Research conclusions: The results of forward computation and the seismic process of a complex model show the staggered － grid high － order numerical simulation is a rapid and efficient simulation method for seismic wave propagation． This method can be used for the selection of acquisition parameters in seismic exploration and for the optimization of the observation system to improve the quality of the acquisition data and solve the geological problems in railway exploration．

Research conclusions: Through the analysis and study on design of disaster prevention and rescue evacuation during operations of long tunnels at home and abroad，and in combination with the terrain conditions and external road conditions of the Dayaoshan Tunnel group，a design scheme was offered that the auxiliary tunnel construction was used as an emergency exit for Dayaoshan Tunnel group and an emergency rescue station was installed in the open area beside Huangtuwan Bridge between the exit of Dayaoshan Tunnel 1 and the entrance of Dayaoshan Tunnel 2． With this design scheme，the requirements of disaster prevention and rescue evacuation forthe single － tunnel double － track tunnel group with length more than 20 km during operation could met． Compared with double － tunnel double － track tunnel，by doing so，the construction costs and investment could be cut and saved．

Research conclusions: By using the geophysical prospecting，the unfavorable geological structure of fault，the lithologic delimitation and the development of underground water can be clearly found out and it can provide the basis for grading the surrounding rock of the tunnel． The scientific arrangement of boring and reduction of boring quantities can much cut the prospecting cost，shorten the prospecting period and enhance the survey quality． So the geophysical prospecting can play great role in the route selection of the watershed tunnel．

Research conclusions: The stratum，geologic structure and hydrogeological condition of the tunnel was found out，and the main parameters related to the RQD，Q max ，crack development and surrounding rock classification were gained． In accordance with the France surrounding rock classification method，the rock mass quality score of RMR was obtained，achieving very good results． The comprehensive geological survey methods should be widely used in foreign projects．

Research conclusions: The infinite element and visco － elastic boundary are used to simulate the semi － infinite space of soil condition，obtaining good effect． The calculation results indicate that the influence on the isolation effect is obvious when the depth of the open trench is in the range from 1m to 4m while the influence of the width of open trench produces a little influence． The isolation effects of the open trench on the near field is better than on the distant field． When the amplitude is fixed，the open trench has better isolation effect under the high － frequency load，and under the low －frequency load，the deeper open trench can have better isolation effect．

Research conclusions: ( 1) During the geological survey，the high － density resistivity method should used for shallow section of the tunnel and the CSAMT sounding should be used for the deep － buried section of the tunnel for the advanced geological forecast to the ground surface． During construction，the geological survey method，TSP method and advanced boring should be used in tunnel for the advanced geological forecast． ( 2) Based on the various data of the advanced geological forecast of all phases obtained by all means，the forecast conclusion is draw up and the proposal on the construction is offered to direct the construction． ( 3) The work procedure of the advanced geological forecast is presented．

Research conclusions: The result of numerical simulation shows the full grouting body and defects of grouting karst can be reflected on the resistivity profile drawing respectively by abnormal high resistance and low resistance． The geophysical anomaly is obvious with large abnormal range and small amplitude when using the Wenner array HDR method，and the geophysical anomaly is weaker with small reflection amplitude and vertical distribution when using the Wenner － Schlumberger array and it is difficult to distinguish．

Research conclusions: Now，substitution of simplified plane member bar mechanic calculation model for the actual structure of the pile － board structure is an available and the most efficient way． The analytical calculation method for getting the structure internal force of the plane member bar mechanic model presented in this paper based on the stiffness method and foundation coefficient method is available for all kinds of pile － board structure，and the obtained result of the internal force of the structure is reasonable and reliable and can be as the control solution．

