Research conclusions: Application of the interpolation of the quintic multinomial can eliminate the error caused by environment factors and the difficulty in selection of measurement spot caused by the non-isochronism in measurement to make the settlement curve smooth. From the prediction results obtained from the four methods mentioned above it can be seen the result obtained from the three- point method is good, getting the max imum relative coefficients while the measured values obtained from the hyperbolic method are the biggest.

Research conclusions:The research result indicates that using the maximum relative altitude in drainage area，the scale of potential debris flow，debris flow frequency，drainage area，length of main ditches，the average slope of main ditches，maximum rainfall in 24 hours，population density and length proportion of debris supplement section to assess the debris flow hazard is reasonable and feasible．Dashuigou debris flow was assessed with this model．The result showed the Dashuigou debris flow was of high—hazard and it Was consistent with the real hazards status and activities trend．So the model for debris flow hazard assessment is effective and feasible with certain theoretical and practical significance．

Research conclusions: From the systematic analysis and research on calculation of the size of the thawing cylinder of the buried oil pipeline in permafrost regions with the calculation model，it is concluded application of coarse—grain soil instead of the heating plate for buried oil pipeline in permafrost region can reduce thawing settlement and frost—-heaving of the oil pipeline foundation and guarantee the the stability of the pipeline foundation．

Research conclusions:The reflection amplitudes of reflection wave was related to the embedment of the pile end．By using the proportional reflection amplitude coefficient T between the reflection amplitudes of the reflection wave and the incident amplitude，the embedment of the CFG pile end and the ultimate bearing capacity of single pile were analyzed． When TA was equal to 0．1-0．2，the embedment of the pile end Was good and the ultimate bearing capacity of the single pile was of 1 200—1 000 kN．When the TA was equal t0 0．2-0．5，the embedment ofthe pile end was rather good and the ultimate bearing capacity of single pile Was of 1 000—800 kN．When TA Was equal to 0．5—0．86．the embedment of the pile end was rather poor and the ultimate beating capacity of single pile was of 400—800 kN．When TA was more than 1，the embedment of the pile end was poor．When n Was negative number，the embedment of the pile end Was excellent．In a word，the better the embedment is，the more load the single pile can bear，otherwise the single pile bears less load．CFG pile should be constructed with gamopetalous—type long screw machine to get a good embedment and enhance the bearing capacity of single pile．

Research conclusions:fter eliminating the effect of vacuum degree，the increases and dissipation characteristics of excess pore water pressure under vacuum combined surcharge preloading foundation is basically consistent with that of single surcharge preloading，and there is no essential difference in reinforcement mechanism of them．Additional stress and reinforcement depth of vacuum preloading foundation is obviously different with that of single surcharge preloading，SO it should be considered in settlement calculation．At last，the control of the post—construction settlement under vacuum combined surcharge preloading is closely related to foundation conditions and embankment height and 80 on，80 its application must be considered in design and construction according to technical standard．

Research conclusions:Based on the analysis of frost—heaving mechanism of the subgrade and its influence factors，and tests to the frost—heaving of filling materials Group A and Group B，the discussion is made on the frost—heaving of the fixed filling materials and it is concluded the frost—heaving of the subgrade base can be effectively controlled by using the 60cm thick crashed—stone filling material with fine grain content less than 15％．However．as the influence factors on the frost—heaving are complicated and the research results have limitations，it is necessary to do the further study on remedying and improving the frost—heaving data to make the design of antifreeze filling material and structure more reasonable for the subgrade．

Research conclusions:From the measured data of the track irregularity of Wuhan—Jiujiang Railway Line，the distribution functions of the power spectrums of the track irregularity are obtained．According to the measured acceleration of the vehicle vibration。the analysis iS made for correlation between the different track irregularities and vibration acceleration and the most unfavorable wavelength that brings about the vehicle vibration is known．

Research conclusions:Through the introduction of the middle method of total station，CP Ⅲ trigonometric leveling network is established and compared to the prerequisite for high precision trigonometric leveling，it is considered to be feasible．At the same time，comparison and statistical analysis among actual accuracy index of large mounts of CP Ⅲ trigonometric leveling network data are done，proving that the method proposed in the paper can meet the accuracy；equirements for the second order leveling and CP Ⅲ vertical control network，SO it is a new method in establishing CP Ⅲ vertical control network．

Research conclusions:：(1)CPⅢ control network is installed evenly along the railway and the multiple—direction intersection in rear is adopted in the measurement．This is crucial to control of the relative error between measurement spots of CPⅢ control network．(2)The relative error between measurement spots of CPⅢ Control Network and the repeatable precision control of the measurement error can meet meet the requirements of the track regularity．

