Mechanical Analysis And Displacement Control Of Integrally Synchronized Jacking

With the rapid development of China's continued economic and urban construction, urban re-planning and large-scale urban renewal in the country widely expanded. Synchronous lifting technology has been rapid development in China, and it's have achieved good results, but most project only stay in the practice stage, the lack of systematic theoretical analysis, the lifting process arising out of sync and a horizontal drift has not yet perfect solution.This paper combine a cut-off and overall rising project in a district capitals in Lanzhou city, the overall rise off the capitals of design ideas and construction processes are summarized, including the lifting cap productions, jack installation, test lift of structure, structural up lift, restore and reinforcement of the cut-up column. It focuses on the technology important point and difficulty of the design and construction process. It clear direction engineering research.Since the model tests are difficult to simulate actual working conditions, the combination of on-site measurement and finite element simulation is a viable means of research. After column are truncated, the structure is in complex boundary conditions in jacking project. According to the engineering characteristics of cutting off column and lifting-up, this paper put forward a finite element modeling method "additional combin for element node" to the dynamic boundary conditions of the column to solve finite element static analysis constraint shortage. In this paper, the horizontal displacement using the finite element modeling method are very close to the results of the site monitoring. It indicates that the finite element modeling method is effective, simple and easy to operate features.By analyzing the cause of liter horizontal drift in project of cutting off column and lifting-up, this paper put forward some control measures such as adjusting the load distribution, cutting at the inflection point, set up control measures targeted support, set the limit devices. The finite element analysis results show that by removing a variable load floor all the way does not make structural drift to a minimum level, but in the span across the board increased slightly smaller floor loads, in the presence of the wall between the carrier beam increased floor loads across a manner that the structure level drift further reduced. At the same time, adjust the load distribution on the local drift and drift overall have good control effect. Horizontal support is provided so that the adjacent column sections reduce or eliminate the reverse moment, thereby reducing the reverse drift, drift on the local level control works well, but can not eliminate the whole structure drift. The horizontal shear limit device transferred to the next column, based on the limited horizontal displacement, is a long trip, and effective measures to solve the difficult level drift jacking project prevented.