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Quick Search     Advanced Search MODERN TUNNELLING TECHNOLOGY   2019 Vol.56 Issue.3 Published 2019-06-25 1 Review of Researches on Mechanical Behaviors of Tunnel Fiber Reinforced Concrete Lining CUI Guangyao1 SUN Lingyun2 ZUO Kuixian1 WANG Mingnian3 JING Hongfei4 Concrete is a kind of composite material composed of fine aggregate, coarse aggregate, cement etc., and the behavior of concrete can be improved if certain amount of fibers are added to the concrete matrix. This paper described and analyzed present status of research on mechanical behaviors of tunnel fiber reinforced concrete lining from static and dynamic aspects. A further study and discussion on the behaviors of compression resistance, shearing resistance and toughness were conducted in terms of fiber content, fiber type, fiber shape, bearing capacity calculation method and so on from the perspective of statics; the deformation failure mechanism of fiber reinforced concrete structure, and the effect of fiber type, fiber content, size etc. on aseismic capacity, shock resistance and explosion resistance of fiber reinforced concrete were analyzed from the perspective of dynamics. The results show that the behaviors of compression resistance, shearing resistance and toughness are significantly improved if certain amount of fibers are added into concrete; it will prevent from cracking and development inside of concrete and improve the structure deformation of concrete under the effect of dynamic response if fiber is added into concrete; it is significant to give full play to the toughness of fiber reinforced concrete and ensure safety of tunnel fiber reinforced concrete lining under complex geological conditions. 2019 Vol. 56 (3): 1-7 [Abstract] ( 667 ) [HTML 1KB] [ PDF 795KB] ( 1699 ) 8 On Failure Mechanism of Surrounding Rocks of the Deep-buried Underground Cavern Group under High Geostress and Its Countermeasures SUN Huixiang Brittle rock mass failures due to geostress release (rock burst and spalling, etc.) and caused by structural plane stress (surrounding rock relaxation, shotcrete spalling and crown collapse, etc.) are very common during underground cavern excavation. Taking the underground cavern group of tailrace connection pipes at the left bank of the Baihetan hydropower station as an example, and based on a statistic and analysis of site survey results, it studied the rock failure mechanism due to geostress release by means of 500 μm microscopic observation and the indoor uniaxial compression test. Rock failure mechanism caused by structural plane stress was also studied by numerical simulation and in-hole video, and some corresponding countermeasures were proposed. The research indicates that the brittle rock mass with good integrity (grade Ⅱ) has certain plasticity, it is prone to inducing shear compression failure and forming a failure plane with a small angle relative to force direction after load release due to cavern excavation, plastic potential energy releases along fracture plane and then causes spalling of thin layer or rock burst; the rock mass with poor integrity (grade Ⅲ) has characteristics of high lithological strength and low rock mass strength due to presence of joints and dislocation interfaces; micro-cracks of rock mass gradually spread and connect each other to form mutual cutting structural planes, and it develops towards further depth of rock mass until stress releases completely under the effect of high geostress; it is inclined to causing collapse due to the vibration effect of cavern blasting, the failure develops from outside to inside and is characterized by time-efficiency from the macroscopic view. 2019 Vol. 56 (3): 8-17 [Abstract] ( 707 ) [HTML 1KB] [ PDF 5612KB] ( 1644 ) 18 Research on Interpretation Method of TRT Test Results Based on GOCAD YUAN Xianfan1 LIAO Dan2 The TRT technology has been more and more widely applied to tunnel geological prediction. However, the result interpretation is always the key and difficult point in geological prediction, since there are a few kinds of interpretation methods and the results are not quite precise. Aiming at the problems in result interpretation of TRT,such as the low combining degree of prediction criteria with actual geological conditions of test area and low prediction accuracy of disaster body′ s development degree and position, some corresponding improvement methods were proposed, namely the actual geological conditions of TRT test section were introduced to GOCAD to create a model and then the TRT 3D data were introduced to the model, realizing the interconnection between TRT test images and actual geological conditions. By adding varieties of color combination in the result image, the TRT result image can reflect both the disaster body and its development degree. A model was established by introducing tunnel coordinates and TRT test data to GOCAD, and the relative position relation between the disaster body and tunnel is understood, the precise prediction of development position and scale of disaster body was realized. Case application shows the improved TRT result interpretation method can greatly increase the accuracy and precision of TRT geological prediction. 