Research conclusions:In order to determine the layer number of the sleepers and make sure the truss steel bars are in normal working conditions，the calculation focuses on the stressing state of truss steel bars in the sleepers．It also provides US with the constraints and the advice of hoisting and storage of the Double—block sleepers．

Research conclusions:The study on simulations of the rail integrity，broken rail status，occupied status of track and failed status of receiving channel shows the ultrasonic guided wave detection method can replace the detection circuits for broken rail in the section without rail circuit，with features of simple principle，easy installation and maintenance and Low consumption of operation power．

Research conclusions:The wear volume of rail specim en and friciton work of contact area of wheel and rail changes with the changes of the axle load and curve radius. There is a corresponding relationship between wear volume and friciton work of wheel and rail This study result offers a certain reference value to study ing rolling contact wear of rail in laboratory.

Research conclusions:The introduction is given to the research on application of metal magnatic memory technology in testing the temperature stress of seamless rail by using TSM一1 M-4 Magnetic Memory Detector．Application of TSM一1 M—·4 Magnetic Memory Detector in testing the temperature stress of 1 5 15 m long rail administrated by Fengtai Track Maintenance Section of Beijing Railway Administration shows this metal magnatic memory technology has a big merits in early—time diagnosis of sudden buckled track．

Research conclusions:(1)Under the shallow bias conditions．the settlement and convergence of the arch of newly—built tunnel are big．(2)The rock pressure distribution is asymmetric like eat ears．(3)The stress on the farther side of the steel bow member is bigger than that on near side of the steel bow member and it plays a big role in supporting．(4)The Arch and side walls with sprayed concrete are in compression while the tensile stress i8 over the bottom．(5)The stress on the anchors of the arch system is small and it produces a little effect on the stability of the structure while the foot anchors produce a certain effect on the structural stability．(6)The existing tunnel is obviously affected by excavation of the new tunnel because excavation of the new tunnel produces two effects of bias and tension on the existing tunnel．(7)The distance between the proximite tunnels produces big effect on the existing tunnel lining．When the space iS fixed，the impact on the near side iS bigger than that on farther side．

Research conclusions:Based on the systematic engineering concept of the adaptability between man and the shield tunneling and the construction environment，the analysis is made for the basic concept and intension of the shield adaptability to the construction environment．According to the characteristics of the construction environment，such as The high hydraulic pressure，the shallow covering and the compound stratum etc，the control measures such as setting and adjusting appropriate face pressure，control of shield tunneling attitude，matching the grouting volume and speed with the shield speed are offered to reduce and control the construction risks，such as destabilization of excavation surface，mud pumping in the river bottom，block of the pumping mouth，mud leaking at the shield end and tunnel floating．This can provide the reference to the similar projects．

Research conclusions:The load testof traction power system is an indispensable testin the phase of the integration tests For passenger dedicated line. The load testmethod and evaluation used for Beijing -Tianjin Intercity Railway are suitable, correctand reliable. The standardized load testnotonly can verify the design, installation and commissioning of traction power system in general, but also can validate and optimize the plan study and and simulated calculation in early time. The acquired data are also very useful to the maintenance for the future.

Research conclusions:Based on the analysis and research on the planning method for grey land use，this paper offers the dynamic plan for grey land use along the Line 2 of the urban rail transit in Suzhou according to the planning for land use along the urban rail transit around the high—speed railway．With this plan．the change number of the plan can be reduced，the use value and use efficiency of the land can be enhanced，the market properties of rail transit can be reflected，and the sustainable development of rail transit construction can be achieved．

Research conclusions:From the calculation of the numerical values of the light rail bridge pier，analysis of the monitored data settlement and comparison with the corresponding codes it is concluded the existing settlement of the light rail bridge call meet the service requirement of light rail．

Research conclusions:The turn—back track of terminal station should be laid out according to the terrain condition．The construction difficulty，the traffic capacity of the turn—back track，the traffic flexibility and the long—term development of urban rail transit network should be compared in technology and economy to choose a reasonable plan for the turn—back track．

Research conclusions:Development of high—speed railway is significant to the sustainable development of society and economy in China．On one hand，it can substitute for the developed western countries transportation development way that cars is as the main transport means with much environment pollution and astonishing traffic accidents．On the other hand，it can make full use of the sequent advantage of the developing countries to quickly build up its modem and rapid traffic system with the concept of putting man first and realize the harmonious developments between the transportation and environmental resources under the guidance of scientific outlook on development．