Research conclusions: The sulfide minerals like pyrite in the black rock can generate sulfuric acid water under water－ rock interaction with the oxygen，and it influences the surrounding mineral composition． These actions can lead to the changes of the mineral composition of the black rock and non － black rock nearby to weaken the physical and mechanical properties of the rock materials， resulting in appearance of the mountain hazards under the gravity action． Based on the test and analysis of the black rock and surface water in Dujun area，the failure mode of the black rock slope in the mountain hazards is researched and some engineering control measures are offered．

Research conclusions: ( 1) When the rock ( rock mass) is dense，hardy，complete and fresh，its vertical wave velocity is big，otherwise its vertical wave velocity is low when the rock ( rock mass) is weak，serious weathering，watery and dissected． ( 2) The vertical wave velocity of the rock is directly proportional to the cube root of rock compressive strength，and the vertical wave velocity of the rock mass is directly proportional to the cube root of the compressive strength of rock mass and the square root of the integrity index of rock mass． ( 3) The practices show the model for the macroscopic quantitative relation between the vertical wave velocity and compressive strength of rock( rock mass) is reliable．

Research conclusions: ( 1) The remote sensing interpretation accuracy for unfavorable geological condition can be enhanced by using the data fusion technology． ( 2) The quantitative interpretation and analysis for the unfavorable geological condition can be realized by using the 2D interpretation method along with the 3D interpretation method．( 3) The study should be strengthened on the application of fusion of remote sensing with the geophysical prospecting to extend the application range of remote sensing interpretation．

Research conclusions: For the railway alignment of the passenger dedicated line in Qinling Mountain area ，the geological conditions in the formation lithology，geological structure，the hydrogeological characteristics and the unfavorable geological conditions of the area in the research range were found out，and the adaptability of the different construction plans to geological conditions in the fields of the track plane position and gradient were analyzed． The comparative analysis of the different construction plans of Xi＇an － Chengdu Passenger Dedicated Line in the Qinling Mountain area showed that the CK plan was better than the others in geological conditions，and the adaptability of the CK plan to geological condition in the fields of the track plane position and gradient was better than the others．

Research conclusions: Through the deep investigation and analysis of the environmental geological conditions and the main engineering geological problems of each alignment scheme，the GRC mathematical model was established to evaluate the alignment，and the evaluating index system and their weights for the geological alignment were offered． With GRC model，the optional schemes of CK，C4K and C19K were evaluated and their scores were respectively 73． 3，74． 3 and 73． 5． So the CK scheme was the final one． With this scheme，the railway keeps away from the unfavorable geological areas of landslide，scatter，collapse and mining area as well as the karst area with serious development．

Research conclusions: The overlapping soil is formed from the red clay caused by the effect of leaching and depositing under the warm and wet environment，and it is a typical unsaturated soil with void ratio being bigger than red clay and saturation degree always being less than 90%． The overlapping soil with high liquid limit and high liquidity index is a high liquid limit soil． This soil is generally in plastic － hard status with strong strength and its bearing capasity can reach to 200kPa in natural condition． The overlapping soil belongs to the medium compressible soil，and the compressibility of the overlapping soil in the low layer is bigger than the soil in the upper layer． This soil is a typical over － consolidated soil with the over consolidation ratio of surface soil up to 15． 4 and the overlapping soil belongs to weak expansive soil．

Research conclusions: Based on the analyses of the horizontal and longitudinal sections of the track crossing the Lulong fault zone，the bridge engineering and the track type of the Tianjin － Qinhuangdao Passenger Dedicated Line， the original design can not meet the requirements that the service life of the main structure of the bridge should be up to 100 years and the service life of the ballastless track should be up to 60 years in light of the seismic safety assessment report stipulating that the displacement of non － earthquake creep sliding is no more than 1mm． It is suggested the new － type bridge supports with large lifting height and horizontal and vertical adjustment and the adaptable and non － longitudinal connected ballastless track should be used． Meanwhile，the horizontal and vertical monitoring network should be established to conduct a dynamic monitoring． The principle of passenger dedicated line crossing fault zone is offered．

Research conclusions: Tertiary and Quaternary igneous rock is largely distributed，unfavorable geology such as landslide，collapse，debris and coal gob area is barely found along alignment，so geological condition is good．Surface and ground water is not well developed，thus it has little effect to engineering foundation，soft soil is not well developed too，but expansive soil and gully is widely distributed． Igneous rock is largely different weathered，the weathering depth various too much and soft layer exist，that has large effect to cutting，tunnel and bridge．Under the effect of landform and structure，dangerous rock and talus is distributed part of section but it is easily cured． Fissure is well developed in some area under the effect of volcanic action that has relative larger effect to alignment，specific research is suggested to do．