2019 Vol. 56 (3): 18-24 [Abstract] ( 732 ) [HTML 1KB] [ PDF 2598KB] ( 1385 ) 25 Characteristics Analysis and Forecast Evaluation of Gas Occurrence of the Longquanshan Tunnel on Chengdu Metro ZHANG Xiaolin1 CAI Jianhua2 LIAO Yankai2 In light of the tunnel construction safety and gas fortification, the regional geological background and gas structure of the Longquan Mountain in Sichuan Basin were investigated from a macro perspective, the Longquanshan tunnel of Chengdu Metro was identified as a gas tunnel in non-coal measure strata considering the development and distribution of geological structure at tunnel site, and its macroscopic characteristics of gas structure were presented. Based on the detailed exploration results of gas detection, geophysical exploration and laboratory test of boreholes, the microscopic characteristics of gas buried depth, elevation, strata and rock mass of the Longquanshan tunnel were stated. By comparing with the Longquanshan water tunnel to be completed soon, the above mentioned characteristics were proved by gas monitoring results, and a prediction and evaluation of gas occurrence and fortification grade of the Longquanshan tunnel were conducted. 2019 Vol. 56 (3): 25-30 [Abstract] ( 741 ) [HTML 1KB] [ PDF 2907KB] ( 1531 ) 31 On Digital Identification of Water Leakage at Tunnel Lining Based on the Panoramic Developed Image PENG Bin1， 2 ZHU Zhiheng2 YANG Junsheng2 FU Jinyang2 HE Hongbo1 Based on the images acquisited in the water leakage area of tunnel lining, the panoramic developed im? age of tunnel lining was obtained by using a image generator software in which the procedures of image feature extraction, image matching, model identification, image spread and mosaic processing can be performed. With techniques of image segmentation and processing, the information identification and correction of water leakage area were realized by means of grayscale image conversion, threshold selection and open-close operation of binary image. On the basis of water leakage at lining of an operated road tunnel in Guizhou, the location, area, length of water leakage and so on were deduced by several algorithmic programs, and a digital identification system of water leakage at tunnel lining was established, providing a convenient, efficient and comprehensive testing method for water leakage of tunnel lining. 2019 Vol. 56 (3): 31-37 [Abstract] ( 630 ) [HTML 1KB] [ PDF 3954KB] ( 1793 ) 38 Study on the Planning Technology for Metro Built by Double Shield TBM in Old Urban Area HUANG Yinding1，2 The Qingdao metro line 2 is located in the old urban area with narrow boundary line of roads and short? age of construction land. With the double shield TBM, it′s necessary to solve the technical difficulties such as mutual interference between TBM excavation and station construction, TBM launching, TBM passing through station,TBM receiving and so on. In light of the environmental characteristics of Qingdao old urban area and the conditions of subway line and stations, the basic principles of project planning were presented; based on a study of TBM launching schemes, the technology of TBM launching from "rail row shaft + hoisting shaft +launching tunnel" was presented; by studying the schemes of TBM passing through station, the station crossing technologies of "station crossing of whole TBM by a curved guidance pedestal " and " station passing of TBM by pilot tunnel " were proposed; on the basis of a study on TBM receiving schemes, the technology of TBM disassembling and hoisting out from "rail siding tunnel + station air shaft " was put forward, and a comprehensive engineering planning technology of double shield TBM suitable for the metro construction in old urban area was summarized and applied in practice. 