Journal of Railway Engineering Society

Research methods: Based on the information about the unfavourable geology of landslide along the line between Lanzhou and Guangyuan, the full analyses and summary are made for the distribution of landslide in the area of Iine passing through and for the universality and law of the cause for formation of landslide through making investigation, drawing and survey in large scale for the area of line passing through.

Research results : The further work on deep knowing about geology has been completed , the regionalization of dangerous landslide dangerous districts has been established and the countermeasures for engineering treatment have been given for construction of Lanzhou-Chongqing Railway.

Research conclusions : In the most cases of building a railway line in the area of valley terrace of loess plateau , it is designed to conduct filling, on which the small influence is made by landslide. In the most cases of building a railway line in the area of gully ridge of loess plateau , it is designed to build bridges or tunnels , but the railway line should be refrained from passing through the place where there are many large-sized landslide , and the treatment should be done in advance for the place where there are many Large-sized landslide and the railway line has to pass through. In the most cases of building a railway line in the intersection of structural systems，it is designed to build tunnels and large or mid-sized bridges so as to avoid most of landslides. For most cases of building a railway line in the impacting area of a river, it is designed to build tunnels and conduct subgrade engineering, on which the small influence is made by landslide. In the most cases of building a railway line in the area of single structural system, it can be designed in many ways, on which the small influence is made by landslide.

Research methods：The comprehensive comments are made on the monitoring methods, equipments, means used at home and abroad and their targets.

Research conclusions：It is proved that monitoring is not only the important composite part of collapse and landslide survey, research and treatment, but also an effective way of obtaining the information on prediction and forecast of collapse and landslide disasters. Through the monitoring, the deformation characters and regularity can be known clearly, and the boundary conditions， scale，slide direction , collapsing mode , happening time and danger can be predicted and forecasted. In this way, the measures can be taken for preventing, reducing and avoiding the disasters as much as possible.

Research methods：According to the standards and regulations, the analyses are made for the previous constructions of special subgrade and bridge beam structure and the researches are done on the advantages and disadvantages of all kinds of structures. For the structural design parameters of flat-slab beamless pile structure which can be directly used for the low embankment of soft weak subgrade of passenger dedicated line, the analyses are made for the all performance indexes of the structure under the static and dynamic conditions by using a space calculation model.

Research results：The checking calculations show the internal force and stress in the slab of the structure are small, it is feasible to support the beamless slab by prefabricated prestressed concrete pipe pile, and the structure design can be made in accordance with the distribution of reinforcements to be laid. The dynamic analyses of the structures of train and track show the structure can satisfy the requirements of safety, stability and comfortableness for high-speed train.

Research conclusions: As a structure of low embankment of soft weak subgrade，beamless slab can satisfy the requirements of ballast and ballastless tracks and can control the structure's settlement. Adapting this structure, it is unnecessary to roll the subgrade with the features of simplifying construction procedures, easy construction，aiding environment protection and saving land, so the good social and economic benefits can be obtained by application of this technology.

Research methods: The method of impact rolling compaction to accelerate settlement with the four sectors and eight flows was adopted to fill the subgrade，the ways of K30，Ev2and Evd were adopted to examine the subgrade compactness, the methods of laying settlement plate and section plane tube were adopted to trace and observe the change of subgrade settlement for long term and record the data on settlement volume, and the software was compiled to predict the regularity of settlement change.

Research results: The design requirements of compactness were met for the subgrades in pile-net reinforcement section and red rock mudstone improved section. The observation results from settlement plate showed the total predicted settlement volume was less than 15 mm and the settlement volume in six months was less than 8 mm, which met the requirement for post-construction settlement volume of 15 mm. The uneven settlement volume of 20 m was 7. 89 mm , which met the requirement of 20 mm/20 m.

Research conclusions: The subgrade construction was done by technologies mentioned above passed the evaluation of subgrade and met the requirement of ballastless track of 200 km/h railway.

