Research On Application Of M900D Tower Crane And Its Wall-Through Bracket Applied In Construction Of High-Rise Building

Compared with the reality that the height of the skyscrapers and the speed ofconstruction are rocketing to ever broken records with each passing year, the researchon such tower crane with tremendous capacity like M900D is scarce, which,technically, is mostly related to Mechanics rather than Civil Engineering. On top ofthat, this kind of research is somehow shallow and superficial, even lacking ofcorresponding parameters and information. Consequently, what current constructionunits are able to do is following experience blindly and indiscriminately. Not onlydoes this circumstance augment undue budget, but it also brings a host of potentialsafety hazard, which is supposed to be researched deeply and elaborately. Based onthis background, this dissertation carries out relative research on M900D.This project aimed to undergo the finite element analysis on Through-Wallbracket, predict its bearing capacity and did field experiment. The birth-deathelements were used to analyze the cause for some perverse results and TopologyAnalysis was done to get the most optimal bracket. In addition, Sensitivity Analysiswas conducted on tower crane being rotated360degrees to study the stress situation,the maximum internal force and stress changes in tower crane as well as bearing beam.The support beams design was optimized after further analysis.What should be highlighted here is that when confronting difficulties in research,this dissertation seldom refers to the ready-made answers but endeavors to work outnew solutions. In the field experiment of bracket, according to the fact that theoriginal plan would damage the shear wall, the remedy is not to strengthen the shearwall as others did but to change the force transfer mechanisms to transform theconcrete tension into concrete compression. Furthermore, differing from laboratorytest, there are many uncertain factors in field experiment and the environment is alsoworse. Nevertheless, by doing theoretical and finite element analysis, this paperfigures out what these adverse factors are and how these affect the experiment result.The Main research contents and results were summarized as follows: (1) Under the design load, the structure of Through-Wall bracket remainedelastic and its performance was good, which met the design requirements; under the1.67times design load, its performance and residual deformation and stress weredecent. And the phenomenon that strain suddenly changed or ascended generally butdescended initially was attributed to the reality that the bulge or pit on the structurerendered it stuck. Besides, the capacity of the bracket is projected to register2400kNif some components are reinforced in accordance with the result of the finite elementanalysis. In addition, this paper embraces that casing pipes are supposed to be set tothe last row of bolts and the shape of middle steel plate of the bracket should beoptimized, which has already afforded the most optimal plan.(2) The amount of loads of in-service and out-of-service were almost identicalduring hoist boom turned360degrees due to the weight of ballast and wind load,thereby rendering their change range nearly the same, which counts equally. Also, theabsolute value of the strain of both the bottom of M900D and the mid-span ofsupporting beams increased firstly and then decreased no matter being subjected totension or compression. Meanwhile, the variation tendency of the strain of thesupports of the bottom of tower crane and the mid-span of supporting beams were ofdissymmetry. Moreover, the sensitivity of axial force of the bottom of M900D relatedto rotation angle is the largest whereas those of stress, deformation and shearing forceof supporting beams were relatively small. However, the sensitivity of deformation ofsupporting beams turned into larger.