Research conclusions: The Guizhou—Guangxi Railway is upgraded as Grade I electrified railway with singkle track， reversing condition for double tracks．The additional second track from Liuzhou to Luoman will be built．The ruling gradient is 6‰ and the ruling gradient is 1 3‰ in the section with double locomotive traction．The driving load is 3 800 t．The 160 km／h speed target value is desined for the Liuzhou—Jinchengjiang section and 140 km／h speed target value is designed for the Jinehengjiang—Longli section with some design margin．

Research conclusions: The speed target value for upgrading Nanjing—Xi’an Railway increases to 160 km／h because the topographty along the railway is flat，the minimum track curve radius is 1 600 m or above．In addition，dong so is to avoid bigger dismantling and changing for the railway and save the investment．The speed target value of 1 60 km/h is also designed for the additional second track of the railway to well match the existing track and neighbour railway according to the functional orientation of the railway that mainly undertakes freight transportation and simultaneously undertakes passenger transportation．

Research conclusions: In the Dongjiakou harbour district，three railway stations can be built at the Dongjiakou Harbour，Water Front and Logistics Center．The railway between Harbor Station and Water Front Station is the main railway line for the port．The railway from Qingdao to Lianyungang or the railway from central and southern part of Shanxi to Rizhao can be chosen as the exterior railway of the port．As thees two railways are planned to build. the choice of the exterior railway is closely related to the time of building the railways．If they will be buih at the same time．The railway from Qingdao to Lianyungang can be chosen as the exterior railway．Later，the railway in port can be connected with the railway from central and southern part of Shanxi to Rizhao，but it depends on the developments of the port and the port industry zone．

Research conclusions: It is very necessary to construct the southern passageway and noahern passageway crossing the Taiwan Strait with priority of construction of the northern passageway．As regards the construction conditions，the problems，such as deep water，strong wind，high wave，earthquake and active fault，should be overcome in construction by using the advanced technology．So far the disturbingly unfavorable sectors for construction are not found．As regards the construction scheme，it is possible to build bridge passageway and tunnel passageway or bridge and tunnel combined passageway to cross the Taiwan Strait．What will be built needs doing much basic works and overcoming much technical difficuhies．

Research conclusions: The calculation of the magnetic response of long wire source could be realized by splitting the long wire source into multiple dipoles with Hankle transform．When doing calculation of the magnetic response of long wire resource，the long wire source could be splited into multiple electric dipoles according to the distance of sender， receiver and the wire length．Then the electric field and magnetic field in level direction on the ground generated by the multiple electric dipoles were calculated with Hankle transform，and the magnetic responses of every electric dipole was Sided to obtain the response of the long wire source．The verification showed the results of some classic models excited by long wire source were right and meaningful to the inversion of CSAMT．

Research conclusions: The image spatial resolution is an important index for the accuracy of image interpretation．Under condition a mapping scale is given，the most suitable resolution of remote sensing images call be calculated，and a topographic map scale M Can be obtained for correcting the remote sensing images．Its mathematical relationship is R={ (L*M)/2 -Rmin}．1he image ground resolution Rc is the key factor for evaluation of image quality and with it，the accuracy of remote sensing interpretation(engineering geological characteristic point P，line P’and area P”)can be 1一calculated．Its mathematical relationship is RG=3P’=P”/3=2a。

Research conclusions: GIS—based railway lalignment design not only provides an extensively applicable platform for engineering planning，engineering design，data acquisition，quantitative statistics and 3D display based on space information technology，but also provides a more reasonable basis and a new and more scientific design means for data organization for space construction of large area．This reflects the advantages of GIS—based digital railway alignment design compared with the traditional plane graphic design．

Research conclusions: The problems exist in application of remote sensing satellite image in ecological impact assessment for railway construction, such as low image resolution, no rectification of image, unmatched timeframe, insufficient field investigation, errors of image interpretation and identification. The independent processes of identical procedure to the images from Sino-Brazilian Resources Satellite and Landsat7 ETM+ Satellite were conducted tomake a comparative analysis for the alignment of Jiangle Station of Hangzhou -Ningbo Railway. The result shows that a considerable difference exists in the landscape structure, particularly in forestry patches. The Landsat images are better than Sino-Brazilian images. To enhance accuracy of the ecological impact assessmen,t it is recommended the satellite images with higher quality should be used, the image rectification should be conducted, the site investigation should be done, and the interpretation quality should be improved.

