Research conclusions: The paper elaborates the development and planning of Chinese heavy haul railway network， presents the principals ought to be followed when planning the heavy haul corridors． Take the railway maximum income as the object function and take the line carrying capacity as well as the investment limit as the constrains，an investment decision － making for heavy haul transformation and cargo flow distribution model based on path selection as well as the solution method are proposed． The model makes the decision of rail heavy haul transformation more reliable．

Research conclusions: ( 1) A practical integrated technology is put forward in this paper to quickly build a 3D railway scene． ( 2) a series of three － dimensional GIS software platforms and tools appropriate are independently developed． The integrated technology and software platforms have been applied in China － Laos railway projects successfully． It verifies the feasibility of the technical system in this paper． So a solution for 3D GIS applications on the railway has been explored．

Research conclusions: In the fault structure exploration for railway，compared with the conventional geophysical methods，the natural source audio frequency magnetotellurics has the features of the rapid survey with less topographical limitation，big survey depth and low cost． With the self － developed data processing methods，the same platform can be used for processing the data of the natural source audio frequency magnetollurics and CSAMT to solve the defect that the inversion is too smooth and abnormal homogenization，getting good survey effect on the fault structure exploration and finding out the distribution pattern of fault structure． It provides a strong basis for the railway alignment and guiding significance to the similar works．

Research conclusions: ( 1) This paper adopts several in － situ testing methods such as double bridge cone penetration test，three bridge rotating penetration test，sample drilling，slab loading test，shear wave test． The three bridge rotating penetration test technology is a new species of in － situ test techniques which overcome the problem as conventional sounding can not penetrate the hard layer and the test depth inadequate，and its penetration depth can reach 60 m in this field． ( 2) This paper use the method of contrast analysis and mutual verification find out the cause of foundation soil era， lithologic features and its distribution law． ( 3) Thus improved the quality of exploration，shorten the cycle of survey and lower the cost，provides a reliable design parameters and practical foundation design suggestions for engineering design．

Research conclusions: By using the concentric circle design method of passenger dedicated line，the left and the right tracks are designed to a approximative concentric circle，and its error with the theoretical concentric circle increases with the decrease of curve radius and the increase of the curve drift angle． When these two factors reach a certain quantitive standard，the traditional strict design method should be used for passenger dedicated line to ensure the technical and economical efficiencies of the design．

Research conclusions: From the comparison of the geological conditions of the various schemes，it is concluded that with the west slope equalization scheme of building two extra － long tunnel through Liupan mountain area，the railway and tunnel can keep away from the area with unfavorable geological condition and the main fault zone，and the tunnel wall is of single lithology cretaceous stratum with less portal and short shallow section． In this way，the risks of construction and operation of the railway in the Liupan mountain area where earthquake occurs frequently are much cut，and the engineering geological condition is optimal．

Research conclusions: The compression indexes of completely decomposed granite obtained from laboratory consolidation test are of low reliability，and using these indexes can easily cause the waste in foundation treatment design． The compression indexes obtained from the standard penetration test are relatively accurate and can be used for the design， but the accuracy and applicability of empirical relation between deformation modulus and SPT blow count is worth further studying in combination with the properties of local decomposed granite．

Research conclusions: The stability calculation of embankment slope in permafrost regions not only refers to ordinary slope analysis methods，but also considers the time factor． In addition，the stability reinforcement of embankment slope still can take the following methods，such as the selection of filter，the geogrid，the anti － slide piles，and so on． The results drawn in this paper can provide reference to the construction and management of plateau railway in the future．

Research conclusions: A dynamic test system is established according to the loading boundary conditions of soaking subgrade paved with CRTS II slab ballastless track for a top speed of 350 km / h． After 5． 5 million times dynamic loading of 9 ～ 13 kPa，the dynamic stress，the dynamic pore pressure and the elastic deformations of the roadbed are in stable states，and the plastic deformation is 0． 48 ～ 0． 56 mm． The results of the sweeping frequency test indicate that the resonance will not happen as the natural vibration frequency of the subgrade is more than train ＇s dynamic loading frequency and the subgrade keep good performance because the natural vibration frequency decreases less after the dynamic test． The design of the experiment about soaking subgrade protection and filling is feasible． The long － term soaking subgrade has stable performance and can meet the strength and deformation requirements of the roadbed with ballastless track．

Research conclusions: It contains retaining walls，culverts and bridge structural design in one system． The top of the wall surface，composed of rigid frame and sidewalk cantilever plate，meets the need of the layout of the station professional ancillary facilities． This structure design not only reflects the innovation and rationality of subgrade design，but also ensures the safety of existing lane and the existing building． After operation，its benefits of small footprint，wide bottom base，better itself stability，high level of resistance，and better anti － slide，anti － dumping effect，are fully reflected． But it also plays with the dual role of slope retaining and slopes receive． So，in the future，this design has the important reference value for the same type of railway roadbed engineering design and construction．

Research conclusions: Under the complex geological and topographical conditions，the geological investigation for the super big bridge should be conducted according to the existing norms and based on the geologic mapping． The variety of survey means should be used to complement and validate each other． By makin the comprehensive analysis，the development characteristics of the rock － soil layer and structure can be judged，the geotechnical parameters can be determined and the site and foundation programmes can be evaluated．

