Journal of Railway Engineering Society

关闭×

The mobile platform

Office Online

Journal Online

Archive

Member Service

2022 Vol. 39, No. 5 Published: 2022-05-15

Engineering Economy and Management Main Line: Engineering Geology and Subgrade Main Line: Railway and Rail Main Line: Communication Signals Main Line: Bridge Engineering Main Line: Tunnel Engineering Main Line: Electrification Engineering

Main Line: Engineering Geology and Subgrade

	1	Experimental Research on the Mechanical and Deformation Characteristics of Anti-slide Structure with I-shaped Plate
		ZHENG Jing, AN Mengkang, LU Changming, SU Junxia
		Research purposes: The existing anti-slide structures are still mainly rectangular and circular section anti-slide piles, but their material consumption is larger, and there is space for further optimization. Therefore, this paper proposed a new anti-slide structure of I-shaped plate, its stress and deformation characteristics, the setting and connection of web plate need to be studied through experiments, in order to provide a basis for theoretical calculation and design. Research conclusions: (1)The deformation of the I-shaped plate anti-slide structure is related to the depth and connection of the web. The deeper the web is set, the smaller the displacement of the top of the structure and the stronger the deformation resistance. The anti deformation ability of cast-in-place rigid joint structure is stronger than that of precast assembly structure. (2) The thrust force distribution of the structure is approximately trapezium. The deeper the web is set, the lower the action point of thrust resultant force. (3) The bending moment distribution of the inner and outer plates is in reverse "S" shape, and the reverse bending point is near the sliding surface, which shows the mechanical characteristics of the flexible structure. (4) With the deepening of web setting depth, the positive and negative extreme bending moment, the maximum bending moment of the roof and the maximum stress of the web decrease, but the difference in absolute value between the positive and negative extreme bending moment of the inner and outer plates increases, and the stress of the plate is uneven. (5) The web should be set to a certain depth below the sliding surface. (6) The research results can be popularized and applied in the treatment of landslide and diseased slope.
		2022 Vol. 39 (5): 1-7 [Abstract] ( 3109 ) HTML (1 KB) PDF (1688 KB) ( 1929 )

	8	Experimental Research on the Subsidence of Anhydrous Sand Pebble Layer Induced by Lining Segment Damage
		WANG Zhongchang, LI Guowei, PAN Ke
		Research purposes: In order to explore the formation collapse caused by tunnel lining damage and sand leakage in the sand gravel layer above the groundwater level, this paper studies the influence law of influencing factors such as pebble particle content and soil thickness on formation collapse and sand burst disaster through a set of self-designed visual test device for underground engineering sand leakage which can control the size of circular leakage, and obtains the influence range of soil collapse and the vertical shape curve of settlement profile under different working conditions, so as to explore the sand migration law and arching mechanism in the sand burst disaster. Research conclusions: (1) The test results show that when the thickness span ratio is greater than 11.1, the soil does not collapse. When the thickness span ratio is greater than 4 and less than 11.1, and the pebble particle content is greater than the critical pebble particle content, the soil only collapses but does not collapse. When the thickness span ratio is less than this value, the soil will collapse. When the thickness span ratio is less than 4, the soil will collapse regardless of the pebble particle content. (2) The sand breaking process can be roughly divided into four stages: initial stage, penetration stage, diameter expansion stage and stability stage. (3) Under the condition of fixed pebble content and leakage diameter, the influence range of collapse and the depth of collapse center increase with the increase of soil thickness; The collapse induced by circular leakage is circular on the plane, approximately conic on the section and funnel-shaped on the facade. (4) The collapse range of soil after sand break is related to the shape failure angle of the failure surface, which is 18° larger than the natural repose angle of soil. (5) The research results of this paper can provide guidance for disaster control and prevention of similar tunnel projects.
		2022 Vol. 39 (5): 8-13 [Abstract] ( 2581 ) HTML (1 KB) PDF (1036 KB) ( 1923 )

