Research conclusions: To engineering geology investigation, we consider not only the special engineering geology condition, but also environmental protection and natural environment influence, especially, the extreme climate influence. These were very striated with the engineering geology investigation about permafrost along Qinghai-Tibet railway. Through summing up engineering geology investigation, a complete set of investigation technology was formed, which was reliable to construction, and suited the Qinghai-Tibet railway. Including; constituted the criterion, organization mode，management, means and measures, supervisal, environment protection, and so on. To research and sum up about technology of engineering geology investigation, which can be referenced to the Qinghai-Tibet altiplano and other regions.

Research conclusions: After improving with lime, the granule constitution of xiashu-clay is obviously changed, the water stability is evidently improved and the static mechanics character is obviously enhanced with excellent dynamic mechanics characteristic. The quality of the improved xiashu-clay with lime can satisfy the standard for bottom bedding of high-speed railway , the improved xiashu-clay with lime can be used as the embankment filling of high-speed railway, but the attention should be paid to the influence of lime content and water content etc in use of it.

Research conclusions : The four kinds of embankments can adjust the energy of radiation, convection and conduction by changing the structure and filler of subgrade. The cool reserves of the four kinds of embankment are increased; the thermal regimes of permafrost foundation，improved. They are the effective engineering measures to protect the permafrost and are applicable to embankment engineering in permafrost zone. The length of subgrade is 380. 30 km along Qinghai-Tibet railway in the permafrost regions, and the lengths of sir-cooled riprap embankment , slope protection of rubble and crushed stone subgrade and heat pipe embankment are respectively 117. 69 km, 127.00 km and 32.0 km. The testing engineering of active protection contractures had experienced at least six freeze-thaw cycles, and the diseases of thawing and sinking did not appeared. The train is stable running with 100 km/h in permafrost regions, which shows the active protection contractures are stability and reliability.

Research conclusions: The given methods of testing moisture absorption water content of oven-fried soil are easy to operate and practicable to be extensively adopted in construction surveying. The results of the test indicate that there is good linear relationship between moisture absorption water content of soil and montmorillonite content, canon exchange capacity or free swelling ratio. Therefore, it can be adopted as a direction of research on ways of identifying expansive soil, and it also has great value for research on determining the expansive potential of expansive soil.

Research conclusions: It is recommended that limited gradient is 9%0 and assisting gradient is 18%0. According to all kinds of analysis, the proposal with limited gradient of 9%o and assisting gradient of 18%0 is adaptable to landform better and save investment of project, satisfies the speed and traction mass requirements of freight train and the transport requirement due to few increase of running time, is more reasonable when the total construction period is the same and balanced in proportion of human power and funds inputted for the whole line and has not appear the situation which is abort of human power and funds and has stronger anti-risk ability for sudden accident as the double spur grade is adopted in tunnels in the soluble rock stratum. Therefore it has been determined that the proposal with limited gradient of 9%0 and assisting gradient of 18%0 is adopted for this route.

Research conclusions: In Sichuan railway construction, we should concentrate onto building the external passage first and later building the internal passage. In proposed railway construction, the double line on the Lanzhou-Chongqing railway and Suining-Chongqing railway will be built immediately. In the plan of railway , the sequence of railway construction is in turn the Chengdu-Kunming railway for raising the speed and transportation capacity, Xian-Chengdu passenger dedicated line, Chengdu-Guiyang railway, Chengdu-Guiyang railway. The four railways mentioned above will be completed and operated in 2018.

Research conclusions : Frame-slab track is be provided with favorable technical and economy, frame-slab is benefit to reduce the influence of wrap deformation of slab. The model calculation model and analysis method established in this paper take in count of the load of train, temperature load and asymmetry settlement, bend of bridge, etc. can systemically analyse the frame-slab track , predominate the rule of force and deformation. By analysis the influence of design parameter to force and deformation，this paper draws a conclusion that the force and deformation of the slab bottom is decrease with the accretion of elastic modulus of CA sand mortar, and increase with the accretion of stiffness of fastener and settlement of substructure.

Research conclusions : If the allowable stress method is used , it is not necessary to differentiate the kinds and condition of service of the members. According to allowable strength, the different load types have the same safety coefficient K to make the structure design safer and more conservative. Probability limit state method based on probability statistics has objectivity and reasonableness, superior to allowable stress method with subjectivity and experience. However for the particularity of railway train load, the reliability of probability limit state method is not mature. Thereby at present the allowable stress method shall be adopted in the design of pile-slab structure. It is hoped that in the near future probability limit state method will take the place of allowable stress method.

