Journal of Railway Engineering Society

Research methods: Considering the landform along the line and city plan , the comments are made on the schemes of in-troducing a railway to Tianjin Beach International Airport, and the overall comparasons are also made in technology and economy with methods of statistics, comparason and evaluating its advantages and disadvantages.

Research results: By the study on the schemes of introducing a railway to Tianjin Beach lnternational Airport, a feasible thinking on alignment, track jointing location and a series of useful technical measures are presented.

Research conclusions: The scheme of introducing a railway to Tianjin Beach International Airport from Beijing-Shan-haiguan Railway is the most reasonable, economical and feasible, considering the factors of the airport current conditions, city plan, removal of exciting buildings and passengers convenience.

Research methods : This paper decomposed the complex object such as house or road to every independent ”surface object"，and constructed 3D model with real coordinates, then made texture to every surface to reach the visual effect of high-fidelity.

Research results: It is feasible to construct 3D model for every real object, but it need high requirement for hardwares of computer and we should consider it when built the models.

Research conclusions: The technology of Virtual Reality based on Photogrammetry can provide visual 3D model construction, data management integration, data analysis and applications, and it can rebuild the real hypsogaphy of the area along the mute. With this technology，the designer and decision-maker can have a direct 3D impression of the study area, thus they can have the gist for evaluation and optimization of the design. It can also be used to evaluate the spatial and geometrical linearity of the designed route, vehicle operation safety, environmental influence and to choose the place for bridge，tunnel and station in railway (road) design.

Research methods: Combining with the circumstance of surface subsidence along the line between Beijing and Jinan of one high-speed railway, the calculation and prediction are made for the amplitude and velocity of surface subsidence and the slope change slung the railway with traditional methods，and also the calculations are made for the influences of uneven surface subsidence on the regularities of the bridge，subgrade and track of high-speed railway according to the relative standards.

Research results : trough doing research，the characteristics of surface deformation in subsidence area and its influence manner and degree on high-speed railway are made clear, and the countermeasures and construction measures arc put forward for prevention of subsidencer.

Research conclusions: The regional surface subsidence can change track slope and produce the certain influence on the relgularities of the badge, subgrade and track of high-speed railway. However the local uneven sut}ace subsidence can produce much influence on construction of high-speed railway, but ii can be prevented by controlling groundwater and adopting rational alignment, tracts gradient and engineering structure

Research methods: Field investigation of landslide, the field and laboratory tests are basic research methods，and theoretical analysis is secondary.

Research results: Residual strength of slip soil has linear regression with peak strength; plastic index can he batter used to estimate residual strength.

Research conclusions: Under condition of ancient landslide revival and certain creep deformation, residual strength can be substituted for shear strength. The field test shows that there has obvious peak strength in curve of shear stress and shear displacement, residual strength appears after certain shear displacement. The strength parameters of laboratory and reverse calculation are consistent, thus it is proved that field laboratory is s good way to estimate residual strength of slip soil.

Research methods: Through making analyses of the causes and features of landslide，the treatment measures are proposed.

Research results: The issues on engineering geology that should be pay attention to in the course of survey and alignment of the track in soft and softer rock foundation section are presented.

Research conclusions: At the bedding area or unfavourable structural surface, the construction should be done by section from up to down and the excavation at the base of slope by large scale is not allowed. If necessary, the calculation，analysis and verification of the stability should done and the construction should be done except in rainy season. When the excavation is done at the embankment and tunnel with large different lithology on the both side foundation or softer rock, t1e support and shelter facilities and monitoring for slope are needed. When the soil on both sides of embankment is thick, the support and shelter facilities should be prepared first and the monitoring should be done for the slopes on both sides. The railway line should avoid the side slopes with thick soil and ditches with large different lithology. The tunnel portal should be far away from ditches and located at the place with good foundation rock and without unfavourable geological condition. The surveys should he made for the slope top and bottom of side slope during period of survey. The enough holes should be drilled far the side slope of embankment and the side slope should be far away from the track if necessary. In the course of design，the attention should be paid to bedding area with large different lithology on both sides，especially to ditches.

Research methods: This paper introduces the kinds of K_0 calculating methods, and analyzes the influence factor, question in test and lots of experimentation data to receive the Tianjin shallow layer soil K_0 rule.

Research results: This paper puts forward the experience formula ofK_0 which is agreement with Tianjin shallow layer soil, and the suggestion of indoor test mensuration.

Research conclusions: Indoor K_0 instrument is easy manipulation and test convenience. In order to ensure the experimentation data reliability and reduce the system error, which avoid the lateral press scattering and assure the instrument airproof is necessary. On the emergency，lacking of test condition, we can use this recursive experience formula to estimate the Tianjin shalIow layer soil K_0.

