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2016 Vol. 33, No. 6 Published: 2016-06-15

Geology and Subgrade Railway and Rail Bridge Engineering Tunnel Engineering Research on Railway Networks Survey and Design Urban Rail Construction Engineering Economy and Management

Research on Railway Networks

	1	The Application of Matter Element Model in the Plan of Zhengzhou to Wanzhou Railway Project ^Hot!
		CHEN Jun
		Abstract ： Research purposes ： The optimal selection of variant schemes in railway location is a multi - objective decision. Traditional optimal selection methods characterized by crossing in qualitative index characteristic value，slight difference of the economic situation are difficult to identify a more optimal solution. Research conclusions:(1) The line selection design scheme optimum comprehensive evaluation model which based on the theory of matter - element extension is put forward. To recommend the design scheme which has best comprehensive effect，the correlation degree of proposed designing schemes ’ level are calculated，and the rank level of schemes are obtained. (2) Extend the scope of matter - element extension theory ’ s application. When comparing different design schemes，matter - element optimization model will be adapted for further analysis and comparison， to determine the optimal design scheme when there is no difference between schemes. (3) This paper expands the application scope of matter - element extension theory， and provides a new method for optimizing evaluation of scheme designing. At the same time， the line scheme comparison solution and comprehensive evaluation index system provide a theoretical foundation for similar project scheme.
		2016 Vol. 33 (6): 1-4 [Abstract] ( 2794 ) HTML (1 KB) PDF (1126 KB) ( 2480 )

	5	Research on the Xiangyang Railway Junction Terminal Train Assembly Station Site of Mengxi - Central China Railway Coal Transport Corridor
		XIAO Shao – jun
		Abstract:Research purposes: The Mengxi - Central China Coal Transportation Corridor is the largest coal line and is a key supporting infrastructure for implementation of the national energy development strategy 11 Transporting Coal from North to South" . In combination with the heavy haul railway transportation and the collecting and dispatching function of this corridor, this paper compares and selects various schemes, to provide the basis for the reasonable selection of the project and the engineering design. Research conclusions： (1 ) For the features of the collection and distribution range of coal transportation corridor, combining with operating range of 10 000 t trains, the research suggests that a train assembly station at Xiangyang hub need to be set up, to complete the conversion of 5 000 tons to 10 000 tons train. (2) Combined with station layout, transport capacity, construction difficulty, engineering investment and other comprehensive comparative analysis, the reasonable program site is chosen. ( 3 ) This paper puts forward the characteristics of the design of heavy haul railway station, which can provide reference for the design of other heavy haul railway projects in the introduction of the hub (region) and the train assembly station.
		2016 Vol. 33 (6): 5-11 [Abstract] ( 3517 ) HTML (1 KB) PDF (697 KB) ( 2448 )

Survey and Design

	12	Application and Analysis of Shallow Seismic Reflection in the Unfavorable Geological Body Survey
		HAN Song
		Abstract ： Research purposes ： In the investigation of the unfavorable geological body survey of railway engineering, the unfavorable geological body survey， such as faults， ground fissures and gob area， are the key control factors of the control railway alignment. The resolution of conventional geophysical prospecting technology sometimes cannot meet the requirements of the survey， but the shallow seismic reflection method has its unique advantages. In this paper， the author studied how to use the shallow seismic reflection method in the unfavorable geological body survey， obtained perfect application effect, and achieved the purpose of finding out development of the unfavorable geological body，and providing the reliable geological basis for the railway line selection engineering. Research conclusions:(1) Proper sedimentary environment and seismic source excitation condition are the precondition of use of the shallow seismic reflection method. The difference of wave impedance between the surrounding medium and the background rock stratum， because of the existence and activity of the unfavorable geological body， is the basic reason of the shallow sismic reflection method working. (2 ) By using the shallow sismic reflection method which has high resolution，we determined the range of gob area， the position and occurrence of faults， and the development of ground fissures，successfully revealed the geological hazard，and provided the detailed and reliable geological basis for the railway line selection. ( 3 ) The research results and experiences of this paper have extensive promotion significance in the similar railway engineering survey.
		2016 Vol. 33 (6): 12-15 [Abstract] ( 2764 ) HTML (1 KB) PDF (2027 KB) ( 2551 )

