Research conclusions： The loess slope has strong dynamic responses to the construction vibrations, and especially, the dynamic responses of the crest part of the slope are much stronger than that of the free field (horizontal surface). The topographic amplification effects should be one of the potential factors for the collapse of loess slope in the foundation reinforcement process. Therefore，to ensure the stability of the slope and construction safety, it is very important to take temporaiy reinforcement measure for loess slope.

Research conclusions ： The rock slopes in base case are re-evaluated and the accuracy ratio of back evaluation is above 85%. The stabilities of 12 structured rock slopes in Changde - Zhangjiajie expressway are evaluated by the model and the results are in good agreement with the actual conditions, which shows that the model of stability evaluation of structured rock slope based on case - based reasoning method in this paper is effective. The stability evaluating method for rock slopes can be a reference for design in rock engineering.

Research conclusions ： Based on the analyses of survey and design flows of new railway lines at different grades, CAD for railway line are presented and researches are done on the key technologies of establishing digital ground model， interaction of the graph with the data, the interactions of track plane section, track longitudinal section and track lateral section, interaction design of railway II line, track scheme management and real 3D visuals of design. The application results show the CAD based on these technologies can be generalized and applied in the construction design.

Research conclusions； By calculating the classification of line accessibility for railway network in Northeast area, the practicability of the method is validated and a great correlation exists between the line accessibility classification and the railway classification. The model built in this paper could be adopted in the fields of network planning，network analysis and evaluation.

Research conclusions ： The prices of China - made special gantry crane for laying slab，twi - direction slab carrier，fine adjustment system for slab，cement-asphalt-mortar carrier and rail layer for 500m long rail are lower than those from foreign countries by over one third. The applications of these equipments in construction of intercity railway between Beijing and Tianjin show China can manufacture the special equipment for construction of CRTS II slab ballastles railway track and a set of construction process and technique have been formed，which mark China - made special equipments for CRTS II slab ballastles railway track have arrived at the advanced level of the world，and promoted the innovation and development of Chinese equipments for construction of slab ballastless track.

Research conclusions： Through analyses of the study and application of ballastless track at home and abroad, the following key points are presented ： (1) The suitable R&D technological of ballastless track for Chinese conditions should be found out so as to establish the research model that takes enterprise as main part with integration of university and academy organizations to realize the industrialization of ballastless track. (2) The research team should be set up to overcome the key problems by doing deep research. (3) The researches should be done on the structural form of ballsdess track that adapts to Chinese conditions through summarization and comparison of different structure forms of ballastless track.

Research conclusions ： The dynamic responses of a railway cable - stayed bridge with 300 m main span are obtained by linear and nonlinear analysis respectively, and the time history curves of structural displacements are given. For railway cable - stayed bridge with long span, the difference between the results of nonlinear analysis and those of linear analysis is obvious. It is necessary to consider the structural geometrical nonlinearity in analysis of vehicle - induced vibration of railway cable - stayed bridges with long span.

Research conclusions ； Seismic mitigation control methods can not make all the seismic responses of bridge less. They make most seismic responses less, but make some other seismic responses larger including bottom shearing force of the bridge tower. Passive control with the most damping force is the best in the 8 control algorithms on vibration - suppressed effectiveness. Semi- active limited Hrovat control algorithm, active control and passive control can not bring acceleration magnified effect, but the other semi - active control algorithms can show acceleration magnified effect with various degrees.

Research conclusions ： For large - sized sectional bended members, the optimum design can be made with the method of controlling cross - section bearing capacity and deflection control to avoid the waste caused by blindly increase of the size and amount of reinforcing bars for the cross-section. With using Matlab, the optimum design of rectangular cross section beam with single reinforcing bar can be easily made, and from it the primary values of the section height and ratio of reinforcement can be obtained and the final design result can be obtained after the slight modification is done in consideration of the requirements of beam, weight and its size, module. For the rectangular cross section beam，its common ratio of reinforcement is within 0. 6% and 1. 6%. With using the substitution principle of reinforcing bar and concrete computing method described in this paper, the substitution outcomes can be easily obtained, which meet the checking calculation requirements of section bearing capacity, deflection control and crack width. The calculation example shows this optimum design method can make perfect economic benefits and is worth wide using.

Research conclusions: ( 1) Flexible bent pile pier is composed of single - row or double - row reinforced concrete pile and reinforced concrete cover beam through connections with the main features of transferring the level force (temperature effect and braking force ) from the top structure to every flexible pier of the bridge and rationa allocating the temperature effect and braking force in accordance with rigidity coefficient. (2) From the calculations of the typical bridge, it is found that the uneven level distribution coefficient of overhead bridge for light rail is larger than that of railway bridge, so more attention should be paid to it.

Research conclusions ： The single cable face cable-stayed bridge can easily integrated into the surrounding scenes because of its light molding and it can meet the requirement of wind resistance in lateral direction with help of buffer. The introductions are given in this paper to the advanced technologies applied in design and construction of scenes, upper and bottom structures, wind resistance and cable staying for Vienames Baicheng Bridge and Chinese Yamen Bridge. In which the innovative technology of steel delta support with prestress and pneumatic caisson method applied in construction of Vienames Baicheng Bridge are worth studying.

