[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   2019 Vol.56 Issue.4 Published 2019-08-25 1 SCDZ133 Intelligent Multi-function Trolley and Its Application in Tunnelling LIU Feixiang1,2 An intelligent SCDZ133 multi-function trolley with independent intellectual property, which is charac? terized by advanced hydraulic system, unique sliding and manipulator devices, good maneuverability and applicability, multifunction, automatic positioning and profile scanning, was developed based on a lot of research work and development experience, solving the problems of inaccurate installation, high labor intensity, low efficiency and poor effect related to steel arch installation, explosion charging, laying of ventilation pipes and measuring. With the advantages of equipments and experience of tunnel steel arch construction, the first developed“322”steel arch installation technique significantly increases construction quality and efficiency, and promotes the development of the technique of tunnel steel arch installation. 2019 Vol. 56 (4): 1-7 [Abstract] ( 1113 ) [HTML 1KB] [ PDF 3182KB] ( 1405 ) 8 On Driving Strategy of the Shield Machine with Atmospheric Cutterhead in Mudstone Strata ZHOU Wenbo WU Huiming ZHAO Jun Shield tunnelling in mudstone strata confronts severe challenges like low advancing efficiency and high cutter wear rate. Cutter replacing under atmospheric pressure improves the efficiency of cutter replacement and evades the risk of cutter replacement under high pressure, but this inevitably brings about a more serious problem of cutterhead clogging caused by mud cake which accelerates the cutter wearing progress. Based on the river-crossing tunnel at Sanyang road of Wuhan city, it studied the encountered technical problems and corresponding countermea?sures during tunnelling, summarized and evaluated the effect of optimization of cutting tool configuration, reform of central flushing system and mud cake removing by chemical way on improving efficiency of shield driving by a parametric analysis on the monitoring data at site. The results show that the method mentioned in this paper can effectively improve the efficiency of tunnel driving, reduce the frequency of cutter replacement and the risks of shield downtime 2019 Vol. 56 (4): 8-15 [Abstract] ( 859 ) [HTML 1KB] [ PDF 3986KB] ( 1569 ) 16 Research on Anchorage Mechanism of Yielding Support in the Deep-buried Tunnel CHEN Zhuoli1,2 ZHU Xunguo1,2 ZHAO Deshen1,2 WANG Yunping1,2 To investigate the effect of yielding support structure on zonal fracturing of surrounding rock and its an? chorage mechanism in the deep-buried tunnel in stratified stratum, a three-dimensional similar material physical model test of the deep-buried tunnel under high geo-stress was carried out. A contrast study on the four kinds of support structures (rigid lining, rigid lining + yielding anchor bolt, flexible lining and flexible lining + yielding anchor bolt) was taken by laying and tamping the similar materials with proportions of 3∶3 and 4∶3 respectively. The stress test results show that peak stress and trough stress both occur at tunnel crown, spandrel and sidewall in conditions of rigid lining and flexible lining, and it has a tendency of zonal fracturing for the surrounding rock, while the tendency of wave-shape stress variation is declining in condition of rigid lining + yielding anchor bolt, which shows the support structure restrains the tendency of zonal fracturing of rock mass. The strain monitoring results of yielding anchor bolt show that tensile strain and compression strain occur alternatively for the yielding anchor bolt at tunnel crown in conditions of rigid lining and flexible lining, while only tensile strain occurs for the yielding anchor bolt at spandrel and sidewall in condition of flexible lining. The combination support of rigid lining + yielding anchor bolt is significant for restraining zonal fracturing of surrounding rock of the deep-buried tunnel. 2019 Vol. 56 (4): 16-22 [Abstract] ( 841 ) [HTML 1KB] [ PDF 3057KB] ( 1536 ) 23 Case Study Based Analysis of Segment Division Principles of Rectangular Shield Tunnels WANG Quansheng By introducing the cases of prefabricated segments division for rectangular shield tunnelling both at home and abroad, the characteristics of segment division for the existing rectangular shield tunnelling were analyzed. Based on the influential factors to be considered regarding the segment division of a circle shield tunnel, the six division principles of prefabricated segment for the rectangular shield tunnel (including the quasi-rectangular shield tunnel) were presented, which involve requirements for structure mechanical behavior, reduction of segment division numbers and manufacturing costs, as well as handling and erection, arrangement of jacking cylinders, distribution of longitudinal and circumferential bolts, and effect of aspect ratio, it can be taken as a reference for the design and construction of the rectangular shield adopted in underground passage, metro and underground utility tunnel. 