Research conclusions: By in － situ test，the study was done on the dynamic responses characteristic of red clay cutting bedding of Wuhan － Guangzhou Passenger Dedicated Line at the locomotive speed of 300 ～ 350 km / h． The horizontal and vertical distribution regularity of the vibration velocity，vibration acceleration，dynamic strain and dynamic stress were analyzed under the condition that the train run in the different directions． The analysis showed all the response parameters of the vibration velocity，vibration acceleration，dynamic strain and dynamic stress were decreasing with the depth increasing． In the lateral test section，the change of response of the subgrade bedding was of the reversed V － shaped under effect of the train on right track and the response decreased with increase of the lateral distance under effect of train on the left track． Compared with the ballast track，the dynamic responses and decay rate of ballastless track were smaller，while the influence depth was larger． So it suggests the thickness of subgrade bedding of ballastless track should be 5 m． This study can provide an important reference to construction of other high － speed railway．

Research conclusions: Through numerical simulation of the typical section，the introduction was given mainly to the creep characteristics of the soil in Shenzhen area for providing the theoretical basis for the safe construction，protection of the surrounding environment and prediction of long － term creep． Before and after creep，the deformation of the supporting structure increased by 16% and the base settlement of the near building increased by about 21% ． At the same time，the more usable calculation parameters for SSC model were obtained and it had the big reference value for the similar works．

Research conclusions: ( 1) The origin of the water － bearing formation in the Taigu Tunnel was complex． The water －bearing formation had a certain compaction property，but it was poor in cementation as the lower Pleistocene stratum，with big influence of rich underground on the construction of the tunnel． ( 2) As the geological condition of the tunnel was complicated with much underground water，the construction plan would be adjusted according to the situation of the surrounding rocks and the volume of water bursting so as to ensure the construction safety． ( 3) The more attention should be paid to the construction in the similar formations in future for the construction safety．

Research conclusions: ( 1) When the distance between the adjacent portals of two tunnels is more than 250 m，the two tunnels may be considered as independent ones． When it is less than 250 m，the pressure fluctuation produced by a train passing through the tunnels will be interacted． The variation of maximum pressure in 3 s can be reduced by the safeguard structure． In this way，the visual fatigue of passengers caused by the " black tunnel" and " white tunnel" due to frequently passing in and out tunnels of train can be relieved． ( 2) Using safeguard structure along with the safeguard protection on the side slope，the threat to the operation safety from the falling stone with small grain size can be effectively protected when the slope surface at the tunnel portal is high and precipitous． ( 3) The flexible net steel safeguard structure can be used for the connecting safeguard structure with the features of high safety，reliability and money saving and it can be used in the actual engineering after doing the rock falling impact test．

Research conclusions: From the comparative study on the fire fighting systems for Shiziyang Tunnel of Guangzhou － Shenzhen － Hong Kong Passenger Dedicated Line and the Tunnel of English Channel，it is concluded that compared with that forthe Tunnel of English Channel，the hardware of the fire fighting system for Shiziyang Tunnel is more completed with high fire fighting efficiency and reliability，the water resource and water pressure needed by fire fighting are guaranteed，the control of the fire fighting facilities is strengthened by using the reliable technology and monitoring equipment and the functions and performances of other auxiliary facilities are improved and strengthened．

Research conclusions: The power SCADA system for passenger dedicated line is a star network in logic and can provides the converged service． As there are numerous power box － type substations along passenger dedicated line，point to point network program can not be adopted and the transmission bandwidth has to be converged． On considering the network mode of transmission system for passenger dedicated line and the communication requirement of power SCADA system，a tree structure network in physics while a star － type in logic should be established to transmit power SCADA system data with way of collection convergence in layers by using EPL and EVPL． With this program，the reliability of the system can be much enhanced and the cost can be much cut with the feature of convenient maintenance． It is the best choice for a communication network of power SCADA system for passenger dedicated line．

Research conclusions: The interaction method that considers the mutual influence of foundation and structure should be used for the structure with the small difference in rigidity on the base and top and largely uneven axial force of the column． The influence of the foundation on the structure is related to the stiffness of the foundation and the structure． The stronger the stiffness of the foundation is，the lower the influence is ． For the structure of big column net along with filling column net used in the large integrated transport center，the influence of the deformation of the top part can not be ignored．

Research conclusions: When the design value H of the head room of the track section is equal to or less than 6． 5 m，the rigid suspension mode of the catenary should be adopted． When the design value is more than 6． 5 m and equal to or less than 8 m，the suspension mode of using ground column should be used along with the ceiling suspension． When the design value is more than 8 m，the suspension mode of the ground column and twist － arm post should be adopted．