	14	Analysis of Retaining System of Secant Pile-rotary Anchor Cable for Foundation Pit Excavation
		ZHANG Guangchao, HOU Qiangsong, JI Zhaoteng, ZHANG Dashuai, XIA Xicen, LIU Guochong, ZHAO Honghua
		Research purposes: With foundation pit support of Yantai Dashang city park project A1 plot as the engineering background, this paper introduced the secant pile-rotary spray anchor supporting structure in the project. An equivalent elastic modulus method was proposed based on the deflection for the secant pile. Using the finite element software ABAQUS, the deformation and mechanical behavior of secant pile and rotary cable was analyzed during the excavation of the foundation pit. The influence of different factors on anchor cable supporting effect and foundation pit stability was studied. Research conclusions: (1) The retaining system of secant pile and rotary cable is safe and economical in the soft soil area. (2) By changing the length, angle and setting of prestress of shotcrete anchor cable, the supporting effect of foundation pit plays an important role. In a certain range, the stability of foundation pit increases with the increase of anchor cable length. When the angle of anchor cable is 15°, the stability of foundation pit is the highest. (3) The comparative analysis of simulation results and experiments shows that the proposed equivalent elastic modulus calculation based on deflection is feasible. The deflection equivalence model can be used for reference in the calculation of elastic modulus of secant pile.
		2022 Vol. 39 (5): 14-19 [Abstract] ( 2483 ) HTML (1 KB) PDF (801 KB) ( 1949 )

Main Line: Railway and Rail

	20	Research on the Minimum Curve Radius of High Speed Railway with Design Speed of 400 km/h
		LIANG Chen
		Research purposes: 400 km/h high-speed railway is the pursuit goal and development direction of many countries. At present, the design standard of 400 km/h high-speed railway has not been established at home and abroad. The minimum plane curve radius is one of the main technical standards of high-speed railway line design, which has a great impact on train speed and construction cost. At present, it has not taken the relevant parameters of the curve under the design conditions of 400 km/h at home and abroad, so it is necessary to carry out preliminary research on the relevant parameters to provide support for the subsequent construction. Research conclusions: (1) Based on the theoretical calculation value of the minimum curve radius of 400 km/h high-speed railway, this paper carries out the field test of driving performance under different deficient superelevation and surplus superelevation conditions with 7 000 m curve radius, and defines the relationship between superelevation and dynamic response index. (2) Using the vehicle rail coupling dynamics method, the differences in driving safety, comfort and rail wear development between R=7 000 m and R=7 500 m curves at 400 km/h are obtained. (3) Based on the test and simulation results, for the new 400 km/h line, it is recommended that the minimum curve radius be 7 500 m (the limit value of deficient superelevation is 90 mm), leaving margin for the subsequent line performance improvement; For the existing 350 km/h high-speed railway speed-up line, it is recommended that the minimum curve radius is 7 000 m (the limit value of deficient superelevation is 100 mm). (4) The research results can provide technical support for the formulation of relevant design standards and engineering application of 400 km/h high-speed railway.
		2022 Vol. 39 (5): 20-25 [Abstract] ( 3812 ) HTML (1 KB) PDF (1657 KB) ( 2005 )

	26	Research on the Influence of V-shaped Groove on the Upper Arch Stability of Type Ⅱ Track Slab
		YANG Junbin, LIU Xueyi, YANG Rongshan
		Research purposes: The upper arch of the type Ⅱ track slab is the main problem in the use of this type of track structure. At present, the formation mechanism of the upper arch on the track slab is not completely clear.In order to study the nature of the influence of the V-shaped groove in different working conditions on the upper arch stability of the track slab,based on the theory of structural stability, this paper establishes a three-dimensional numerical model of the upper arch stability of type Ⅱ track slabs that can fully characterize the shape and damage form of the V-shaped groove,and on the basis of fully considering the detailed and overall structural characteristics of type Ⅱ track slab, various calculation schemes and working conditions corresponding to different research contents have been drawn up; The numerical model established in this paper is used to calculate the vertical displacement of the track slab under the above various schemes and working conditions,by comparing the calculated vertical displacement of the track slab with the allowable vector of the upper arch on the track slab,the influence of the V-shaped groove under normal and damaged conditions on the stability of the track slab arch is analyzed, and a new groove scheme to improve the stability of upper arch on track slab is determined. Research conclusions: (1) V-shaped groove are beneficial to maintaining the stability of the upper arch of the track slab. (2) V-shaped groove has little effect on the line shape of the upper arch deformation of the track slab. (3)Under the condition that the depth and opening width of the original V-shaped groove remain unchanged, when the "V" section is changed into a rectangular section,the upper arch of the track slab is reduced by about 11%.(4)The damage at the V-shaped groove is beneficial to the stability of the track slab. (5)The research results of this paper can provide a reference for further clarifying the formation mechanism of the upper arch on the track slab and reasonably formulating the maintenance method of ballastless track.
		2022 Vol. 39 (5): 26-32 [Abstract] ( 3135 ) HTML (1 KB) PDF (708 KB) ( 1898 )