2019 Vol. 56 (4): 23-29 [Abstract] ( 846 ) [HTML 1KB] [ PDF 3660KB] ( 1644 ) 30 Study on Optimum Excavation Height of Middle Bench in an Underground Cavern Based on Q System Design ZHANG Heng1 ZHU Yimo1 LIN Fang1 CHEN Shougen1 YANG Jiasong2 In order to determine the optimum excavation height of middle bench in an underground cavern based on Q system design, taking the large underground oil storage cavern in Jinzhou for example, the Q value method was compared with other rock mass classification methods and the mathematic function relationship was established among the Q value, RMR value and BQ value on basis of the statistics of Q value, RMR value and BQ value at site.The effect of different bench heights on excavation deformation and stress, and the distribution scope of the maximum values under different rock mass conditions were analyzed by numerical simulation and site monitoring. The research results show that the vertical and horizontal displacements increase with a decrease of Q value under the same height of middle bench; the height of middle bench has little effect on vertical and horizontal displacements in condition of same Q value; different heights of middle bench under different Q values have significant effect on the maximum horizontal and vertical stresses and the locations. Reasonable heights of middle bench were proposed considering the maximum stress and the location. 2019 Vol. 56 (4): 30-37 [Abstract] ( 904 ) [HTML 1KB] [ PDF 4450KB] ( 1426 ) 38 Geological Survey on Breakthrough Section of the Large-section Karst Tunnel by Radio Wave Penetration Method LI Hao It has high risks for the construction of breakthrough section of a large-section karst tunnel, and water burst, mud burst and collapse are often encountered. Accurate geological survey is one of the key measures to realize safe and efficient breakthrough of a tunnel, however it is difficult to meet the accuracy requirement of exploration by traditional geophysical prospecting of reflective seismic wave or electromagnetic wave. A penetration prospecting of geological condition of breakthrough section of a large-section karst tunnel was conducted by radio wave penetration method considering the high reliability of penetration geophysical prospecting and spatial characteristics of the breakthrough section of the tunnel, a small dot pitch based radio wave penetration prospecting for the large-section tunnel was proposed and successfully applied in the construction of Huayingshan tunnel, and good results were obtained and no water burst occured. 2019 Vol. 56 (4): 38-42 [Abstract] ( 979 ) [HTML 1KB] [ PDF 1762KB] ( 1724 ) 43 Study on Gas Hazard Assessment of Yangshan Tunnel on Inner MongoliaJiangxi Railway CEN Peishan1 TIAN Kunyun2 WANG Ximin3 Gas emission occurred many times at the pondings of some sections after excavation of invert arch of Yangshan tunnel on Inner Mongolia- Jiangxi railway, threatening the tunnel construction to a large extent. In order to determine the gas grade of Yangshan tunnel, gas occurrence laws of coal measures and shallow oil and gas reservoirs in tunnel work area were studied, and the gas hazard of coal measures and shallow oil and gas reservoirs was evaluated by an identification method for gas burst hazard and drill-hole based gas volume model. The results show that the disclosed coal seam of tunnel work area is located at gas weathering zone and there is no risk of gas burst;the main source of tunnel gas is the Yanchang 1 oil and gas reservoir below the tunnel base, gas emits through tectonic fracture zone or joint fissure zone, the maximum gas emission at work face is 0.23 m3/min, so this is a tunnel with low gas. 2019 Vol. 56 (4): 43-49 [Abstract] ( 950 ) [HTML 1KB] [ PDF 1499KB] ( 1613 ) 49 Centrifugal Model Test on Long-term Settlement of Shield Tunnels in Soft Soils ZHU Jianfeng1 GONG Quanmei2 Large settlement or differential settlement of shield tunnels built in soft soils occurs in long-term service,affecting performance of segment structure and operating safety. On the background of Foshan metro line 3, this article studied the development law of medium and long-term settlement of shield tunnels in soft soils with different thicknesses and the influence of subsoil reinforcement on long-term settlement by centrifugal model test. The results indicate that the worse and thicker the underlying stratum of tunnel is, the larger the long-term settlement is,and the longer the long-term settlement development is. At the same time, long-term settlement increases under large buried depth; long-term tunnel settlement and ground surface deformation