·Peer Review ·Editor Work ·Office Work ·Editor-in-chief  Journal Online ·Forthcoming Articles ·Current Issue ·Next Issue ·Archive ·Advanced Search ·Read Articles ·Download Articles ·Email Alert ·  Download · More>>

Quick Search     Advanced Search MODERN TUNNELLING TECHNOLOGY   2014 Vol.51 Issue.4 Published 2014-08-25 Article 1 Overview of Design Criteria for a Road-Tunnel Structure in Shanghai NING Zuo-Li Through the investigation and summary of design documents for the existing 15 shield tunnels in Shanghai, the prevailing defects in existing tunnels are categorized and analyzed, and the prevention and treatment measures for tunnel issues are proposed. The design and selection of protection enclosures in an open-cut section, along with structural engineering scales and geometric design parameters of shield tunnels, are statistically analyzed, and some suggestions about the selection and insertion ratio of an enclosing structure in an open-cut connecting section are put forward. Additionally, a calculation model and method of parameter calculation for open-cut structures are determined. The geometric parameters of overburden, minimum curve radius, minimum distance between line centers, and maximum gradient are analyzed in detail, and a method to determine the plane dimension of the launching shaft and the key techniques for shield launching and arrival are concluded. 2014 Vol. 51 (4): 1-7 [Abstract] ( 2135 ) [HTML 1KB] [ PDF 0KB] ( 465 ) 8 Analysis of a Flash-Flood Induced Debris Flow at a Highway Tunnel Portal in a Seismic Region LIAO WEI , LI Yu-Wen, ZHU Chang-An, LI Yong-Shen Resisting secondary disasters like a debris flow is critical during the design and construction of tunnels in regions with high seismic intensity. Based on the field survey and system analysis of the flash-flood induced portal damage to the Yingxiu-Wenchuan highway tunnel on July 9th, 2013, this paper concludes mountain loosening by the Wenchuan earthquake, stiffness and thickness insufficiencies of the backfilling material, and poor anti-erosion of the foundation in the cut-and-cover section of the tunnel are the main reasons for portal damage. It also puts forward relevant design ideas which can prevent and reduce disasters and minimize state asset losses, such as strengthening the evaluation for post-seismic potential hazards, designing beyond expectation, emphasizing quality and effectiveness of backfilling, and providing bridge-type channels for potential debris flows. 2014 Vol. 51 (4): 8-12 [Abstract] ( 2043 ) [HTML 1KB] [ PDF 0KB] ( 468 ) 13 Selection of a Shield for Tunnelling in Waterless Strata with Large-Particle Cobbles and Boulders GUO Cai-Xia-1, 2 , Wang-Meng-Shu-1, Kong, HENG 3, Qiao-Guo-Gang-3, Shi-Lei-Lei-2 Aimed at the problems encountered during shield tunnelling in a waterless strata with large-particle cobbles and boulders in Beijing, and using the construction of Beijing Metro Line 9 as an example, this paper puts forward a shield-selection concept, i.e. "discharging as the main measure, sealing as the supplementary measure," and conducts adaptability research and upgrades to some key equipments like the cutterhead, cutting tools, slurry and foam injection system, screw conveyor system, synchronous grouting system, and cutterhead driving system. The results show that the upgraded shield has a higher driving speed and lower construction costs, and is applicable to the waterless strata with large-particle cobbles and boulders. 2014 Vol. 51 (4): 13-17 [Abstract] ( 2064 ) [HTML 1KB] [ PDF 0KB] ( 464 ) 18 Analysis of Water Seepage Characteristics and Formation Mechanisms in Seasonal Water-Rich Tunnels in a Karst Area of Chongqing ZOU Yu-Lin, He, CHUAN , He, CONG , Zhang, ZHENG , Wang, BO Based on an investigation of 66 of the 187 operational highway tunnels with water seepage in Chongqing, this paper selects 15 tunnels with serious water seepage for a statistical analysis and indicates a connection of water seepage to karst landforms and seasonal rainfall according to its distribution characteristics. Using the Xiushan tunnel as an example, the paper discusses water seepage characteristics and relevant formation mechanisms. The results shows that: (1) water seepage in tunnels in the Chongqing karst area typically has the characteristics of zonal distribution, temporal continuance, dynamic karst water changes, unfavorable geological conditions, and an intermittent connection between water surrounding the tunnel and the underground river; (2) passing through a developed karst area, three working conditions may be encountered by tunnel construction at different stages, i.e., a normal condition, high water-pressure condition, and low water-pressure condition; and (3) water seepage is a result of multiple factors, especially the hydrogeologic conditions, design factors, construction quality of the waterproofing and drainage facilities, failures during operation, etc. The practice indicates that tunnels in these geological conditions should follow the principle of drainage first with blocking to follow. 