	16	Analysis and Application of 3D Remote Sensing Interpretation System in Railway
		LIU Gui - wei,NING Xin - wen,DU Hui，WANG Chun - lei,ZHOU Yong – jun
		Abstract ： Research purposes ： Some unfavourable geological conditions，such as landslide and debris flow，which had important influence on the track alignment，were difficult to be identified under the 2D interpretation system. The 3D remote sensing interpretation technique can make it easier, but the professional interpretation software was still lack, and needed to be studied quickly. Research conclusions:(1) Combined with the production demand of the railway survey and design stage，using the C #. Net language and the C/S structure，we developed the 3Dremote sensing interpretation and quantitative analysis system.(2) It can realize the three dimensional interpretation and quantitative analysis of unfavourable geological conditions， furthermore，the unified management of field data， and the function of multi - type data output and drawing. ( 3 ) The software has been applied to surey the unfavourable geological conditions along the Taiyuan - Jiaozuo railway， 27 landslides, more than 50 faulted structures， 17 unstable rocks， and 4 slumped deposits were checked out with the average accuracy rate of 80 percent. The results indicate that the application of the software have effectively improved the accuracy and efficiency of the remote sensing interpretation, and provided a reliable basis for the engineering geological alignment.
		2016 Vol. 33 (6): 16-21 [Abstract] ( 2842 ) HTML (1 KB) PDF (1253 KB) ( 2500 )

Geology and Subgrade

	22	Research on the Engineering Geology Characteristics of Completely Weathering Layer of Biotite Granite
		CHEN Ai – yun
		Abstract：Research purposes： Biotite granites are widespread in eastern and southern China, where large quantities of high speed railways are under construction or on their research stage. Because of the great depth of completely weathering layer of granite and the special engineering geology characteristics，the slope treatment and subgrade filling become a key problem. To have a full understanding of the engineering geology characteristics of completely weathering layer of biotite granite in eastern and southern China，samples are taken in many places within the research region and laboratory tests are taken to research the mineral weathering characteristics， physical property， strength property and expansibility，which can provide certain technical support for the railway construction within this region. Research conclusions：! The mineral contents of the biotite granite in eastern and southern China are mainly quarts， feldspar and biotite，of which feldspar turns into kaolinite， illite and montmorillonite， and biotite turns into illite and composite of ferro - manganese. (2) The structure of weathering layer is loose and is mainly argillaceous cement，with the plasticity index of 10%，which belongs to the category of the silty clay. (3) The friction degree of the weathering layer of biotite granite is about 27°， but the cohesion force is less than 100 kPa， which differs from areas to areas. (4) The completely weathering layer of granite does not belong to expansive soil. (5) The research results can provide certain references to the railway survey and design passing through granites areas.
		2016 Vol. 33 (6): 22-25 [Abstract] ( 2926 ) HTML (1 KB) PDF (745 KB) ( 2488 )