decrease with an increase of foundation soil reinforcement depth, but the decrease extent reduces gradually, and the long-term settlement decreases by 16.7%, 30.2% and 41.3% respectively when the reinforcement depths of foundation soil are 3 m, 6 m and beyond the soft soil, and the ground surface deformation right above the tunnel decreases by 25.4%, 44.9% and 66.3% respectively 2019 Vol. 56 (4): 49-55 [Abstract] ( 924 ) [HTML 1KB] [ PDF 2728KB] ( 1342 ) 56 Prediction of Tunnel Settlements by Optimized Wavelet Neural Network Based on ABC CHEN Youzhou1 REN Tao2 DENG Peng2 WANG Bin3 Since the wavelet neural network has the defects of slow convergence rate and proneness of local opti? mum, while the artificial bee colony algorithm is capable of local and global search, an optimization of wavelet neural network (WNN) was conducted using artificial bee colony (ABC) algorithm to form artificial bee colony-wavelet neural network (ABC-WNN) and it was applied to prediction of settlement of metro tunnels. Taking the Shenzhen metro line 10 for example, a comparison and analysis were carried out regarding the predicted results and that of BP neural network (BPNN) and WNN. The results show that the prediction result of ABC-WNN is more accurate and stable than that of other two models. 2019 Vol. 56 (4): 56-61 [Abstract] ( 959 ) [HTML 1KB] [ PDF 2432KB] ( 1534 ) 62 Reflection on Disease Treatment and Design Issues of Unconventional Rockburst of Bamiao Tunnel on Taoyuan-Bazhong Highway WANG Dengmao TENG Zhennan TIAN Zhiyu CHEN Zhixue The maximum buried-depth of Bamiao tunnel on Taoyuan-Bazhong highway is 312 m, the rock stratum is nearly of horizontal form and it presents as interbed of sand and mudstone. Unconventional rockburst events occurred during the tunnel construction, and a series of diseases were found at these sections after operation. The causes of the diseases were summarized by analyzing the phenomena and data as well as the results of special tunnel inspection. Based on the on-site geostress test results during construction, it was assumed that the seriously cracked secondary lining was in the critical state of failure, thus the load borne by the structure was deduced. The formula for calculating safety coefficient of concrete structure with additional lining was deduced, and the relationship between the safety coefficient of tunnel with additional lining and the thickness of additional lining was obtained. 2019 Vol. 56 (4): 62-68 [Abstract] ( 939 ) [HTML 1KB] [ PDF 3409KB] ( 1434 ) 69 Analysis on the Causes of the Large Deformation of Surrounding Rocks of Milashan Tunnel in Tibet WU Shuyuan1 CHENG Yong1 XIE Quanmin2 LIU Jiguo1 CHEN Biguang1 Large deformation of tunnel surrounding rocks is a sophisticated problem during tunnel construction. Taking the large deformation of surrounding rocks of Milashan tunnel in Tibet for example, the causes of large deformation were studied by site investigation and experimental analysis. The results show that properties of tuff such as poor weather resistance and softening upon meeting water are the two radical reasons of large deformation, and improper construction technology is a main inducement. A treatment scheme and control measures were proposed based on an analysis of causes of large deformation of Milashan tunnel 2019 Vol. 56 (4): 69-73 [Abstract] ( 929 ) [HTML 1KB] [ PDF 2060KB] ( 2057 ) 74 D-P Yield Criterion Based Elastoplastic Solution of the Circular Pressure Tunnel WANG Sui1,2,3 ZHONG Zuliang3 LIU Xinrong3 WU Bo1,2,4 ZHAO Yongbo1,2 LI Zhantao1,2 With the construction of large-scale water conservancy projects in China, many deep-buried hydraulic pressure tunnels have been built. The principal stress of tunnel lining and surrounding rock will be changed under different conditions of construction and operation for the deep buried pressure tunnel. Based on D-P yield criterion,the elastoplastic solution of the deep-buried circular pressure tunnel was derived when the first principal stress is the radial stress or tangential stress under the condition of plane strain. The research shows that the calculated values by this model were consistent with the calculated values by M-C criterion, which verifies the correctness of this model and it is more conservative compared with the calculated results by M-C criterion; radiuses of plastic zones of lining and surrounding rock will change in different stresses levels and internal water pressures; plastic zone distribution can be divided into five stages and the yield radius of lining develops faster with an increase of internal water pressure during high water pressure stage. 