Research methods : Based on Winkler Assumption and adopting continuous elastic grade beam method , the calculation method of tie static response is worked out with regarding the tie rigidity as influence variable and consideration of the influence on the tie response volume by the change of tie rigidity , such as displacement , striking angle , flexural torque and shear force.

Research results : The analysis method of tie structural static response is worked out, the distribution curves of tie response volume are given and the influence on tie response by tie rigidity is presented.

Research conclusions : The perfect analyses can be made for the static response of the tie on elastic foundation by adopting tie static analysis method. It shows the change of static response of the tie on elastic foundation becomes large with the increase of elastic modulus of tie.

Research methods： The discussion and comparison are made for the excavation programs and methods of deep foundation pit for underground pump house of Wangtan Power Station from the areas of technology, construction and economy., and the simulation computing and analyses are also made for the processes of different excavation methods with computer technology.

Research conclusions：The theory and engineering practices show not only the construction quality can be guaranteed , but also the requirement of construction schedule can be satisfied by adopting the program of combining the method of excavation on half slope from 3. 5 m of ground elevation to-9 m underground with the method of underground continuous wall from -9m to -13. 5 m. In this way, the foundation is stable, construction is easy and the good economic benefits can be obtained.

Research methods：Through studying the information and doing site experiment on filling, the researches are doing on the construction technique , quality inspection method and quality evaluation standard for subgrade compact of 200 km/h railway line for mixed passenger and freight traffic. The rational construction parameters and evaluation standard are presented through doing research on the construction techniques, including the techniques of smashing, mixing and compacting rending improved soil.

Research results：The improvement program is given for meeting the requirement of construction of the subgrade, the construction technique is presented for smashing, mixing and compacting improved expansive soil and the suitable quality inspection method is proposed for filling subgrade through making experiment, design and discussion on suitable structural mode for subgrade and prevention mode for side slope.

Research conclusions： Compared with the expansive soil, the plastic index of improved expansive soil with lime is better, the liquid-limit water content remains no change basically，the plastics-limit water content is increased and the plastic index is lowered. The best water content is increased and the max. dry density is lowered after mixing lime.

Research methods: In combination with the engineering practice of reinforcing soft compound subgrade in Wuhan experiment section of Wuchang-Guangzhou Passenger Dedicated Line with CFG pile, the systematically applied researches are done on the application of CFG pile by long auger machine in reinforcing compound subgrade of passenger dedicated line , including the choose of construction method , design of technical process and quality control , according to the engineering geological conditions.

Research results: With the considerations of the performances of common construction machinery for CFG pile, geological conditions suited for CFG pile, quality of pile formation and its influence on the adjacent pile, and the features of CFG pile by long auger machine, it can better meet the requirements of bearing capacity and deformation value of design, better control of post-construction settlement, good reinforcement result and financial feasibility.

Research conclusions: CFG pile by long auger machine is suitable for reinforcing the compound subgrade of passenger dedicated line.

Research methods： Through making analyses of the frame and mode of the existing index system , the factors are decided and selected by adopting experts evaluation method and main component analysis method, and the calculation of the weight of green railway is also made by adopting step analysis method.

Research results：The frame and procedure have been established for fuzzy evaluation of green railway in all-round way , the explanation is given of the thoughts and method of experts evaluation of green railway , and the method and thoughts put forward on decision and evaluation of the weight of green railway system.

Research conclusions：Green railway is a new transport concept for sustainable development of transport, and its core intension is harmonious developments in the areas of society, economy, resource and environment. Construction of green railway can reduce and make no negative effects on ecological environment for the purpose of sustainable development of railway. Green railway is a natural choose for taking a scientific approach to development, building a harmonious society and a resource conservation-minded society as well as an environment-friendly society.

Research results: The wastewater treated with technique of soil capillary percolation meets the drainage requirements of Standard GB8978-96.

Research conclusions : This technique has the features of low costs for construction and maintenance and high efficiency for treating sanitary wastewater with meeting requirements of drainage and effective protection of underground water, which is suitable for treating the sanitary wastewater for the stations along railway lines.