	26	Research on the Engineering Properties of Clay Soil of Sheshan Group in Lijiang Basin ^Hot!
		CHAI Chun - yang1, ZHANG Guang - ze2，WU Xi - yong1
		Abstract ： Research purposes ： Clay soil of Sheshan group is a special kind of clay which distributes widely in the edge of the Lijiang basin， with the thickness of ten meters. Compared with other kinds of clay soil， Sheshan clay soil possesses special micro - geological characteristics and engineering geological characteristics due to the different depositional environment， climate and other factors. The clay group was repeatedly passed through during the construction of the Dali - Ruili railway line and the Ruili - Shangri-La railway line. The research on the formation reasons and the characteristics can provide a basis for the choice of the construction scheme and measure. Research conclusions ： (1) The clay soil of Sheshan group owns the characteristics of low density, high porosity ratio， high water content，high plasticity，high dispersibility and organic matter content，with the engineering characteristics of constitutive property and swell - shrink characteristic. (2) The structure of the clay can easily be destroyed after leaching at the surface layer under the condition of the alternation of wetting and dryig environment and the mechanical property of the clay decays obviously. In consequence， the clay may transform into soft soil and cause discrepant deformation and destruction of the slope. ( 3 ) The research result can guide the engineering geological survey and design in the area of the structure clay.
		2016 Vol. 33 (6): 26-30 [Abstract] ( 2745 ) HTML (1 KB) PDF (853 KB) ( 2453 )

	31	Research on the Collapse Characteristics of Coarse Grained Soil in Gobi Region
		HOU Yan – kai
		Abstract ： Research purposes ： Te control of foundation settlement is extremely strict for high - speed railway, Lanzhou - Urumchi High - speed Railway crosses a wide range of Xinjiang and Gansu Gobi region，however the coarse - grained soils in Gobi region have collapsibility， so it will have large settlement when meeting water. Currently， the study of coarse - grained soils foundation mainly focuses on bearing capacity and shear strength，etc. There are few studies on collapse characteristics and deformation mechanism of coarse soils in Gobi region, so the study on collapse characteristics and deformation mechanism of coarse soils in Gobi region have very important significance for constructing high speed railway and other similar projects in Gobi region. Research conclusions ： (1) The deformation properties of Gobi coarse soil under flooding conditions can be divided into three stages ： compression deformation， collapse deformation and complex deformation. Collapse deformation stage has the fastest growing and the largest settlement. (2) The coarse grained soil in Gobi region have large collapsibility, and its mineral composition，microstructure and salinity are main internal causes for the collapsibility. (3) The mechanism of collapsing of coarse soil in Gobi region under flooding conditions is that the bond strength between particles decreases， the structures are destroyed under external force， movement of soil particles resulting in the occurrence of a large settlement. (4) This research enriches the collapse deformation theory of coarse soils in Gobi region， and provides reference for constructing high speed railway and other similar projects in Gobi region.
		2016 Vol. 33 (6): 31-35 [Abstract] ( 2727 ) HTML (1 KB) PDF (733 KB) ( 2447 )

	36	Calculation Study and Engineering Application of Frame Pile - slab Retaining Wall in Deep Cutting
		LI Kun
		Abstract ： Research purposes ： Based on the impact of the surrounding urban architecture and environment on the road construction and the requirements of the height, safety and reliability of retaining structure, this paper proposed a new structure of 11 frame pile - slab retaining wall in deep cuttingM includes multiple anchor piles and transverse bracings, by which the structure are fixedly connected. Drawing on the experience of calculation on the retaining of sheet - pile wall, this paper uses analytic method and finite element software in 2D and 3D view separately to study the overall stability of frame pile - slab retaining wall, and then the results calculated by different methods are compared and analyzed to ensure the reliability. Research conclusions:(1) By using the pile - slab retaining wall of type Hthe transverse bracings connected by the cast - in - place concrete with piles are set in the lower part of subgrade to increase the integrity and safety of the structure. (2) Using the transverse bracing reduces the burden of pile and limits the horizontal deformation which is from pile - slab structure to cut dues to bearing a part of bending moment, shear force and axial force. The combination of transverse bracing and 11 embedded pile - slab structure in foundation treatment" also effectively controls the settlement of subgrade and improves the bearing capacity of foundation. ( 3 ) Ultra - high retaining under the soil condition is realized by geotechnical engineering application of new structure, which also ensures the engineering stability, and has obvious social and economic benefit.
		2016 Vol. 33 (6): 36-40 [Abstract] ( 2756 ) HTML (1 KB) PDF (718 KB) ( 2457 )

