Study On Cost-benefit Of Prefabricated Steel Structure Residence In Life Cycle

In the context of my country’s promotion of the transformation and upgrading of the construction industry,the acceleration of the urbanization process,and the outstanding contradiction of steel overcapacity,steel structure housing with natural assembly properties has become the future development direction of industrialized housing.In the past,steel structures were mainly used in large venues,industrial plants,and public buildings because of their suitability for large spans.Residential applications were rare.In addition,the design is too conservative,modularized,and the degree of standardization is low.As a result,the initial investment of prefabricated steel structure houses is higher than that of traditional cast-in-place structure houses.At this stage,the measured data of transportation and demolition costs are basically blank,and social benefits are difficult to monetize.The immediate benefits drive people to ignore the transportation and dismantling costs and comprehensive benefits,so that the price advantage of prefabricated steel structure houses is not fully utilized,leading to its slow promotion.Therefore,a comprehensive study on the cost-benefit of prefabricated steel structure residences from the perspective of life cycle is of great significance to increase the enthusiasm of related enterprises and smoothly implement prefabricated steel structure residences.In this paper,through the theoretical analysis,life cycle cost analysis and estimation,benefit analysis and calculation,and empirical project cost-benefit comprehensive research on the prefabricated steel structure house,a deeper study of its life-cycle cost-benefit.(1)Using the life cycle cost theory,combined with the characteristics of prefabricated steel structure houses and the convenience of calculation,determine the life cycle cost composition,and discuss each cost in detail with reference to the current relevant regulations.The results show that: the initial investment of prefabricated steel structure residences is estimated according to certain costs,and the transportation and dismantling costs are estimated according to uncertain costs.Based on the analysis process and characteristics of the life cycle cost at home and abroad,the unascertained mathematical theory is selected to establish a life cycle cost estimation model for the problem that the measured data of the prefabricated steel structure housing transportation and dismantling costs are basically blank at this stage.(2)On the basis of life cycle cost analysis,systematically analyze the economic,environmental and social benefits of prefabricated steel structure residences in the life cycle through field investigation and comparative analysis methods.And integrate the analysis results to form a benefit evaluation index system for prefabricated steel structure houses including 3first-level indicators and 15 second-level indicators.Among them,economic benefits and environmental benefits are monetized through measurement formulas,and social benefits that are difficult to monetize are quantified using expert scoring methods.(3)Based on the life cycle cost estimation and the results of economic and environmental benefit calculations,a comprehensive evaluation model for the life cycle cost and benefit of prefabricated steel structure residences based on the cost-benefit ratio method is established;in order to make up for the lack of monetization of social benefit indicators,combined weighting is adopted The cost-benefit index ratio method is used to comprehensively evaluate the costbenefit of prefabricated steel structure residences.(4)Taking the 9# residential building in Lanzhou New District prefabricated steel structure housing industrialization demonstration district as the research object,use unascertained mathematical theory to estimate its life cycle cost,and compare the estimated result with prefabricated concrete structure and cast-in-place concrete structure.System comparison and analysis,and the cost-benefit ratio method and cost-benefit index ratio method are used to comprehensively evaluate the cost-benefit of the three residential systems.The results show that:(1)The life cycle cost of the prefabricated steel structure house is shorter than that of the other two housing systems.(2)The comprehensive benefit of the prefabricated steel structure house is significant;(3)The prefabricated steel structure house is better than the other two housing systems in comprehensive consideration of cost-effectiveness.The benefits of prefabricated steel structure houses can make up for the increased costs.(4)The combination of the two cost-benefit evaluation methods provides a more comprehensive understanding of the benefits of prefabricated steel structure houses.This not only provides a theoretical method for the cost estimation and benefit quantification of prefabricated steel structure residences,but also provides a scientific decision-making basis for the development and construction of prefabricated steel structure residences.(5)Based on the results of cost estimation and benefit analysis,the countermeasures for the development of prefabricated steel structure residences are put forward.Including improving the standard system,strengthening government incentive policies,reducing initial investment,and strengthening the publicity of comprehensive benefits.