Journal of Railway Engineering Society

Research methods : Through making analyses of the requirements of the economic developments along the line, the situations of the railway network composition, mine resources along the line, development of tourism resources and the demands of getting off poverty and becoming better off of the people in reservoir and mountain areas, the demonstrations are made for the necessity and feasibility of building Fuyang-Jinhua Railway to establish the third corridor in East China.

Research results: The railway with single line in short term and double line in long term mainly undertakes freight traffic along with passenger traffic. The target values are different for the different sections.

Research Conclusions: Establishing the third corridor in East China can meet the requirements of economic developments along the line and solve the problem of transporting energy and raw materials to the areas of middle arid down stream of Yangtze River for sustainable development of economy of the seacoast.

Research methods: In the course of the survey, many advanced technical means are adopted, including using remote sensing technology to indirect ground mapping work. The geological and hydrogeologic conditions of the area where tunnel passes through can be made clear through integrated geophysical prospecting along with the verification of hydrogeologic drilling and the parameters of geology , and hydrogeologic conditions can be obtained by testing the earth interior stress within drilled hole and integrated hydrology logging. The data for predicting volume of surging water of tunnel can be obtained by determining the flow of spring and the relations of supplement, route and drainage of underwater can be made clear by making sampling analyses of chemistry and tritium. The volume of surging water can be predicted by making calculation of hydrogeology.

Research results: Through making integrated survey, the lithology , geological structure and enriching water situation of strata in the area where the tunnel passes through can be made clear and the relative parameters of hydrageology can be obtained for providing basis for design and construction of tunnel.

Research conclusions: Through making survey of North Tianshan Mountain Summit Tunnel, the importance of application of many technical means together and the importance of hydrogeology in surveying deep buried large tunnel are recognized further and at the same time some problems are found

Research methods ：Through review of the geological problems in tunnel construction and investigation of the present situation of geology forecast, the summary is made for means and their characteristics of geology forecast in advance for tunnel construction arid the analyses are made for the problems from the areas of means and ways.

Research results：As a result , the key point of geology forecast in advance for tunnel construction is to forecast disaster geology which should be made after making an evaluation of construction safety and stability with geological theory and should cover a wide range，except survey of unfavourable geology. The suggested values of the vertical and lateral survey ranges are put forward for geology forecast in advance.

Research conclusions： The following views should be had; the work of geology forecast is an extension of informationalized construction, the geologic process should be taken into account in the forecast and the prospecting technology should be tried to monitor and control the characteristics of geology in front of excavation face. The following coordinated forecast thoughts should be encouraged: the geology forecast rule should be worked out, the operation standard should be uniformed, the evaluation system for geology forecast should be established and many means and ways should adopted together.

Research methods: Through making investigation and survey of the geological conditions of depletion region, exploitation of coal and surface deformation in details, the calculation, analysis and evaluation are made for the stability of depletion region with the theory, and the rational design program is proposed based on making comparisons among three programs of route selection.

Research results: The surface deformation of depletion region is big, the depletion region is in the active period of movement and deformation and the max. estimated subsidence value will be 1 .61 m.

Research conclusions : The stability of depletion region is very bad. If treating it , there are lots of difficulties and it needs lots of money, so the proposals are made that the railway should keep away from the depletion region and the CK Program should be adopted，which can save lots of cost.

Research methods: The railway subgrade inspection car is equipped with Ground Penetrating Radar System(GPR ) to inspect the status of railway subgrade. GPR system transmits short electromagnetic pulse into subsurface and receives the reflections from the interface underground. The collected reflections are displayed as a waveform. When the antenna is moving, a continuous profile is obtained and based on which the geometric shape of subgrade and water content of soil can be deduced to seek the subgrade diseases.

Research results: The subgrade inspection car, developed by Scientific and Technological Research Institute of Xi'an Railway Administration and Xi' an Jiaotong University, is equipped with GPR, with testing speed of 45 km/h and penetrating depth of about 3. 0 m. The three sets of antenna are located at the centre of track and on both sides of tie for inspecting three profiles at the same time. The car has been tested on Beijing-Kowloon, Yangpingguan-Ankang and Liangyungan-Lanzhou railways with good results.