Railway and Rail

	41	Research on the Speed Target Values for Kunming Urban Regional Railway ^Hot!
		HUANG Wei - li
		Abstract ： Research purposes ： Kunming city urban regional railway is mainly responsible for between the various cities and towns of the urban area of Kunming city regional passenger and central Yunnan urban agglomeration intercity passenger flow, taking into account the city passenger groups, and it is an important transportation infrastructure to support the construction of central Yunnan urban agglomeration economic circle and promote Kunming urban district development. Research conclusions:(1) Kunming railway network domain recommended 160 knmh, the line reserved for engineering 200 k〇mh speed target value has an advantage in project investment, adaptation and distribution station, and the target time adaptability，coordination and wire mesh extending. (2) The recommended speed meets the standard of project positioning function and facilitates passenger travel，to better promote the development of local economy. (3) Considering the factors in the central city of both city rail traffic function，short distance between stations and city construction intensive， in the main urban areas may be appropriate to reduce the speed of standard，flexibly select the appropriate speed target value，and further research section. (4) The research results can provide some references for other urban regional railway standard research.
		2016 Vol. 33 (6): 41-45 [Abstract] ( 3186 ) HTML (1 KB) PDF (1302 KB) ( 2495 )

	46	Research on the Influence of Heyuan Fault Zone on the Safety of Beijing - Jiulong High Speed Railway Construction
		GU Cheng – quan
		Abstract ： Research purposes ： Beijing - Jiulong High Speed Railway is designed to travel along Heyuan Fault Zone， which is an active earth - triggering fault，and triggered the only reservoir induced destructive earthquake as a result of the impoundment of Xinfengjiang Reservoir. The activeness of Heyuan Fault Zone has a great effect on the line location and engineering measures of high speed railway. Based on data collection， remote sensing interpretation and field geological survey , combined with geophysical prospecting , drilling , fault material survey and other comprehensive survey methods，this paper studies the structure，earthquake features of Heyuan Fault Zone，as well as the influence on high speed railways. Research conclusions:( 1 ) Heyuan Fault Zone，with the southeast trend and the dip ranging from 30° ?60°，is constituted by three branch faults，which are south part， middle part and north part. (2) Heyuan Fault Zone formed during early to middle Pleistocene of Quaternary， not during Holocene of Quaternary ( 3 ) Earthquakes，which concentrate mainly on the middle part of the fault zone， close to Xinfengiang Reservoir， are manly induced by the reservoir，and can be classified as shallow - focus earthquakes. (4) Because the earthquakes in the middle part of Heyuan Fault Zone are very active, and the Quaternary loose bed will magnify the vibration, the seismic fortification criterion should be raised by one level. (5 ) There is an insensible differential settlement between the two walls of the fault, and the low^ filled subgrade is a better engineering method for the railway. The subgrade and slope can be defended with flexible structures. ( 6 ) The right line, which has a greater distance from the fault, can avoid the fracture zones caused by Heyuan Fault and its secondary faults. ( 7 ) The research results can provide a certain reference to high speed railway route selection and construction passing through active fault.
		2016 Vol. 33 (6): 46-49 [Abstract] ( 2725 ) HTML (1 KB) PDF (1537 KB) ( 2437 )