2019 Vol. 56 (4): 74-80 [Abstract] ( 981 ) [HTML 1KB] [ PDF 1266KB] ( 1502 ) 81 Analysis of Fluid-Solid Coupling Effect during Excavation of the Water-rich Large-section Loess Tunnel LI Ming YAN Songhong PAN Chunyang ZHANG Xubin The water content of loess layer of the tunnel body with a large section in the rear distribution area of Donggang station of Lanzhou rail transit line 1 is about 28.5% and the saturation is over 95%, which induces large settlement of primary support and long time to get stable for the surrounding rock. Based on the data of laboratory geotechnical test, a three-dimensional finite element model was established, the mechanical and deformation charac?teristics of primary support, ground surface settlement and pore water pressure distribution during construction by CRD method and double side drift method were compared and analyzed based on fluid-solid coupling and uncoupling effects. The results show that the ground surface settlement, vertical and horizontal displacements and their increase rates of primary support considering the effect of fluid-solid coupling are larger than that without considering the effect of fluid-solid coupling, there is no significant decrease in the later period and they are closer to the measured values at site, while there is no big change of mechanical behavior; it is more favorable to adopt the construction method of CRD with six excavation sections to control ground surface settlement and tunnel deformation based on fluid-solid coupling effect and the force applied on primary support are approximate under the two construction methods but the distribution forms is different; under the effect of fluid-solid coupling, the places with large hydraulic gradient of groundwater are mainly located at tunnel sidewall and invert, which is prone to leakage during construction, and compaction of shotcrete at crown and backfill grouting should be carried out to prevent the seepage field from shifting. 2019 Vol. 56 (4): 81-88 [Abstract] ( 985 ) [HTML 1KB] [ PDF 4167KB] ( 1667 ) 89 Extension Assessment Model for the Risk of Water Inflow in Karst Tunnels and Its Application ZHANG Kai1 CHEN Shougen2 HUO Xiaolong3 TAN Xinrong4 It is prone to encountering water inflow for the karst tunnel. An extension model for assessing the risk of water inflow in karst tunnels was established, in which a multi-index evaluation system of water inflow in karst tunnels was set up and the evaluation indices were nondimensionalized; a matter-element to be evaluated was built based on the measured data of the evaluation indices of water inflow in karst tunnels; comprehensive weighting method was used to assign weights for the evaluation indices, the objective weights are determined by measured data based correlation function, and the subjective weights are determined by fuzzy analytical hierarchy process based on the expert knowledge; the correlation function value of the matter-element to be evaluated with respect to the risk grades of water inflow was calculated, and the maximum correlation degree principle was adopted to determine the risk grade of water inflow of the tunnel to be evaluated; the variable characteristic value was calculated to determine the tendency of the risk grade being classified to the next risk grade. This extension model was used to assess the risk of water inflow of a section of certain karst tunnel and the assessment results agree well with the measured data, verifying the reliability of this extension assessment model. 2019 Vol. 56 (4): 89-96 [Abstract] ( 891 ) [HTML 1KB] [ PDF 1267KB] ( 1593 ) 97 Site Data Based Prediction of Shield Driving Performance in Compound Strata LI Jie1 ZHANG Bin1 FU Ke1 MA Chao1 GUO Jingbo1 NIU Decao2 Performance prediction of shield driving plays an important role in evaluation of construction period and construction cost. Taking a construction lot of Guangzhou- Dongguan-Shenzhen intercity rail transit for example, a multivariate nonlinear regression analysis on advance rate of the EPB shield with diameter of 8.8 m in compound strata was conducted based on site data, a direct multivariate nonlinear prediction model, and a multivariate linear prediction model after linear treatment were established, the predicted and actual advance rates of the same section were compared. The results show that the error of advance rate measured by direct multivariate nonlinear prediction model is 9.035% compared with the actual advance rate, while the error of advance rate measured by multivariate linear prediction model after linear treatment is 5.987% compared with the actual advance. 