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Quick Search     Advanced Search MODERN TUNNELLING TECHNOLOGY   2016 Vol.53 Issue.4 Published 2016-08-25 Article 1 Concept, Architecture and Key Techniques of Smart Highway Tunnels ZENG Lei- 1 Wang-Shao-Fei- 2, 3 He-Xu-Chun- 2, 3 Ruan-Zhi-Min- 2, 3 In light of the current status of existing highway tunnels in China regarding their enormous scale and difficult management, this paper proposes an concept of smart highway tunnels with new information techniques andthe general architecute with five levels involving sensing, communication, calculation, application and the user. It establishes the five application platforms of intelligent management and control, maintenance management, analytical judgment, disaster prevention and mitigation, and information service based on the core businesses of the tunnel’ soperation and management, with the characteristics of holographic sensing, indepth integration, accurate cognition,optimized decision, cooperative control and efficient management 2016 Vol. 53 (4): 1-8 [Abstract] ( 1890 ) [HTML 1KB] [ PDF 3282KB] ( 3356 ) 9 Study on Performance-Based Seismic Fortification Standards of Highway Tunnels LIN Zhi- Chen- Xiang According to an analysis of the actual degree of seismic damage to highway tunnels under different conditions, and referring to seismic fortification goals for other sectors, such as buildings, bridges, rail transit and railway engineering, the performance-based highway tunnel seismic fortification goals and standards are put forward and compared with the existing standards considering the current economic and technical conditions in China. The results show that the plastic seismic design against the effects of an E2 earthquake is explicitly defined by the“twolevel seismic fortification and two-stage seismic design”given in this paper, which is extremely important for immersed tunnels, shield tunnels and open-cut tunnels and complements the existing specifications and standards. 2016 Vol. 53 (4): 9-15 [Abstract] ( 1344 ) [HTML 1KB] [ PDF 1063KB] ( 2346 ) 16 Rock Classification for a Tunnel Excavated by Rotary Drum Cutter WU Dong-Peng- 1 Yang-Xin-An- 2 In light of the fact that traditional rock classifications for mined tunnels have difficulty meeting the construction requirements for a tunnel excavated by rotary drum cutter (RDC), it is necessary to set up a rock classification system for tunnels excavated by RDC and to understand the influences on RDC excavation. Using the RDC excavation of the Zhaojiawan tunnel as an example, a rock classification is proposed for the RDC excavated tunnel by considering tunnel stability and construction efficiency based on an analysis of the adaptability of the stratum. To be specific, based on characteristics of different surrounding rocks and the normal and secondary excavation velocities,the rock conditions are divided into 5 grades, i.e., A (good), B(fair), C (poor), D (very poor) and E (unsuited for RDC excavation). 2016 Vol. 53 (4): 16-21 [Abstract] ( 1703 ) [HTML 1KB] [ PDF 1212KB] ( 2653 ) 22 The Influences of Enlarged Sections and Ventilation Shafts on Pressure Waves in High-Speed Metro Tunnels LUO Jian-Jun In an effort to address the problems of aerodynamics in intercity rail transit tunnels and the difficulties of setting up relief sheds at tunnel entrances given the speedup of intercity rail transit trains, research on the changing transient pressure through the combination of an enlarged section and ventilation shafts was conducted for a highspeed metro tunnel. Additionally, a numerical simulation of three dimensional compressible, viscous and un-steady flow fields was conducted regarding changing pressure as a high-speed train passes through the enlarged section and ventilation shafts. Research results show that: 1) the enlarged section could decrease the air pressure wave and pressure gradient to some extent; 2) the wave-front pressure gradient and peak of the compression wave is effectively decreased with the placement of the enlarged section at a position 100 m to 150 m away from the tunnel entrance; 3) the length of the enlarged section has little effect on the air pressure variation in the tunnel, and it is ap?propriate for the enlarged section not to exceed the length of the train, i.e., approximately 200 m to 250 m long; 4) increasing the area of the enlarged section could also effectively decrease the pressure wave and pressure gradient in the tunnel; 5) a combination of an enlarged section and ventilation shafts could decrease the pressure wave and pres?sure gradient; 6) the ventilation shaft is positioned 10 m to 15 m within the enlarged section near the entrance of the tunnel. 