| Dispersive Tube Structure is a new type of structural system applying tohigh-rise buildings and super high-rise buildings with excellent performance instructure and economic, and according to preliminary research, it also has greatprospect. Based on the existing research results, the practical engineering structurehas been optimized design by SATWE in software PKPM. Thin wall-beam-plate jointand the cylinder’s corner joint under complex stress situation in dispersive tubestructure. The finite element analysis software ANSYS was used to analyze. Variousstructural measures were taken to solve the unreasonable destruction according to thedifferent joints.First, the paper has studied the reasonableness of the thickness of the wall instructure, and got the conclusion that the deflection and crack width of thickness200mm wall both met requirements of codes. But the thickness and reinforcement ofthe wall in the upper floors has a larger surplus. To get more reasonable and practicalstructure, an optimized design was conducted to the structure. And analyze thewall-beam-plate joint extract from the structure. Found that maximum crack width inthe tensile zone of the beam met the limit crack width in Concrete Code. The jointwas under normal Working state. However, the phenomenon of concrete crackingoccurs in the middle of the non-beam side wall in the upper floors. Maximum crackwidth in the wall was close to the limits, considering the depth of the cracks in thewall almost throughout and across a wide range, the wall was weaken obviously,which might lead to shear bearing capacity does not meet the demand. Because ofthe thin wall, the horizontal anchorage length of rebar in beam does not meet currentcode’s requirements. Another considerate the structure is new to engineering practice,structural measures must be taken to solve the problem.Focusing On The Problem and provisions of codes, the paper given the solutions.And the numerical simulation analysis was done for4kinds of construction measures.,the outside beam, the outside column, the extended beam and the haunched beam.After a lot of comparison of research results, the unreasonable stress in the wall wasnot resolved by the measure of haunched beam while it works by the measure of theoutside beam, the outside column and the extended beam. Cracks in the walldisappear and the stress was getting more reasonable. Among them, this paper picked11kinds of outside beams and6kinds of outside columns as the constructionmeasures, and used the way of grouping contrast to determine the reasonable andeconomical structural measures. The specific solution was given to guide theengineering practice.Then, the paper selected a joint of the cylinder’s corner under complex stresssituation in dispersive tube structure, and did the numerical simulation analysis withyield loads, and made the following conclusions:(1)The horizontal anchorage length in the wall of rebar in the top of the beam does not meet the limits in current codes which brought negative impacts.Structural measures should be taken to solve the problem.(2)When the rebar of beam anchoring in wall just reached the yield state, thereinforcement stress of rebar that didn’t anchoring in wall was small,Steel barintensity wasn’t used effectively and The stress state in this joint does not match theexisting design method, so structural measures should be taken to solve the problem.(3)Before all tensile rebar been fully utilized, the concrete at bottom of the beamconnected the wall was under the stress concentration state. the concrete compressivestrain has exceeded the limits ultimate compressive strain, which could indicating thatwhen some of the rebar at upper part of beam just reached the yield strength, partialconcrete walls were crushed, the joint had brittle failure which phenomenon wasunreasonable, poor ductility and weak, structural measures should be taken to solvethe problem.For above problems, this paper did numerical analysis of two improved joint thatwere haunched beam and adding head on beam. Under the measure of haunched beam,mechanical performance improved greatly, anchorage length of rebar in beam met theregulatory requirements. All tensile reinforcement get to yield state almost the sametime while the compressive strain of the concrete under the beam close to the ultimatecompressive strain. Under the measure of adding head on beam, the rebar not anchorinto the wall were under the bad anchoring environment, which could not solve theasynchronous of rebar in beam. Another, considering the use functions, the measure ofadding head on beam has A raised on wall which might affect the normal use of thelift. So the measure of adding head on beam was not recommended.To further improve the premature crushing destruction on the wall, this articlecontrasted and analyzed two different height of the haunch, twice height of the beamand the height of floor. The study found that large bureau pressure of wall could beresolved by each of two measures. There was no obvious improvement to add theheight of the haunch from twice height of the beam to the height of floor. So themeasure of haunched beam could improve the mechanical performance of joint andthe anchorage length meet the requirements. The haunch choose twice height of thebeam could get good effect. In the specific project, a comprehensive considerationwhich includes economical efficiency and convenient construction could beconducted between the two measures. |
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