2019 Vol. 56 (4): 97-104 [Abstract] ( 894 ) [HTML 1KB] [ PDF 2646KB] ( 1415 ) 105 Study on Driving Posture and Deviation Correction Curve of the Shield Machine LIU Cheng GUAN Huisheng XIE Youhui SONG Yingpeng The posture problem of the shield machine during tunnelling might affect the tunnel construction quali? ty. In this paper, the posture parameters of shield machine were expounded, and the designed tunnel axis was divided into horizontal alignment and vertical alignment. Through an analysis of the effect of shield tail gap, articulated device, and stroke difference of thrust cylinders on the minimum radius of deviation correction curve, the range of minimum deviation correction radius was obtained. Based on the Winkel foundation model, the relation between deviation correction moment and the minimum radius of deviation correction curve was derived. Based on a research of existing deviation correction curves, an optimized deviation correction curve model of horizontal alignment was put forward. The simulation results show the deviation correction curve meets the requirement, and the obtained variation curve of deviation correction moment based on changes of curvature radius of deviation correction curve accords with the law of thrust changes of hydraulic cylinders during practical deviation correcting. 2019 Vol. 56 (4): 105-112 [Abstract] ( 652 ) [HTML 1KB] [ PDF 2898KB] ( 1809 ) 113 Calculation Model of Earth Chamber Pressure during Non-Barrier Launching of EPB Shield LIU Jun1 NAN Zhiling1,2 JIN Xin3 Pressure in earth chamber can′ t be built up in time during conventional launching of EPB shield since it needs to manually remove the retaining structure of steel reinforced concrete in advance. Even though water stopping and reinforcement are carried out at the tunnel entrance, but the problems of soil mass collapse, water inflow and sand gushing can′ t be thoroughly solved. In view of this a calculation model of earth chamber pressure during nonbarrier launching of EPB shield was established by building retaining structure of fiber glass reinforced concrete at tunnel portal, and a formula to calculate earth chamber pressure during non-barrier launching of EPB shield was presented. The application of this calculation model to Beijing metro line 16 shows the calculation model can reflect the build-up process of earth chamber pressure, and the volume of added material like soil and so on before launching is a key factor related to build-up of earth chamber pressure 2019 Vol. 56 (4): 113-118 [Abstract] ( 639 ) [HTML 1KB] [ PDF 2001KB] ( 1513 ) 119 Influence of Construction Sequence and Different Types of Pipes on Ground Surface Settlement Caused by the Construction of Two-layer Jacking-pipes AN Guanfeng1,2 WANG Tan1,2 SI Haifeng1,2 LIU Tianjun1,2 Aiming at the ground surface settlement caused by two-layer jacking-pipes construction and its influen? tial factors, a three-dimensional model was established by finite element software to simulate and calculate pipejacking construction under considering interaction of bulkhead pressure, ground loss and grouting, to discuss the impact of construction sequence and pipe type on ground surface settlement. The results show that the maximum settlement caused by two-layer jacking-pipes construction occurs on the upper side of the lower jacking pipe and it reduces by 17.84% with the excavation of upper jacking-pipe, and the heaving at lower side barely changes; the main affected area of ground surface settlement is within the scope of - 3.2D1~3.2D1 around the jacking-pipe axis; the maximum ground surface settlement caused by the antecedent construction of the lower jacking-pipe occupies 78.05% of the total settlement; subsequent excavation of the upper jacking-pipe results in obvious heaving in front of it, the total settlement decreases and ground surface settlement increases after passing of jacking-pipe head, the maximum settlement increases by 21.95%, the increasing and attenuation rates of ground heaving both reduce with the advance of jacking-pipe; the ground surface settlement caused by the precedent construction of the upper-layer jacking-pipe increases largely by 20.5% compared with that of precedent construction of the lower-layer jackingpipe; the ground surface settlement caused by concrete jacking-pipe is larger than that of steel jacking-pipe, the maximum settlement increases by 26.13% and the affected scope increases to -4.8D1~4.8D1. 2019 Vol. 56 (4): 119-126 [Abstract] ( 612 ) [HTML 1KB] [ PDF 4041KB] ( 1348 ) 127 Sensitivity and Its Impact of Strata Parameters on Ground Surface Settlements during Shield Tunnelling ZHANG Yang1 LIU Shannan1 WU Jun1 CHEN Jiakang1 XIAO Xiaochun2 LI Lei2 During the construction of shield tunnels, the changes of strata parameters have impact on ground sur? face settlements. Based on the Shanghai Beiheng channel project, the law of impact of cohesion, internal friction angle and compression modulus on ground surface settlements was summarized by 3D numerical analysis, and the sensitivities of strata parameters to ground surface settlements were obtained. The results show that the ground surface settlement is significantly reduced with an increase of cohesion, internal friction angle and compression modulus of shield tunnels with different buried depths; the cohesion has the lowest sensitivity to ground surface settlement and the stratum compression modulus has the highest sensitivity to ground surface settlement. 