2019 Vol. 56 (3): 38-44 [Abstract] ( 754 ) [HTML 1KB] [ PDF 2559KB] ( 1399 ) 45 On Application and Promotion of BIM Technique in Urban Rail Transit Engineering ZHANG Jinwei1 LIU Zhiguang1 LU qingquan2 ZHANG zhiwei2 With the development of BIM technique, it is significant to promote and integrate the BIM technique with the construction of urban rail transit engineering, make the best of its advantages, speed up process of information development in construction sector, and realize smart metro in new era. Based on an application of BIM technique in the Beijing metro line 19, a discussion on BIM application and promotion in urban rail transit engineering was conducted, with a focus to understand the goal, make a plan, establish standards and integrate resources. In light of the requirements of project, demonstration application was carried out, and the key problems were studied,realizing universal acknowledge and wide application and promotion of BIM technique. 2019 Vol. 56 (3): 45-52 [Abstract] ( 722 ) [HTML 1KB] [ PDF 3595KB] ( 1576 ) 53 Economical and Ecological Evaluation Index System of the Urban Utility Tunnel Based on PSO-BP Neural Network XUE Gang ZHANG Xia Urban utility tunnel is one of the most important infrastructures that ensures the sustainable develop? ment of cities, there is few evaluation index systems due to late development of urban utility tunnel construction in China. An economical and ecological evaluation index system of the urban utility tunnel, which contains three hierarchies, five dimensions and forty two indexes, was structured by establishing the elevation system framework based on DPSIR framework model, calculating index weights by BP neural and optimizing the weights by particle swarm algorithm. Taking the Xindu unban utility tunnel in Baotou as an example, it verified the feasibility of this evaluation index system. A prediction was taken by PSO-BP neural network model and the simulation output is 72.181 08,which shows good economical and ecological construction effect of this project. 2019 Vol. 56 (3): 53-58 [Abstract] ( 788 ) [HTML 1KB] [ PDF 2411KB] ( 1426 ) 59 Conception of IOT Technology Based Information System for Subway Patrol WEN Xiaokai SUN Kun LIU Liang A IOT technology based system for subway patrol was conceived considering low intelligence degree and big data level of subway patrol at present. By using technologies of IOT, GIS and big data, the standardization,systematization, intelligentization of subway patrol operation and the application of big data are improved, providing support for the maintenance data management and decision making. 2019 Vol. 56 (3): 59-64 [Abstract] ( 797 ) [HTML 1KB] [ PDF 3271KB] ( 1695 ) 65 Effects of a Tunnel on Ground Motion Amplification SUN Qiangqiang1 BO JingShan1, 2 LIU Hongshuai3 JING Liping2 Site conditions have significant effect on seismic wave propagation, and the presence of a shallow-bur? ied tunnel will change the site conditions of subsurface and has certain impact on ground motion, affecting seismic response of adjacent ground structure. By taking the Ricker wavelet as input motion, it studied the impact of a circular tunnel in the uniform elastic site on horizontal peak acceleration of subsurface by numerical method, analyzed the variation law of horizontal subsurface acceleration under different tunnel buried depths and frequencies of incident wave. The results show that the effect on peak subsurface acceleration decreases with an increase of tunnel overburden, the scope of influence increases linearly and it is mainly within the range of five times of tunnel radius;the amplification effect of tunnel on subsurface PGA is most significant when the dimensionless period λ/D is around 6-8 while the effect of tunnel on subsurface motion can be ignored when λ/D is more than 10. 2019 Vol. 56 (3): 65-71 [Abstract] ( 679 ) [HTML 1KB] [ PDF 4689KB] ( 1342 ) 72 Seismic Response of the Metro Station with Pre-constructed Pipe-roof Integrating Support and Structure under Strong Earthquake Effect LI Jidong1,2 YOU Xinhua1 Support-structure integrated pipe-roof pre-construction method is a new mined construction method in? tegrating reinforcement, supporting and major structure. At present the aseismic research on underground structure mainly involves in analyzing the seismic response of underground structure built by traditional construction technology and there is few seismic research of structure by large-section pipe-roof pre-construction method. Based on finite difference software FLAC3D, it studied the seismic response of metro station by pipe-roof pre-construction method. The results show that relative horizontal displacement of various measuring points along the height of station structure is in a shape of inversed S under the effect of strong earthquake; large stress of station structure under effect of earthquake often occurs at the junctions of various pipe-roofs, middle plate and pipe-roof as well as piperoof and base; compared with that under unidirectional earthquake effect, the acceleration and max. horizontal stress of station structure both increase and horizontal displacement and relative horizontal displacement decrease under bidirectional earthquake effect. 