Research conclusions: Through making the comparisons of the four current methods in China for beam deflection, the bridge deflection measuring instrument is developed based on the program of using CCD imaging technology to measure the deflection. The experimental results of measuring the bridge deflection on site with this instrument and the special deflection measuring instrument from the bridge examine organization of Beijing Railway Administration show the error is between 3. 0% - 6. 9% and the average measuring difference between them is between 3. 9% , which meets the requirement.

Research conclusions；(1) The surface subsidence calculated by Peck Formula is consistent with the actual situation, so Peck Formula has better applicability in Wuhan. (2) Damage level of the building caused by tunnel construction mainly depends on the buried depth of the tunnel, the distance of building to the tunnel and strata loss caused by the construction. The less buried depth of the tunnel and the less distance of building to the tunnel cause larger loss of strata, resulting in larger deformations of surface and building. (3) Damage levels of the buildings caused by tunnel construction can be divided into five categories. To the I and E extent affected buildings, it does not need to take the measures for protection and treatment. To the extent IH - V extent buildings, it must take effective measures for protection.

Research conclusions ： With multivariate statistical analysis method, the mathematical water bursting prediction model is established, taking stratum joint density increment, ground water pressure, ratio between longitudinal waves and transverse waves and apparent resistance as prediction variables. The established model can bring active effect on the full use and integration of the available geo 一 physical prospecting information and improving the reliability of water bursting prediction，and is helpful to the probing into the practical multi-source cooperative prediction technology.

Research results ： Through doing study on and analysis of local geological conditions and hydrographic conditions，the measures of blocking with mortar - stopping wall, radial and ahead grouting reinforcement, central draining water by pipe and by - pass pilot tunnel are taken to the flat pilot tunnel on main line，which avoid the risk of water bursting and guarantee the construction safety, resulting in saving the construction cost and time.

Research conclusions ： Concrete compaction pile can effectively eliminate the moist and sinking of loess to reinforce the foundation. Hie buffer structure with open and cap brim type incline gate are adopted to the entry of the tunnel，which brings good buffering effect and meets the environmental requirement with good looking and integration of topographical features. But it is proposed to adopt typical design to the gate and buffering section so as to enhance the utilization coefficient of model loop wheel machine because there are lots of difficulties in construction of cap brim type Incline gate with low working efficiency and high cost of model loop wheel machine.

Research conclusions ： Single - tube drill pipe level retrograde grouting can obtain better grouting effect，but the grouting process and technical parameters should be controlled strictly. In order to obtain a better result of stopping water, it is proposed to use ultra - fine cement or solute grouting liquid.

Research conclusions ： As an important evaluation index of the durability of high property concrete for passenger dedicated line，electric flux is influenced by many factors ； The electric flux of concrete increases gradually with increase of water - glue ratio. The air content has less influence on the electric flux of concrete and the electric flux of concrete still meets the requirement of the concrete durability when it is up to 4%. The mud content of sand for concrete should be less than 4%. The 40% fly ash blend ratio is not only the return point of the pressure resistance of concrete, but also the limitation point of the concrete durability. The ignition loss of fly ash has big influence on the early electric flux and 28d electric flux of concrete, but less influence on 58d electric flux. To the electric flux of concrete, the external agent should have the max. limitation ratio.

Research conclusions ： In construction, impregnation with WQ serial or SRA type concrete corrosion - prevention combining with other measures can improve the sulfate corrosion resistance of concrete. Therefore, WQ serial or SRA type concrete corrosion - prevention can be spread and applied in sulfate - rich areas to improve the sulfate corrosion resistance and quality of concrete.

Research conclusions ： The design and research scheme mentioned in this paper can notably improve the operation level, management level and production capacity of the marshalling station by transferring the information in time and accurately.

Research conclusions ； The small ribbed plate should be adopted to the large-span and small-curvature canopy roofing because the curved part requires smooth transition, but the work should be done well on leak - proof with waterproof structure and waterproof paints. The canopy structure should be truss structure with structural rods crossing each other.

Research conclusions ； The equivalent stiffness ration has an important impact on the sudden changes of the absolute displacement and the displacement angel between floors in transfer floor. When the floor shear suddenly changes in transfer floor and the equivalent stiffness ration is far away from 1.0，earthquake action may be more acute to this structure. It is suitable for control of the equivalent stiffness ration by 0. 8 to 1.5.

Research conclusions ： The rapid predicting model for the pre - estimated investment in railway construction project established with fuzzy mathematics method is easy to use with good applicability, which can realize rapid predict the pre - estimated investment in railway construction project，satisfy the requirement of accuracy，enhance the management level of railway construction and the competition capacity of construction enterprise.

Research conclusions ： It is proposed that the policy should be implemented at the beginning stage of construction in order to strengthen the force of green construction and the policy should rely mainly on the forced indexes while making non - forced indexes as assistance, and the cost of the project funded by the state should be brought into the project budget.