2019 Vol. 56 (4): 127-134 [Abstract] ( 634 ) [HTML 1KB] [ PDF 3112KB] ( 1648 ) 135 Research on Evolution Law of Freezing Temperature Field in Seepage Formation of Fractured Rock Mass without Filling CHEN Xin1, 2,3 ZHANG Ze1 LI Dongqing1 ZHOU Panfeng4 ZHANG Hu1 The solution of freezing temperature field under effect of seepage is a kind of multi-field coupling, and the moving boundary, phase change, internal heat source, temperature field and seepage field affect each other. A model coupled seepage and temperature with phase change of fractured rock mass without filling was established.The influence of spacing of frozen tubes on the evolution of frozen walls under the function of seepage of fractured rock mass without filling was studied by single factor method. The results show that the spacing of frozen tube and the frozen wall closure time can be fitted with an exponential function. The larger the freezing tube spacing, the longer the frozen wall closure time, the larger the increase and the longer the freezing time required to form same interface frozen wall thickness; there is a critical value for the spacing of the frozen tubes, after this value is exceeded,the freezing time required for forming the same interface frozen wall thickness increases sharply with an increase of the spacing of freezing tube, and the longer the spacing of freezing tube, the longer the freezing time required to drop the average temperature of frozen wall to the designed temperature. 2019 Vol. 56 (4): 135-142 [Abstract] ( 681 ) [HTML 1KB] [ PDF 2130KB] ( 1299 ) 143 Modeling and Analysis of Temperature Field of Tunnel Concrete Structure with Cold Plates QIU Peiyun1 SHI Rongjian2 It is common to lay a cold plate on the concrete structure to improve freezing effect during tunnel con? struction by freezing method. Taking a water blocking project by freezing method on Guangzhou-Foshan line of Guangzhou metro for example, a numerical calculation model of temperature field regarding the cold plate applied on the tunnel structure was established with Ansys software based on existing theoretic researches, and the factors affecting freezing temperature field were analyzed. The results show that the distribution curves of temperatures on main face and interface of frozen wall varying with depth are of the logarithmic curve form, the temperature difference on the main face is large at the first freezing stage and it becomes small with the time of freezing; the temperature distribution curve on the interface between segment and soil mass near the cold source is of the parabolic form and it gradually transits to a flat curve in the distance; the temperature on the interface is obviously lower than that on main freezing face after ten days of freezing in the case of small interval of cold plates due to superposition of double cold plates, and the freezing effect of the interface is better than that of the main face. The cooling rate significantly slows down and the increase of freezing scope is small after 40 days of freezing; there is an optimal interval for cold plates in the case of keeping all parameters unchanged, which makes the frozen wall thickness on the interface being maximum. 2019 Vol. 56 (4): 143-148 [Abstract] ( 611 ) [HTML 1KB] [ PDF 3531KB] ( 1263 ) 149 Research and Practice of Vertical Shaft Construction Technology for the Cangshan Tunnel Project SUN Chensheng With the construction of domestic road projects in mountainous and hilly areas, more and more extralong road tunnels have been built. And the shaft is one of the key parts of tunnelling. However there are little rele? vant experience and a few codes and specifications for the design and construction of tunnel shaft. Based on the shaft construction of the Cangshan tunnel on Wutaishan-Yuxian expressway, comparison and selection were conducted regarding shaft construction scheme and main construction equipment (raise boring machines) in view of downward boring method and raise boring method, and the control measures for shaft construction were described in detail. The results show that significant effect of environmental protection was obtained and less land was occupied for this tunnel shaft constructed by raise boring method. This technology has a prospect to be promoted widely since the vegetation won′t be destroyed and the environment won′t be impacted due to mucking inside the tunnel. 