2019 Vol. 56 (3): 72-78 [Abstract] ( 784 ) [HTML 1KB] [ PDF 2592KB] ( 1313 ) 79 Study on Mechanical Characteristics and Section Design of Trench Type Opencut Tunnel Lining Structure with Deep Covering Soil under Load Reduction ZHUO Bin1 LI Sheng1 HE Chuan2 WANG Huan3 WANG Qicai1 MA Li4 In order to improve the internal force of lining structure and reduce the lining thickness of high-filled trench type open-cut tunnel in loess, it studies the variation law of internal forces and lining thickness of structure as well as the effect law of slope angle on internal force of open-cut tunnel and lining thickness before and after load reduction from the perspectives of mechanical behaviors and load reduction mechanism of EPS board by numerical simulation method. The result shows that the internal force and lining thickness of high-filled open-cut structure in loess increase with an increase of filling height; reduction effects of internal force and lining thickness of open-cut tunnel under load reduction are related to EPS board thickness and stress-strain curve, the load reduction effect is the best when EPS board is at the end of plastic stage, and an optimized design for load reduction of EPS board under this density was presented; the greater the slope angle, the smaller the structural internal force of open-cut tunnel before and after load reduction; the lining thickness of open-cut tunnel tends to decrease except the vault; thickness reduction effect of the lining at tunnel roof is most obvious after load reduction while the thickness reduction of other sections decreases in an accelerate way. It is suggested that designs for different EPS board density and thickness should be optimized regarding different filling heights and slope angles of trench type high-filled open-cut tunnels. 2019 Vol. 56 (3): 79-87 [Abstract] ( 729 ) [HTML 1KB] [ PDF 3964KB] ( 1473 ) 88 Research on Pitch and Thrust Allocation of Shield Used in Inclined Shaft CHEN Ming GUAN Huisheng XIE Youhui Cutterhead pitch of shield used in inclined shaft is an unfavorable posture in downhill shield tunnelling, and the extent of pitch affects the forming quality of inclined tunnel directly. At present, there is little domestic research on cutterhead pitch of shield used in inclined shaft, and there are few models describing the cutterhead pitch of shield used in inclined shaft. Furthermore, the thrust system is adopted to adjust cutterhead pitch of shield, but its thrust allocation is mainly based on experience which has certain blindness. In light of the different settlements at shield head and tail, a subgrade reaction distribution model was established, which can describe the cutterhead pitch of shield used in inclined shaft, the relationship between thrust allocation of thrust system and extent of cutterhead pitch was studied, and a scheme of critical thrust allocation of thrusting system was obtained. 2019 Vol. 56 (3): 88-94 [Abstract] ( 671 ) [HTML 1KB] [ PDF 2008KB] ( 1370 ) 95 Monitoring and Analysis of Pipe Jacking Force in the Shenyang Urban Stratum WANG Xueliang1 JI Xinbo2 XIA Mengran1 TAN Zhiming2 HOU Zhiqiang2 ZHANG Jihua2 Jacking force is an important parameter in pipe jacking, proper control of jacking force can guarantee the stability of excavation face and optimize the arrangement of jacking shafts and immediate jacking stations. Based on an analysis of monitored jacking force of flanged steel jacking pipe and reinforced concrete jacking pipe, the variation law of jacking force under different structure styles, materials, diameters and excavation methods of jacking pipes was obtained. The results show that the variations of jacking forces and curve patterns of friction resistance per unit area versus pipe jacking distance are different during construction of steel pipe jacking, manual concrete pipe jacking, concrete pipe jacking with EPB shield and concrete pipe jacking with slurry shield. 2019 Vol. 56 (3): 95-101 [Abstract] ( 753 ) [HTML 1KB] [ PDF 4354KB] ( 1438 ) 102 Optimization of Loosing Circle Support of Stoping Roadway with Large Inclination ZENG Lai1 LIU Yong2 YANG Hongyun2,3 GUO Ping4 With the wide mining of coal seam with large inclination, failure at roof and floor of stoping roadway sig? nificantly affects the safety of mining construction. Based on the six stoping roadways of five mining areas in southwest China, site test was conducted by a geological radar on the loosing circles at roofs and two sides of six stoping roadways with large inclinations, simulation and analysis were performed by 3DEC software regarding the mode of rock mass failure and plastic zone of failure, an areal map of loosing circle of stoping roadway with large inclination was drawn by taking the measured data into consideration, and the support scheme of stoping roadway was optimized. The results show that it will effectively control rock mass failure of stoping roadway and reduce the failure scope at floor and two sides with the scheme of“anchor bolt+ anchor cable+ steel strip”, guaranteeing the safety of mining construction. 