Research conclusions: This paper systemically summarizes the principle of the “route selection combining geology and environmental geology for railway engineering in high-intensity earthquake zone.By the means of remote sensing interpretation， geological mapping，geophysical prospecting(by electricity，seismic waves，or magnetotellurics etc.)， drilling exploration，hole testing，in-situ testing，indoor tests and other comprehensive prospecting technique，as well as seismic safety evaluation(including active fault identification)，environmental effect appraisal，this complete system is constituted，which has an important value to promote. An optimal route scheme is selected through overall comparison among three schemes from the aspects of seismic geological conditions and environmental sensitive area，and then verified by engineering construction and practical operation to be scientific and reasonable，which not only protects the ecological environment to a maximum extent，but also includes the route into a“safe island”.With outstanding economic，social and environmental benefits，it is the “Example of Route Selection Combining accumulating experience for railway route selection praised by experts from the Ministry of Environmental Protection as Engineering Geology and Environmental Geology Organically” ， in similar region.

Research conclusions: In this paper，we studied the formation mechanism and changing process of secondary harmful frozen soil in permafrost regions and got the following conclusions:(1)Thermal differences exist between shady slope and sunny slope of roadbed，melting depth in sunny slope is bigger than shady slope when absorbing heat，and the effect of shady and sunny slope on the depth of roadbed melting cannot be ignored;(2)Considering the seepage effect，roadbed transverse inhomogeneous deformation will increase，which will form the disease of roadbed longitudinal cracks and have serious influence on the stability of the roadbed;(3)In this paper, we provide some theoretical foundations about the engineering construction m permafrost regions，which have reference meaning for controlling the secondary harmful frozen soil.

Research conclusions: (1)As the bar-system FEM complete analysis method for beam on elastic foundation was adopted to calculate the internal force and the displacement of the foundation ditch enclosure structure，the inner bracing was defined as compression-only bar unit with initial gap，and the width of the initial gap was equal to the lateral displacement of fender piles(or enclosure wall) on the point which the inner bracings were applied at the erection time. With that the erection time of the bracings were considered in the model，which makes the internal force and displacement calculations of the enclosure structure accord the actual better.(2)Without considering the erection time of the bracings while using the complete analysis method for beam on elastic foundation，the calculated values of the lateral displacements and moments of the fender piles(or enclosure wall ) were smaller , that was not safety in practice. ( 3 ) Research findings of this paper can provide reference for the design and construction of foundation ditch enclosure structure.

Research conclusions: The research results indicate: (1)The geosynthetic reinforcement layer can partially afford bearing capacity but the columns make ground strengthen. The frictional resistance is main in the bearing capacity of the columns and the columns belong to frictional type pile.(2)The distance between adjacent two columns has important effect on the settlement of the subgrade. The distance can be 2 m that is proposed by the test results. The column-net structure can make accumulative settlement during construction and settlement after construction smaller. It can adapt to the ballastless track railway project.(3 ) These results may give references to subgrade design in express railway projects.

Research conclusions:(1)GM(1，1)model can accurately predict the grouting effect，and its accuracy relates to the influence factors and complexity of surrounding rock.(2)The degree of improvement of GM(1，1)model based on optimization of background value depends on the prediction accuracy of the model. The improved model is suitable for complex surrounding rock which has more influence factors.(3)This paper based the engineering example，the calculation was compared with the actual value to verify the accuracy of the improved grey model，which can provide some reference to predict the grouting effect of surrounding rock.

Research conclusions: The results shows that the pile side friction is easier to play as the surface of pile is rougher, for this reason the pile side friction get bigger and the pile settlement become smaller. In the same time，the rate of transfer load on pile top to the surrounding rock and soil is faster，and the depth of transfer the same level of vertical load become smaller. However, the roughness does not much affect the load proportion of pile tip. The conclusions can provide a reference for design and construction of super-long rock-socketed pile.

Research conclusions:The results show:(1)The critical loading position of CRTS III ballstless track structure is slab end position:(2)The maximum transverse tensile stress is larger than the maximum longitudinal tensile stress in the bottom of track slab，the disadvantageous position is slab corner:(3)The maximum compressive stress of packed bed happens under the load:(4)The maximum longitudinal tensile stress is larger than the maximum transverse tensile stress on the support layer of ballstless track structure on the subgrade，the disadvantageous position is the load position， the longitudinal tensile stress does not happen on the base plate of ballstless track structure on the bridge，the transverse tensile stress happens on the longitudinal edge of support layer:(5)The research can provide reference for China getting the independent intellectual property rights and the international advanced design of ballastless track and method theory.

Research conclusions:(1)On this basis，a universal algorithm for chord deflection offset was established which is based on short chord MCO data. The result of computer simulation has verified the accuracy of the universal algorithm.(2)By means of frequency characteristics and error characteristics analysis，this paper argued that:contrast with bias-chord offset differential method，MCO method has some characteristics in the same chord length，e. g. zero phase shifting， richness of irregularities information，location convenience and characterization of dynamic properties. Not only that，the MCO method is able to extract the information of long wave irregularities with extended algorithm.(3)The universal algorithm established in this paper should provide a new method for the measurement of chord deflection offset in HSR survey.