Research conclusions: In statically indeterminate beam, press line of concrete has something with eccentric distance in beam end and the shape in girder span of bundled bars, and has nothing with eccentric distance in middle support. It would static , no matter how to alter eccentric distance in middle support , so long as maintain the location of the two ends and shape of bundled bars.

Research conclusions: In the paper, the study shows in the river reach with above-mentioned characteristics of river reach the design of bridge is generally controlled by multiple factors. Therefore, the comparison can be made on multiple schemes in combination with practical circumstances. It is thought that the abnormal-shape prestressed concrete continuous beam bridge of which side-middle span ratio is smaller obviously than normal that is sometime a better selection of bridge type. For this bridge type, it is key to take measures for preventing bridge side bearing from occurrence of tension. It is suggested to take such a counter weight measure that the side span is solid section and widened transversely and thickened vetically, if necessary, the concrete blocks can be set at the bottom of beam for counter weight.

Research conclusions: The paper discusses considerations and methods for the design of tunnels in high altitude, cold and permafrost area by analyzing the technical solutions for Fenghuoshan tunnel, and presents references for the similar project. The general design idea for the permafrost tunnel is ”protecting permafrost" with mufti-technique measures, including heat insulation, complex frost heave resistance, integrated waterproof, etc.，to effectively restrict freeze-thaw cycle development and to eradicate the root causes of frost heave.

Research conclusions: The research , such as tunnel hydrological conditions, immersed structure, the water resistance of immersed sinking, calculation of GINA joint selection, project design measures durability, etc.，solved the several key tunnel technical problems. With the help of research, the design of Shenjiamengang immersed tunnel was successfully completed. The reference experience of channel immersed tunnel design was accumulated.

Research conclusions: Application success of waterproof compound tunnel liner rests with the following respects : firstly, whether structure design , especially inverted arch design is reasonable ; Secondly , whether waterproof system is strict and waterproof measure is put into effect, in which stickable flashing is one of waterproof guarantee measures of waterproof tunnel; Thirdly, water table effect at the course of construction can not be neglected which may be very serious when there exists weak stratum on the earth's surface; Fourthly, whether strict construction technics request and quality guarantee measure are put into effect.

Research conclusions：(1) A suitable integrated geophysical exploration technology and the modern and advanced instrument and computing technology are adopted for full use of integrated geophysical exploration technology; (2) Various influence factors are analyzed and abnormities are distinguished fully with a comprehensive evaluation system，the colorful diagrams gained in the integrated geophysical exploration to manifests the large varieties of a geological bodies in the earth's surface and deep underground which shows soft rock exists; (3)It can provide a demonstration and reference to the engineering geological investigation of railway under the similar geological condition.

Research conclusions： Several factors should be taken into account during the design of water supply and drainage system and fire fighting system of railway tunnel crossing a river according to our research and discussion on the design of Shiziyang Tunnel crossing Pearl River on the Guangzhou-Shenzhen-Hongkong passenger dedicated line. Three independent fire fighting systems( i. e.，hydrant, water spray and fire extinguisher) were set simultaneously. To put out the fire not caused by oil, the water spraying system that is high efficient, water-saving and environmental protective was recommended, while the water sprinkle system was not recommended. The water supply system must meet the requirements of total water consumption, water quality, water pressure and the safety standards. The drainage system includes sewage drainage system and rainwater drainage system. Pump room is set at the lowest point of the tunnel for wastewater discharge from fire fighting, rinse and structure leakage. Both wastewater and rainwater were discharged into nearby water body.

Research conclusions: Through studying of two estimating method, it is fixed that capacitor per km of Qinghai-Tibet railway continuous power cable lines is between 0. 124 0～0. 133 1 uF, Then three compensation modes, namely, undercompensation, overcompensation and synthesized compensation are discussed through simulating and calculating to confirm whether it can satisfy the operating demands in all kinds of power transmission. A decision to adopt undercompensation was made to avoid resonance and lead to more fault. When overhead lines and cable lines run together, it has a little impact to the cable when overhead lines cast in, on the contrary, it has much more impact to the overhead lines when cable lines cast in, but it would be sustainable. After analyzed the over voltage，the conclusion of it would satisfy the system operational reliability and overvoltage needs if it adopted the undercompensation, both cable line end grounding method and reactor neutrality point grounding method. When one phase has a grounded fault, the other two phase voltage would turn into line voltage，just like the usual little current grounding system.