Research methods: The explanation is given to the mechanism of causing flexure from beginning with the rigidity of beam bridge , and then the analyses are made for the impacts on post flexure by prestress effects, contracting slow change effects and crack of beam body.

Research conclusions : The shortage of availability of longitudinal and vertical stresses cause the post flexure becoming overlarge and crack of beam body and then the crack of beam body cause the rigidity of beam body becoming weak, resulting in development of post down-warping.

Research methods : We summarized the practice experiences and adopted the pulling method for swinging vertical swivel, namely one herringbone derrick mast was installed on the pulled steel towel to form a stable triangle structure, then choosing anchor point, and the swivel of steel towel was controlled by computer, to ensure the safety and success of construction for vertical swivel of steel tavel.

Research results : It took 9 hours and 18 minutes to swing the steel towel in place with 580successfully. The closure accuracy met the design request with the error only of 2 mm and the cord force conformed to the calculated result.

Research conclusions :This was the first time in China to vertically swing a steel towel with total length of 88 m by adopting pulling method, and it was also the most advanced installation technology to hoist large-sized component with control of swinging cause by computer in China

Research methods ： Compared the new and old design standards on steel structure of Railroad Bridge , this paper found out the main difference , and analyzed whether the load-carrying capacity of some old steel bridge satisfied the design requirement of the new code through theory calculation.

Research results：This paper found out the main difference between the new and old design standards in the respect of the longitudinal join slenderness ratio limit, the center pressure bar axial-allowable stress discount factor, the checking computation of various components fatigue allowable stress , lateral rigidity , and also obtained stricter result from the new code. Through further analysis, this paper got that the major components inner force and the transverse direction natural vibration frequency of the 64 m simply supported bolted and welded steel truss girders bridge , and found out this bridge did not satisfy the design requirement of the new code in the respect of lateral rigidity and constructional detail, and the strength reached the critical value which defined in the new.

Research conclusions :The promotion in the speed of train code. and the capacity of the train carriage required strengthen on the old steel bridge for train safe service.

Research methods: Closely around the characteristics of the existing operational line, the comparisons are made for the influence on the safety of bridge foundation by conducting churning jet pile and for the reinforcement achievements from the angle of technology by adopting the methods of overall analyses, theoretical calculation and practical verification for the purposes of making research conclusion more believable and reinforcement achievement more reliable.

Research conclusions : As a method of reinforcing foundation , churning jet pile has the features of wide application , easy construction, less influence on foundation, good reinforcement result and money saving, so it is necessary to do the further research on churning jet pile.

Research methods: The theoretic analysis of the cause for raising temperature in the tunnel is made and also the theoretic and simulation testing researches are made on the saline water-air compound decoupling charge structure.

Research conclusions: Explosive gas is one of heat resources which influence the balance of frozen soil. Saline water medium has a good result in lowering the temperature of explosive gas with 70%.The aims of lowering the temperature of working face and reducing dust can be achieved by using NaCI saline water taming plug to block explosive mouth, and also the damage to rock wall can be reduced effectively by adopting complex decoupling structure.

Research methods: According to the previous experience and lessons of construction of tunnel , the risk grade of karst tunnel was classified, the essential factors of safety of karst tunnel were analysed and the research was made on the main contents of essential factors of safety.

Research conclusions : The discrimination should be done and the countermeasures should be worked out in the courses of design, construction and management of karst tunnel for avoiding the risk. In the design period, the classification of risk degree should be made for karst tunnel and with it the relative design should be made. In the construction period, the training should be reinforced for security and the relative construction principle and method, risk discrimination and fleeing system should be implemented and provided in the whole course of construction. For those complicated karat tunnels, the prediction and forecast should be done in advance with special management and the treatment of karst should be done based on pragram and system with management of the special fund.

Research methods: The research and analysis are made for construction of the tunnel by adopting engineering analogy and structural analysis methods.

Research results : Through making analogy and analysis , it is decided to adopt the program of application of pilot tunnel with double-sided wall and steel pipe cast-in-place pile in construction so as to improve the bearing capacity of foundation base of the tunnel.