Research methods: The modified methods of secondary consolidation and K value were determined through making analysis and comparison of the standardized testing results with that of fast consolidation testing. Then the analyses were made for the errors between the modified results and standardized testing results based on the statistical method.

Research results: The comparative data of the testings show that，after being modified by the 2 methods，the results of 12-hour Fast consolidation test are well correspond to those of standardized consolidation test with trusting degree of 95% and there are no significant differences between the 2 methods. The duration of testing can be shortened from 9 days to S days.

Research conclusions: The tests results show that the 12-hour fast consolidation test method can be used to determine the preconsolidation pressure of subsoil, which will improve the productivity efficiency of highpressure consolidation test and can he widely used in construction of railway passenger dedicated line

Research methods: Adopting the methods of combining study of theory with analysis through testing, statistation by calculating and checking.

Research results: This paper set up an expression for designing the gravity retaining wall based on Reliability Theory, calculated and counted reliability index for designing the gravity retaining wall according to current code, proposed objective reliability index, finally put forward reference value fur design principle and calculating methods with reliability theory of gravity retaining wall.

Research conclusions: The objective reliability index suggested can satisfy the demand of engineering. The size of gravity retaining wall designed by the expression advanced is close to tradition. The reference value of Load partial coefficients is near to the value in America standard. The formulas, the objective reliability index and the partial coefficients about gravity retaining wall may he regard as reference，when”Code for design on retaining structures of railway subgrade " is compiled

Research methods: lt is assumed from the forces polygon that the geo-grids develop their stretching strength at the same time and then a theoretical analysis method is used to analyze the engineering technology for the geo-grids how to decrease the earth pressure acted on an embankment retaining structure

Research results: The theoretical analysis has acquired a calculation method for the geo-grids how to decrease the earth pressure acted on an embankment retaining structure.

Research conclusions: The method put forward in this paper is simple and practical. It carp Le used for calculating the active breaking angle and the total active earth pressure on the embankment pile-slab wall with the geo-grids. For a high pile-slab wall，the earth pressure can be decreased by means of each layer of the fillings paved with each layer of geo-grids，then the pile section size and the slab thickness can he decreased. But the fillings shall be hard such as rock with less weathering; the geo-grids shall be positioned at the middle-upper below the fillings, the more details must be determined according to its stretching strength and the friction resistance provided by the earth fillings within the breaking surface. Finally it is suggested chat a further research must he performed of their arrangement, layer-distance and deformation characteristics etc.，to make the theory more conforming to match the practice

Research methods：Using finite element theory，beam-slab model of plane slab and frame slab ballastless tracks are built, the model calculation is caught by the invite element Coal software ANSYS.

Research results：Same parameters are adopted to make the mechanical results out, the mechanical distinctness between plane slab and frame slab ballastless track structures is obtained, the effects on slab track conduced because different action position by loads is researched，too.

Research conclusions: (1)Under the action of same loads, except the longitudinal positive moment of pedestal, longitudinal and transverse moment of slab, longitudinal negative moment of pedestal, transverse moment of pedestal and reaction of CA mortar are larger for frame slab ballastless track than those for plane ballastless track (2)When considering the mechanical response, there are few differences between frame slab track structures and plane slab structures，but frame slab structures hold many other advantages, such us cost saving, improving construction capability and so on，which make frame slab ballastless track meet a bright foreground in China. (3) The position acted by loads influenced greatly on mechanical action of ballastless track structures, the middle of slab and the border of slab are two worst load action positions，so the larger value brought by those two load action ways should be taken in ballastless track structures design.

Research methods: Based on the coupling dynamics theory o# vehicle and track, the spatial dynamic model of train and ballastless track and the movement equations of slab laid on the elastic base had been set up. With the developed dynamic simulation software TRACKDYNA, the dynamic performances of the ballastless track in Suining-Chongqing Railway had been studied systematically.

Research results: When the high-speed passenger train，heavy-haul freight train and ordinary train pass, the wheel/ rail vertical force, wheel/rail horizontal force，derailment coefficient, reduction rate of wheel load，dynamic stresses of CA mortar, dynamic stresses of subgrade surface etc. are less than their allowances.

Research conclusions: The dynamics performance of the ballastless track of Suining-Chongqing Railway can meet the design requirement and the structure of track in transition area is rational. For the transition area of double slab ballast track，to reduce the stiffness of rubber cushion under rail of fastening joint at two kinds of track joints in front of double slab can improve the dynamic performance in transition area.

Research methods:Based the vehicle-track coupling dynamics, the embankment-rigidity bed transit model is provided, then computer program is worked, and dynamics characteristic of embankment-rigidity bed transit section is simulated.

