Unloading Analysis For Steel Reinforced Concrete The Large Cantilevered Structure

The steel reinforced concrete the large cantilevered structure has the unique andnovel shape. On the one hand, it is increasing the aesthetical results and architecturaluse of space of buildings; and on the other hand, the complexity of the structure andconstruction of difficulty, because of the large cantilevered structure has the longconstruction period and the complexity of the influence factors. In the process ofdesign and construction, comparing with the traditional structure, the internal forcetransmission of large cantilevered structure is completely different. Construction ofthis structure should not follow the process of construction of the traditionalstructure. Therefore, in order to guarantee the construction project quality andconstruction security, economic, smooth, and analysis of stress of the cantileveredstructure in the whole construction process, Especially, analysis of stress anddisplacement of the cantilevered structure and temporary supporting system in theprocess of unloading. In the process of whole construction, monitoring main verticalforced members in the system of temporary supports by install vibrating wire straingauge. According to the data measured values in the field were compared with thetheoretical results, which determined the reasonable unloading time and removalorder which has significant importance and practical value for construction anddesign.Base on the large cantilevered structure of Raffles City Chengdu, this paperpresents the following work:①At first, this paper introduces the large cantilevered structure and thesuspension structure and stress characteristics of these two structures, thedevelopment Process of composite structure for steel reinforced concrete and thepresent domestic and foreign situation is are reviewed and generalizedsystematically in this paper.②The unloading method whose temporary supporting system of the largecantilevered structure is described in details; Base on construction mechanics andAnalysis methods of construction in stages which analyses the process ofconstruction for the large cantilevered structure; Analysis of the process of which thespace stressed system of the large cantilevered structure. The unloading controlmethod, the unloading principle and reasonable sequence of unloading the temporary supporting system are checked.③The application of finite software-MIDAS GTS build finite element analysismodel. Designing and calculating the temporary supporting system, design andload-carrying capacity and stability of temporary supporting system are checked.The anti-force of temporary supporting system is calculated and designing thetemporary supporting system under the most unfavorable loading.④Finite element analysis software SAP2000was adopted to simulate theunloading process for the large cantilevered structure.“With force-controlled anddisplacement-controlled” was adopted for numerical simulation of unloading processof which temporary supporting system. Using of “symmetry, Step-by-step,Circulation, Micro-declining” unloading approach is a reasonable method.⑤The content of on-site measurement include measuring point,vibrating Wirestrain Gauge Installation and data collection which the large cantilevered structure oftower2and the temporary supporting system in Raffles City Chengdu are describedin detail. According to the data measured values in the field were compared with thetheoretical results, it verifies the plans and methods feasibility and operation.