Main Line: Bridge Engineering

	33	Calculation Formula of Flexural Capacity of Normal Section of UHPC Railway Beams and Its Application
		LIN Pengzhen, ZHAO Hongwei, MA Junjun
		Research purposes: In order to give full play to the high tensile strength of UHPC and explore the reasonable inclusion of UHPC tensile strength in the design of railway UHPC beam flexural capacity, based on the existing railway bridge and culvert specifications, the calculation formulas of normal section flexural capacity of prestressed UHPC rectangular and T-section beams considering UHPC tensile strength are established. Compared with the test results of 27 groups of test beams, the feasibility of the calculation formula of flexural capacity is verified. Combined with the design example of 24 m span prestressed UHPC railway bridge, the flexural bearing capacity and safety factor of beam body considering UHPC tensile strength are compared and analyzed. Research conclusions: (1) Combined with the railway bridge design code system, the calculation formula of flexural capacity of railway UHPC bridge considering UHPC tensile strength is deduced. (2) Compared with the results of 27 groups of test beams, the calculation formula of flexural capacity in this paper is in good agreement with the test results, which can be used for engineering design. (3) Compared with the bearing capacity results without considering the tensile strength of UHPC, the ultimate bearing capacity of prestressed UHPC beams considering the tensile strength of UHPC in the tensile area can be increased by about 6%. When designing railway UHPC beams, considering the contribution of UHPC in the tensile area of the section can further optimize the section and save materials. (4) The research results have theoretical guiding significance for the design of railway UHPC beams.
		2022 Vol. 39 (5): 33-38 [Abstract] ( 3976 ) HTML (1 KB) PDF (722 KB) ( 1945 )

	39	Experimental Research on the Railway Gravity Bridge Piers with Reinforced Longitudinal Reinforcement at Pier Bottom
		LU Jinhua, CHEN Xingchong, DING Mingbo, MA Huajun
		Research purposes: In order to improve the seismic performance of railway gravity bridge piers with low longitudinal reinforcement ratio, the design method is proposed to locally increase the amount of longitudinal reinforcement at the bottom of the pier. Five model piers with different reinforcement height are made, and the seismic performance of the piers with only increased the longitudinal reinforcement ratio at the bottom of the pier is compared and analyzed through the pseudo-static test. Research conclusions: (1)The calculation method of the height of the longitudinal reinforcement is determined and the calculation formula of the height of the longitudinal reinforcement is deduced. (2)The horizontal bearing capacity and energy dissipation capacity of the pier can be effectively improved by increasing longitudinal reinforcement ratio at the bottom of the pier. (3)The bearing capacity and energy dissipation capacity of the pier with the supplementary longitudinal bars at the bottom are basically the same as that of the pier with the same longitudinal reinforcement ratio at the supplementary place, and the stiffness will not be reduced basically. (4)The results of the pseudo-static test verify the feasibility of enhancing the seismic performance of the pier by increasing the number of longitudinal bars on the bottom of the pier and the rationality of the calculation method of the height of the increased longitudinal reinforcement. (5)The research results can be applied to the design of piers which need to improve the seismic performance.
		2022 Vol. 39 (5): 39-46 [Abstract] ( 3290 ) HTML (1 KB) PDF (1304 KB) ( 1883 )

