Construction Effect Analysis Of Railway Subgrade Earthwork In Northwest Cold And Dry Area Based On Green Construction

Green and sustainable development is the common goal of the whole world.In the 13 th Five-Year Plan,ecological construction is listed as the goal of struggle,and the concept of green development is established.As a giant in the field of civil engineering,the railway industry consumes a lot of resources and energy,with many negative environmental impacts,especially in the construction phase of the railway.Frequent construction activities often lead to extremely prominent resource consumption and rather bad environmental negative output,thus restricting the balanced development of resources,environment and social-economic activities within the region,forming a vicious circle.Based on this background,the concept of railway green construction is put forward.But the northwest cold and arid area soil and water conservation effect is stern,the soil barren degree is serious,the ecological environment is fragile,the sustainable development condition is worrisome,therefore the green construction implementation is extremely urgent.At present,the research on railway green construction mainly focuses on the construction of green construction evaluation index system and the grade evaluation of green construction,and the discussion on the construction of evaluation index system.And did not form a set of suitable for the northwest cold and arid areas of the system.Therefore,combined with the regional characteristics of cold and arid areas in Northwest China,it is of great practical significance for the green construction of railway to form a set of complete and feasible regulations as soon as possible by analyzing and discussing a certain part or point of the railway project at a deep level.Based on the research background of railway green construction in northwest cold and arid area,taking the subgrade earthwork in railway construction as the research object,aiming at the huge consumption of resources,serious environmental pollution and bad social influence in the construction stage,this paper takes the subgrade earthwork as the research object.The concept of construction group is defined,and barrel model is introduced to construct the bucket model of subgrade earthwork construction group considering the short slab effect,taking full account of the regional characteristics of fragile ecological environment,drought and barrenness in the cold and arid areas of northwest China.The relationship between "construction activities,resources,environment and green construction" is fully explained.Based on the analysis of wooden bucket model,the evaluation index system of green construction effect of earth-rock engineering of railway roadbed in northwest cold and arid region is constructed,and different quantitative treatments are carried out according to different indexes.And the improved Malmquist model and the optimal configuration modelare constructed to accurately the initial data of the green construction class.At the same time,the evaluation model of green construction effect is constructed by using random forest algorithm,short board factor measurement model and state space model.Finally,the feasibility of the model is verified by the application of the model in the construction of the roadbed earthwork of Lanxin high-speed railway.Firstly,the green construction behavior of railway is analyzed based on game theory,and the necessity of green construction of railway is discussed.The concept of construction group is defined,the short slab effect is introduced,the bucket model of embankment earthwork construction group is constructed,and the regional characteristics of landform,soil and water environment,climate condition and ecological level in the cold and arid areas of northwest China are analyzed.This paper discusses the influence factors of construction activities,resources,environment and acquired support brought by green construction in subgrade earthwork construction group.Combined with the expert decision-making advice,3 first-level evaluation indexes,6 second-level evaluation indexes and 34 third-level evaluation indexes are selected and integrated to form a set of special green construction effect evaluation indicators for the earth-rock engineering of railway roadbed in the cold and arid areas of Northwest China.According to the different nature of the evaluation index,different methods are selected to quantify the different indicators.In order to process the initial theoretical data accurately,the improved Malmquist model and the optimized configuration model are constructed to determine the initial value of the evaluation index of acquired support,namely the green degree index,which can be used to judge the green construction situation of the process with obvious non-green effect.It is also conducive to the comparative analysis of the overall green construction effect.Considering the limitation of evaluation index volume data acquisition,this paper makes full use of the strong data mining ability of random forest algorithm to fully mine the limited data of evaluation index.And through its strong fitting performance and good tolerance to accurately evaluate the initial weight of the index.Considering the existence of short board effect in some evaluation indexes,the measurement model of short board factor is used to measure the measurement value and tolerance threshold of short board factor,and the limiting effect of short board factor is emphasized,thus the weight vector of evaluation index system is established.Taking the bucket bottom,the barrel wall and the water in the barrel as the coordinate axes of three-dimensional degree,and taking the comprehensive bearing degree of theroadbed earthwork construction group as the research object,the state space model is constructed to evaluate the green construction effect of the roadbed earthwork.Selecting the construction stage of the roadbed earthwork of Lanxin high speed railway as an example,this paper uses the established model and method,and evaluates the radar map by comparing the green degree index of construction and green construction.The feasibility of the model and method is verified.