Technical And Economic Analysis Of Reinforcement Schemes Of The Structure Attached By External Hanging Luffing-jib Tower Crane

The building structure is becoming increasingly complex and the construction site is limited,it brings great challenges to construction;As building heights continue to climb,it requires higher performance vertical transport equipment for construction site,so the external hanging luffing-jib tower crane came into being.But so far,domestic research about external hanging luffing-jib tower crane is relatively small,leading to the lack of appropriate reference data in co nstruction site.It makes the construction companies can only rely on the construction experience and enlarging the safety factor to use the external hanging luffing-jib tower crane to construct,this not only increases the cost,but also has significant s ecurity risks.The walls of super high-rise frame-core tube structure become thinner with the increase of building height,the thinnest place is only 400 mm thick.Based on the above situation,in this paper,the theory and method of technical and economic analysis are adopted to systematically analyze the reinforcement of the structure attached by external hanging luffing-jib tower crane and select the reinforcement scheme.In this paper,the main research contents are as follows:(1)Through extensive reading of relevant literature at home and abroad,the current status of the research on the external hanging luffing-jib tower crane can be known.At the same time,the research results of domestic and foreign scholars on the external hanging luffing-jib tower crane are summarized,for the paper research reference;(2)The related theoretical basis of this paper is expounded.The relevant theories of technical analysis,economic analysis and scheme comparison are introduced.Combined with reinforcement technology,the evaluation index system of value engineering is constructed;(3)Based on engineering practice,finite element models of the external bracing frame and the structures attached by tower cranes were dev eloped for mechanical analysis.It is concluded that the stress and strain of the attached structure exceed the limit state.Its bearing capacity can't meet the safety requirements of construction,and needs reinforcement.(4)Relevant code calculation and finite element modeling analysis of reinf orcement methods of increasing the number of local steel bars and pasting carbon fiber cloth were done.It can be known that the two reinforcement methods can make the attached structure meet the construction safety requirements and the function evaluation coefficient(F)of two reinforcement methods is obtain ed;(5)After the economic analysis of the two reinforcement methods,the eco nomic indexes of the two reinforcement methods are obtained,and the cost coe fficients(C)are calculated accordingly.The value coefficients(V)of the two r einforcement methods were compared to optimize the scheme.