2014 Vol. 51 (4): 18-27 [Abstract] ( 2263 ) [HTML 1KB] [ PDF 0KB] ( 522 ) 28 Establishment and Visualization of an Integrated Surrounding-Rock Classification System for Large-Span Underground Caverns SHEN Yan-Jun-1, Xu-Guang-Li-2, Wei-Zhi-Yun-3 Commonly used surrounding-rock classification methods were integrated, and the correlation among the evaluation indexes and criteria of each method was analyzed to establish the equivalent conversion formulae and empirical correlation charts in terms of various classification methods based on the inherent essence. Considering the significant disturbance effect caused by large-span underground caverns, a quantitative representation regarding the impacts of the engineering factors on the quality deterioration of surrounding rock is presented based on the limited deterioration principle, and an integrated surrounding-rock classification system considering the engineering factors was established. A visualization program for an integrated surrounding-rock classification system for large-span underground caverns (ISRCS) was developed based on VB.Net language. This program can realize the typical function, namely inputting parameters and outputting various evaluation results at the same time. By using the arch of the main powerhouse of the Dagangshan hydropower station at section 0-60~0+166 as an example, a comprehensive assessment was carried out by this program regarding surrounding-rock classification, stability results, and support recommendations, and the analysis results agree well with the actual conditions. 2014 Vol. 51 (4): 28-38 [Abstract] ( 2009 ) [HTML 1KB] [ PDF 0KB] ( 451 ) 39 Failure Characteristics and the Mechanical Effect of Mica Schist in an Anchored Tunnel ZUO Chang-Qun-1, 2 , Ding-Shao-Lin-1, LIU Dai-Guo-1, Sun-Jin-Shan-1, XU , YING 1 In a deep mica schist stratum, the anchor bolt support structure of a tunnel will frequently fail, resulting in large surrounding-rock deformation and endangering the safety of tunnel construction and reliability of the structure. Combining field experiments and numerical calculations, the characteristics of stress-strain and forms of loosening circles around a tunnel in a mica schist stratum are analyzed and the stress relationship and failure characteristics of the anchor-rock complex in a mica schist stratum are studied, providing a reference for support design, rock deformation control, and disaster prevention in mica schist and stratified anisotropic rock masses. 2014 Vol. 51 (4): 39-45 [Abstract] ( 2033 ) [HTML 1KB] [ PDF 0KB] ( 460 ) 46 DDARF Multi-Scale Meshing Method and its Application CHEN Yun-Juan, LI Shu-Cai, ZHU Wei-Shen, YU SONG , WANG WEN , ZHAO Cheng-Long To optimize the relationship between calculation accuracy and calculation time in the process of DDARF (discontinuous deformation analysis for rock failure), a DDARF multi-scale meshing method is set up in this paper, in which uniaxial compression models with multi-scale meshes and uniform meshes are established and a comparison between a numerical test and laboratory experiment is carried out. The multi-scale meshing method is applied to study areas adjacent to large underground caverns. Results show that the DDARF multi-scale meshing method is feasible; compared with the uniaxial compression test in the uniform meshing model, the calculation accuracy around the cracks is improved with the multi-scale meshing model using the same total mesh numbers, and the crack propagation law is more consistent with that obtained by the laboratory experiment; with the DDARF multi-scale meshing method applied to a large underground excavation, calculation time is reduced and efficiency is improved while the accuracy of calculations is maintained; and the displacement law is well aligned with that of the FLAC calculation results. The multi-scale meshing method improves the ability of the DDARF model to simulate propagation of cracks in the rock and has practical significance in the optimization analysis of stability for large geotechnical engineering. 