Research conclusions:At transit section,dynamic interaction is very slight due to track stiffness difference，but the variety of rail deflection is obvious. Asymmetrical settlement of foundation has remarkable influence on track stmcture and the steady of vehicle，the acceleration of vehicle will attain 1 .0 m/ s2 if there exits 30 mm/10 m Asymmetrical settlement, and the influence becomes greater with inereaning of speed; the length of transit section should make the acceleration of vehicle as chief index, the length of transit section can establish as 25-30 m if there exits 30 mm asymmetrical settlement.

Research methods: By doing the simulation tests and making theoretical analysis of error, the inverse calculation was done for the precisions of control nets at all levels and the researches were done on the method of distributing control oat and the principle of precision design.

Research results: The method of distributing plane control net and principles of precision design are presented.

Research conclusions：The limitation value of long deformation of coordinate projection of the control net for construction of ballastless of passenger dedicated railway should not be over 10 mm/km. A pair of inter-visible GPS spots far away of approximate l km should be laid out within the range of S km along the railway fur the control net. The extending aux- diary facilities with approximate values and conducting wires should be installed between the GPS spots and the side length of the suite should be between 400-60D mm. The angle error caused by the error of any three adjacent control foundation pile spots should not he over 8 minutes.

Research methods: With condition of geology, length, section，ground and organizing traffic, this paper studied the adaptability of TBM, constructing scheme，constructing time limit for project and constructing risks.

Research results : Guancen Mountain Tunnel has conditions to use open-type TBM.

Research conclusions:(1)The open-type T13M can adapt the construction of Guancen Mountain Tunnel.(2 ) The Guancen Mountain Tunnel may adopt the scheme that TBM was installed in outside of the tunnel，used mine construction in soft rock sector, walked into tunnel to dig or that TBM was installed into the tunnel and dig directly, used mine construction in soft rock sector.(3)The constructing least time limit for the project is 42. 5 months to adopt open-type TBM in Guancen Mountain Tunnel(4)The Guancw Mountain Tunnel can adopt open-type TBM to construct，but there are some constructing risks

Research methods: Through making the analyses haled on the geological conditions at the eastern portal of Huaying Mountain Tunnel，it is concluded there is possibility of karst stratum at the eastern portal of Huaying Mountain Tunnel. Therefore，the treatment ways are presented for the prevention of the appearance of disaster in the course of karst tunnel construction.

Research conclusions: The process of geological forecast in advance taken to karst tunnel is as follows; long distance geological survey-medium distance geological survey- -short distance geological survey. The survey in advance and location are done for the karst within the range of 50 m in front of the working face of Karst development area by adopting geological radar and other physical survey means. Based on the result of long distance survey, the precision location is done for drilling hales in advance to suspected places within the range of 25 m in front of the working face in order to make clear of watery and mud situations of karst in front of the working face. The karst condition is made clear through drilling holes and geological sketch of the working face. The preventive measures of drainage or block should be taken in advance according to the situation of surveyed karst.

Research methods: Combining with relative specifications and taking severe cold area mountain tunnel in Neimeng province for example，this paper analyses the technic and economic feature about electric tracer heating system，water release thermal retardation system and dry type hydrant system.

Research results: This paper gives the consists of electric tracer heating system, water release thermal retardation system and dry type hydrant systems, premie preference and methods of calculation.

Research conclusions: Electric tracer heating system, water release thermal retardation system and dry type hydrant systems are all feasible in function. Cost of the electric tracer heating system is higher; water release thermal retardation system is the most economic system; dry type hydrant system must be qualified by fire fighting department. And it depends on the specific engineering to choose the system.

Research methods: Through making analyses of the geological conditions of tunnel portal in unfavourable geological section, the different construction methods are presented and the brief introduction is given to the characteristics of these methods, the analyses are made for the harms and causes for tunnel collapse, and the relative prevention and treatment measures are proposed.

Research results: When working out construction program far tunnel portal, the geological conditions should be taken in account fully. Before conducting construction, the design and construction program should be adjusted according to tire real site conditions and at the same time the necessary preparation should be done for possible sudden events. The relative measures should be taken in construction.

Research conclusions: Since the geological condition of the tunnel in mountain area is complicated, the available and effective construction technology and method should be adopted according to the different conditions, in order to ensure the construction and service safety of tunnel.

Research methods: Based on the new technical standard of engineering measurement for ballastless track and 200-250 km/h ballast track, the analysis and research are done on existing engineering control net of Shijiazhuang-Taiyuan Passenger Dedicated Railway Line, and the overall evaluation is made.

Research results: It is necessary to build the control measurement net which meets the engineering measurement technical request of the 200-250 km/h ballast track, when using the existing tunnel engineering control net in the section of ballastless track.