Research conclusions:The study of track precise adjustment processes and engineering practices have demonstrated: (1)The self-developed data simulation and analysis software on the principle of track adjustment data simulation and analysis serves to support track precise adjustment and improve work efficiency:(2)Such proposed working procedures in precise adjustment as “first track irregularity，then track level，first track alignment，then track guage” has reduced workload:(3)The proposal to use the same rail as the reference to adjust irregularities and alignment has protected the track from disturbance generated during precise adjustment，reduced repeated adjustments and improved its efficiency and quality:(4)The research conclusions are applicable to static precise adjustment on high speed lines and dedicated passenger lines with CRTS I slab ballastless track and elastic split fastenings.

Research conclusions:From the research on the choice of the European bridge specifications，the author reveals the following findings:(1)The new version of the European specifications，which resulted partially from deletion and combination of relevant contents of the old version and was edited with layout according to professional codes，has optimized systematization and methodization of the system.(2)Values range and calculation methods have been stipulated for various parameters on train load，derailment load，traction-braking load，wind load，etc. for railway bridge design according to the new specifications system.(3)The ultimate-limit design based on complete probability is adopted for the European specifications. Being different from the Chinese specifications，its anti-seismic design is arranged in two stages for seismic fortification with an effective checking-calculation method，i. e. linear analysis and time-lapse technique.(4)The above-stated choice of various parameters for railway bridge design under the new specifications system and the main differences on bridge design between the European and the Chinese specifications may provide valuable reference to the Chinese engineers who intend to adopt the European specifications for bridge design.

Research conclusions: It is sure that the main influence factors of the hydrostatical pressure characteristics of the tunnel lining are tunnel radius，structural characteristics of primary support，characteristics of grouting reinforcement and drainage capacity of the tunnel drainage system，and the secondary lining external water pressure can be controlled by adjusting every parameters of the tunnel structure part. With the increasing of the tunnel radius，and the enhancing of the impervious capacity of grouting reinforcement and primary support and drainage capacity of the tunnel drainage system，the lining water pressure is decreasing. When the thickness of the grouting reinforcement less than 8cm，the effect of decreases the lining water pressure is significant，while the permeability coefficient of grouting reinforcement should be matched the permeability coefficient of primary support and surrounding rock，otherwise，the effect of grouting reinforcement will be affected. This paper analyses influencing factors and changing rules of water pressure upon lining to high hydraulic pressure mountain tunnel that have guiding significance for design of lining，surrounding rock grouting and drainage system.

Research conclusions:(1)Taking into account seepage body force，strain softening of rock mass，dilatancy and lateral pressure coefficient，elastic-plastic mechanics theory is applied to derive distribution laws of stress and displacement of surrounding rock under two-dimension unequal pressure considering seepage，strain softening and dilatancy，and establish relationships between different partition range of surrounding rocks，pore water pressure，strain softening coefficient of rock mass，dilatancy factor and lateral pressure coefficient.(2)The results have shown that pore water pressure，lateral pressure coefficient，strain softening of rock mass and dilatancy have greater impact on the fractured zone than the plastic zone. Considering lateral pressure coefficient，the impact of seepage field，strain softening of rock mass and dilatancy on the plastic zone and the fractured zone of tunnel along the different directions show inhomogeneity. (3)The results provided a theoretical basis for the stability analysis on surrounding rock of tunnel in high water pressure area. And it is practical meaningful for underground engineering like supporting structure design of the tunnel in the high pressure water-rich area and decision of the scope of the pre-grouting works.

Research conclusions:(1)Advance geological forecast shall have special design，in view of the different geological shall take reasonable and effective method，should further clarify the advance geological forecast expenses and liability. (2)Step construction，the step height is 2. 5 m，to facilitate the rapid positioning that at the top of the installation of steel frame positioning，is conducive to the construction safety，step length should be 1 times of the diameter of the tunnel.(3)The construction safety step is an effective measure to step construction safety，mandatory implementation. (4)The excavation footage control is an effective measure to prevent the loss of stability of tunnel face，must be strictly controlled in the construction step method.(5)Research results can be applied to the bench method for construction of railway tunnel.

Research conclusions:(1)A combination of surface grouting curtain grouting ,pipe shed advanced support and inside tunnel face reinforcement can make the control of large deformation zones tunnel construction on debris flow deposits and the force of structure best. Especially the tunnel surrounding displacement control effect is very obvious by reinforced tunnel face strata. (2) In order to ensure the safety and construction period the surface strata and tunnel face grouting large basement arch and tunnel reinforcement root piles supporting measures are used as construction auxiliary measures. Through a variety of construction methods comparison，three-steps-seven-footwork tunneling method is chosen as the final method. (3) The reasonable steps parameters of three-steps-seven-footwork tunneling method are as follows:the appropriate length of the step is about 4 m，not more than 6m each step's height is 3 .5 m, the length of dislocation is 2～3m; bench excavation footage is not more than 0.6～1.2m.(4) Research results can be used to cross the debris flow body formation and similar types of loose strata tunnel project.