	50	The Overview of Design of CRTS III Slab Track on Roadbed - bridge Transition Section
		WANG Wei - hua
		Abstract ： Research purposes ： Roadbed - bridge transition section is the weakness position of non - ballasted track， which need to be reinforced to make sure the structure safe. The design methods of the abutment - roadbed transition sction and the roadbed - frame - bridge without covering soil transition section were introduced to provide reference for other similar engineering questions. Research conclusions ： The stiffness difference on the roadbed - bridge transition section and the potential uneven settlement may have an important impact on the structure stress and even result in structure damage，which affect the running safety and comfort. Therefore，the following measures can be took to guarantee the structure safety ： ( 1 ) The abutment groove or the side wall bracket of frame - shaped culvert should be set with approach slab; ( 2 ) The high strengthplastic extrusion plate should be set on theabutment - roadbed transition section and thearea above the abutment and approach slab; (3 ) In the abutment approach slab and roadbed transition section， the double layer supporting structure is needed; (4) This research conclusion can provide certain reference for the structure design of non - ballasted track on the roadbed - bridge transition section， in order to improve the safety of the non - ballasted track structure of the high - speed railway，improve the security and stability of high speed train running.
		2016 Vol. 33 (6): 50-53 [Abstract] ( 3235 ) HTML (1 KB) PDF (1212 KB) ( 2497 )

	54	Research on the Key Parameters of Corrugated Pipe Culvert
		ZHENG Xiao - yan1, HU Lian - jun2
		Abstract ： Research purposes ： Corrugated pipe culvert has been applied in highway engineering frequently, but not yet used in railway. Thus, the main design parameters of corrugated pipe culvert were analyzed theoretically with ABAQUS, and the force and deformation characteristics of corrugated pipe culvert under the influence of various factors were studied , to provide data support for the application of corrugated pipe culvert in railway engineering. Research conclusions ： (1) With the increase of filling height , corrugated steel culvert earth pressure , internal force , the horizontal deformation showed the linear growth trend. (2) The stress deformation of waveform D , E and F showed a consistent trend , with a little difference value among them. While , waveform C owned a smaller stress , but a larger deformation. (3) The thinner the wall - thickness is , the greater the corrugated pipe culvert’s stress is, but the deformation was not sensitive to the thickness. ( 4 ) The larger the diameter is , the larger corrugated pipe culvert stress and deformation are. (5 ) The research results can povide the references for the study of railway corrugated pipe culvert.
		2016 Vol. 33 (6): 54-58 [Abstract] ( 3500 ) HTML (1 KB) PDF (998 KB) ( 2498 )

	59	Type Research on the Embedded Ballastless Track Structures and Key Components of Modern Tram Way
		LIN Hong - song, YAN Hua
		Abstract ： Research purposes ： According to the characteristics of the steel - wheeled modem tramway， comparative analysis onright of way, maintenance, environmental impact and costs were carried out among ballast track, ballastless track and embedded ballastless track. Track type selection advices were proposed for tram way with common right of way. On such a basis，for the embeeded ballastless track structure，an analysis is carried out on the structure type of key components such as rail，rail fixing mode，track bed structure，track bed laying，and rail side filling，and advices were given. Research conclusions:(1) An embedded ballastless track is suggested on sections with common right of way. (2) For rail, 59R2 or 60R2 grooved rails should be employed. (3) A cast - in - place track bed structure should be employed for new lines，while a precast slab track structure should be employed for renewal and reconstruction of existing lines. (4) When the line is required for bearng the road traffic loads, an asphalt concrete pavement layer should be employed unless there are special requirements. (5) Rubber materials or polymer materials should be selected for railside filling. (6) The research conclusions can provide references for the embedded ballastless track design of modern tram way.
		2016 Vol. 33 (6): 59-64 [Abstract] ( 2869 ) HTML (1 KB) PDF (1183 KB) ( 2512 )