2016 Vol. 53 (4): 22-28 [Abstract] ( 1493 ) [HTML 1KB] [ PDF 3135KB] ( 2202 ) 29 Geostress Measurement and 3D Multivariate Regression An Geostress Field of the Liangshui Tunnel YU Yun-Yan- 1 Li-Guo-Liang- 2 Zhao-De-An- 3 Chen-Zhi-Min- 1 Wei-Ming-Qiang- 3 Yin-Jian-Min- 4 Li-Yong-Song- 4 A hydraulic fracturing test was conducted on a selected testing hole and seven test sections in the Liangshui tunnel of the Lanzhou-Chongqing railway. The results show that the present stress field of the Liangshui tunnel is dominated by a horizontal stress whose magnitude of stress is extremely high, and the maximum principal stress orientation is N80°W～EW, the same as that of the regional tectonic stress field. Due to the small angle be tween the tunnel axis and the maximum horizontal stress orientation at the testing point, this is a great advantage to the stability of the surrounding rock. Using the practical geological conditions and formation parameters, two largescale 3D computational models were established based on measured geostress values; the gravity stress field and tec tonic stress field wre calculated by ANSYS under four condions regarding the gravity, horizontal compression and shear; a macro extended analysis on the protolith geostress field was carried out by a multiple regression equation. The analysis results show that the horizontal lateral geostress value is between 7.0 and 9.0 MPa, and the horizontal lateral pressure coefficient is between 1.0 and 1.5 in most sections of the Liangshui tunnel. 2016 Vol. 53 (4): 29-36 [Abstract] ( 1937 ) [HTML 1KB] [ PDF 3905KB] ( 2765 ) 37 High-Temperature Mechanical Test for Surrounding Rock of the Shihuoshan Tunnel XU Chong-Bang Based on laboratory tests, the variation laws of several mechanical factors of rock specimens (sandstone) from the Shihuoshan tunnel of Xinjiang were studied, including the wave velocity, mass, triaxial compressive strength, uniaxial compressive strength and elasticity modulus with burning temperatures of 400℃ , 600℃ , 800℃ and 1 000℃. The results show that: 1) the wave velocity changes little for temperatures less than 400℃, while it decreases under temperatures more than 400℃, especially between 400℃ and 600℃; 2) the relationship between the triaxial compressive strength and burning temperature/confining pressure is complex and the variation laws of the triaxial compressive strength and its relevant parameters are different under the critical temperatures just below or above 800℃; 3) the uniaxial compressive strength increases with an increase of temperature when the temperature is below 600℃, while it decreases when the temperature exceeds 600℃. 2016 Vol. 53 (4): 37-42 [Abstract] ( 1420 ) [HTML 1KB] [ PDF 2938KB] ( 2093 ) 43 Heuristic Calculation-Support Vector Machine Method for Parameter Identification in a Rock Rheological Model XU Guo-Wen- He- Chuan- Wang- Wei In light of the precision and efficiency problems related to the traditional inversion method, an inversion for the rock rheological parameters was carried out by introducing the support vector machine, heuristic optimization algorithm and 3D numerical model. Specifically, a non-linear support vector model was established for the relationship between the mechanical parameters and the displacement of the rock mass based on training sample sets provided by a uniform design and a 3D numerical model and the optimal parameters of the support vector model obtained by the heuristic algorithm; for any given set of rock parameters, the extrapolating ability of SVM was used instead of the numerical computation, and an adjustment of the inversion parameters related to the rock′s mechanical behaviors was conducted by an heuristic algorithm and an iteration calculation. Based on the case of the Dujiashan tunnel on the Guangyuan-Gansu expressway, the above inversion method is proven to be reasonable and reliable for guiding parameter design and construction control of a tunnel. 