Main Line: Tunnel Engineering

	47	Research on the Classification Standard and Control Technology of Large Extrusion Deformation in Deep Tunnel
		ZHU Zhengguo, FANG Zhichun, HAN Zhiming, DING Xiang, MA Chaoyi, SUN Minglei, WANG Zhiwei
		Research purposes: Various geological disasters will be encountered in the construction of deep buried tunnel, among which the large extrusion deformation and failure under the condition of high ground stress and weak surrounding rock has become one of the problems to be solved urgently. In order to explore the classification standard of large deformation of deep buried tunnel and put forward corresponding control measures, taking Jianshan tunnel of Zhongwei-Lanzhou passenger dedicated line as the background, the stress and deformation law of deep buried extrusion large deformation tunnel are analyzed through numerical simulation, and the evaluation system of large deformation classification standard is proposed. The classification standard is established by analytic hierarchy process and fuzzy comprehensive evaluation method, to provide scientific guidance for the safe construction of deep tunnel engineering. Research conclusions: (1) The stress of the initial support structure is mainly compressive stress, the compressive stress at the left arch waist is large, and the tensile stress is distributed at the arch bottom and arch foot.(2) The maximum settlement and uplift around the tunnel are at the arch crown and arch bottom, the part with large horizontal convergence is at the upper step, and the deformation speed of the tunnel face in the initial stage is relatively large. (3)The grade of large deformation is divided into severe large deformation, medium large deformation, slight large deformation and no large deformation. The risk assessment of Jianshan tunnel is carried out according to the classification standard evaluation system of large deformation of deep buried tunnel.(4)The field monitoring results show that the control technical measures of small conduit advance grouting, optimization of bolt length and angle, setting foot locking bolt and multi-layer support have a good effect on deformation control.(5)The research results can provide reference for the design and construction of related deep tunnel projects.
		2022 Vol. 39 (5): 47-52 [Abstract] ( 3259 ) HTML (1 KB) PDF (588 KB) ( 1937 )

	53	Stability Analysis of Construction Process of New Tunnel Passing through High-speed Railway Foundation
		ZHANG Fei
		Research purposes: In order to study the stability of the high-speed railway foundation in the underpass construction process of the new tunnel, this paper takes the Qingping intercity rail transit passing through the Weifangbei-Laixi high-speed railway section as the research background, and uses FLAC^3D numerical simulation software to compare and select the tunnel excavation method, and finally adopts the three-step method to excavate the new tunnel. Based on the on-site monitoring results, combined with the numerical calculation results of the stability of the high-speed railway foundation, the safety and stability of the Weifangbei-Laixi high-speed railway section are deeply discussed and analyzed. Research conclusions: (1) Both the CD method and the three-step method are suitable for this type of tunnel, but the construction efficiency of the CD method is low. It is recommended to use the three-step method to excavate the tunnel under the premise of ensuring safe construction. (2) The surface settlement shows the largest settlement at the tunnel centerline, and the smaller the settlement is farther from the tunnel centerline. (3) In the case of excavation to the edge of the high railway foundation and completion of the underpass, the increase of the settlement of the tunnel section from large to small is the tunnel vault, arch bottom, spandrel and arch foot. Specifically, the vault is 1.62 mm, the arch foot is 0.73 mm, the spandrel is 0.63 mm, and the arch bottom is 0.45 mm. (4) The research can provide technical support and theoretical reference for the design and construction of new tunnels under the existing high-speed railway foundation in a short distance.
		2022 Vol. 39 (5): 53-58 [Abstract] ( 2899 ) HTML (1 KB) PDF (1119 KB) ( 1967 )

	59	Theoretical Solution of Tunnel Temperature Field in Cold Region and Fortification Length of Cold Proof and Thermal Insulation
		YUAN Jinxiu, WANG Daoyuan, WANG Yue, ZHU Yongquan, LUAN Yongjun, CUI Guangyao, CUI Hailong
		Research purposes: When the train running speed and frequency increase, there is a certain difference between the length of cold proof and thermal insulation at the tunnel portal and the length recommended in the specification. Firstly, based on the unsteady heat conduction theory, superposition principle and Bessel equation, the theoretical solution of tunnel temperature field in cold area considering the influence of train wind is derived; Secondly, the influence of train speed and running interval on the temperature field distribution in the tunnel is analyzed; Finally, the suggestion of tunnel fortification length in cold area considering the influence of train wind is given. Research conclusions: (1)The error between the theoretical solution of temperature field of tunnel in cold area considering the influence of train wind recommended in this paper and the field measurement is less than 10%, which can be applied to the design of cold proof and thermal insulation of tunnel in cold area. (2)The temperature field distribution in the tunnel is not affected by the train speed and running interval, but the longitudinal temperature curve in the tunnel shifts as a whole, increasing the length of negative temperature of the tunnel. (3)When the train speed is 100 km/h, 150 km/h, 200 km/h, 250 km/h, 300 km/h, 350 km/h and 400 km/h respectively, the cold proof and thermal insulation fortification length of tunnel portal needs to be increased by 45.76%, 65.55%, 84.65%, 110.31%, 127.02%, 155.21% and 222.70%. (4)When the train running interval is 30 min, 15 min, 10 min and 5 min, the cold proof and thermal insulation fortification length of tunnel portal shall be increased by 4.28%, 12.21%, 28.34% and 48.65%. (5)The research results can provide reference for cold proof and thermal insulation design of tunnels in cold regions.
		2022 Vol. 39 (5): 59-64 [Abstract] ( 2741 ) HTML (1 KB) PDF (631 KB) ( 1918 )