Research conclusions: The layer － wise summation method was modified based on the brief analysis of the chord modulus，and a related calculation program was written using VB computer language． Then，the settlements of gravel pile and cement mixed pile composite foundation of a railway engineering were calculated using the program．It shows that the p － s curves have good agreement with the actual values，and the method proposed in this article is applicable in the settlement calculation of railway composite foundation，which provides a preference to the similarly engineering．

Research conclusions: The finite element analysis was made to the test piles of the Hongqiao comprehensive transportation terminal project and piles of deep foundation pit with the MIDAS /GTS software，and the comparative analysis was made among the analysis results，the test pile result and the monitoring result of engineering pile rebound． The method was offered for determining the frictional interface parameters of the pile － soil when the analyzing the impact of the foundation pit rebound on the pile foundation in deep foundation pit． The principle，method and the relative suggestions were presented for design of the pile in the deep foundation pit on considering of the rebound impact of the foundation pit． The discussion was made on the impact of the foundation pit rebound on the uplift bearing capacity of the pile．

Research conclusions: Relying on in － situ tests of Shangqiu － Hangzhou high － speed railway，the paper studied the comparison and analyzed the correlation between dilatometer modulus ED and static cone penetration test Ps and vane shear test Su，then obtained the calculation formula of soft soil foundation bearing capacity through DMT，fak =0． 019ED +15( ED≤5 000 kPa) ． Calculated results were compared with other tests and DMT reflected soft soil foundation bearing capacity better．

Research conclusions: The closed underground diaphragm wall was in form of the whole settlement，and the up and middle parts of soil core presented the basic synchro settlement with the wall． The bottom part of soil core behaved the compressive deformation feature． The vertical load － bearing of the base relied on its settlement with the bearing characteristic of end skin friction bearing wall． As the inside and outside skin frictions of the wall presented the dissimilar operation mechanism，the most deformation of the the soil outside of the wall were the shearing deformation featured with effects of the outside skin friction from top to bottom． However，the inside skin friction，due to suffering upward compressive deformation， took place gradually from the bottom to the top when the bottom part of soil core was subjected to the reaction． The effect of the outside skin friction preexisted the end － resistance，sequentially the inside skin friction． The inside resistance along the depth presented exponential function expression．

Research conclusions: The axis force of large － diameter and lengthy bored pile reduces from the upper portion of pile to the bottom portion，the rate of reduction indicates the magnitude of lateral friction resistance of pile． The function of lateral friction resistance at the upper portion of pile takes precedence of the bottom portion． Moreover，the majority of the load is born by lateral friction resistance of pile for the large － diameter and lengthy bored pile，and the magnitude of resistance at pile end is usually very small． Therefore，most of the large － diameter and lengthy bored piles are friction piles or end － bearing friction piles．

Research conclusions: From the analysis of the results of the several box culverts and bridges，it is concluded that application of the multiple － coverage and multiple － channel transient rayleigh wave prospecting along with the CMP analytic method to detect the subsidence can effectively reduce the influence of the interference wave and enhance the noise － signal ratio，getting good effect of detecting subsidence of the box culvert and bridge．

Research conclusions: For the comprehensive geophysical prospecting for the long Taihangshan Tunnel，the comprehensive prospecting was used，obtaining rapid，economical and high efficient effects，the data processing and interpreting technologies were developed，getting the clear abnormal pictures． The 73 abnormal areas were found by conducting the comprehensive geophysical prospecting and it provided the basis for determining the unfavorable geological body and water － rich area and arranging deep boring． So the survey precision was much enhanced． In the rather high level，it shows the basic study is crucial to the development and progress of the geophysical prospecting，having good scientific sense．

Research conclusions: First proposed a new type of the large diameter shield tunnel structure，which is“general －purpose and wedge － shaped，2 －meter width， nine uniform blocks ”， and by comparing with the different thickness of the segments under stress，recommends adoption of 0． 5 －meter thickness of the segment． This structure is safe and reliable，economic and effective，more adaptive to the construction of the project． This paper studied on the distribution of internal force of the structure by using the 3D shell － spring model， reveals the feature of the large － width segment that the bending moment at both sides are bigger than that in the middle． So it can draw a conclusion that different parts of the segment use the different reinforcement along the width of the segment to cut down engineering cost．