Research Conclusions: The construction program of adopting double-under-wall pilot tunnel is suitable for treatment of the foundation of shallow and extra large span tunnel which requires strict control of decline volume of surface under bad condition of building wall rock. It is easy to operate and control deformation because of the small section of double- under-wall pilot tunnel, and the stressed condition is improved much because of adopting the support with full section enclosure. In addition , the geological condition can be surveyed clearly and the foundation can be treated in advance for providing enough bearing capacity of foundation for supporting tunnel because of the construction of pilot tunnel in advance. The steel pipe pile for treating foundation can enhance the bearing capacity of the soils between the piles, improve the inverted arch foundation of the tunnel and form large inverted arch foundation against the settlement of entire tunnel.

Research methods: According to the landform and geological conditions and collapse situation of outlet of Heluo Mountain Tunnel , the economic and rational treatment measures were decided by adopting the methods of comparing similar constructions , data analyses and optimising programs , and survey and analyses were made for the wall rock and structure deformation, including doing necessary verifications for the main structures.

Research results: According to the landform and geological conditions and collapse situation of outlet of Heluo Mountain Tunnel , the effective measures were taken and good treatment result was obtained.

Research conclusions : For construction of large span tunnel with the conditions of complicated landform and geology and weak wall rock, effective prevention and treatment of collapse and smooth engineering at tunnel opening were the key points for successful tunnelling. The big pipe fence and small pilot pipe grouting were adopted along with remaining core soil for excavation in advance in this construction , so collapse was controlled and treated effectively , engineering succeeded in collapse section and the hard problem in tunnelling was solved.

Research methods: On the basis of survey and design data, studies are made on the karat development regularity and on the relations between the water inflow and the karat development by investigations on the engineering geology and hydrogeology of ground surface along the tunnel alignment and inside the tunnel.

Research results :By means of studying on the development states and distribution regularity of the karats in the prediction region , it is concluded that huge and deep fractures control the development of the deep karat caves and underground rivers and the critical water inflow sections within the tunneling region are determined; Small-medium distance electrical prediction methods compatible with the prediction aims are selected for the detailed prediction and determination of the water inflow scales in the critical water inflow sections. The geological data recorded inside the tunnel are used to modify the prediction programme and the relevant technical parameters so as to gradually optimize the prediction system.

Research conclusions: Huge and deep factures control the development of the karsts and the general development orientations of the large-scale water-filling karst caves are the same as the orientations of the fractures; the highly- accurate electrical prediction methods for small-medium distances, which are more sensitive to water than elastic- wave prediction method , is suitable for the detailed predictions in critical water inflow sections. A combination of different prediction methods should be adopted for the prediction of the water inflow in karst regions so as to improve the prediction reliability and the working efficiency; the prediction process is a gradually-optimized process.

Research methods: Though investigating and studying several mining method tunnels , the analysis , comparison and conclusion for various auxiliary construction measures have been made under different engineering geological and hydrogeological conditions.

Research Conclusions: In the design and construction for mining method tunnels in urban metro, combining with the basic engineering method of tunnel construction, this paper compares, chooses and adopts some reasonable auxiliary construction measures according to the circumference environment of the project, the embedded depth of tunnel, engineering and hydrogeological conditions, and the tunnel section size. Strata and surrounding rock shall be necessarily strengthened and water sealed which can avoid the major construction risks and save engineering investment but also reduce the influence and damage of the circumjacent environments and meet the requirement of the construction period.

Research methods: This paper simulatedly calculated with ANSYS software the excavating process of center drifts excavation method , and analyzed the nonlinear numerical model with reasonable parameter and ”dead and live" element method. The weak area was reinforced in time to ensure the surrounding soil in stable condition.

Research results: Through comparing and analyzing the monitoring information with numerical result, this paper approved that the numerical model and parameter selection were rational and the calculation results were right and reasonable.

Research conclusions: The theoretical computation subsidence curve was fundamentally unanimous with the practical monitoring curve. It proved that the numerical simulation was in agreement with practice. The numerical simulation result was valuable in qualitative analysis the stability of the soil, but quantitative analysis was quite difficult. It was necessary that the key parameter (such as deformation modulus etc.)and its sensitivity were discussed and analyzed when the numerical simulation was carried out.