Research conclusions: Strengthening the transverse connection of the diaphragm of the concrete simple － supported beam can well control the lateral vibration of the bridge． Adding the beam bonding steel plates and the external prestressing steel strands can effectively increase the load － bearing capacity of the beam． Enlarging the cross section of the pier can greatly enhance the lateral rigidity of the piers． The existing railway concrete simply － supported beam bridge reinforced by taking the above measures can meet the speed － raise requirements．

Research conclusions: The identification results show that: ( 1) The proposed hierarchical damage identification method has a identified precision and efficiency，it is suitable to intelligent diagnosis process of hybrid girder cable － stayed bridges． ( 2) The combined static － dynamic damage identification index is also sensitive to cable － stayed hybrid girder bridges． ( 3) The identified precision for single damage cases is nearly to 100% ． ( 4) For double and triple damage cases individually，the identified precision is nearly to 82． 61% and 78． 3% ．

Research conclusions: After a targeted analysis，through spatial models established by the finite element method，the data shows that spatial models can truly simulate the forcing property of single support curved girder bridges． And it also shows that，the appropriate choice of pier beam consolidation measures can effectively reduce the risk of overturning， and reasonable eccentricity of structure can improve the stability and security of different structures． It may provide reference in bridges of the same structure．

Research conclusions: ( 1) In bridge － tunnel connection section in series，using enlarged cross － section and digging filling piles can effectively solve the problems that bridge abutment enters tunnel difficultly and aerodynamic effect exists in tunnel portal． ( 2) According to different portal types and lengths of open cut sections，excavation methods of bridge abutment pits are classified into two types: protection of digging filling piles and step － slope excavation behind the pit in bridge － tunnel docking connection section． ( 3) For the situation that retaining wall exists outside of the portal in bridge － tunnel docking connection section，the following two measures that pile foundation and joist are set under the retaining wall and the retaining wall is designed into anchor retaining wall，can solve the difficult problems that the retaining wall is unstable because of pit excavation． ( 4) By the measure that transition section is set in tunnel portal，cable channels can link smoothly in bridge － tunnel connection section． ( 5) Inspection well which is set in the lower tunnel portal，can effectively solve the drainage problem of tunnel．

Research conclusions: In order to make the prediction of water bursting volume more closed to the real situation，more reasonable and more scientific，on consideration of the strength reduction factor of the fissure and the asymmetry of the boundary condition，the calculation should be made for the steady flow with the parcel superposition method，the calculation should be made for the non － steady flow with the osmotic coefficient that conforms to the real situation and thickness of the water － bearing stratum，the water bursting volume should be predicted by using the effective catchment area when the underground runoff method is used on the base of the analysis the topographic and structural conditions， and the hydrology method has macro estimate role，so it is unsuitable to be used for the quantitative evaluation． When the condition is allowable，the numerical model should be established for calculation，especially to establish the 3D flow numerical model．

Research conclusions: During the development of railway tunnel engineering CAD system，professionals demand － oriented adhere to establishment of designing logic model of framework and sub － systems． The system finished all functions efficiently because it use the OOP technologies to design objects and their reasonable components． The software are having been used to many railway lines and have a good effects． It also will be a reference practice solution because it is easy integration an maintenance． The applications show that technology framework and development methods are practical．

Research conclusions: ( 1) It’s necessary to upgrade design method to ensure safety of the grounding grids of special or very important traction substations by using computer － aided design software． ( 2) The maximum short － circuit current should not be taken as the grounding current，the effect of overhead ground wire connected with the grid should be considered，and the current divider coefficient should be calculated． ( 3) The designers should adopt unequally spaced arrangement in optimizing grounding grid when necessary． ( 4) The designers should not hold the opinion that copper must be resistant to corrosion，they also should take the effect of galvanic corrosion and environmental factor of the soil into consideration．

Research conclusions: Through systematic analysis of marshalling station as well as study on the layout of locomotive facilities，the conclusion indicates that the existing locomotive depot should be utilized after overhaul，sub － locomotive depot should be adopted，i． e． locomotive turnaround depot be built at Guiyang south station，and at the same time， rebuild the existing Guiyang locomotive depot． This scheme has such merits as fully utilizing existing locomotive facilities，more smooth for locomotive operation，shortening route distance，saving operation expenses，with better transition construction and preserving condition for future development．

Research conclusions: According to the load － bearing characteristics of the elevated station structure with " integration of building bridge structure" of Line 3 of the Shenzhen metro，the targeted measures for the structure design were taken and the relative checking methods were used． In this way，the good points and shortcomings of the such kind structure could be adopted and avoided to meet the requirements of the structure safety of the elevated station and passengers' comfortableness of urban rail transit．

Research conclusions: Taking the design of the field plateau height of Harbin Taipingqiao Vehicle Depot and comprehensive base as an example，the factors about the hundred － year flood level，the ponding depth and the rail top height were analyzed on the premise of meeting the relative design principle and technical standard，and at the same time，the geographical and hydrological environment，the municipal facilities and the earthwork were considered and the relative proposal was made． The result showed the design could meet the various demands and it could be as the reference to the similar works．

Research conclusions: The integrated energy － saving tactics should be adopted in the energy － saving design of the architecture and the passive energy － saving should be combined with active energy － saving． The energy consumption of the railway building can be much cut by improving the ventilation condition and processing set － up，and taking measures of the heat insulation and machinery blowing － in．