2014 Vol. 51 (4): 46-52 [Abstract] ( 2124 ) [HTML 1KB] [ PDF 0KB] ( 500 ) 53 Dynamic Comprehensive Evaluation Model for Surrounding-Rock Stability Based on Variation Speed Characteristics of Measurements YANG CHAO 1, 2 , HUANG DA 1, 3 , ZHANG Yong-Xing-1, 3 , ZHU QIAN 4 Considering that the mechanical behaviors of surrounding rock are affected by various factors, the comprehensive evaluation model of surrounding-rock stability is being accepted by more and more researchers. Monitoring and measuring are the most direct ways of reflecting the stress and deformation state of surrounding rock, since the characteristic of variation speed is the important indicator of surrounding-rock stability. As for the establishment of a comprehensive evaluation model for surrounding-rock stability, the time factor must be taken into account to provide a dynamic evaluation. In light of the advantage of incorporating both variation speed and its trend, a modeling method and the relevant evaluation criteria for the dynamic comprehensive evaluation model for surrounding-rock stability are put forward. From the perspective of multiple factors, this model can measure the variation speed of evaluated targets in multiple time periods comprehensively. The model is also appropriate for short-time monitoring, or a case when the correspondence between simulated and measured results is not good enough. The feasibility of the model is verified by the Huayinshan tunnel, providing a new approach for evaluating the surrounding-rock stability. 2014 Vol. 51 (4): 53-57 [Abstract] ( 2045 ) [HTML 1KB] [ PDF 0KB] ( 447 ) 58 Dynamic Back-Analysis and Prediction of Overlying Subway Station Displacement Induced by Approaching Excavation WANG Jian-Chen, ZHANG Ding-Li, ZHANG Cheng-Ping, SU JIE , TAI Qi-Min The separated double-tube tunnel of the Xuanwumen station passes vertically beneath an existing station of the Beijing Metro Line 2. To ensure smooth construction, deformation of the existing station needs to be predicted properly. In order to do this, a displacement back-analysis is introduced, and a finite-element model for the dynamic simulation of the construction process is set up. Calculation parameters are determined based on the measured displacement in previous construction steps of the trial section, then the station deformation in the next construction step is predicted by back analysis. The method shows that: the back-analysis is more accurate than the direct analysis, with a maximum deformation error of 0~2.16mm and a maximum differential settlement error of 0.12~2.59mm; its prediction accuracy is influenced by the approaching construction method; and in a case where construction schemes for the previous and subsequent construction steps are similar, the prediction is more accurate. 2014 Vol. 51 (4): 58-66 [Abstract] ( 1969 ) [HTML 1KB] [ PDF 0KB] ( 434 ) 67 Analysis of Excessive Pore Water Pressure of Soil Induced by Shield Tunnelling WANG Zhi-Liang-1, 2 , SHEN Lin-Fang-2, WEI Gang-1 The surrounding soil is inevitably disturbed during the process of shield tunnelling, thus excessive pore water pressure is formed in the soil mass. In order to study the value, disturbance range, and distribution law of the excessive pore water pressure caused by shield tunnelling, the stress path method is applied to calculate the peak value of the excessive pore water pressure based on a modified Cambridge Model. The scope of the disturbance is determined by considering such factors as pressure in the soil chamber, static soil pressure at the tunnel center, and soil cohesion. According to Darcy's law, the distribution law of excessive pore water pressure is obtained without considering longitudinal seepage. The calculation and analysis show that: there is a linear relationship between the peak value of excessive pore water pressure and tunnel overburden; the scope of disturbance to the shield tunnelling and peak value of excessive pore water pressure are increased with an increased tunnel overburden; and the variation tendency of excessive pore water pressure is gradually slowed down with an increase of the tunnel overburden, and it tends to be linear as H/D is equal to 1.5. 