Research conclusions: Regarding the Nanjing -Hangzhou Railway as a system, according to the track alignment, to pographical conditions and geological characteristics along the railway, the analyses of the effects of the different maximum track gradients on the construction safety and reliability, train operating costand adaptability of EMU are made with fuzzy analytic hierarchy process. Based on the analyses, it is recommended that the maximum track gradient of this railway is 12‰ for optimizing this railway system and the maximum track gradient in some areas can be 20‰ for protecting environmentand saving investment. Application of this method in choice of the maximum track gradient is effective and operable and it can be the reference to the similar work.

Research conclusions: The assessment of radioactive impact to railway engineering includes following several steps：assessment limitation standard，analysis and assessment of present situation investigation，and prediction of radiological impact etc．The study shows the uranium probably becomes anomalous locally in mountain—crossing area along Jining— Tongliao Railway，but it is difficult to form uranium deposit．All indexes related to the rock，soil，groundwater and air are in the ranges of the state standards，and the radioactive impact on the workers is acceptable during the railway construction and operation．The engineering wastes has no radioactivity，they do not need to be disposed as a radioactive waste．

Research conclusions: From the prediction analysis with curve fitting method it is concluded after excavation or filling of the subgrade，the subgrade settlement is large when the subgrade stands within 4 months，the subgrade settlement tends to slow down when the subgrade stands for 4-6 months and the subgrade settlement tends to stable when the subgrade stands for more than 6 months．Although there is the difference of settlement prediction between using logarithmic curve method and hyperbola method，but the difference Call be solved by using the medium value of these two methods to ensure the prediction conforming to the real situation．

Research conclusions: The stability of the single pile composite foundation of high—speed railway in the hard—plastic silty clay could be determined by static test of the single pile composite foundation．During the test，the bearing plate was placed on the compacted soil of the composite foundation．The characteristic value of bearing capacity of the single pile composite foundation could meet the design requirements and its range Was not be more 30％than the average value．The settlement of the width of the bearing plate corresponding to the characteristic value of the bearing capacity of the single pile composite foundation bearing plate did not exceed S=0．004 d，and the settlement range of the characteristics value for bearing capacity of the single pile composite foundation did not exceed 30％of the average vahe．

Research conclusions: The railway alignment in sand storm area should be conducted according the type of sand storm，and the control measures should be taken for sand storm．It is proposed the control measures of railway itself should be taken along with plane control measures to guarantee the safety of railway traffic．

Research conclusions: The transitional slab is installed at the girder joint at the end of the girder to reduce force on the ballasfless track and the model for the transitional slab structure is establish to analyze the difference between the force on the track structure with transitional slab and the force on that without transitional slab under the conditions of girder ration angel and vertical relative displacement of bridge on both sides of the girder joint．The result shows that using the transitional slab Can reduce the maximum pressure and tension of rail fastening and the rail additional moment by 20％—80％．So using the transitional slab at the girder end Can reduce force on the track structure at the end of girder so as to ensure normal operation of ballastless track．

Research conclusions: The design and application of orthogonal continuous beam along with skew pier in Cihuaixinhe Double—track Bridge to cross the Cihuaixin River show that the stress level in the lateral area pallet under the pad stone is biggerr than other areas because of orthogonal layout of pad stone，and when the size of the pad stone exceeds the pier size is controlled in a certain range，the stress level of the tray can be controlled in the specification allowable value．Using skew is a good solution when the oblique crossing is needed over road and river because of the limitation of railway alignment．

Research conclusions: ：(1)Compared with the three main trussess，the maximum axial force of truss web increases 24．1％．when the two main trusses are adopted and the bending moment outside the vertical post increases much because of the framing effects．(2)Compared with the two trusses bridge，the reflection span ratio and rotation angle at the end of beam decrease 14％and 12％separately because of the deck load transferring directly and much more structural rigidity being provided by three trusses bridge．(3)The structure weight of orthotropic steel deck plate is 35％ lighter than the steel—concrete composite structure，SO the mechanical behavior of main trusses is improved significantly．Compared with the latter，the maximum axial force of the top chord and the truss web of the former decreases about 34．6％ and 10％ separately．