Research conclusions：However the speed of 45 km/h is lower to use in main lines ， GPR system of higher scan speed should be developed.

Research methods: The exploration is made on the advantages and disadvantages of aluminium alloy bridge through making analyses of the structure and application situations of existing aluminium alloy bridges at home and abroad.

Research conclusions: Although aluminium alloy materials need much investment, but it still has a bright applicable prospect because of its high strength-weight ratio, easy assembly, perfect durability and low maintenance cost.

Research methods：Take 11# pile cap of Yichang Yangtze River Bridge of Yichang-Wanzhou Railway Route for example, using the method of combining theory analysis and engineering construction, this paper studies the construction scheme , technics and the type of water-proofing structure.

Research results：The steel caisson cofferdam with double-shell and interspace tremie seal in construction of bridge foundation is a new and efficient method, which is used in the construction of 11} pile ,cap of Yichang Yangtze River Bridge and gets a very good effect.

Research conclusions：when the height between bottom of bridge pile cap and river bed surface is too little to do the full tremie seal, the circular cofferdam with ring tremie seal is an ideal method of water-proofing. But hen we take in account the problem of how to install and carry on under water the cofferdam, the quadrate steel caisson cofferdam with double-shell and interspace trimie seal will possibly be a good and practical method

Research methods :On the basis of the error control theory based on the least bi-multiplication and the construction characteristics of Sanmenjiang Bridge in Liuzhou，the linear control model is established with the software of finite- element analysis to ensure the construction quality by using the tested data and results of theoretic calculation.

Research conclusions: The aracteristics of the deflection and change in elevation of main beam structure of partial cable-stayed bridge with super wide deck are close to the stressed concrete continuous box beam. Using the tested data to modify the parameters of calculation model, a perfect match is achieved between theoretic calculation and the real situation of the bridge，which ensures the safe construction of main beam. In the construction , it is necessary to monitor the distortion in real time and adjust the pre-elevation volume according to the weights of the section.

Research methods : Through changing the composite parameters of magneto-theological damper(such as the effective length of piston, inner diameter of cylinder and fluid viscosity)，input current and frequency of simple harmonic motion of magneto-rheological damper against cylinder, the analyses are made for the parameters of influencing magneto- theological damper for providing the theoretical basis for better design of magneto-theological damper. Then the analytical researches are done on the semi-active control of earthquake response to building structure with the modified Bouc - Wen Model of magneto-theological damper and Clipped-Optimal Control Method, and the results of semi- active control are compared with the results of semi-passive control of structure.

Research Conclusions : The compared result shows there are different control effects on horizontal displacement and velocity of structure under the effects of EI-centro earthquake and the effects of semi-active control is better than that of passive control in control of horizontal displacement and velocity.

Research methods: The site tests are done for the displacements of buildings and underground pipelines and changes of underwater level during shield tunnelling and through making analyses of these tested data, the valuable conclusion is obtained for reference to construction.

Research conclusions：Modification and right choice of the parameters for shield tunnelling, keeping effective balance of soil pressures and ensuring the effect of synchronous grouting are the effective means and important measures for control of the loss in stratum and reduction of displacement of stratum and impact of shield tunnelling on the surrounding environment.

Research methods: With the integration of theoretical model with 2D and 3d mathematical models, rational setting the boundary conditions makes the mathematical models close to real conditions.

Research results : The predicted results obtained by 2D and 3D models with finite-element method are matching each other and very close to the observed data on site.

Research conclusions : This prediction method can direct the construction and provide the reference to the calculation of water-gushing volume of the tunnel in the similar areas. However, the value of water-gushing volume predicted with 3D model is smaller than that with 2D model because of simplifying classifcation of units, so the improvement of the program will be made in future.

