Settlement And Post-cast Zone Setting Of Super High-rise Structure With Hard Rock Foundation

The uneven foundation settlement of super high-rise structure's building and podium has been plagued by many scholars, experts at home and abroad.Through several hundred years of development, the construction settlement calculation theory still fails to reach a consensus, there are still many uncertain factors.Although post-cast zone can better solve the problem of uneven settlement, setting post-cast zone offen seriously affect construction period, increase the difficulty in construction and even affect the use-function, and the standard of subsidence and the related provisions of post-cast zone are not unified,no detailed and complete terms guiding the design and construction.Therefore, it exists great misunderstandings in the issue of the settlement of super high-rise structures and the setting problem of the post-cast zone .The paper based on the geological conditions in Qingdao region ,around the settlement of the super high-rise structures with the hard rock foundation and the setting problem of the post-cast strip this article opens the following research work.Firstly,this paper described several Constitutive Models about rock mass subgrade at home and abroad , simply summarized their principles and applicable conditions .While experts and scholars domestic and overseas put forward the settlement of the structure of a comparative analysis of the calculating method is presented, applicable to super high-rise structure with hard rock foundation of settlement calculation method, and the application scope and value of related parameter to each calculation method also explained and defined.Secondly, the statistics of settlement data of dozens of super high-rise structures based on qingdao region, analyzed from two aspects about maximum settlement of the structure and settlement difference between main building and podium,then sum up the settlement regularity of super high-rise structure with hard rock foundation.Again, through the analysis of dozens of engineering geological exploration of Qingdao area, summarized the report of the geological characteristics and the elastic modulus value was also briefly discussed. Take two practical engineering for example, using different settlement calculation methods to calculate the settlement and the structure of a comparative analysis of the results obtained in the geological conditions to the settlement of super-high structure calculation method.Apply ANSYS finite lement program to the two engineering building and the podium foundation slab and expansion strengthening belt for stress analysising, understanding their stress distribution. Finally, according to post-cast zone suitable closure time, this paper puts forward three kinds of different construction conditions.Take a practical engineering for example to use the ANSYS finite element program calculating the maximum settlement of the structure ,the settlement difference of the main building and the podium , the floor stress in different conditions respectively and the results are analyzed. Through the different factors affecting the structural conditions and the expansion of post-cast zone stress of regression analysis , the 95 percent assurance of stress formula is given. In the above analysis based on the results, this paper proposes that it may cancel the suggestions of the building height of the subsidence of post-cast strip in the conditions of hard rock foundations and it can offer some reference for design and construction through the comprehensive analysis and practical engineering experiences.