2016 Vol. 53 (4): 43-51 [Abstract] ( 1485 ) [HTML 1KB] [ PDF 4842KB] ( 2337 ) 52 Influence of a Large Karst Cave on Rock Mass Stability during Tunnelling LI Yuan-Hai- 1.2 Yang- Su- 1.2 Yu- Jun- 1, 3 Gan-Kun-Rong- 4 In light of the rock mass stability problem induced by a karst water burst during the construction of the Dayaoshan tunnel on the Wuhan-Guangzhou passenger dedicated line, and based on a FLAC3D numerical simula tion, this paper studies the influence of the karst cave on the rock mass stability and analyzes the filling and grouting schemes for the karst stratum that the tunnel passes through. The results show that: 1) the influence distance of the karst cave is 0~1 times the tunnel′s diameter, and the karst cave on one side of the sidewall has slight influence on the deformation of the other side of the sidewall; 2) there is a tensile failure zone in the rock stratum between the karst cave and the tunnel, with obvious stress and large deformation; 3) filling and grouting can improve the stress state of the surrounding rock and reduce the rock′s deformation and plastic range, and the optimum thickness of the radial grouting circle is 5 m. 2016 Vol. 53 (4): 52-60 [Abstract] ( 1423 ) [HTML 1KB] [ PDF 6793KB] ( 2183 ) 61 Analysis of the Safe Distance between a Karst Tunnel and a Concealed Karst Cave Based on Catastrophe Theory SHI Hai- 1 Bai-Ming-Zhou- 1, 2 Xu-Zhao-Yi- 1 Tian- Gang Based on elastic mechanics, a nonlinear-cusp catastrophic model is built to research the safe distance between the working face and a concealed cave during excavation of a karst tunnel in accordance with catastrophe theory. Two models are established with the rock beam assumed to be an elastic beam with fixed and supported ends of unit-width and an elastic circular plate with fixed and supported periphery. Additionally, a formula is presented for the safe distance concerning catastrophe theory in a case where the working face is skewed or orthogonal to the karst cave with different sizes (i.e., the span of the karst cave is smaller or larger than the diameter of the tunnel),and the factors regarding the safe distance between the working face and the karst caves under the above different spatial states are analyzed. Based on a case study of the Shanghai-Kunming passenger dedicated line (the Guizhou section), it is determined that it is reasonable and feasible to use a cusp catastrophic model to describe the safe distance between the tunnel and concealed karst caves with different spatial states, and this model has certain guidance functions for the construction of karst tunnels. 2016 Vol. 53 (4): 61-69 [Abstract] ( 1433 ) [HTML 1KB] [ PDF 2452KB] ( 2116 ) 70 Influence of Small-Scale Underlying Mined-out Areas with Different Dip Angles in Thin Seam on Tunnel Excavation Stability FU Ya-Peng- 1 Fang- Yong- 2 Cui- Ge- 2 Guo-Jian-Ning- 2 The original equilibrium state of underlying mined-out area is surely to be broken by the approaching construction of highway tunnels, and it will cause stress redistribution. In order to study the influence law of underlying mined-out areas with different dip angles on tunnel construction stability, it used finite element software to build a calculation model of tunnel in mined-out layer, carried out a numerical simulation, studied the influence law of underlying mined-out area with different dip angles on displacements around tunnel periphery, inner force of primary support and the plastic zone. The calculations indicate that the displacement around tunnel periphery increases with the decrease of dip angles of underlying mined-out areas; the distribution discreteness of inner force of primary support increases due to the mined-out area, the axial force of crown is largely influenced by this and characterized by the decreasing of axial force which has a verse relationship with the dip angle; the plastic zone of surrounding rock enlarges, even penetrates through the caving zone of mined-out area and has a verse relationship with the dip angle. Thus the smaller the angle of underlying mined-out area, the higher the construction risk, the worse the stability of surrounding rock and the more unfavorable regarding force applied on structure, which makes it necessary to take effective measures to improve the treatment for underlying mined-out areas. 