Research conclusions: In this paper，the safety of structure，the safety and stability of train and the comfortableness of passenger are fully evaluated with the train—structure coupling dynamic analyse method．The analyse results show when the train rails at a speed of at least 200 km／h over the main—line bridge with frame structure in Hongqiao Railway Station，the safety of structure，the safety and stability of train and the comfortableness of passengem meet the design demand．As a result，in order to satisfy the requirement of integration of building function with the building style，it is suggested that the frame structure system is applied in the main—line railway bridge when the building and bridge are integrated in the railway station．It is also suggested that the train—structure coupling dynamic analysis should be made on premise of meeting the requirement of static calculation．

Research conclusions: There is big gap between the current seismic design intensity and actual seismic requirement for the main city and town in China，So the seismic code should be improved and revised．The design principle of the bridge crossing active geological structure zone should be added in the seismic code．The seismic code should require doing the research on the seismic intensity for the bridge structure of main highway．The more seismic measures should be taken for the seismic structure．The comprehensive seismic design measures should be taken in high earthquake intensity area to enhance the seismic capacity of the structure．The clear seismic requirements should be presented for construction of bridge in high earthquake intensity area．

Research conclusions: There are some very big limitations for getting the P—waves of the surrounding rock of deep buffed tunnel with the shallow seismic refraction method．Therefore，the telluric electromagnetic sounding sounding has become the major method for railway geological exploration．Using the telluric electromagnetic sounding Call effectively distinguish the resistivity and its outcomes can be as the basis to judge the integffty of surrounding rock，So it is feasible to use the telluric electromagnetic sounding to sort the surrounding rock．

Research conclusions: When the traction power network separately supplies the upward track and downward track of double—track electrified railway，the equivalent current of the feeding section for upward track(or downward track)is approximately equal to the product of the interval number and the average current of upward(or downward)train．When the traction power network parallel supplies the upward track and downward track，the equivalent current of the feeding section for upward track(or downward track)is approximately equal to the 3／4 equivalent current of the upward track (or downward track)when separately supplying and plus the 1／4 equivalent current of the downward track(or upward track)when supplying separately．The the current carrying capacity of feeding section cab be improved by adopting parallel supply．More improvement can be achieved with the increasing of the average current difference between upward track and downward track，and the current difference can be reduced by 1／4 under the condition of electric load of the track on single direction slope．The equivalent current of section post is related to the average current difference between trains running on upward track and downward track．The equivalent current of section post is the minimum when the current of upward train is equM to that of downward train．The equivalent current of section post is the maximum and approximately equal to the 1／4 equivalent current of train running on the track with power supply separately when there is no train on one track or the average current of train is equM to zero．

Research conclusions: The urban rail transit is needed urgently for Lanzhou．Only when the special basic conditions of Lanzhou are analyzed and the actual passenger flow in Lanzhou is considered can the plan of the urban rail transit be well mapped out to lay a perfect foundation for the urban rail transit in Lanzhou in future．

Research conclusions: The evaluation of urban rail transit plan network is the key link of rail transit plan and is very important for determining optimal and the most satisfactory plans which are advanced in technology，reasonable in economy，and feasible in implementation．The researches shows that there are many advantages by adopting DEA method to evaluate urban rail transit network plan．This method has features of easy operation and using the input and output indexes to optimize the scheme．So it has a certain practical value．

Research conclusions: To better layout design of pipehnes，before making design，the pipelines corridors，the cable trenches，the direction and control elevation of gravity drainage pipes and the reserved space for gas pipes should be well planned，In the course of design，attention should be paid to deMing with the crossing nodes of pipelines．During construction of Xiajiao vehicle depot project，no design modification for pipelines caused by improper layout of pipelines occurred．The application shows the design principle and method for layout of pipelines in Xiajiao Vehicle Depot are correct and effective．

Research conclusions: This paper offers some commonly—used schemes for evacuating people．Namely，the special evacuation passage parallel with the main tunnel；the emergency exit along the main tunnel；rescue station in the middle of the tunnel．Longitudinal smoke emission model should be adopted with making full use of the shaft．The water supply for fire demand should be considered inside and outside the tunnel．