Research conclusions: The analysis of causes of Karst tunnel risk is made to find out the influence of the intrinsic factors，external conditions and engineering technical conditions on tunnel risk，and delete the overlapped factors．Based on the study， it is aware of that the formation lithology and geological structure that promote the development of Karst and Karst water are the intrinsic factors of the karst tunnel risk and play the leading role in the risk while the external conditions and engineering technical conditions play the auxiliary role in the risk． According to this ，the basic grading standard and method are formulated and the scoring formula is used for grading the tunnel risk．As long as the intrinsic factors exist，there is a possibility that the karst tunnel has high risk． The high risk and extremely high risk Karst tunnel should be avoided as much as possible． If there is no way to avoid，the traditional idea should be changed and the risk should be under control．

Research conclusions: The research and test were done on the ice － melting characteristics of the power through line by using LGJ － 35、LGJ － 50 and LGJ － 70 three different types of steel reinforced cable and 10kV cross －linked cables of the same section area with simulation of the field environment in lab． The influences of the ice －melting current on the bearing ability of the power through line，ice － melting time and the de － iceing method are analyzed． It is concluded the optimum ice － melting currents of the railway 10kV power through lines of LGJ － 35，LGJ － 50 and LGJ － 70 are separately 175 A ～ 195 A，210 A ～ 240 A and 265A ～ 305A and the optimum ice －melting time varies from 1h to 2 h．

Research conclusions: After the comparison of the bridge or tunnel sites in Siheshan，Yijishan or Weisilu from the fields of the construction investment and the hazards of construction and operation，the bridge site inYijishan was recommended． After comparison of the passenger station sites in the existing Wuhu Station，New Yijiang Station and the new Wuhudong Station from areas of the technology and economy，the upgrading of the existing Wuhu Station was recommended to form the overall arrangement of the " π" character terminal．

Research conclusions: The module was successfully applied in upgrading of the Chengdu － Chongqing railway． The application showed the module interface was friendly and its performance was stable． It could automatically search the scope of the closure mouth，calculate the plane and vertical data of the closure mouth according to the given track space，detect the plane data that got out of line，gave alarm for the mistaken information with tracing indication to the mistaken area，and rapidly and accurately draw the plane and cross － section drawings． It could provide a audio － visual platform for the designer to check the design rationality of the closure mouth to improve the design quality．

Research conclusions: The system based on CPT collecting and dealing the parameters，consists of 51 series single － chip receiver on the ground and the collection and storage system underground． This system can measure and store two parameters on the ground as well as three parameters underground． And the parameters stored in the system underground can be reverted to curves according to the depth points． Then the data also can be copied as well as post － processed through the host computer．

Research conclusions: Combined with the application of the Internet of Things in the intelligent traffic and through analyzing the sufficient condition of popularizing and applying the Internet of Things technology in China railway system currently，the research is done on the possibility of wide application of the Internet of Things technology in automatic fare collection system，train tracking and positioning systems，station train information sharing system，integrated security early warning system，cargo management system and warehouse management system etc and the development direction of Internet of Things technology in railway traffic is expounded．

Research conclusions: According to the situations of the Changsha － Zhuzhou － Xiangtan rail transit that its traffic capacity will not meet the traffic demand，the relative equipment technologies are not mature and the project needs lots of investment and based on the arrangement of the intercity railway of Changsha － Zhuzhou － Xiangtan urban agglomeration，the intercity railway should be built in the near future and it will undertake the certain function of the urban rail transit in the city proper． The planned urban rail transit should be built in the appropriate time with the integration of Changsha，Zhuzhou and Xiangtan．

Research conclusions: Based on the analysis of the Ranjiaba Station with the three － dimension model，the design method for the stress reinforcement in the transfer node region is offered． According to the load － bearing characteristics of the plate thickness of the transfer node，the double － plate arrangement mode is presented．According the load － bearing situation of the middle column，the scheme of the steel section concrete column is given． Based on the simulation analysis of TBM passing the station，the scheme of bearing the TBM load with the rail － mounted middle plater by temporary support and bearing the structure load by the permanent load － bearing structure is pointed out．

Research conclusions: Based on the summary of the design of the comprehensive pipelines of the ground metro car depot and double － layer metro car depot，the idea on using backstepping method to design the comprehensive pipelines is offered． In this way，the design time of the comprehensive pipelines can be reduced by 50% and the design quality and the comprehensive quality of the designer can also be improved．