Bridge Engineering

	65	Analysis Metliod for the Stability of Slope Considering Bridge Foundation Additional Load ^Hot!
		DONG Jie1, SONG Xu - guo2
		Abstract ： Research purposes ： The stability analysis of hard high steep slopes with bridge foundations is a hard work which technicians encountered in complex mountain railway and highway engineering. The base load is delivered from the bridge foundation above by the additional load which will translate into the lateral stress acting on the inner slope， and the risk of slope sliding will increase. The design quality of bridge foundations in slopes is not effectively guaranteed because of the complexity about stability analysis to these slopes and the immaturity of bridge slope stability analysis methods. Therefore, a method about stability analysis of slope considering bridge foundation additional load is studied in order to provide help for the dsign of slope bridge foundation engineering. Research conclusions:( 1 ) A stability analysis method considering the additional load transfer， the rock and soil mechanics parameters and the geometric shape of bridge foundation slope is established，and this method is applied to research on the slope stability ^fected by the additional load in different locations of bridge foundation. ( 2 ) A calculation model for safety factor about bridge slope can be used for design work of bridge foundation, and the stability safety factor of the bridge foundation slope can be calculated for the known layout parameters of horizontal distance and depth , or , the different bridge foundation arrangement schemes are optimized and selected under a given safety factor conditions through the analysis on different excavation angles. (3 ) In the course of preliminary design of the 0#abutment of the 3# Benxi Bridge of Shenyang - Dandong Passenger Dedicated Line, the abutment arrangement scheme and slope stability factor were successfully analyzed by programming based on the theory put forward in this paper, and the research result can be successfully applied to the optimal design of the bridge foundation in mountain area.
		2016 Vol. 33 (6): 65-69 [Abstract] ( 2896 ) HTML (1 KB) PDF (765 KB) ( 2517 )

	70	Research on the Progress of Seismic Control for High Pier Railway Bridge
		HU Lian - jun，YANG Ji – zhong
		Abstract：Research purposes： With large - scale railway construction in complicated geographical mountainous areas in west China，thousands of large - span bridges with high - pier have been built. It is significant to conduct research on seismic control of high pier railway bridge in earthquake zone. The development of China’s high pier railway bridge was summarized，the main principles and measures of seismic control of railway bridge were reviewed. The development trends of high pier railway bridge were discussed. Some references for damping control of high pier railway bridge were provided. Research conclusions:(1) The high pier railway bridge belongs to irregular structure. Current codes for seismic design do not apply to this type of bridge structure，thus, new researches need to be carried out. (2) Rail restraints increase the longitudinal contact of the adjacent bridge span，so it is beneficial to overall seismic for adjacent pier height with a large difference. Track deformation effect on bridge sismic when the earthquake strikes should be carried out. (3) It is suitable for high pier railway bridge to adopt additional damping devices. It is better to detemine the parameters and arrangements of the damping devices according to the specific analysis. (4) According to the successful application of passive energy dissipation system in tall buildings，it is possible to introduce passive energy dissipation system to high pier brdge. (5) Active/semi - active/ hybrd control technology has great development prospects. (6) The research results can provide the references for the study of seismic control of high pier railway brdge.
		2016 Vol. 33 (6): 70-75 [Abstract] ( 2947 ) HTML (1 KB) PDF (838 KB) ( 2503 )

Tunnel Engineering

	76	Research on the Key Technology for Special Shaped Deep Shaft in Water - rich Gravel Formation and Complex Environment ^Hot!
		WANG Tin – ming
		Abstract ： Research purposes ： As for the special shaped deep shaft located in the triangular block encircled by existing shield tunnel and ventilation pavilion, based on the protection of surrounding environment in water - rich gravel formation, this paper proposes the design and construction scheme for the special shaped deep shaft, which can guarantee the stability of shaft structure and the surrounding environment safety. Research conclusions ： (1) Dewatering scheme for deep shaft which can efficiently control the outflow of fine particles is put forward. (2) The structural safety of the expansion excavation in deep shaft can be ensured on the basis of the large pipe shed installed downward on the shaft wall, the length of which is beyond the potential failure plane. (3) The adverse impacts of the special shaped deep shaft construction are mainly concentrated on the left side of shield tunnel, and the initial disturb should be controlled. ( 4 ) The overall structural stiffness of ventilation pavilion on the right side is bigger, the limited earth pressure btween ventilation pavilion and dep shaft is lesser, and the influence of shaft excavation on the ventilation pavilion is smaller. ( 5 ) The schemes for special shaped deep shaft construction, especially the large pipe shed method, are feasible and economical, which can be applied in deep shaft engineering under the strict environmental protection requirements.
		2016 Vol. 33 (6): 76-81 [Abstract] ( 2781 ) HTML (1 KB) PDF (1268 KB) ( 2468 )