2016 Vol. 53 (4): 70-76 [Abstract] ( 1448 ) [HTML 1KB] [ PDF 4267KB] ( 2461 ) 77 Prediction and Analysis of Surface Settlement Induced by Shield Tunnelling Adjacent to Buildings DING Zhi- 1 Zhu-Shao-Jie- 2 Qin-Jian-She- 2 Wei-Xin-Jiang- 1 Wang-Fan-Yong- 1 Zhang- Xiao Though the shield tunnelling method is mainly used in metro construction, to a certain extent it affects the existing buildings that are adjacent to the construction site. There is a little research on surface settlement induced by shield tunnelling adjacent to buildings, and the impacts of adjacent buildings and different stiffnesses on the settlement distribution curve are not considered when settlement is predicted using the“Peck” empirical formula. The law of soil deformation caused by shield tunnelling adjacent to buildings is analyzed and it is found that when the surface settlement varies in a cork-shaped distribution curve, skewed distribution curve and normal distribution curve, it indicates that the tunnel is constructed under buildings, within and beyond the disturbance range, respectively. The calculation formulas and relative parameters for a cork-shaped distribution curve and skewed distribution curve are given in this paper. By analyzing calculation examples, the applicability of the surface settlement distribution forms of cork-shaped, skewed and normal curves is verified regarding shield tunnelling at different positions in relation to adjacent buildings. 2016 Vol. 53 (4): 77-83 [Abstract] ( 1339 ) [HTML 1KB] [ PDF 2871KB] ( 2071 ) 84 Application of Wavelet Transform and Kalman Filtering Based GM(1,1) Model in Analyzing Settlement Deformation of High-Speed Railway Tunnels GAO Hong- 1, 3, 4 Wen-Hong-Yan- 1, 2, 3 Li-Yun-Jian- 4 Nie-Guang-Yu- 1, 3 Yang- Zhi- 1, 2 Although the settlement deformation of high-speed railway tunnels is not high, it is possible that a settle? ment curve may not reflect actual settlement deformation due to random noise interference. An RLG denoising method combining a wavelet transform with a Kalman filter is put forward that has the functions of noise-related interference removal and multiple resolution analysis by wavelet transform, and also has the advantages of linear unbiased minimum variance estimation to unknown signals by Kalman filtering. By applying the GM(1,1) model to analyze the data after denoising, it is detemined that the GM(1,1) model combining the wavelet transform and Kalman filtering is higher in precision than that of the GM(1,1) model based only on Kalman filtering and can be used for settlement analysis in high-speed railway tunnels. 2016 Vol. 53 (4): 84-89 [Abstract] ( 1403 ) [HTML 1KB] [ PDF 1909KB] ( 2089 ) 90 Layout Optimization of TBM Gauge Disc Cutters LIN Lai-Kuang- Guo-Jin-Cheng- Xia-Yi-Min- Wu- Yuan In order to study the layout rule of TBM gauge disc cutters, cutter layout principles are put forward as per the actual rock-breaking conditions and the technical requirements of cutterhead design. The optimization goals and constraints are determined, and an optimized multi-targeting mathematical model of a TBM gauge disc cutter is built to analyze its objective function and constraint condition function and solve it by using a genetic algorithm. Finally, the aforementioned model and algorithm are verified based on the TBM gauge disc cutter layout of the NASOUND tunnel in Iran, which is compared with the original layout. The analysis results show that the unbalanced radial force and overturning moment of the optimized cutterhead decrease by 19.4% and 20.6% , respectively; the strength and rigidity of the cuttterhead are improved; and after layout optimization the maximum stress and deformation of the cutterhead decrease by 36.6% and 30.3%, respectively, which proves the correctness and feasibility of the mathematical model for cutter layout optimization.This research method can serve as a theoretical foundation for cutterhead design and modification. 2016 Vol. 53 (4): 90-96 [Abstract] ( 1437 ) [HTML 1KB] [ PDF 2764KB] ( 2206 ) 97 Study on the Failure Modes of a New Tunnel Adjacent to an Existing Building ZHANG Hui-Jian- Chou-Wen-Ge- Kong- Chao The primary impact of construction of a new tunnel adjacent to an existing building is the redistribution of surrounding rock stress, which results in variations to a series of mechanical behaviors. This paper introduces the strength reduction method and the numerical simulation for studying the failure modes during the construction of a new tunnel approaching existing buildings. The results indicate that when the new tunnel is far from the existing buildings, the instability affects only the tunnel itself, not the buildings; however, when the new tunnel is adjacent to the buildings, the rock sandwiched between them is damaged. Based on the different failure modes, the following criteria are