	65	Study and Application of Information Monitoring Technology for TBM Construction of Railway Tunnel
		ZHANG Minqing, WANG Jiang, WANG Wanqi, YANG Wei, JIA Dapeng
		Research purposes: TBM construction of large tunnel has been applied in the subway, hydropower, municipal, highway, railway and other projects. Due to its complex structure and poor working conditions, under the influence of factors such as the decision-making errors, insufficient risk estimate, and site operation error, some abnormal situation easily appeared in the TBM tunneling process, which may affect the construction schedule, or cause major accidents. A great deal of research has been carried out on TBM construction information monitoring technology by scholars at home and abroad, and some achievements have been achieved. However, the achievements are mainly focused on real-time monitoring, which can only reflect the operation status of TBM and the general situation of construction site, and lack of key functions such as data processing and analysis, risk warning, business management, feedback and guidance of construction. Based on Gaoligong Mountain tunnel of Dali-Ruili Railway, this paper studies and develops the railway tunnel TBM construction information monitoring system, which provides a foundation for safe tunneling and systematic management of TBM. Research conclusions: (1) The overall architecture of TBM construction information monitoring system is composed of 5 parts, including business architecture, logical architecture, data architecture, technical architecture and functional architecture, with comprehensive and reasonable design. (2) The security protection level of the railway tunnel TBM construction information monitoring system is the third level, and the systems are all deployed in the main data center of China Railway. The existing security measures of the main data center are fully utilized and the network security protection technology system is constructed based on the actual needs. (3) TBM construction monitoring system adopts file interface and OPC interface to extract TBM construction data. (4) The data automatically collected by TBM is transmitted to the computer of the project department in real time, and then transmitted to the server through the Internet. Users can read and analyze TBM construction data in real time by accessing the server. (5) Gaoligong Mountain tunnel plays an important role in reducing construction risks and accelerating information communication between construction site and management through application practice. (6) The research results can be applied in TBM construction of similar tunnels.
		2022 Vol. 39 (5): 65-72 [Abstract] ( 3928 ) HTML (1 KB) PDF (979 KB) ( 1981 )

	73	Analysis of the Influence of Reinforcement Corrosion Expansion on Cracking of Concrete Cover
		LI Yonglong, ZHANG Zhiqiang, LIN Dirui, GONG Ruikai
		Research purposes: The volume expansion generated by the corrosion of reinforcement forces the concrete cover to crack, "accelerating" the corrosion expansion of reinforcement, and the crack gradually expands and penetrates until the struc-tural failure, which is a long-term concern of civil engineering. Few existing concrete meso-scale studies have considered aggregate gradation, particle size and other aggregate parameter factors and comparative multi-factor analysis under different corrosion modes. Based on this, this paper characterizes uniform and non-uniform corrosion by setting different reinforcement corrosion expansion excess and extracts the corrosion rate of reinforcements when cracks are generated on the surface of the concrete cover in combination with the CDP model. The effects of aggregate parameters, cover thickness and interfacial layer strength on the corrosion rate of uniform and non-uniform corrosion expansion cracking of concrete are investigated. Research conclusions: (1) The durability of reinforced concrete improves with the raise of aggregate gradation and particle size and the decrease of aggregate content. (2) The increase of the cover thickness and the strength of the interface layer could reduce the number of micro cracks and the length of main cracks in the specimen, while delaying the cracking of the cover surface. (3) The research results can provide useful references for the design of reinforced concrete structures.
		2022 Vol. 39 (5): 73-79 [Abstract] ( 2134 ) HTML (1 KB) PDF (1425 KB) ( 1890 )