2019 Vol. 56 (3): 102-108 [Abstract] ( 739 ) [HTML 1KB] [ PDF 2834KB] ( 1497 ) 108 On Deformation Control for the Shield Passing through Old Embankment to Be Rebuilt in Soft Soil Area JI Chang1 WANG Li2 Regarding safety control of the shield passing through the old embankment to be rebuilt in deep soft soil area in Shanghai, a reinforcement method of vacuum combined with surcharge preloading was determined after comparing several reinforcement methods, the ground deformation was measured at site and pore pressure variation law was obtained during embankment reinforcement with vacuum combined with surcharge preloading, and the embankment surface deformation and tunnel deformation during shield construction underneath the embankment were also measured. The results show that: the risks of shield construction under the old embankment can be well managed;the soft soil within a scope of two times shield diameter beneath the shield tunnel with normal overburden can be reinforced with the method of vacuum combined surcharge preloading; hyperbolic empirical method can well predict the ground settlement of old embankment under the effect of preloading reinforcement; the solidification deformation induced by shield construction passing through pre-reinforced embankment is small 2019 Vol. 56 (3): 108-117 [Abstract] ( 740 ) [HTML 1KB] [ PDF 3624KB] ( 1285 ) 118 Influence of Perforation in Steel Arch on Structural Stiffness WANG Yue SHI Jiyao Steel arch is often used as supporting element in soft rock tunnelling, while it is difficult to control the external angle of advanced condulet when the distance between two rows of steel arch is less than 1 m. In order to reduce the external angle, perforation in web of steel arch was conducted during site construction. A 3D model was established to calculate the deformation of steel arch under different ranges and densities of perforation, and the influence of perforation on stiffness of steel arch and support system was studied. In light of the results of contrast test,measured deformation of primary support, pressure of surrounding rock and internal force of steel arch, it is found that perforation interval is the main factor affecting stiffness of steel arch; for the studied tunnel project, the recommended safe perforation interval of steel arch is 40 cm or larger than 40 cm, with stiffness decrease of the steel arch being less than 4% and the stiffness of primary support being barely decreased. 2019 Vol. 56 (3): 118-124 [Abstract] ( 539 ) [HTML 1KB] [ PDF 4597KB] ( 1365 ) 125 Field Test and Analysis of Mechanical Behaviors of the Self-drilling Hollow Grouting Anchor Bolt for the Tunnel in Sandy Pebble Stratum CAO Xiaoyong1 FENG Zhihua1,3 SHI Yanwen2 SONG Feiting2 LAI Jinxing2 In order to study the support effect of self-drilling hollow anchor bolt in sandy pebble stratum, a drilling test and pullout test were conducted based on a tunnel in sandy pebble stratum of Tibet. The tests show that the average drilling depth of ?25 anchor bolt is 1.50 m which is 42.7% of the designed length, torsion failure or idling occurs when it reaches the limit depth and drilling can′ t go further; the average drilling depth of ?51 bolt without drill bit is 1.15 m which is 38.3% of the designed length, and continuous drilling can′ t be fulfilled; the average drilling depth of ?25 anchor bolt increases by 23.1% when the drill bit is removed and the average drilling depth of ?51 bolt increases by 95.2% when the drill bit is removed; the average pullout force of ?25 bolt is close to the designed value of 50 kN, but the anchoring effect doesn′ t work. 4 optimization measures for construction support were determined based on the test results of anchor bolts, specifically systematic bolts is eliminated to reduce disturbance of sur? rounding rock; the drill bit is removed and the anchor bolt is drilled directly; the group number of feet-lock bolt is increased from 1 to 2 to ensure total support length; the ?25 advanced anchor bolt with a length of 1.8 m is selected instead of the ?51 anchor bolt with a length of 2.5 m. The monitoring data show that convergence deformation of the tunnel increases slightly after scheme adjustment while the crown settlement decreases obviously, the tunnel construction speed increases significantly and the safety is quite improved. 