Research methods: The comprehensive introductions are given to the design and construction of Baiyunshan, Nanjing Metro, Hangzhou Jiefanglu and Xiaoyangshan tunnels and based on which the summary is made for the key points of design and construction of similar tunnels.

Research results: Nowadays the main means of design of tunnel still depends on the engineering experience and calculation. The basis for quantitative analysis of design of tunnel can be obtained by learning the previous experience and doing calculations and the feed back of information on construction can make the design more perfect.

Research Conclusions: Application of the technology for double vault tunnel and extreme small space tunnel can shorten midway between tracks and reduce the quantities of requisition land and high side slope at the tunnel portal and work of filling soil outside the tunnel. The small guide pipe and large pipe shed for support in advance applied in Baiyunshan Tunnel made good effects on protection of wall rock during small blast, so the wall rock can set function of self bearing capacity. In the course of excavation under track, the works of fastening rail and patrol should be done well for ensuring operation safety of railway. In the courses of construction of double vault tunnel and extreme small space tunnel , the construction monitoring should be conducted.

Research methods : The simulations with 3 D finite-element numerical values are made for the surface deformation caused by the blast for construction of Shiqiaotu Shallow buried tunnel with triple steps temporary inverted arch method and two-side pilot tunnel method.

Research results : The excavation of tunnel in first step makes big influence on the surface settlement when triple steps temporary inverted arch method is adopted and excavations of tunnel in the fifth and sixth steps make big changes of settlement when two- side pilot tunnel method is adopted. The analyses of surface incline, surface curvature and level deformation show two-side pilot tunnel method is superior than triple steps temporary inverted arch method.

Research conclusions : For construction of the 5hiqiaotu Tunnel , it is proposed to adopt two-side pilot tunnel method along with necessary support and reinforcement measures for controlling the surface settlement and deformation and guaranteeing the safety of surface buildings.

Research methods : The demonstrations of the progresses and developments of tunnel construction technology with bored blast in China are made in the fields of the historic achievements, technical characteristics, key technologies and sustainable development.

Research conclusions: China bas made leaping technical development in tunnel construction technology with bored blast method with huge achievements, so the security of tunnel blast has been improved much in China. At present, the limiting capacity of tunnel construction with bored blast method is being challenged by the unprecedented speed and scale of tunnel construction in China, so it is necessary to develop the program software for tunnel blast design based on the computer technology for improving the management level of tunnel blast and making the further development of tunnel construction technology with bored blast method in China.

Research methods: The study was done on the construction experiences of transfer stations in foreign countries，the analyses are made for the problems in construction of transfer station in China and the clarification is made for the design of large-sized integrated transportation terminals in China.

Research conclusions: The principle of ”Integration of station location with advanced functions and integration of transfer function with city function" should be followed in the design of large-sized integrated transportation terminals. The design of transfer hall should have the characteristics of integration , harmony , automation , informationnization and humaneness.

Research methods: Based on the construction practice and the surrounding environmental and hydrological conditions of construction, the deep explanations are given to the forms of exterior-protected construction for Metro station and its construction technology, and the analyses are made for the comparison of support form of fender post alone and soil-nailed wall with the combined forms of fender post.

Research results : In the phases of excavation of foundation pit and construction of the main body of station , the fender for the foundation experienced the tests of time and bad weather. Through making measurements to the foundation pit, the displacement of foundation pit and surface subsidence were in the range of control values，which showed foundation pit is in the safety.

Research conclusions: If the geologic and surrounding environmental conditions allow, what can be done for supporting foundation pit is that the top of foundation pit is supported by soil-nail and the bottom is supported by raw piles plus interior support or stressed anchors, so it is helpful for excavation and movement of earth, enhancing utilization of machinery, speeding up the construction process and saving cost. In the course of design, the design parameters should be modified on time in accordance with the geological survey report，soil characteristics, theoretical analysis results , experience of similar construction and measurement results.