presented for judging whether or not the new tunnel construction influences the existing buildings: 1) If the tunnel depth is fixed (namely at a direction of 0°), and when the safety factor obtained by the strength reduction method is tending to be constant, then it can be used as a criterion regarding the inluence. If the tunnel depth is varied (namely not at a direction of 0°), the safety factor can be used as a criterion only when it reaches the peak; 2) Whether or not the slip band indicated by the shear strain increment goes through the sandwiched rock between the tunnel and buildings, it can be regard as the intuitive criterion regarding the influence. The research findings provide a theoretical foundation for managing the safety risk, studying the influence zoning and establishing corresponding standards and specifications in the future. 2016 Vol. 53 (4): 97-101 [Abstract] ( 1330 ) [HTML 1KB] [ PDF 2138KB] ( 1966 ) 102 Strain Monitoring Based Analysis of Concrete Sidewall Cracking in Immersed Tunnels DENG Chun-Lin- 1, 2 Wang-Sheng-Nian- 1, 2 Xiong-Jian-Bo- 1, 2 Fan-Zhi-Hong- 1, 2 Xu-Zhao-Quan- 1, 2 As for an immersed tunnel that was constructed using cast-in-place concrete in two layers, vertical and diagonal cracks were regularly found on the sidewall above the horizontal cast-in-place interface with height of 2 m.In order to analyze the cause of this sidewall cracking, vibrating wire strain sensors were embedded in the bottom plate and sidewall of the immersed tunnel. The results show that: 1) shrinkage strains were found at each monitoring point; 2) shrinkage strains gradually increased from the middle to the end of the sidewall in the horizontal direction;and 3) the shrinkage strains gradually increased from the bottom to the top of the sidewall in the vertical direction.Based on the horizontal tensile stress and shear stress of some of the monitoring points, the plane stress state analytical method was introduced to calculate the maximum principal stress and principal stress angle and to compare them with the development of cracks near the monitoring points. This analysis shows that the maximum principal stress angle is identical to the development direction of the cracks 2016 Vol. 53 (4): 102-107 [Abstract] ( 1590 ) [HTML 1KB] [ PDF 1987KB] ( 2662 ) 108 Numerical Analysis of the Shielding Effect of a 2×2 Passive Pile Group Adjacent to Tunnelling ZHAO Jiang-Tao- 1, 2 Niu-Xiao-Kai- 1, 2 Su- Jie- 1 Yang-Guang-Wu- 3 Xu-Hui-Jie- 4 This paper proves that the application of a numerical simulation method is reliable for studying the influ? ence of tunnel excavation on an adjacent pile group by comparision of the two-phase method and numerical simulation method. Based on the Mohr-Coulomb elastic-plastic yield criterion, a three-dimensional numerical model was established with the finite difference numerical analysis software to study the variation law of the shielding effect of a pile group under different stress release rates, pile spacings and pile lengths. The analysis results show that the stress release caused by tunnelling has little influence on the shielding effect; the curves of the pile group shielding effect coefficient decrease with the increase of pile spacing except for the pile settlement; the influence of pile length difference on the shielding effect is more complicated, because the variation of various indexes does not exhibits the same law with changing of the pile length. 2016 Vol. 53 (4): 108-115 [Abstract] ( 1257 ) [HTML 1KB] [ PDF 2947KB] ( 1898 ) 116 Interference of Metal Materials in Tunnels on the Detection Results by Transient Electromagnetic Method LIU Zong-Hui- 1, 2 Huang-Wen-Bin- 3 Huang-Jun-Ping- 1, 2 Wu- Heng- 1, 2 Wang-Ye-Tian- 1, 2 Zhou- Dong- 1, 2 Combining field detection with physical simulation, it studied the metal interference from drilling jum? bo, steel arch, etc on the detection results by transient electromagnetic method. The results show that: 1) the metallic body behind the working face has some interference on the detection results by transient electromagnetic method, of which the interference coefficient will decrease with an increase of the distance between the metallic body and the detection line, indicating that the results from physical simulation agree well with the ones from field test; 2) the interference coefficient has something to do with the signal strength of detection target, i.e. with a constant location of the metallic body, its interference coefficient will decrease with an increase of the low-resistant anomalous value ahead of working face; 3) to reduce the metal interference during the advance geological forecast, the drilling jumbo shall be at least 30 m away from the working face and the detection line shall be at least 1 m away from the sidewall. 