2019 Vol. 56 (3): 125-132 [Abstract] ( 633 ) [HTML 1KB] [ PDF 4574KB] ( 1487 ) 133 Construction Technology for the Shaft of Extra-long Micangshan Tunnel HAN Yuxuan1 LENG Xiqiao2,3 YAN Jinxiu4 ZHANG Rui5 It is often for the extra-long deep-buried road tunnel to adopt sectional longitudinal ventilation with shaft. As a special type of structure, shaft is characterized by challenging construction, much equipments investment and high risks of safety management. Based on construction of a large and deep shaft of the extra-long Micangshan tunnel on the Batao expressway, it discussed the construction technique, equipment matching and management of large and deep shaft in an environment protection area. Short section advancing and single-layer cast concrete lining were adopted in a ventilation shaft of the extra-long Micangshan tunnel, and the construction equipments are mainly head frame, hoisting equipment, drilling equipment and mucking equipment. 2019 Vol. 56 (3): 133-138 [Abstract] ( 755 ) [HTML 1KB] [ PDF 3144KB] ( 1806 ) 139 Study on Construction Sequence of Four Overlapped Bored Tunnels with Small-spacing WANG Meng SHI Mengxiao XU Manji WU Wenpeng Selection and optimization of construction sequence of the small-spacing and overlapped tunnels are key factors affecting construction safety and progress. Based on the four small-spacing and overlapped bored tunnels of Line 4I and Line 9 on Chongqing Rail Transit, the influences of four different construction sequences on ground surface settlement, internal force and deformation of tunnel structure were studied using finite element simulation. The results show that the construction of overlapped mined tunnel causes settlement of ground surface, the closer the overlapped mined tunnels are, the larger the ground surface settlements are; the“lower-upper”construction sequence is superior to the“upper-lower”sequence for controlling ground surface settlement, tunnel crown settlement and lining stress, and construction sequence of the following tunnels has little effect; for the four small-spacing and overlapped mined tunnels, it is optimal to adopt a construction sequence of“lower-upper and left-right”with the ground surface settlement and crown settlement no more than 10 mm, meeting the requirements of technical standards concerned, and the variation law of settlement is consistent with the results of finite element simulation. 2019 Vol. 56 (3): 139-146 [Abstract] ( 625 ) [HTML 1KB] [ PDF 4250KB] ( 1539 ) 147 Exploration of Large Confined Aquifer of the Yonglian Tunnel and Relevant Treatment Measures WANG Deming WU Yueyue SUN Huadong TIAN Shanjun Water inflow and mud burst occurred frequently in the Yonglian tunnel passing through fault fracture zone, seriously affecting tunnel construction and operation safety. Geophysical prospecting and advanced drilling method were used to determine the spatial location, distribution pattern and water abundance of confined aquifer in unfavorable geology body. Based on the exploration results, relevant treatment measures for left and right tubes were conducted, such as in-situ hole cleaning and grouting of the key drill holes with water inflow in left tube, dense hole drilling and grouting of left tube in aquifer zone, thickening of grout curtain reinforcement circle of key sections, water drain and energy release by hole drilling and then grouting in working chamber of right tube. Evaluation of grouting effect and actual excavation result show that the treatment effect of confined aquifer is fine, the strength, stability and permeability of rock mass in aquifer area are significantly improved and the tunnel successfully passes through F2 fault fracture zone with the above mentioned method. 2019 Vol. 56 (3): 147-153 [Abstract] ( 584 ) [HTML 1KB] [ PDF 4976KB] ( 1328 ) 154 Experimental Study on Ground Dewatering of the Soft Plastic Loess Tunnel on the Yinchuan-Xi′an Railway ZHANG Xiaoyu The Yima No. 1 tunnel on the Yinchuan-Xi′ an high-speed railway passes through loess aquifer, the stratum is mainly composed of the soft and plastic loess. And it encountered such construction problems as water leakage, water inflow, softening of tunnel floor, increasing of water content in loess, failure of working face, decrease of rock mass stability and so on during tunnel construction. A experimental test on advanced ground dewatering was conducted, and the results show that by means of ground dewatering it can drain the underground water around main tunnel, reduce the risk of large amount water inflow and underground water pressure; after ground dewatering, the water content of loess decreases from 34.4 % to 27.2 % and the liquidity index decreases from 0.84 to 0.6, the physical properties and stability of loess rock mass are increased. The measured and monitored data show that accumulated crown settlements and deformation rate decrease significantly and the effect of ground dewatering is obvious. 