2019 Vol. 56 (4): 149-153 [Abstract] ( 670 ) [HTML 1KB] [ PDF 1269KB] ( 1656 ) 154 Horizontal Directional Drilling and Grouting Technique for the Shield Tunnel Passing beside Buildings in Water-rich Sand Stratum YUAN Dongfeng1, 2 LI Fangzheng1, 2 ZHOU Yuliang1, 2 YUAN Hui1, 2 GAQ Xiaogeng1, 2 LIU Shujie1, 2 During shield construction of metro tunnels approaching the buildings, it is necessary to conduct grouting reinforcement for the soft and unconsolidated soil layers above the shield-driven tunnel to avoid damage of buildings caused by excessive uneven settlement, but it is difficult to implement for most of the traditional ground reinforcement techniques due to site coordination problem. The horizontal directional drilling and grouting (HDDG) technique was adopted to reinforce the water-rich sand stratum underlying the Xingzhongwei building group, taking the Dengcun-Jiangpu running tunnel project of Guangzhou metro line 14 as background. With combination of MWD (measurement while drilling) and HDD( horizontal directional drilling) techniques, horizontal grouting holes were drilled along the alignment of the shield tunnel, and repeated grouting at positioned points can be achieved by combining grouting valve tube and grouting packer. Practice proves that this new technology plays a significant role on controlling of uneven settlement of ground surface during shield tunnelling approaching buildings. 2019 Vol. 56 (4): 154-159 [Abstract] ( 625 ) [HTML 1KB] [ PDF 3040KB] ( 1469 ) 160 Construction Techniques of Shield Tunnels Approaching Existing Metro Tunnels in Soft Ground at Seafront Areas LIU Jianguo XU Tianhua SONG Chengpeng The running shield tunnel of Qianwan station-Guiwan station on the southern extension line of Shen? zhen Metro Line 5 passes closely over the existing tunnel of Shenzhen Metro Line 11, the overlapped region is located in the soft silt stratum at the seafront, a lot of buildings and underground structures are under construction nearby and they are greatly affected each other. To prevent from over-deformation or failure of the existing tunnel on metro line 11 during the construction of new shield tunnel, some preparation measures like supplementary geological survey, reinforcement of soil mass, additional reinforcement and sleeve valve grouting reinforcement were adopted before construction of the Qianwan-Guiwan running tunnel, and sectional construction, parameter adjustment, strict control of shield driving, quality management of segment erection, conditioning of soil mass, simultaneous grouting and compensation grouting were taken to ensure safe shield construction. The construction monitoring results show that the maximum tunnel displacement of metro line 11 induced by the shield construction of Qianwan-Guiwan running tunnel is 5.0 mm, meeting the safety requirements of metro protection. 2019 Vol. 56 (4): 160-167 [Abstract] ( 623 ) [HTML 1KB] [ PDF 4948KB] ( 1496 ) 168 Influence on Deformation and Control Measures: A Case Study of Bored Running Tunnel Construction Adjacent to Existing Subway Tunnels LI Junjie Aiming at the structure deformation and ground surface settlement caused by construction of a new tun? nel approaching existing tunnel, the comprehensive control measures like grouting reinforcement of soil mass of the existing metro line, pre-supporting of newly bored running tunnel, strict control of construction technology, monitoring and early warning were proposed based on the bored running tunnel of Chengdu metro line 8 passing beneath existing shield-driven running tunnel of Chengdu metro line 7. The key points of dewatering and drainage, pipe-roofing and ductile grouting were described. The research shows that the monitoring data present a strong correlation with the construction process, the maximum ground surface settlement is up to 9-10 mm, while the maximum ground surface settlement of monitoring section with the comprehensive control measures is less than 7 mm, and the maximum settlement of the existing metro tunnel structure is less than 6 mm, meeting the requirements of design and specification. 2019 Vol. 56 (4): 168-174 [Abstract] ( 688 ) [HTML 1KB] [ PDF 4515KB] ( 1415 ) 175 Formation Mechanism and Treatment Measures of Special Mud Cake for Shield Tunnelling in Sandy Cobble Strata WANG Zhenyong1 DONG Zhenyong2 JIANG Yusheng1 DONG Linwei1 XIONG Yunchao1 YANG Jianan1 A kind of special mud cake might be formed in earth chamber during shield construction in water-rich sandy cobble stratum, which causes many difficulties for smooth construction. Based on the running tunnel section of Xiyuan station-Wanquanheqiao station of Beijing metro line 16, the special mud cake formed during shield tunnelling in sandy cobble strata was studied, the formation mechanism and basis of pre-judgement of special mud cake were analyzed; a kind of new mixed solution which can better dissolve the mud cake was developed through dissolution test; the treatment and control technologies for the special mud cake were proposed in light of the test results. Case application shows that the problem of special mud cake has been well solved and the solution can be used to dissolve mud cake when it′s not convenient to open the chamber. 