Research conclusions: According to the project characteristics that the work occupation time was short，the precision requires high and it was the first time to do，the several design plans were made． The rail cap was poured between the existing rail and tie on the Beam 3，the short track caps were prefabricated in the beam manufacturing field for the beds on the 4 － 7 beams and the in － site welding was conducted for the welded rail track，with successful completion of the project． The project can be considered to explore the way of upgrading and maintaining the full track bed and can provide the reference to the similar works．

Research conclusions: ( 1) The seamless joint of the people travel can be realized and the station and commerce are integrated by connecting the second floor of the underground space with the floor of the station hall． ( 2) The convenient underground environment and space are realized for the people by introducing the light from the middle yard of the square． ( 3) Also the fire alarm system，the interaction control system，monitoring systems for environment and devices and communication system should be considered in the design．

Research conclusions: This paper analyzes the advantages and disadvantages of the steel girder，continuous girder and steel truss girder，compares the advantages and disadvantages of all schemes in the fields of the construction difficulty，influence on the traffic and engineering cost etc，and determines to use the continuous girder bridge by rotation construction，which is the most suitable bridge type for this project． This scheme satisfies the track usage conditions with eatures of the small influence on the traffic，low engineering cost，simple construction and a little maintenance cost，having good social and economic benefits．

Research conclusions: Based on the statistics of the metro operation and design data ，this paper reviews the result of the forecasted passenger flow and qualitatively analyzed the influence factors when the passenger flow is more than the design capacity． It is concluded that the passengers flow will rise severely after the metro network is established in Shenzhen，and it suggests more cars should be installed for Shenzhen metro to deal with rapid increase of the passenger flow．

Research conclusions: The utilization of the land can be enhanced after the depot laid out with double － layer，but there are some impacts on the design of the general layout． In order to improve the capacities of car coming in，going out and car washin as well as meeting the traffic requirement，some facilities should be added and operation management measures should be taken after the depot is laid out with double － layer． This can be as the reference to the similar works in future．

Research conclusions: The construction condition of intercity railway should fully consider the influence of the difference in social and economic fields among the east，middle and west regions of China on the transportation demand，and the different construction conditions should be defined for the different regions． From the analysis with the model，it is concluded in east region，the construction condition of the intercity railway is the density of passenger flow will be up to 16 million person km / km in the near future，in the middle region，the density of the passenger flow will be up to 12 million person km / km and in the west region，the density of the passenger flow will be up to 10 million person km / km．

Research conclusions: The UIC gauge code is very different from China in concepts． The UIC Kinematic guage reference profile is provided as the fixed value，and is used for defining the manufacturing clearance of rolling stock and the profile clearance of the wayside building along the track． But in China railway codes，thees two ones are the fixed values in accordance with requirement to inverse the " vehicle dynamic envelope" ． So the China railway code should be improved and the specific design parameters should tend to more basic theory，basic principles and the calculation process with new ideas to maintain design flexibility and operability．

Research conclusions: Fuzzy comprehensive evaluation can be used for analtzing the condition of operating the through transportation ． Based on the relevant influnce factors，the evaluation factors collection is built and according to the actual situation，the comment collection is built． Based on these，the fuzzy relation matrix and the weighting collection are established to make the comprehensive evaluation calculation with weight average operator to make final decision． The actual calculation shows by using the comprehensive fuzzy evaluation method，the basis for making decision whether the through transportation is operated or not can be offered．

Research conclusions:The technical innovation of the communication engineering enterprise is a complex system engineering, involving in all operational factors of the enterprise. The proper innovation mode should be chosen，the internal power of the enterprise should be cultivated and accumulated，the outside power of the enterprise should be introduced and made use of, the innovation system should be established and improved，the innovation management level should be enhanced continuously and the technical innovation system should be built for the sustainable development of the enterprise according to the real situation of China, the features of the communication engineering industry and the condition，development target and environment of the enterprise. In this way, the technical innovation can become the powerful engine to lay the strong foundation for the sustainable development of the enterprise.