2019 Vol. 56 (3): 154-160 [Abstract] ( 567 ) [HTML 1KB] [ PDF 1847KB] ( 1455 ) 161 Analysis on Construction Schemes and Deformation of Multi-layer Support Structure for a Soft Rock Tunnel under High Geostress LI Yanzong ZHAO Shuang Aiming at the challenge of large deformation control at the crucial mountain ridge section of a soft rock single-track railway tunnel under high geostress, two kinds of construction schemes of‘resisting after releasing” and“releasing after resisting”were proposed. By means of site test and monitoring, the effect of various excavation and support procedures on deformation of four-layer support structure (three layers of primary support + one layer of steel concrete lining) with curved wall was analyzed and summarized, the deformation law of each support layer was obtained. The results show that the deformation control concept of“resisting goes before releasing and resisting is preferred ”is recommended considering construction safety and time efficiency of this crucial mountain ridge section and taking full advantage of time-space effect of deformation control. 2019 Vol. 56 (3): 161-165 [Abstract] ( 597 ) [HTML 1KB] [ PDF 1014KB] ( 1406 ) 166 Some Issues Concerning Construction of High Speed Railway Tunnels and Corresponding Countermeasures：A Case Study of Beitaizi Tunnel on the Beijing-Shengyang Railway KONG Qingxiang ZHAI Renfeng In light of the poor effect of smooth blasting, restriction of excavation progress by step pitch of tunnel construction, occurrence of void and cavity at crown of secondary lining as well as ventilation problem in long tunnels, a thorough analysis was conducted and some countermeasures were proposed based on the Beitaizi tunnel on the Beijing-Shenyang high speed railway. 2019 Vol. 56 (3): 166-171 [Abstract] ( 644 ) [HTML 1KB] [ PDF 3443KB] ( 1240 ) 172 Pre-reinforcement Technology of Shield Tunnelling in Compound Stratum with Sand and Gravel HOU Ceyuan CHEN Tian XUE Hongping It is often to encounter deterioration of tunnelling parameters, decrease of advance rates and so on during shield tunnelling in compound stratum with sand and gravel. Pre-reinforcement techniques, which are composed of two-component grouting on ground and pipe-roof grouting in tunnel, were adopted in phase Ⅲ of Chengdu metro line 1 in compound stratum with sand and gravel. The results show that cutterhead torque and thrust decrease and advance rates increase significantly during shield tunnelling after ground pre-reinforcement, these two pre-reinforcement methods both can improve shield tunnelling in the compound stratum with sand and gravel. 2019 Vol. 56 (3): 172-176 [Abstract] ( 675 ) [HTML 1KB] [ PDF 1532KB] ( 1417 ) 177 Optimization of Mined Construction Method for the Super-large Section Liuhualu Station of Guangzhou Metro SHANG Youlei1 TAN Zhun2 The construction methods of side drift, CD or double side drift are often adopted for the super-large sec? tion metro station, and the construction procedures are complex and construction technique is challenging due to excavation of many pilot tunnels. An optimization was conducted for the mined construction method taken in the largesection metro station considering the actual geological conditions based on the Liuhualu station of Guangzhou metro line 11, and the safety and reliability of the optimized construction method were calculated and analyzed by MidasGTS. The results show this optimized construction method is favorable for reducing construction period, the structural settlement and heaving both meet relevant requirements, and the construction safety and structural reliability can be guaranteed; site monitoring should be strengthened, primary support should be taken in time and secondary lining should be carried out at proper time. 2019 Vol. 56 (3): 177-185 [Abstract] ( 674 ) [HTML 1KB] [ PDF 6357KB] ( 1456 ) 186 Research and Application of New Grouting Technology with Rigid Sleeve Valve Pipe Strand SUN Guoqing PENG Feng ZOU Mingbo Most of the tunnels and underground works of railways, highways and water conservancies to be con? structed in north-west China pass through Tertiary system water-rich silty fine sand stratum, and it is very often to encounter water burst, sand inrush and so on, resulting in slowing down construction progress and threatening construction safety as well as adverse effect on water environment in this region. Based on construction of the Humaling tunnel