Research conclusions: lf specific conditions allow, it should make full use of existing engineering control net and its measuring spots，but the works of linking new control net with existing engineering control net and designing measurement technology schema should be done well wall in order to reduce the influence on excavation work and ensure the quality of the construction.

Research methods: From the paint of views of the construction and characteristics of multimedia technology，the analyses are made for the applicable research and development of multimedia technology based on the actual condition of the Third of Railway Survey and Resign Institute Group Corporation.

Research construction: Application of multimedia technology can commonly share the basic multimedia data as much as possible, which can avoid producing same elements of multimedia products repeatedly, enhance the production efficiency of multimedia and ensure the safety and reliability of multimedia products and files. .4pplication of high quality- computer video technology in multimedia can make computer multimedia produced with digital video to scientifically integrate the capacity of computer multimedia for handling engineering drawings with the capacity of digital video for handling pictures so as to produce high quality video products for construction. Application of large volume video data storage technology can stare video data far being used again to form a multimedia management system- The storage mode can be on line or off line according to the real requirements and equipment's condition.

Research methods：First of all, the summary and classification of the overvoltage of the traction substation for electrified Railway are made, then the analyses and explanation are given on the prevention of all kinds of overvoltage, finally the reduction and explanation，presented for the calculation formulas of operational overvoltage based on the calculation example.

Research conclusions: Overvoltage is an important problem regarding to the safety of electric equipments. The overvoltage problem of traction substation is the basically same as that of substation o# power system, but the traction substation has much differences in wiring mode, load characteristics and working conditions from the substation of power system ,so the overvoltage of fraction substation should be handled differently from that of pourer system.

Research methods: By combining the function and land quantities of designing stations on passenger dedicated lines, the statistics, analysis and summarization on the land acquisition are conducted, and the index of land acquisition on different stations are also confirmed.

Research results: According to the functioning requirements of stations and depots, sorts of land acquisition are analyzed, the principle of economizing and centralizing land, decreasing the occupancy of plantation and fertile land, which should be carried out in the design, are put forward. The viewpoint of selecting the location and disposal graph of stations in reason, and making out the land acquisition of stations uniformly are provided. Land acquisition indices of medium-or-miniature-sized stations which located in the different terrains such as plain，hill and mountain，and large and oversized stations and depots which located in the plain are all researched.

Research construction: The component of land acquisition indices of all kinds of stations and depots in passenger dedicated lines are confirmed. Land acquisition indices of different stations and depots which located in the different terrains are put forward.

Research methods: Through making analyses of the current conditions and traffic volume of Zhangjiakou area, the research and comparison are made for the programs of introducing Zhangjiakou-Dining Double Line and Beijing-Baotou Line to Kongjiazhuang Station in Zhangjiakou area.

Research results: The comments are made on the necessity of introducing Zhangjiakou-Dining Double Line to Zhangjiakou，the determinations are made for the program of station innovation, mode of track untwining and proposed program of introducing Zhangjiakou-Dining Double Line to Zhangjiakou, the research and analyses are made for the advantages and disadvantages of the program of Zhangjiakou-Dining Line going around Beijing-Baotou Line and the program of Zhangjiakou-Jiving Line crossing Beijing-Baotou Line in middle，and the recommendation is made to adopt the program of Zhangjiakou-Dining Line going around Beijing-Baotou Line.

Research conclusions: The operational modes of main stations in railway terminal and the local development plan should be taken into account when working out the untwining program，and the analyses should he made for the programs in order to obtain optiumu programs of station innovation and traffic untwing.

Research methods: The comparison and research are done on the aspects of communication network technology，system constitution for Guangzhou Metro Line 2 accoding to the operational requirements and the development of communication technology.

Research results: The technological choices and network constitution are put forward, which can largely reduce the investment in communications system.

Research conclusions: The study should be done on the problems in designing the communication system when designing a new Metro line. The proposals are made that the skilled and experience integrator should be hired to control the whole construction process of communication system, the UPS of two hours should be equipped to the transmission system， wireless system, telephone system and main clock in control center and LIPS of one hour to the other systems, the main optical cables from car depot to the ground should be laid down in cable pipe and the pipe quantity should meet the long-term requirement, and the rainage system should be installed in rainy area for the manhole, which should be connected with the main drainage system of car depot to solve the problem of ponding in manhole.

Research methods: The researches are done on the maintenance and operation systems of Shenshuo-Huanghua Railway and railways at home and abroad by adopting analysis and summary methods.

Research Conclusions: The maintenance and operation systems applied in Shenshuo-Huanghua Railway satisfy the investment requirements and its management mode has reference significance to the railway reform in China and is worth being used widely