2016 Vol. 53 (4): 116-122 [Abstract] ( 1407 ) [HTML 1KB] [ PDF 3168KB] ( 1962 ) 123 Experimental Study on the Optimal Interval of Exhaust Outlets in a Concentrated Smoke Extraction System JIANG Xue-Peng- 1 Wang-Cheng-Wei- 1 Yu-Nian-Hao- 2 The spacing of exhaust outlets is a key factor for the concentrated smoke extraction system, which impacts the smoke control effect. A 22 m-long tunnel model with 1∶20 scale was used to test the effects of a concentrated smoke extraction system with four bi-directional exhaust outlets opened symmetrically with a spacing of 3 m and 5 m, respectively. A contrastive analysis of the temperature beneath the tunnel roof, spread length and thickness of the smoke layer was then carried out with those two different spacings. Results show that while both of the spacings can meet the requirements of safe smoke extraction in tunnel fires, it is safer and more conservative to choose the 3 m spacing, which means the design of an exhaust outlet with 3 m spacing is better than that with 5 m spacing. 2016 Vol. 53 (4): 123-128 [Abstract] ( 1455 ) [HTML 1KB] [ PDF 2903KB] ( 2249 ) 129 Blasting Vibration Reduction Model for Large-Section Shallow Tunnels Approaching Existing Buildings NIU Ze-Lin- 1, 2 Wu-Huan-Tong- 2 Qi-Yan-Bo- 2 Dai-Ya-Lei- 2 Huang-Jie-Sheng- 3 Wang- Chao- 3 Xiang- Yu- 3 In order to study the effects of blasting construction on structure safety for shallow tunnels with large sections that pass through or approach existing buildings in mountain areas, two blasting vibration reduction models were established based on engineering practices. The findings of the experimental study and analysis of the two models are as follows: 1) during upper bench excavation, the ring vibration reduction model for the bench had a more remarkable damping capacity than the left-and-right alternating vibration reduction model in terms of blasting construction; 2) the rational design of the maximum explosive charge for a single section and the detonator rank are key indicators for controlled blasting; 3) as for controlled blasting construction at the middle and lower benches in shallow tunnels with large sections, the layered and segmented blasting is superior to blasting from left to right. 2016 Vol. 53 (4): 129-133 [Abstract] ( 1321 ) [HTML 1KB] [ PDF 2393KB] ( 2069 ) 134 Construction Technology for the Shield Tunnel Passing under the Existing Metro Line at the Launching End WU Quan-Li- 1, 2 Wang-Meng-Shu- 1 Zhu- Lei- 3 Dong-Xin-Ping- 3 Sun-Zheng-Yang- 4 The construction of a new shield tunnel passing under the existing metro line often causes a superimposi? tion of surface settlement at the intersection area, which threatens the operating safety of the existing line. Based on shield tunnel construction from the Meicun station to the Shangmeilin station of Shenzhen Metro Line 9, this paper addresses the problems of earth-pressure build-up, settlement control and construction safety risks involved with the construction of an underpass adjacent to the shield launching end by using comprehensive technical construction measures and management means. These include: pressure maintenance using a steel sleeve at launching section, shield gap filling by the clay shock method,auxiliary grouting rectification, risk-zoning management, automatic real-time monitoring and theoretical analysis. These measures help to ensure the smooth construction of a shield tunnel under an existing metro line. 2016 Vol. 53 (4): 134-142 [Abstract] ( 1478 ) [HTML 1KB] [ PDF 3456KB] ( 2456 ) 143 Formation and Treatment of the High-Pressure Water Inflow in the Extra-Long Feixianguan Tunnel CHEN Qi-Xue- 1 Jiang-Yong-Shun- 1 Tang- Hao- 2 Using the inflow at K23+708 of the extra-long Feixianguan tunnel on the Yakang highway as an example, the formation mechanism of the water inflow was analyzed based on data from site investigations, monitoring and statistics regarding the time-history characteristics of the inflow; it was determined to exhibit a“combination of draining and blocking with limited discharging.”A comprehensive treatment scheme is put forward that includes temporarily reinforcing the deformed primary support, draining the ground water, employing peripheral grouting with condulets and strengthening the stiffness of inverted arch and lining. 