Research methods: Taking the design of underground continuous wall as the side wall of main structure of Songhong Metro Station on Line 2 of Shanghai Metro as an example, the researches are done on the waterproof technologies for self waterproof of concrete structure, joint of continuous wall, induction joint, and for the rigid four-plastering coating of crazing resistant mortar, following the ”Technical Code for waterproofing of Underground Works" and ”Code for Design of Metro".

Research conclusions: There are more technical difficulties in waterproofing by application of single wall lining in rich water and soft soil ground than double wall structure , so high quality design and construction are required , for which the joint of underground continuous wall is a key factor. Application of cross-shaped steel rigid water stop joint can meet the requirement of waterproof to the structure. When the joint of continuous wall is aligned with the induction joint, the cross-shaped steel plate coated with butadiene styrene rubber lutein not only makes effect on waterproof, but also meets the requirement of structural deformation for induction joint.

Research methods : Taking construction of one metro station with shallow burying and surface excavation method as an example, the researches are done on the non-linear emulation of entire excavation and support processes for tri-span arch tunnel with double deck and pillar surface excavation structure by using ANSYS finite-element software as platform and adopting plane strain mode based on the theory of excavation and support for shallow burying tunnel.

Research results: The results of emulation calculation are basically correspondent to the site monitored data, so it can be used for instructing emulation research on stratum settlement and construction of similar tunnel.

Research conclusions: The influencing range on surface subsidence is about three times than the tunnel diameter, the max. settlement amount is 20. 75mm and the max. crown settlement is 29. 93 mm. For excavation of super long-span shallow burying tunnel, the ”group caves effect" is obvious and the control of surface crown settlements is key procedure with the support in the upper section in wall rock stratum with soft top and weak bottom. The blasting shock should be reduced for the lower section for controlling distortion. The settlement and subsidence values are different for excavation in different areas in the process of excavation and support of super long-span tunnel.

Research methods: Based on the management theory of modern construction and information engineering methodology , first of all , the definitions should be made clear for the contents of construction evaluation , attribution of evaluated data and their analysis requirements, then the analysis of system functions and design of system should be made and finally the system applicable program should be put forward.

Research conclusions: Considering the characteristics of complication and stage construction of rail communication, they are effective and feasible ways to apply computer technology and integrated data of construction management in post evaluation of rail communication construction.

Research methods: Through making the demonstrations of the significance and target of changing talents resources to talents capital, the relative methods and countermeasures are presented for changing talents resources to talents capital.

Research Conclusions: What enterprises should do for changing talents resources to talents capital are to change concepts for setting up the advanced talents thoughts and managing concept, innovate the system for enhancing talents' market allocation level, make reforms for establishing the system of giving full scope to the talents and create good environment far talents' growth.

Research methods ： Through giving introductions to the concepts, characteristics , organization structure and operational mode of PPP financing mode and the advantages of railway to adopt this mode , the countermeasures and proposals are presented for realization of PPP financing mode according to the real conditions of railway in China.

Research conclusions ：PPP financing mode is adaptive to and an effective way of getting more financing for the railway construction in China. Introduction of this mode not only can enhance overall efficiency with changing the management system from high centralized management to market mechanism, but also make the investment channel multiple with breaking down mono-system of investment and financing for railway for attracting more investments in railway construction form non-governmental organization.

Research methods ： In combination with the labour cost indexes , analysis method of them and experience of controlling labour cost in foreign countries, and based on the thoughts of taking the business income and content factor of labour cost in business income as the dominant factors and taking the adjustable factor for profits rate of labour cost of enterprise and annually examined achievements as secondary factors, the ways are presented for deciding the reference and guiding labour cost of enterprise.

Research conclusions ： The operational situation of enterprise，social environment , industrial influence and fluctuation range of total labour cost in the industry should be taken into account when deciding the reference and guiding labour cost. The methods of deciding the reference and guiding labour cost are helpful for uniform control of labour cost of state -owned large-sized enterprise by state-owned assets department, adjustment of the labour cost of enterprise in time and solving the problem of high or low labour cost of enterprise.