2019 Vol. 56 (4): 175-181 [Abstract] ( 617 ) [HTML 1KB] [ PDF 3117KB] ( 1306 ) 182 Application of Jacking Technology with Adjustable Counter Weights in Box Culvert Construction above Existing Metro Tunnels XU Futian The comprehensive utility tunnel in the Beijing sub-center project passes above the shield-driven run? ning tunnel between Haojiafu station and Dongxiayuan station of Beijing metro line 6, the box culvert jacking technology is designed to construction the utility tunnel and it is prone to resulting in excessive vertical displacement of the existing metro tunnel during jacking construction. The key technical points concerning structure counter weight,jacking force calculation and jack configuration as well as controlling of axis and elevation variations of box culvert structure were introduced in detail. Reinforcement measures of soil mass at both sides of jacking area by high pressure jet grouting pile and soil mass beneath box culvert by deep-hole grouting were carried out, decreasing the frictional resistance induced by tunnel excavation and improving bearing capacity of the strata above the existing metro tunnel. The monitoring data show that the deformation of the existing metro tunnel caused by jacking construction is strictly controlled within the scope of the requirements of metro operation and design. 2019 Vol. 56 (4): 182-187 [Abstract] ( 720 ) [HTML 1KB] [ PDF 1966KB] ( 1614 ) 188 Analysis on Dewatering Test of Foundation Pit in Stratum with Small Permeability REN Wei1 WANG Song2 WANG Long3 It is often to encounter silt clay with small permeability during excavation of metro foundation pit, and difficult to dewater effectively with tube well method, the residual water could significantly affect the safety of foundation pit. Dewatering test and numerical simulation were conducted to study the dewatering techniques by tube well and vacuum tube well. The results show that the volume of water inflow in condition of vacuum tube dewatering is 1.1-1.4 times larger than that of tube well method, with obvious time effect and shorter construction period; the drawdown in condition of vacuum tube well is 1.2-1.6 times larger than that of tube well method; the phreatic line of dewatering is more flat and the affected radius of dewatering increases significantly, which is favorable to increase interval of dewatering wells and obtain good economic benefit. 2019 Vol. 56 (4): 188-193 [Abstract] ( 697 ) [HTML 1KB] [ PDF 2419KB] ( 1298 ) 194 Experimental Study of Soil Conditioning with Foam for the Shield Tunnel in Composite Stratum ZHOU Jixue1，2 Blow-out, mud cake, high torque of cutterhead and serious wear of cutting tools could be encountered during long distance shield driving in the composite stratum. A foam based soil conditioning experiment was carried out by a self-made foam generator, and the variations of various physical parameters of soils of completely weathered stratum, composite stratum or strongly weathered stratum under different injection rates of foam were analyzed. The results show that the permeability coefficient, cohesion and internal friction angle of soils could decrease effectively by foam injection; the permeability coefficient may decrease to 10-6 m/s by the foam with injection rate of 20%, meeting the requirement of permeability resistance of shield tunnel construction; the optimal foam injection rates meeting the requirement of“plastic flow”of soil mass under ideal condition are 30%, 10% and 10% respectively during shield construction in strongly weathered stratum, composite stratum and completely weathered stratum. 2019 Vol. 56 (4): 194-199 [Abstract] ( 531 ) [HTML 1KB] [ PDF 6209KB] ( 874 ) 200 Study on the Comprehensive Treatment Techniques for the Floor Disease during Operation of a Railway Tunnel in Swelling Rock Mass WANG Wutian Cracking and heaving occurred at the floor of a railway tunnel during operation, endangering the traffic safety. An analysis on the causes of diseases was conducted in terms of formation lithology, groundwater and construction factors, and a comprehensive treatment scheme was proposed, including compacted grouting reinforcement at the tunnel floor, low-pressure epoxy grouting at cracks of track slab (BICS method) and high-pressure injection of cement grout at longitudinal cracks of the floor. The monitoring results of treatment show that tunnel invert and track slab are in a tendency of heaving with a small rate, and the accumulated heavings (180 d) are between 0.5-1.6 mm, which indicates it is basically in a stable state. 2019 Vol. 56 (4): 200-204 [Abstract] ( 614 ) [HTML 1KB] [ PDF 1305KB] ( 1746 )

More>>   · · More>>

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