2016 Vol. 53 (4): 143-147 [Abstract] ( 1543 ) [HTML 1KB] [ PDF 2199KB] ( 2082 ) 148 Test Design and Construction Techniques for the Collapse Treatment of a Tunnel with an Extra-Large Section WU Xue-Zhi- 1 Zhang-Shao-Hui- 1 Wang- Jian- 1 Xiao-Chun-Qiang- 2 Using the treatment of a chimney collapse at the portal section of a tunnel with an extra-large section as an example, and based on a field test as well as monitoring and measuring, this paper successfully solves the problem of drilling holes in an overhead fragmental/massive collapsed body by replacing the condulet with a self-drilling hollow anchor bolt and deals with the collapse based on proper support parameters, grouting volume and relevant construction methods. 2016 Vol. 53 (4): 148-153 [Abstract] ( 1263 ) [HTML 1KB] [ PDF 3770KB] ( 2195 ) 154 Safety Analysis of an Existing Tunnel Lining Structure during Water Diversion Tunnel Blasting Construction ZHANG Wen-Xin Because it is affected by water pressure, lining leakage tends to occur in the core region of a karst cave. In order to solve this problem, a water diversion tunnel was constructed at the top of a main tunnel to drain karst water in order to reduce the water pressure around the tunnel lining. Based on construction of a water diversion tunnel for a railway tunnel in western China, this paper shows that the blasting vibration velocity and the structural stress were acceptable and the tunnel structure had basically no deformation and a relatively stable structural stress based on the monitoring of the water diversion tunnel blasting vibration velocity, structural stress and deformation of the main tunnel lining. The monitoring data indicate that construction of the water diversion tunnel had little influence on the main tunnel lining structure, which ensured the stability of the tunnel structure and operation safety of the railway. 2016 Vol. 53 (4): 154-158 [Abstract] ( 1281 ) [HTML 1KB] [ PDF 3890KB] ( 2363 ) 159 Control Technique for Displacement Behind the Working Face of a Shallow-Buried Tunnel in Water-Rich Soft Rock MA Guo-Min- 1 Li-Guo-Feng- 2 Chen-Yu-Liu- 3 Lu-Zhi-Hong- 4 Using the Naxu tunnel on the Funing-Longliu expressway as an example, this paper analyzes the causes of deformation acceleration and the cumulative deformation increment of a tunnel in soft rock, and proposes a combined control technique for displacement behind the working face, i.e. protective arch + locking anchor pipe + steel pipe pile at the invert bottom . The results show that by adopting this method, relative monitoring data decreases significantly and later tends to be stable, the events such as cracking, clearance intrusion and collapse of the primary support are avoided and construction safety is ensured. 2016 Vol. 53 (4): 159-164 [Abstract] ( 1120 ) [HTML 1KB] [ PDF 2476KB] ( 2256 ) 165 Study on Construction Technology for Shield Tunnels Approaching Existing Ancient Buildings WANG Yan-Feng Since the tunnel from Longhualu station to Longchaolu station of Shanghai metro line 12 would pass underneath a thousand-year old monastery—the Longhua Temple—the shield was refitted by adding more grouting holes on the segments before tunneling in order to reduce the settlement and incline of the Longhua Pagoda. With the application of balanced construction and refined management, as well as the adoption grouting reinforcement method after completion of the undercrossing construction, the Longhua pagoda was kept safe and stable while the construction of the subway tunnel was successfully completed. 2016 Vol. 53 (4): 165-171 [Abstract] ( 1244 ) [HTML 1KB] [ PDF 3105KB] ( 2358 ) 172 Design of Dewatering Plan for Trapped Shield in Water-Rich Sand Stratum and Its Effect Analysis TANG Zhuo-Hua- 1 Yang-Xin-An- 2 Xu-Qian-Wei- 2 Gong-Zhen-Yu- 3 Li- Zhou- 3 Zhu-Xue-Chun- 3 In order to release the shield trapped in the consolidated water-rich sand stratum in a Shenzhen subway tunnel, the waterproof curtain by three-axis mixing piles was used to surround the shield in construction site, and the dewatering wells were laid out inside and outside the curtain for drainage. When the water level is down to the bottom of the shield machine, the chamber would be cleaned by hand. The theoretical dewatering arithmetic was used to calculate parameters such as the water inflow due to dewatering inside and outside the curtain and its influence radius, the number and spacing of dewatering wells, as well as the surface subsidence induced by drainage.Based on the relative reasonable initial design scheme of dewatering wells, a numerical simulation was carried out for further confirmation of the rationality and feasibility of the design scheme. The successful practice at site shows that it is very effective to dewater and release the trapped shield by the method combining theoretical arithmetic and numerical simulation, providing a reference to similar projects. 