Research Conclusions： For the structures over the railway with low net height which can not meet the requirement for two layer container convey , special structure treatment scheme of contact line will be considered at the first place on condition that the main technical standards of the existing railways are not be lowered. If it is impossible to use special contact line scheme to solve the problem, lowering the level of railway, lifting or rebuilding the existing structure over the railway will be considered. Temporary line and measurement can be considered when it is difficult for the reconstruction of the existing railway so that the existing mainline can be shut down for the reconstruction of level lowering of the existing line. The height of the lowerest point of contact line on the two Iayer container passage will be 6 250 mm. At the place where it is not allowed to raise the line level, the height of the lowerest point of the contact line on the two layer container passage can be 6 200 mm. The height of the hanging point of contact line will be 6330mm normally.

Research conclusions: We established a mathematical model between mechanical parameters(mechanical intensity, working tense , wear rate and the number of pantograph use ) and stress for studying. We can draw conclusions that the contact line mechanical reliability will decrease when train running speed, the number of pantograph and wear rate increase ; it will increase by increasing the contact line intensity , lowering the pantograph raising force and increasing the contact line working tense at a certain level. As a result, we should consider some factors such as pantograph slider to reduce wear rate when choosing the contact line. The contact line working tense should be determined by comprehensive consideration of the current-carrying between the contact line and pantograph and the reliability. When the traction power can meet the requirements , we should choose contact line with high intensity to reduce stress-strength interference area, and further increase the contact line's reliability.

Research conclusions: Whereas the accident of lightning strike occurs frequently in electrical railway in China, after the statistical analysis of the switch-off occurrence due to the lightning, the conclusion was drawn that the earthing lines shall be installed along the Guangzhou to Shenzhen railway and arranged on the top of the poles. In the strong lightning areas, the arrester is necessary to be fixed. In order to guarantee the lightning facility running safely, the grounding of the lightning conductors and the arrester is suggested in the DPL lines.

Research conclusions: In this paper, the analysis has been made on electric wave transmission performance in free space and the multipath effect is produced by reflection wave and refraction wave. The field strength distributing curve is drawn by theoretical calculation，and the blind spots of signal are analyzed, so the viewpoint of that multi-antennae signal covering with 99% of area is put forward. If the signals of multiple networks are distributed in the metro, it is impossible to separately establish the network for each system, accordingly the concept that the multiple networks signals are combined into one network is used for the design of antenna subsystem for attaining the best result.

Research conclusions :Monitoring and measuring data during the construction of tunnels in Gangding-Shipaiqiao section illustrates that the new design concept and construction method not only can shorten the construction period and improve the waterproof property, but also can overcome the difficulties on unsymmetrical earth press and crown settlement of tunnels compared with the original double-arch structure. It provides references to similar works in future.

Research conclusions: When urban rail transit engineering begins operating, the primary structure may occur transmutation generally. So, it is necessary to adopt some proper means to observe and it is necessary to master the structural transmutation status in time. These are of advantage to operating safely and these should be much accounted of by correlative departments.

Research conclusions：The maximal deformation in the vertical direction is 0. 662 mm when the train passes in the unidirectional way; it turns to 0. 775mm when the trains pass in reversible ways. The vertical deformation of the canopy truss will attach to its maximum with the downward direction under the action of other combinatorial loads which does not take the temperature in consideration. There are two aspects when the contribution of temperature is concerned: negative temperature makes the canopy shrink which increases the vertical downward deformation of the truss, while positive temperature makes the canopy expand which cancels out partial vertical downward deformation, the deformation value will reduce consequently. On the strength aspect , the maximal stress of the truss is less than the yield extreme of the material under the action of the considered load condition , so the canopy is feasible.

Research conclusions: The present countermeasures brought forth in this paper are to insist on operation in credibility, to introduce internationally advanced IS09001 quality assurance system, to insist on scientific outlook and putting man first, to implement the principles of "focusing on customers" and competitive strategy of popular market plus top market. And the development trends pointed out in this paper are to establish the initiative concept instead of passive one , to develop entire engineering project management, to attract and nurture high quality talents who can work for the development strategy, to strengthen the training work of the employees in charge of supervision and consulting services, to establish data system, to pay more attention to the engineering supervision marketing, to explore the regulation and mode for international supervision and consulting services, to actively take part in Sino-foreign cooperation and to implement the” two major international standards and one regional standard" for enhancing the competitive ability in international market.