2014 Vol. 51 (4): 67-72 [Abstract] ( 1989 ) [HTML 1KB] [ PDF 0KB] ( 492 ) 73 Analysis of Soil Deformation Induced by the Floating of a River-Crossing Metro Tunnel YUAN Wen-Jun-1, Zhang-Shao-Qin-2 Based on a uniform soil-movement model for shield tunnelling, a soil-movement model with two tangential circles was established regarding the action of tunnel floating, and a two-dimensional solution for soil deformation under the superimposed effects of upward buoyancy and soil loss was obtained by the Melan formula. Using the Fuheqiao tunnel project, which is under construction, of the Nanchang Metro Line 1 as an example, a calculation model was established with the finite-element analysis software ABAQUS and an analog computation of soil deformation induced by tunnel floating was conducted. The calculations show that the derived two-dimensional solution to soil deformation was consistent with the results of the numerical simulation. The rule of soil deformation induced by floating a river-crossing tunnel was that the deformation pattern at the top of the river bottom was in the form of an "inverse settlement trough," the deformation pattern at the deep soil layer was a "double bow" shape, and its amplitude decreased with an increased distance to the tunnel axis. 2014 Vol. 51 (4): 73-80 [Abstract] ( 2207 ) [HTML 1KB] [ PDF 0KB] ( 484 ) 81 Study on Effects of Group Foundation Pits Excavation on Heaving/Settlement of Adjacent Metro Tunnel in Operation LIU Ji-Qiang-1, 2 , 欧Xue-Feng-3, Zhang-Xue-Min-3, Liang-Qing-Huai-1, Yang-Jun-Sheng-3, Liu-Xue-Qin-2 The Che Kung Temple interchange project of Shenzhen Metro is used as an example in this paper to study the heaving/settlement laws and the displacement control measures for the adjacent metro tunnel in operation which is effected by excavation of group foundation pits. In order to control the displacement of existing tunnel and track structure, the deformation control standards for track structure in each construction step of group foundation pits are set by means of scheme optimization, theoretical analysis and numerical simulation based on the distribution principle of structure displacement. With the unloading effect induced by foundation pit excavation, the displacement superimposed effect of adjacent existing tunnel is noticeable, therefore the excavation and dewatering of the pit are the key steps among the construction sequence of group foundation pits. Foundation pit dewatering is a favorable factor for controlling the heaving of underneath tunnel, while it is an unfavorable factor for controlling the horizontal deformation. Consequently, the displacement reference values of the underground structure in different orientations shall be taken into account as for the reasonable dewatering measures in the progress of design and construction. The actual measurements show that during the excavation of group foundation pits, deformation of existing subway structure is not beyond the specific standard, the deformation control standards are reasonable and the engineering measures are effective. 2014 Vol. 51 (4): 81-87 [Abstract] ( 2215 ) [HTML 1KB] [ PDF 0KB] ( 472 ) 88 Analysis of the Influence of the Foundation Pit Construction on the Adjacent Metro Tunnel Structure GUO Dian-Ta-1, 2 , Zhou-Cui-Ying- 1, Xie-Lin-2 Based on the static and dynamic finite element analysis, a hybrid discrete element model is established in terms of the interaction between the foundation pit and the tunnel structure, in order to analyze the influence of the foundation pit construction on the tunnel structural mechanic behaviors under different excavation depths, spacing, dimensions, etc and the vibration response characteristics of the tunnel. The results show that: the aforesaid factors have significant effects on the static deformation and vibration response of the tunnel. Combining with the engineering practice and the calculation results, this paper provides some relevant control measures. 2014 Vol. 51 (4): 88-95 [Abstract] ( 2094 ) [HTML 1KB] [ PDF 0KB] ( 492 ) 96 Influence of Bored Subway Tunnel Construction on the Deformation of Existing Pipelines and Control Techniques GAO Bing-Li It is critical to guarantee the safety of adjacent pipelines during the construction of an urban subway tunnel. Using the Tonghuamen-Hujiamiao section of Xi'an Metro Line 3 as an example, a FLAC numerical simulation was used to obtain the law of influence of bored subway tunnel construction on the deformation of adjacent pipelines that are parallel or perpendicular to the tunnel axis. The deformation tendency of pipelines after the subway passed through the f4 ground fissure was analyzed and predicted, and the technical measures for a subway tunnel passing through the f4 ground fissure, as well as the protective measures for adjacent pipelines, were put presented. The engineering practices show that the control measures proposed in this paper were reasonable and effective. 