Research conclusions:(1)The method is that rods are installed in accordance with the order of nodes and then the system are enhanced the overall and tensioned. Construction control and monitoring methods were given.(2)The construction process was simulated by the improved dynamic relaxation method. Implementation strategy was given. Program was programmed by using FORTRAN language and ANSYS APDL language.(3)Numerical example shows that super-tensioned problem can be effectively reduced through the proposed construction and installation methods. (4) References to the construction and analysis are provided by the results for practical engineering of rigid bracing dome.

Research conclusions:(1)This paper points out that it is should be use qualitative evaluation and quantitative evaluation method for the comprehensive evaluation of energy-saving and emission reduction for expressway tunnel. (2)Four levels evaluation indices for energy-saving and emission reduction of expressway tunnel include target layer (evaluation indices for energy-saving and emission reduction of expressway tunnel)，object layer( energy-waving and emission reduction achievement and emission reduction measure)，index layer(unit·km power consumption level， organizational leadership，energy-saving and emission reduction system，manageable energy-saving，structural energy-saving，technological energy-saving），sub item index layer.(3)The comprehensive evaluation results can be used for improvement energy-saving and emission reduction work and promotion energy efficiency.

Research conclusions:(1)Compared with the results of the traditional analytical method in many typical conditions，a high accuracy and reliability multi-body model of the steering mechanisms of a low velocity city maglev train with 87 degree of freedom has been built. The model can simulate dynamic response characteristics of the system under various special conditions which can not be calculated accurately by the traditional analytical method.(2)Virtue no mass moving 5 planets which contour maglev railway are created in the model.(3)Non-linear air-springs，non-contact maglev force elements and railway constraints are expressed in the built model.(4)The stylized simulation model developed in this paper is more suitable for parameter optimization design of the steering mechanisms and can be meaningful to the virtue platform of low velocity city maglev trains which will be created in the future.

Research conclusions:(1)The lateral pressure coefficient results of pressure meter test are quite close to that of traditional method，the result did not change significantly with depth arden，and pressure meter test takes the advantages of simple operation and economical compared with other methods，therefore it is perfectly suitable for geotechnical in-situ test in loess area.(2)The result of pressure meter test has suggested the change of horizontal foundation coefficient with soil，the soil limit pressure and deformation property parameters can be measured by pressure meter test. But it should be multiplied by 0. 3～0. 5 in calculation of horizontal foundation coefficient when used in parameter design of tunnel lining.(3)The research results will provide theoretical support for reasonable design of subway tunnel lining in loess area.

Research conclusions:(1)Public security wireless communication system scheme of urban rail transit should be consistent with the urban existing public security wireless communication system，and government affairs wireless communication system of city rail.(2)Centralized way is recommended，which combining the scheme of wired and wireless introduction that wired scheme is given priority to and wireless solutions is standby.(3)At the station platform layer and the underground tunnel，the leakage coaxial cable should be applied to for field coverage. At the station hall layer，the way of ceiling-mounted antenna should be adopted for coverage.(4)Broadband multimedia cluster, such as TD-LTE with independent intellectual property，is the future development direction of public security wireless commumcation system m our country.

Research conclusions:(1)Because of the short time development，poor legal mechanism and multi-party participation，there are various potential problems in the application of BT mode in the infrastructure construction. (2)Key problems in the actual construction of BT projects are identified，including insufficient early preparations， frequent design changes，difficulty in investment control，unregulated transferring behaviors，and the improper risk allocation.(3)Solutions corresponding to the above problems are proposed accordingly，including strengthening the early preparations for the decision management，improving the change management mechanism，adopting the fixed- price contracts as to standardize the investment management，setting up the transfer committee to standardize the transfer behaviors，and building the comprehensive risk management system.(4)The research conclusions can be applied in the construction and management fields of BT projects.

Research conclusions:(1)Budget prices for client-supplied goods and materials should be determined by a comprehensive analysis of compiled unit price and transportation charges.(2)Contracting parties should respectively estimate materials’prices and client-supplied goods and materials’prices before bidding and projects implementation. (3)Risk and responsibility for client-supplied goods and materials should be classified as designated place of delivery. For number problems in price difference adjustment，you should finally confirm to construction drawings checking of investment amount.(4)Price difference adjustment involves the supply of excess or insufficient amount. Deducted price of excessive amount should use supply price，Deducted price of insufficient amount should use budget price.(5)The results will provide references for management and policy-making of client-supplied goods and materials in railway construction projects.