Main Line: Communication Signals

	80	Research on the System Scheme of Adding Level Crossing Monitoring Function to CTCS System
		ZHANG Youbing, CUI Jianuo, WANG Jianmin, CHEN Zhiqiang, ZHANG Guozhen
		Research purposes: Level crossing is the intersection of railway and highway. Effective management and safety monitoring of level crossing can improve the safety and passing efficiency of level crossing. The existing level crossing technology in China has some problems, such as low degree of automation and low efficiency. Moreover, the CTCS system does not take level crossing monitoring as a part of the system function, and the CTCS system is separated from the level crossing system, which reduces the safety and passing efficiency of level crossing. This paper draws lessons from the security protection scheme of ETCS system level crossing, and puts forward the system scheme of adding level crossing monitoring function to CTCS system. Research conclusions: (1) Level crossing monitoring function is added to CTCS system. On-board equipment reports train position and speed to trackside equipment in real time, and trackside equipment closes level crossing at a reasonable time to shorten the closing time of level crossing and improve the road passing capacity of level crossing. (2) The trackside equipment sends the level crossing information to the on-board equipment on the train, and the on-board equipment monitors the speed limit of level crossing safely, reducing the driver's labor intensity, avoiding human error and improving the automation level and safety level of safety monitoring in level crossing. (3) The research results can provide a reference for CTCS system to increase level crossing monitoring function.
		2022 Vol. 39 (5): 80-84 [Abstract] ( 2882 ) HTML (1 KB) PDF (668 KB) ( 1921 )

	85	Research on the QoS Index of Intercity Railway Wireless Communication Service
		JIANG Bo, LIN Wei, LIANG Yiqun, XU Hao
		Research purposes: In order to accelerate the new development pattern and boost economic development, the construction of modern comprehensive transportation railway network with rail transit as the backbone has become an important support to serve the major national strategy, and the developing interoperability requirement of intercity railway is increasingly urgent. Although intercity railway has interconnection requirements with national railway and urban railway system, there is no specific standard for wireless communication service. A variety of mobile communication technology standards coexist in intercity railway, such as GSM-R, LTE, 5G, Wi-Fi and millimeter-wave. In order to achieve requirement of intercity railway and promote the process of interoperability, it is urgent to study on the types, carrying mode and QoS index of intercity railway wireless communication service. Research conclusions: (1) The application scenarios, communication mode, application characteristics and service quality index of 15 kinds of intercity railway wireless communication service are proposed. (2) Combined with the current mainstream communication technology such as 5G, the communication system suitable for intercity railway and its communication services are proposed. (3) The feasibility of raised QoS index of intercity railway wireless communication service is verified. (4) The research results have important reference significance for the interoperability of inter-city railway, national railway and urban rail transit in mobile communication technical specifications, and the improvement of transportation production safety efficiency, as well as the improvement of transportation service quality.
		2022 Vol. 39 (5): 85-90 [Abstract] ( 3259 ) HTML (1 KB) PDF (366 KB) ( 1903 )

Main Line: Electrification Engineering

	91	Machine Vision-based Research on the Inspection of Dropper Defects of Overhead Contact Line
		LIU Jie, XU Jianguo, GAO Chunli, LIU Qiuhang
		Research purposes: To solve the problem of low efficiency and long time due to manual inspection, we create an intelligent inspection system of dropper defects of overhead contact line by applying high-definition image acquisition technology and image defect recognition modelling technology. Research conclusions: (1) By introducing visual intelligence technology, the research can establish the image detection standard for the installation status of overhead contact line dropper, create a database of defect images of overhead contact line dropper, and perform dynamic intelligent and rapid recognition and detection of overhead contact line dropper defect status. (2) The system uses the Faster R-CNN neural network model to train the defect data of overhead contact line dropper. With data transformation processing on the image data, the mean average precision (mAP) of the training results can reach 81.36%. (3) The system has high recognition rate accuracy, whichcan improve the detection efficiency and reduce omission. (4) The research results can provide a new way to change the traditional overhead contact line inspection method into intelligent inspection, and have certain reference value.
		2022 Vol. 39 (5): 91-97 [Abstract] ( 3144 ) HTML (1 KB) PDF (906 KB) ( 2081 )