2014 Vol. 51 (4): 96-101 [Abstract] ( 2033 ) [HTML 1KB] [ PDF 0KB] ( 432 ) 102 The Law of Building Foundation Deformation Induced by Shield Construction in a Loess Area and the Relevant Control Techniques CAO Zhen-1, YANG Feng-2, 3 , ZHANG Ning-1, 3 Taking the construction of the Dayanta--Beichitou shield-driven tunnel on the Xi'an Metro Line 3 as an example and using the FLAC3D software, this paper studies the laws of building foundation deformation induced by shield construction in a loess area under two working conditions, provides relevant countermeasures for controlling the deformation of the Shanxi Zhenghe Hospital building and gives the monitoring scheme as well. The results show that: the soil layer around the hospital building shall be firstly reinforced by grouting to ensure that the foundation deformation keeps in the allowable value range. Practically, using appropriate excavation parameters and ground reinforcements, the shield underpasses the building safely with an allowable foundation settlement, thus proving that the above control techniques are sound and effective. 2014 Vol. 51 (4): 102-107 [Abstract] ( 2014 ) [HTML 1KB] [ PDF 0KB] ( 464 ) 108 Mechanical Behaviors of a Shallow-Bias Tunnel with a Small Clear Distance in Different Geological Conditions QI Han-1, Gao-Bo-1, Wang-Shuai-Shuai-1, Xu-Chuan-2 The mechanical behaviors of shallow bias tunnels with small clear distances in different geological conditions are quite different. In half-soft and half-hard rock especially, rock stability at the interface of the soft and hard rock will be disturbed by tunnelling and is characterized by very special mechanical behaviors. In this paper, tunnel excavations in 15 different conditions are simulated by applying the finite difference software FLAC3D to analyses of crown settlement, middle-wall horizontal displacement, middle-wall maximum principle stress, and the plastic zone of rock for tunnels with different clear distances in homogeneous hard rock, homogeneous soft rock, and half-soft and half-hard rock. The results show that: tunnel crown settlement is minimized in the homogeneous hard rock, similar for the half-soft and half-hard rock, and maximized in soft rock; for the tunnel in the half-soft and half-hard rock, the rock-mass stability is poor at the upper part of the rock pillar, and horizontal displacement reaches a maximum at the middle part; and stability of the overlying rock of the cavern at the soft-rock side is worsened and may result in collapse. 2014 Vol. 51 (4): 108-112 [Abstract] ( 1881 ) [HTML 1KB] [ PDF 0KB] ( 439 ) 113 Study of Engineering Properties and Subsidence Characteristics after Driving of the Shenzhen Metro Tunnel in Water-Rich Soft Ground ZHANG Cheng-Ping, ZHANG Ding-Li, HAN Kai-Hang, WANG Jian-Chen In order to study the engineering properties and characteristics of driving-induced subsidence of water-rich soft ground, the physical and mechanical parameters for the strata of the Shenzhen metro tunnel section from Guomao to Laojie were tested and analyzed by laboratory experiments. The results show that: (1) there are large pores and micro-fissures that are mutually connected, with high soil compressibility and consolidation settlement; (2) the ground is mainly composed of granular mixtures and has a high water and sand content, which leads to uncontrollable ground loss caused by construction drainage erosion; and (3) the low formation strength leads to poor stability of the surrounding rock during tunnelling. The above factors mean that this kind of ground has the obvious characteristics of a large disturbance scope, large ground settlement, and surface subsidence. Through actual measurement of ground settlement, the accuracy of the experimental results are verified; the maximum ground settlement caused by excavation of the Guomao-Laojie section is about 193.5mm, with a trough width of 80m, and surface subsidence occurring twice. Thus, the ground settlement caused by tunnel excavation is closely related to the geological conditions, and it is necessary and feasible to predict the ground settlement caused by tunnel excavation based on physical and mechanical properties. 