2016 Vol. 53 (4): 172-178 [Abstract] ( 1294 ) [HTML 1KB] [ PDF 2978KB] ( 2005 ) 179 Defect Detection for the Overlying Strata of a Metro Tunnel Based on the Rayleigh Wave Method LU Song- 1 Sun-Xiao-Qiang- 2 Hua-Xiao-Ming- 1 To detect the overlying strata defects for an urban metro tunnel during construction, the Rayleigh wave method was adopted, in which the signal-noise ratio can be increased by avoiding the peak environmental noise hour and improving the coupling between the detector and the hardened ground surface. Furthermore, the detection data were calculated by the simulated annealing inversion method, which has the advantages of reducing the impacts from the initial model and avoiding the local optimization solution. Engineering practices show that the results of the Rayleigh wave method agree well with those of the low-frequency GPR method/core-drilling method/site construction log in terms of abnormal location. 2016 Vol. 53 (4): 179-184 [Abstract] ( 1275 ) [HTML 1KB] [ PDF 2815KB] ( 1855 ) 185 A New Type of Railway Tunnel Lining Jumbo with Grouting through Molds GONG Cheng-Ming- 1 Zhu-Jia-Bin- 2 Dai-Hong-Ming- 3 In order to address quality defects of lining voids, cracking or spalling that occur in operating tunnels, and based on the practices of casting concrete by lining jumbos on site, a conventional tunnel lining jumbo is renovated and new technology is proposed for grouting of the secondary lining with molds . The stubborn void defects existing in conventional secondary linings are solved by injecting the micro-expansion retarded mortar, characterized by good workability and early-strengthening, through an embedded RPC pipe, which improves the quality of the tunnel lining and provides a solid support for safe tunnel operation in the future. 2016 Vol. 53 (4): 185-188 [Abstract] ( 1561 ) [HTML 1KB] [ PDF 2128KB] ( 2501 ) 189 Experimental Study on Energy-Storing Self-Illuminated Multi-Functional Coating for Auxiliary Lighting in Tunnels FENG Shou-Zhong- 1, 2 Gao- Wei- 2 Wang- Jun- 2 Considering that the energy-storing self-illuminated multi-functional coating material would enhance the brightness inside a tunnel and the illumination uniformity of the road pavement, as well as improve visual comfort inside the tunnel, a test model was established to quantitatively analyze this material′s auxiliary lighting effects.The increase rate of brightness, color rendering index (CRI) and light-wave color temperature were tested under different illuminants using an HAAS-2000 high-precision rapid spectroradiometer. The results show that: 1) the increase rate of brightness is more than 25%; 2) its CRI is 3~17 higher than that of the normal material; 3) the deviation ratio of its light-wave color temperature decreases to varying degrees, which helps to improve the visual range of small objects inside the tunnel. 2016 Vol. 53 (4): 189-194 [Abstract] ( 1313 ) [HTML 1KB] [ PDF 2436KB] ( 2147 ) 195 Impact Analysis of the New Quick-Setting Grouts on Groundwater Quality JIN Hua Grouting is an effective means to deal with geological disasters, but it may affect groundwater quality during construction. Using the Shangyuanmen station in Nanjing Metro as an example, this paper examines the influence of the new quick-setting grouts on groundwater quality by selecting eight monitoring points inside and outside the foundation pit and analyzing the sample data with a comprehensive evaluation method. The results show that the water quality factors near the grouting area are greatly influenced, while those outside the grouting area are slightly influenced, indicating that new quick-setting grout is applicable to underground works for which groundwater protection is requested. 2016 Vol. 53 (4): 195-202 [Abstract] ( 1231 ) [HTML 1KB] [ PDF 2639KB] ( 2049 )

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