	82	Analysis of Mechanism of Water - inrusti of the 1# Transverse of Gangwu Tunnel in the Shanghai - Kunming Passenger Special Line ^Hot!
		MAO Bang - yan,ZHANG Guang - zhe，TANG Bing，YU Hong – ping
		Abstract ： Research purposes ： The constructing Gangwu extra - long deep tunnel is one of the key projects and the tunnels controlling construcion period in the Guizhou segment of Shanghai - Kunming passenger transportation. Several large cavities were revealed in the construction of tunnel, some of which are followed by water and mud inrush. D1K 871 + 775 ?D1K 871 +809 of the 1# transverse tunnel broke out sudden water and mud inrush which seriously affected the tunnel construction. Finding out the type and mechanism of the karst water burst is of great guiding significance to prevent the water bursting and mud surging in karst tunnel locates in the variable karst zone of vertical recycling. Research conclusions ： ( 1 ) Gangwu tunnel passes through karst area， serious water or mud bursting accidents occur frequently. (2) Under the dual influence of the leap of hydrostatic pressure caused by sudden heavy rain and tunnel blasting，the weak space between tunnel and the static reserve dissolved space (eg. filling fracture, paleo karst pipeline) is punctured, the hydrostatic - storm water outburst will occur in D1K 871 + 775 ?D1K 871 + 809 of the 1 transverse tunnel. ( 3 ) When revealing dry or damp caves with sinkholes in the tunnel ^s excavation process, the engineering treatment measures should be choosen carefully, such as set enough drainage measures as far as possible. ( 4 ) It is widely believed that the possibility of water and mud bursting in vertical cycle karst zone is slim. The example of the 1# transverse of Gangwu tunnel showed that water and mud bursting disaster may occur when a once - in -100 - years storm occur in the stage of tunnel construction and operation. The hydrostatic pressure of tunnel roof will increase suddenly, which will seriously influence the tunnel construction and the safety of railway operation. (5) This research result can provide guidance for route selection of the karst and karst cave treatment.
		2016 Vol. 33 (6): 82-86 [Abstract] ( 2713 ) HTML (1 KB) PDF (919 KB) ( 2470 )

	87	Discussion and Analysis of Gradient Discount of Heavy - haul Railway Tunnel ^Hot!
		ZHAO Dou
		Abstract ： Research purposes ： If we can calculate the value of gradient discount of heavy - haul railway tunnel reasonably, construction investment is saved, the length of tunnel is shorten, construction risk and difficulty is reduced. Combined with feature of heavy - haul railway, this paper calculates and analyzes the value of gradient discount of heavy -haul railway tunnel，and compares the value of heavy - haul railway with normal railway. At the same time the feasibility of elimination of gradient discount of tunnel is analyzed from the theoretical calculation and operation，finally suggestion on the value of gradient discount of heavy - haul railway tunnel is proposed. Research conclusions:( 1) The value of gradient discount of heavy - haul railway tunnel is not same as the value in code for design of railway line，and should be calculated on addition air drag parameter in tunnel. （2 ) In order to save investment，the value of gradient discount of heavy - haul railway tunnel can be reduced or eliminated in difficult geographic and geomorphic conditions. (3) The conclusions can provide some references for designing value of gradient discount of heavy - haul railway tunnel.
		2016 Vol. 33 (6): 87-90 [Abstract] ( 2927 ) HTML (1 KB) PDF (328 KB) ( 2504 )