2014 Vol. 51 (4): 113-120 [Abstract] ( 1933 ) [HTML 1KB] [ PDF 0KB] ( 454 ) 121 Tracking and Determination of Cutter Damage Based on the Driving Parameters of a Shield ZHANG Hou-Mei-1, Qu-Xi-2, Yi-Jue-3 At present, the determination of cutter wear is empirical. Based on an analytical calculation model with tunnelling parameters, this paper modifies the calculation models for advance rate and cutter torque by further considering the influence of pressure in the earth chamber. Combined with construction examples, it tracks and judges the data relative to driving and cutter conditions of the EPB shield, slurry shield, TBM, and so on in hard rock using the modified calculation model. The results show that the calculation results are in good agreement with reality regarding wear condition, and this method is feasible for determining cutter damage. 2014 Vol. 51 (4): 121-126 [Abstract] ( 2099 ) [HTML 1KB] [ PDF 0KB] ( 443 ) 127 Optimization Design of Parameters for the Thermal Insulation Layer in Permafrost Tunnelling ZHOU Yuan-Fu-1, ZHANG Xue-Fu-2 A thermal insulation layer is often used in permafrost tunnels to protect the tunnel structure from freeze-thaw damage. In this paper, in order to study the rationality and economy of the thermal insulation layer, a mathematical optimization model for the insulation layer in a permafrost tunnel was derived based on the characteristics of permafrost and optimization theory, and a solution was conducted by using the Fenghuoshan Tunnel as an example. The results show that this mathematical optimization model for the insulation layer is rational and the solution method is feasible; as for the permafrost tunnel, the effect of surface temperature on the surrounding-rock temperature is limited with increased depth, so the insulation layer used in permafrost tunnels should be designed according to the tunnel depth, annual average temperature, and the annual range. 2014 Vol. 51 (4): 127-132 [Abstract] ( 2098 ) [HTML 1KB] [ PDF 0KB] ( 442 ) 133 Development of theφ800 mm EPB Shield Model Testing System HU Xiong-Yu, HE Chuan, FANG Yong, DAI Guang-Hui, JIANG Ying-Chao The self-developed φ800 mm EPB shield model system is composed of a φ800 mm EPB shield, the driving control system, the segment lining structure, and other accessories. This paper presents the detailed description of structure type, layout feature, parameter determination and specific function etc respectively for 5 important components of the shield shell, cutting system, screw conveyor, thrusting system and control panel. By use of the model system, the excavation test in the original soil and similar model test can be carried out according to different requirements, even for approaching construction case under complex conditions. Therefore, for validation of the reliability of model system, the excavation test in original sand stratum is carried out to obtain the ground surface settlement pattern and the development process as well as the relationship between the ground loss ratio and the ground displacement; meanwhile, the ground surface settlement is calculated by Peck formula and compared with the test values, verifying the reliability of this EPB shield model system. 2014 Vol. 51 (4): 133-140 [Abstract] ( 2092 ) [HTML 1KB] [ PDF 0KB] ( 423 ) 141 Experimental Study of the Deformation Law of Cracked Tunnel Lining Reinforced by Separated Cover Arch YU Wen-Sheng-1, 2 , Sang-Yun-Long-3 Based on the similarity ratio of 1:10, a tunnel secondary lining model was made in which the depth of a single longitudinal crown crack was one-third of the original lining thickness. With the ground resistance simulated as the spring, the radial load test of the tunnel secondary lining model was carried out, which was reinforced by the new cover arch separated with the original lining by additional waterproof broad, and the deformation law and failure mode of cracked lining after reinforced by separated cover arch were achieved. The results show that under the action of loosening pressure, the loading process of separated cover arch reinforced structure can be divided into three phases: initial loading-radial penetration of the prefabricated crack-radial penetration of the cover arch crown crack-failure of the specimen; the failure load is governed by the haunch section of original lining, and the overall failure property acts as the brittle failure with a failure sequence of key parts as crown cracking-haunch fracture-crown failure. 