Research methods: According to the professional characteristics of production quota, the mathematic model is established for production quota, and the accuracy of the result made by mathematic model is also inspected.

Research results: The standard of production quota can be presented by mathematic formulas. After these formulas are recorded in computer and when it is necessary to find the standard of production quota in computer, the quota of time and quota of output are displayed only if the numerical values influencing the consumption of working days are transmitted into the computer, then the working days of quota can be displayed when the quantity of works is transmitted into computer.

Research conclusions: Nowadays the expression form for production quota is constrained by the following sections; The first one is the advanced level of production means, such as the mechanization and automation of production means and the second one is the popular level of computer used for management of enterprise. Therefore，the expression forms for production quota of enterprises will be three forms basically in the future: The first one is the math expression form, the second one is the tabular expression form along with math form and the third one is tabular expression form.

Research methods: By adopting contrastive analysis method , the quantitative analyses are made for the impact on real estate corporation by liquidating value-added tax on land and the achievements made by taking the countermeasure.

Research results: Under the situation of levying value-added tax on land , the comprehensive tax burden of real estate enterprise is higher than that under the condition of pre-levy. Meanwhile , for a project , the amount of added value is larger, the gap of the comprehensive tax burdens is greater between two situations.

Research conclusions : Aiming at the situation of big impact on Real Estate enterprise by value-added tax on land, we can adopt the internally transferring pricing in enterprise and shortening the periods of the project. They are helpful for the enterprise to reserve more profits and reduce its tax burden reasonably and legally.

Research methods: Based on the positive researching, this paper analyzes the whole course of disaster forecast and emergency rescue to taking place of the secondary continual tragedies and ex post resumption of reconstruction.

Research results : Some shortcomings were found about implementation and implementary ability of our country' s emergency management system. This paper put forward that the cornerstones of emergency management were implementation and implementary ability, summarized the five key factors of emergency management, and also proposed that six important mechanisms should be set up to cultivate the high efficient implementary ability.

Research conclusions: Strengthening construction of implementing ability is the base for China to improve emergency management level. It is necessary to further improve the framework of emergency system, especially in the areas of construction and improvement of supervision system for it. The construction of culture should be emphasized in the course of construction of emergency system, not only to make the whole nation having crisis ideas, more importantly to make the whole ,nation having the ideas of dealing with the crisis event. The research can be improved by certain sense on theory and practice of construction of emergency system in China through establishing efficiency-based six systems of enhancing implementing ability.

Research methods: Through discussing the effects of information network , the deep analyses are made for the work range and procedure of establishing information network and the further analyses are also made for the problems in establishing information network from the areas of leader's knowledge , overall plan , system structure , quantity of energy that had been put into and concept, so as to find the causes for the problem and point out the main works to be done for establishing information network and resolutions to the problems.

Research conclusions: In the course of establishing information network，the work thoughts would be set up, the overall plan would be strengthened, the suitable work platform for real conditions would be built, the information system would be normalized, the standard data bank will be established, the organization structure would be optimised, the examination would be strengthened, the information recourse provider would be selected perfectly and more energy would be put into.

Research methods： From beginning with the background of issue of ”Model Text of Bid Documents on Railway Construction Project"，the analyses are made for the characteristics of the Model Text and the explanation is made for how to use this Model Text by railway construction enterprises with contracting mode.

Research conclusions: The tenderer should pay attention to the following points ; firstly , the biggest differences among three model texts are Chapter 4”the Clauses of Special Contract" and Chapter 5”List of quantities of Works" of bid documents; secondly, the most important things for tenderer to read are those lists in front of all chapters, and thirdly, it is unnecessary for the tenderer to carefully study those appendixes and attached lists in Chapter 3”Qualification Examination Method" of qualification examination in advance documents and in Chapter 3”Method of Evaluation of Bid" of bid documents , which are used by the bidder and evaluation committee.