	91	Analysis of Abnormal Joints witli Variable Cross - section Column of the Canopy of Hangzhou South Railway Station
		YU Yang
		Abstract：Research purposes： For the structure layout of platform canopy, a class of variable cross section column abnormal joints has been designed. In order to make the joints have good mechanical performance, many plans for the structural arrangement are optimized, non - linear finite element analysis of a steel abnormal joint was performed using ABAQUS computation program. By comparing several different cross section forms and influence of connection way on the mechanical performance of the joints, the thickness of different round steel tube concrete column end plates and height of internal reinforced rib are offered, the stress analysis of the upper square steel tube and lower round steel tube concrete columns is performed. Research conclusions:( 1 ) The thickness of end plate, the reasonable value of height of reinforced rib and the arrangement direction of reinforced ribs are aligned with the pipe wall stress which is much higher, and it can meet the requirements of the joint. (2 ) The shape of the cast - steel joint shape can meet the requirements of architectural modeling because of the big freedom. ( 3 ) The strength, local stability and deformation of joints can meet the design code. (4) The stress can be reduced, the joint stiffness can be enhanced and the local deformation of the joint can be avoided by reasonably setting the wall thickness of the joint and the internal reinforced rib to meet the design requirements. (5)The abnormal joints can be used for the design of similar canopy.
		2016 Vol. 33 (6): 91-94 [Abstract] ( 2806 ) HTML (1 KB) PDF (1224 KB) ( 2758 )

Urban Rail Construction

	95	Application of CFD Technology and Hot Smoke Test in the Study of Metro Fire
		LIU Shu
		Abstract: Research purposes: It is very important that how to take the effective measures to ensure the passengers scurity when the fir^ happens in the metro station which is taken as the closed space underground. The CFD simulation technology and hot smoke test method are applied to analyze the smoke evacuation effect of the supply and exhaust air system in the station in this paper, which can provide some references for the simulation of large scale fire. Research conclusions ：( 1) There exists the phenomenon of smoke flowing here and there through the hot smoke test. Thus, the normally closed electric smoke fire damper should take place of the manual fire damper in the pipe when designing the natural air makeup on the smoke evacuation of the corridor. ( 2 ) Through the field test, the wind speed and temperature of test points can meet the requirements of national regulation, and the effect of smoke evacuation is good, which prove that the supply and exhaust air system is feasible and provide references for other metro engineering. Establish the mathematic model of smoke evacuation system in metro station, and solve the model by the fluent software. The accuracy of established model is verified by comparing the field test data in hot smoke test with the simulation values, which can also prove that the settings of boundary conditions are reasonable and provide introduction for large scale fire simulation.
		2016 Vol. 33 (6): 95-100 [Abstract] ( 2790 ) HTML (1 KB) PDF (1210 KB) ( 2455 )

Engineering Economy and Management

	101	Research on the Project Cost Prediction in the Process of Bidding for Construction Enterprises
		LU Rui,LI Xue - wei
		Abstract：Research purposes： Cost prediction is the basis of project bidding quotation for the construction enterprises. The accuracy of the prediction is the ultimate factors influencing the bidding results and corporate profits. There are a large number of factors affecting the project cost，and the relationship is complex. Based on the identification of project cost affecting factors, a cost forecasting model based on artificial neural network is established in this paper. Considering some factors change with time，the paper improves the model which can guide the engineering construction enterprises especially railway construction enterprises in project bidding decision. Research conclusions:(1) The cost forecasting model of artificial neural network based on project cost analysis can effectively predict the project cost, and the model is easy to use and more objective. (2) Considering the influence of the construction period on the part of the relevant factors, the neural network model combined with time series data after correction can further enhance the prediction accuracy. (3) The model and the output results can provide decision support for project construction related enterprises in the project bidding stage.
		2016 Vol. 33 (6): 101-105 [Abstract] ( 2797 ) HTML (1 KB) PDF (956 KB) ( 2501 )