on the Lanzhou-Chongqing railway in water-rich silty fine sand stratum, a new grouting technology with rigid sleeve valve pipe strand, which plays roles of ground anchoring in longitudinal direction to improve the work face stability, and advanced supporting in radial direction to effective restrain the loosening circle and control tunnel deformation, was proposed. With this new grouting technology applied in the Humaling tunnel, it has successfully solved the difficulties of hole drilling, grout diffusion and injectability, improved grouting effect and efficiency and guaranteed the construction safety of tunnel in water-rich silty fine sand. 2019 Vol. 56 (3): 186-191 [Abstract] ( 733 ) [HTML 1KB] [ PDF 1920KB] ( 1468 ) 192 Recycle Application of the Shield Waste Slurry in Backfill Grouting Material: A Case Study of a Slurry Shield Tunnelling in the River-crossing Fuzhou Metro YANG Zhao1,3 HE Zuhao1,2 LIU Yi1,2 CHEN Peishuai1,2 LI Dejie1,3 A large amount of waste slurry would be generated in slurry shield tunnelling, and it will result in high cost of handling and transportation, even more serious pollution problem. Based on the Houting-Juyuan running tunnel section of the Fuzhou metro, which was driven by a slurry shield underneath the Wulong River, it studied the feasibility to prepare the backfilling grouting material with waste slurry generated from slurry shield excavation, optimized the four factors affecting mortar performance by the orthogonal test, discussed the effect law of water-cement ratio, flyash-cement ratio, cement-sand ratio and specific gravity of slurry on backfilling grouting material. The results show: 1) water-cement ratio and specific gravity of slurry are the main factors affecting mortar consistency, fluidity and bleeding rate; 2) water-cement ratio and flyash-cement ratio are the main factors affecting setting time; 3)water-cement ratio, cement-sand ratio and specific gravity of slurry are the main factors affecting mortar density; 4)by controlling specific gravity of slurry and water-cement ratio the backfilling grouting material can be prepared with good working and strength performances. 2019 Vol. 56 (3): 192-199 [Abstract] ( 713 ) [HTML 1KB] [ PDF 2536KB] ( 1338 ) 200 Development and Application of the Steel-Wood Combined End Formwork for Construction Joints of Tunnel Secondary Lining WAN Li1 ZHOU Leisheng2 SUN Changhai1 Water leakage of construction joints of secondary lining of the mountain tunnels is closely related to the construction technology and quality of tunnels. In light of the construction defects of end formwork of traditional lining jumbo and improving the quality of construction joint of secondary lining as well as speeding up installation of water stop, improvement was conducted to end wood formwork, and a steel-wood combined end formwork was developed based on a tunnel on the second ring road of Jinan city. With this type of formwork, it offers a space for bending of exposed half-range water stop, eliminates the fixing and positioning bars to avoid damaging of water stop, saves installation cost during construction of secondary lining, improves water resistance of construction joints of secondary lining; its segmental design option facilitates processing, installation and demoulding of the end formwork, and significantly improves the construction speed and quality. 2019 Vol. 56 (3): 200-205 [Abstract] ( 721 ) [HTML 1KB] [ PDF 2906KB] ( 1475 ) 206 Application of Innovative Waterproof Board Laying Trolley in the Beitaizi Tunnel YUAN Rongtao1 ZHAI Renfeng2 CHEN Haitao1 Water leakage which is mainly caused by unqualified installation of waterproof board is a common disease for the mountain tunnel, and not only will it affect tunnel aesthetic outlook but also tunnel quality and traffic safetyAiming at the problems concerning equipment of waterproof board laying and construction technology, an innovative waterproof board laying trolley was introduced and the system constitution, working principle and construction technology were described based on the Beitaizi tunnel on the Beijing-Shenyang passenger dedicated line, a comparison with existing equipment for waterproof board laying was conducted in perspective of efficacy and economy. The engineering practice shows that mechanization and automation of waterproof board laying are realized, labor intensity is significantly reduced, work efficiency is increased, operator′ s safety is guaranteed, and construction quality of geotextil and waterproof board are improved by using this innovative waterproof board laying trolley. 2019 Vol. 56 (3): 206-211 [Abstract] ( 605 ) [HTML 1KB] [ PDF 2817KB] ( 1455 )

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