2014 Vol. 51 (4): 141-149 [Abstract] ( 2088 ) [HTML 1KB] [ PDF 0KB] ( 446 ) 150 Experimental Study of Blasting-Fume Diffusion and Concentration Prediction in a Blind Tunnel ZHANG Ge-1, CAO Yang-2, JI Hong-Guang-2, LI Song-3 In underground metal mines, monitoring and predicting the diffusion of toxic gas induced by the drilling and blasting method is essential for ensuring personnel security and improving production efficiency. A test to monitor the variation of blasting-fume concentration in a blind tunnel with forced ventilation was conducted. The data fitting reveals that the blasting-fume concentration decreases with the index e, and there is a clear linear relationship between the maximum concentration at each tunnel section and the theoretical initial concentration at the starting area. This paper is a reference for predicting the time required for reaching a safe CO concentration and choosing sensors for assembling the hardware system. 2014 Vol. 51 (4): 150-154 [Abstract] ( 2028 ) [HTML 1KB] [ PDF 0KB] ( 433 ) 155 Analytical Formula for Segment Dimensions of a Shield Tunnel YANG Qun-1, Xie-Li-Guang-2 The AutoCAD software drawing method is commonly used for the design of segment dimensions of a shield tunnel. However, some approximations and a cumbersome design process make the results hard to be verify. In this paper, an analytic formula associated with segment dimensions is derived based on knowledge of analytic geometry and segment structure characteristics. The analyses show that not only can an exact solution of segment dimensions be achieved by using this method, but also that design efficiency can be improved and drawing results can be verified conveniently. 2014 Vol. 51 (4): 155-160 [Abstract] ( 3323 ) [HTML 1KB] [ PDF 0KB] ( 437 ) 161 Key Techniques for the Overall Design of the Rail-and-Road Combined Yangtze River Tunnel on Sanyang Road in Wuhan XIAO Ming-Qing-1, 2 , LING Han-Dong-1, SUN Wen-Hao-1, 2 The Wuhan Yangtze River tunnel on Sanyang Road, the first rail-and-road combined shield tunnel in the world, has encountered some difficulties in overall design because of its extra-large diameter, high water pressure, small spacing, complicated geological conditions, and difficult construction conditions. Thus, based on the interactive factors of environmental conditions, relevant construction safety and risk, technical requirements for rail and road, and disaster prevention and rescue during operation, this paper analyzes some key design techniques for the tunnel plane, longitudinal profile, cross section, and evacuation and rescue in order to reduce the risks of construction and operation. Additionally, a proper overall design scheme is proposed, providing a good reference for similar projects in the future. 2014 Vol. 51 (4): 161-167 [Abstract] ( 2484 ) [HTML 1KB] [ PDF 0KB] ( 447 ) 168 Design Option for the Extra-Large Rail-and-Road Shield Tunnel on Sanyang Road in Wuhan CHEN Kui-1, 2 , Feng-Huan-Huan-2 With the rapid development of urban construction, the construction of rail-and-road combined tunnels is getting to be an effective way to realize efficient utilization of underground space. Based on the construction conditions of the Sanyang river-crossing tunnel in Wuhan, this paper proposes a construction scheme for the rail-and-road combined tunnel with six lanes based on a comprehensive comparison and analysis of the influences of urban planning and land use, construction difficulties, and construction organization. It describes the relevant calculations and analyses regarding the cross-section arrangement and tunnel structure, etc. Additionally, it discusses a feasibility study of technical difficulties such as equipment manufacturing, long-distance driving, constructing with a small clearance, and adjacent construction, and ultimately provides guidance for this project and similar ones in the future. 2014 Vol. 51 (4): 168-177 [Abstract] ( 2378 ) [HTML 1KB] [ PDF 0KB] ( 424 ) 178 Risks and Countermeasures for the Shenzhen-Guangzhou-Zhongshan (SGZ) Shield-Tunnel Project Crossing the Pearl River Estuary HUANG Wei-Ran-1, 3 , Zhu-Wei-Bin-2, Liu-Ren-Huai-1 Regarding the risks involved in the construction of a long and deep submarine tunnel, such as complex geology, environmental protection, port industry, waterway transportation, air transportation, and abnormal meteorology, the environmentally friendly shield-driven tunnel construction method option has unique advantages. Based on the construction characteristics of the Shenzhen-Guangzhou-Zhongshan (SGZ) fixed link that crosses the Pearl River estuary, the achievements of the Guangzhou Metro in similar mixed ground, as well as the construction experience gained from international large-diameter, high-hydraulic-pressure and long-distance shield tunnel projects, the following conclusion is derived in this paper: the three-tube tunnel system is the optimal construction scheme because of its suitable functions, guaranteed quality, reasonable costs, and controllable risks. Additionally, a further analysis of the risks and countermeasures is described as a reference for similar projects. 