Research On Optimization Of Budget Estimate For Whole Life Design Of High-speed Railway Projects

From the completion of the first high-speed railway in 2008 to now,China’s high-speed railway has realized the leapfrog development from catching up to taking the lead,and China’s high-speed railway has been in the forefront of the world.However,at the same time of the rapid development of China’s high-speed rail,there are also some problems and difficulties that are incompatible with it and need to be solved in the investment and construction.In the international market,China’s high-speed railway bidding has failed repeatedly,and the loss phenomenon is relatively serious after winning the bid.In the domestic market,the construction investment exceeds the total,the operation loss phenomenon is more serious;At the level of domestic industrial demand,the intelligent level of investment decision-making in China’s high-speed rail is far from reaching higher requirements.Based on the design stage,through investigation and analysis,it is found that the main causes of the above problems and difficulties are as follows: the design optimization method of China’s high-speed rail is not scientific,which is manifested as the low degree of collaborative,systematic,visualization and intelligent optimization;The compilation of the design budget estimate based on the estimated budget quota has some defects such as fixity,lag and poor reliability.There are some problems such as linearity,simplicity and large amount of work.The contents of the design budget estimate compilation are not comprehensive,which directly affects the economic benefits of the high-speed railway project’s life investment and can not better meet the needs of the green development of high-speed railway.Therefore,it is urgent to explore a set of systematic optimization model of the whole life design estimate of high-speed railway engineering,and build a set of scientific,practical and reliable nonlinear pre-decision model of the whole life design estimate of high-speed railway engineering,so as to provide theoretical support and decision reference for effectively improving the investment decision-making level of high-speed railway engineering and investment economic and social benefits.Based on the above problems and research objectives,based on the preliminary design stage of high-speed railway project,this thesis starts from reforming the current optimization method of design scheme,budget content,budget basis and method,and on the basis of extensive collection and mining of basic spatio-temporal historical databases at home and abroad,Based theory,literature review,Delphi method,structural equation and other methods are used to identify and determine the influencing factors and action mechanism of the design estimate of high-speed railway engineering.Through online and offline research,web crawler,literature reading,UIC database and other ways to collect relevant data,comprehensive use of Python,My SQL,BIM,GIS and other technologies to design and build the high-speed railway engineering design budget estimates based on time-space historical database.The integrated optimization model of the budget estimate of high-speed railway engineering is constructed by applying the theory and technology of logistics integration,BIM and nonlinear predecision.Based on the significant cost theory,a set of universal whole-life design budget prediction model suitable for high-speed railway project,individual project,unit project and sub-project is established by comprehensive use of PSO-RBF,PSO-LSSVM,system dynamics,FIS and other methods.Combined with the actual engineering case,the optimization model of the design budget estimate and the prediction model of the design budget estimate were demonstrated,which further verified the feasibility,science and applicability of the constructed model,and realized the all-round,multi-dimensional and visualization depth optimization decision of the design budget estimate of the high-speed railway engineering and the rapid and accurate prediction of the design budget estimate of the whole life of the high-speed railway engineering.Conclusions: An empirical study was carried out on the influencing factors of the design budget estimate and their mechanism of action.The complexity,nonlinearity,coupling and multiple feedback of the influencing factors were further demonstrated,and the relationship between the influencing factors was clarified,which provided an important basis for the construction of the theoretical model of the optimization of the design budget estimate and the selection of the prediction method of the design budget estimate.The design and preliminary construction of the spatial-temporal historical database of the design budget can realize the functions of timely query,three-dimensional dynamic display,spatial-temporal data analysis,etc.,and provide important data support for the construction of the optimization model of the design budget and the prediction of the design budget.The prediction model of high-speed railway project design budget estimates can effectively overcome the shortcomings of low prediction accuracy,complicated procedure and low efficiency under the current linear and static quota mode,and effectively solve the problem of the limitation of the scope of application of single prediction model in the past.It is conducive to promoting the railway engineering cost model and international standards,and can provide theoretical and practical reference for the prediction of high-speed railway design budget estimates.The integrated optimization model of the budget estimate of high-speed railway engineering can provide theoretical and practical reference for the deep optimization decision of the budget estimate of high-speed railway engineering,and provides theoretical support and reference for effectively improving the investment decision-making level,economic and social benefits of high-speed rail projects.