| As an important symbol of building industrialization,ready mixed concrete(RMC),also known as commercial concrete,is one of the most important materials of modern building engineering structure.It has the characteristics of factory production,centralized mixing,mechanized transportation,three-dimensional pumping and so on.It is widely used in urban construction engineering,and has great application prospects.At the same time,ready mixed concrete is a very special building material,the formation of its final product needs to go through many processes,such as mixing,transportation,pouring and tamping,molding,curing and so on.As an intermediate transitional product with unstable nature,it must be poured and tamped in the mold before initial setting.It is highly time sensitive and requires continuous operation in each stage,with strict time interval and time limit.Once the delay may lead to construction cold joint and other quality defects,serious cases will lead to construction accidents.Therefore,to realize the effective organization and coordination of the operation process in each stage of the life cycle of ready mixed concrete is very important for fully reflecting the excellent performance of concrete structure and ensuring the quality of construction products.It is the difficulty of the current production,construction and operation management,and has been paid close attention to by theoretical research and engineering application fields at home and abroad.This project focuses on in plant production and external transportation process,and realizes multi-stage scheduling decision-making based on the perspective of supply chain.The main contents include:(1)The concrete pouring process of large-scale foundation engineering usually has the characteristics of large quantity,long duration and outstanding parallelism.It is attributed to the production and transportation coordination scheduling problem of multiple factories supplying a single construction site.Considering the constraints of initial setting time and pouring interruption time interval,a model is established to minimize the total vehicle transportation mileage,vehicle queuing waiting time and pouring interruption time.Based on the multi-objective optimization model,heuristic algorithm is designed to solve the problem.The transportation solution is generated by factory selection and vehicle allocation,and then the order schedule is further generated.(2)In view of the characteristics of large concrete demand and tight construction period brought by the simultaneous commencement of multiple projects in the region,it is attributed to the production and transportation collaborative scheduling problem of multiple factories supplying multiple construction sites.Considering the constraints of initial setting time,pouring interruption interval,vehicle fuel consumption,vehicle waiting penalty cost and pouring interruption penalty cost,the model with the lowest total distribution cost is established The optimization model for the target.According to the characteristics of the problem,a synchronous evolutionary genetic algorithm is designed to solve the model.In the process of solving,according to the corresponding relationship between the ready mixed concrete factory and the construction site,a two-layer coding form is designed.In the process of evolution operator,the two-layer coding is used for roulette selection,shift mutation,inversion mutation and transposition mutation respectively.Through the data experiment,the production and transportation scheme meeting the constraints is obtained,and the total distribution cost is optimized.(3)Considering the characteristics of production and transportation under green transformation in ready mixed concrete enterprises.In the production and transportation cooperative scheduling problem of multiple factories supplying multiple construction sites,the increase in service time caused by the recycling of vehicle wastewater and the decrease in transportation capacity caused by the use of new energy ready-mixed concrete trucks are considered.When modeling,the wastewater recovery time and vehicle mileage constraints were added.A heuristic algorithm is designed to solve and obtain a vehicle transportation plan and an order allocation plan that meets the constraints.In this paper,the ready mixed concrete industry is selected as the basic industry background to study the scheduling problem,and the focus problems to be solved in the production and construction management of ready mixed concrete are systematically and deeply studied at the operation level,so as to provide theoretical basis and core technology for the effective organization of relevant enterprises and engineering projects,and promote the industrial upgrading of buildings and green intelligent construction. |