2014 Vol. 51 (4): 178-184 [Abstract] ( 2141 ) [HTML 1KB] [ PDF 0KB] ( 431 ) 185 Study of the Treatment Scheme for a Large, Dry Karst Cave in the Yangqiaoba Tunnel CAO Xiao-Yong, Zhang-Long, Lin-Yong-Feng Due to the restrictions of investigative techniques, construction and operation risks of tunnelling in a karst region may result in large karst caves. Based on the present conditions and supplementary investigation information concerning the large karst cave encountered during construction of the Yangqiaoba tunnel on the Fengjie-Wuxi expressway in Chongqing, construction schemes are put forward, including: bridge crossing, subgrade filling and open cut tunnel, backfilling and bored tunnel, and five realignment options. Through a comprehensive comparison regarding the geological conditions, construction risks, project cost and construction schedule, the realignment option with the least additional costs and shortest construction time was finally adopted, in which the alignment of the left tunnel tube would be skewed to the left in order to bypass the karst cave. During the construction period, no large caves have been encountered, therefore geological risks have been avoided, and construction safety, schedule, and cost savings have been ensured. 2014 Vol. 51 (4): 185-190 [Abstract] ( 2100 ) [HTML 1KB] [ PDF 0KB] ( 473 ) 191 Technical Measures for Blasting Vibration Control in Urban Underground Works XUE Xian-Bin, Zhang-Ji-Can, Sun-Xue-Qin This paper presents the generating mechanism of blasting vibration and analyzes the hazards induced by the blasting vibration of urban underground works. It concludes eight kinds of technical measures for blasting vibration control, such as controlling the initialing charge per delay interval, a reasonable interval time of initiation, proper cut type, and non-explosive blasting based on the engineering practice. Ultimately, it points out that the selection of appropriate vibration control measures should be based on the specific conditions during blasting of urban underground works. 2014 Vol. 51 (4): 191-194 [Abstract] ( 2109 ) [HTML 1KB] [ PDF 0KB] ( 411 ) 195 Rehabilitation Scheme and Safety Analysis of an Underwater Tunnel WANG Zhan-1, WANG You-Yuan-1, SU Lin-Wang-1, WANG Jin-Chang-2 Using the rehabilitation of an underwater shield-driven tunnel being damaged by sand gushing as an example, this paper introduces the technological process of the casing method and analyzes construction safety by a 3D finite-element model. The results show that: though the impact force of a hydraulic vibratory hammer has little influence on an existing tunnel, the construction process needs to be calculated and verified; and maximum deformation and stress occur at the opening of the tunnel vault, necessitating structure reinforcement and water-stop measures. 2014 Vol. 51 (4): 195-202 [Abstract] ( 2022 ) [HTML 1KB] [ PDF 0KB] ( 422 ) 203 Study of the Construction Organization of Non-Ballasted Track in Long Mountain Railway Tunnel Groups XIA Run-He Using domestic and foreign experiences in non-ballasted track construction and related technical documents as references and the double-block non-ballasted track construction of tunnel groups on the Gui-Guang railway as a background, the equipment configuration and organization of logistics for non-ballasted track construction for tunnel groups in mountain areas were studied and the related procedures for construction in a double-track tunnel are proposed in this paper. Engineering practices indicate that in-situ assembly of the track panel using a combined track framework could be adapted to adjust to the curve radius of the track and guarantee the technical indexes of non-ballasted track construction, therefore having rapid construction conversion capability. With high precision and stiffness, the assembled track framework is recyclable to shorten the construction period and save construction costs. 2014 Vol. 51 (4): 203-210 [Abstract] ( 1899 ) [HTML 1KB] [ PDF 0KB] ( 431 )

More>>   · · More>>

Copyright © 2011  Editorial By MODERN TUNNELLING TECHNOLOGY Supported by:Beijing Magtech Co.ltd  Email:support@magtech.com.cn