	98	Optimization Discussion of Anchor Channel Standard for Overhead Contact Line in Railway Tunnel
		ZHU Feixiong, WANG Tao
		Research purposes: There are great disputes on the design service life and anti-corrosion treatment method of carbon steel channel of OCS anchor channel in railway tunnel, which makes it difficult to implement Anchor Channel for Overhead Contact System in Electrified Railway TB/T 3329—2013. Through the investigation and technical analysis of the requirements of relevant railway standards at home and abroad, this paper comprehensively compares the three anti-corrosion schemes of hot-dip galvanizing, co-permeating-passivating-coating anticorrosion (PCA), hot dip galvanizing + surface coating from railway standard support, inspection test pass, engineering application, environmental protection, energy conservation and anti-corrosion production cost, and finds out the solutions. Research conclusions: (1) The design service life of the channel is related to the environmental corrosion grade, and there is no direct quantitative conversion relationship with the corrosion resistance of the channel anti-corrosion coating. (2) The designed service life of the channel shall meet the design life requirements of the OCS system operation department for the channel, or it shall be divided into three grades of 30 years, 50 years and 100 years according to the importance grade of the tunnel OCS for selection of specific engineering construction projects. (3) The comprehensive comparison of three anti-corrosion schemes of hot-dip galvanizing, PCA and hot-dip galvanizing + surface coating shows that PCA scheme is the best. (4) PCA anti-corrosion treatment process is added to TB/T 3329—2013 standard to meet the engineering requirements. (5) The research results can provide reference for the revision of TB/T 3329—2013 standard and the design, manufacture, operation and maintenance of OCS anchor channel in railway tunnel.
		2022 Vol. 39 (5): 98-101 [Abstract] ( 2170 ) HTML (1 KB) PDF (356 KB) ( 1941 )

Engineering Economy and Management

	102	Research on the Intelligent Decision-making Method for Investment Plan of Transportation Construction Project
		DUAN Xiaochen, DONG Ruping, HAO Jingjing
		Research purposes: The current investment estimation methods for transportation construction projects are difficult to accurately reflect the complexity, nonlinearity and the characteristics of the whole life cycle of transportation construction projects. Taking Xibaipo-Fuping Expressway as an example, this paper comprehensively uses PSO, BPNN, FIS and BIM three-dimensional technology to carry out the whole life cycle cost estimation and investment option comparison of transportation construction project. Research conclusions: (1) The traffic construction project investment estimation information database is established to provide certain historical data for the selection of investment plans. (2) Combining the characteristics of the proposed project, using the PSO method to screen out similar projects, based on BP neural network model, this paper separately predicts its construction cost and operating cost in the next 20 years, and then uses FIS to predict its operating cost in the next 21~100 years, combining three parts of data to obtain the whole life cycle cost. (3) From an economic point of view, with the best life-cycle cost as the decision criterion, BIM three-dimensional technology is used to establish a visual model of the investment plan, so that decision makers can find the best one. (4) The research result can provide a reference for the decision-making of investment plans for transportation construction projects.
		2022 Vol. 39 (5): 102-107 [Abstract] ( 3254 ) HTML (1 KB) PDF (1414 KB) ( 1915 )

	108	Construction Cost Prediction of Main Tunnel in Railway Tunnel Based on Support Vector Machine
		LIU Shaofei, HOU Dashan
		Research purposes: The accuracy of the preliminary investment estimation of railway engineering projects plays a vital role in the comparison and selection of railway construction projects and investment control. At present, our country's railway engineering investment estimation is mainly carried out by the unit index method and the budget quota method. However, the whole process is relatively complicated and time-consuming, and the accuracy of the estimation also depends on the working experience and ability of the practitioners. In this paper, machine learning algorithms is used, main tunnel in railway tunnel engineering as the research object, to build a cost prediction model based on support vector machine (SVM) and extreme learning machine (ELM), and collect several tunnel samples to train and test the model. Through actual verification and comparison, a more applicable algorithm is selected, which can use historical data to quickly predict the cost of the main tunnel, thereby improving investment estimation and program comparison precision and efficiency. Research conclusions: (1) The result shows that SVM has high prediction accuracy and stability, compared with the ELM algorithm, and the mean absolute percentage error (MAPE) of the prediction results is only 3.41%, which meets the accuracy requirements. (2) The research results can provide a new and intelligent data-driven modeling method for the cost evaluation and prediction of main tunnel in railway tunnel engineering, and the simulation results show that the model has good feasibility and applicability.
		2022 Vol. 39 (5): 108-114 [Abstract] ( 3228 ) HTML (1 KB) PDF (727 KB) ( 1984 )