Analysis And Contrast On The Demolishing Column Engineering Of The Reinforced Concrete Frame Structure

Demolishing column underpinning reformation is developing based on the reformation of the existing architecture, which is one of the most important contents of building renovation. It is just essential to lightly manipulate parcel area of a few components or structure in order to strengthen the existing building after span expansion transformation through the undeipinning structure. That would meet the requests of bearing capacity limit state of a structure and normal use limit state, which has advantages of short duration, small engineering quantity, saving construction material and environmental protection. At present, there are a variety of forms of extraction column of reinforced concrete frame structure underpinning and many of those has been applied to the practical engineering, including enlarging section method, prestressed concrete beam, truss underpinning method, additional web column method, paste the steel reinforcement method, externally bonded steel strengthening method, etc. Each method has their own advantages and disadvantages and applicable scope as long as each has different regulation effects for structure extraction column stress system.This paper has collected the typical engineering examples for each corresponding form of demolishing column undeipinning reformation and has summarized the scope of application for concrete beam enlarging section method, prestressed beam method, additional web column method and the double angle bracing method.By using SATWE in the PKPM module or the MIDAS Building software, we have simulated the column-removing engineering of a regular frame structures in a variety of underpinning structure and Qingdao Olympic game business center. Meanwhile, we have established the extraction column supporting different entity model change before and after according to the different form of the extraction column underpinning support and made a comparison between the index model under different conditions by way of chart. Analysis results show that, the double angle support method has significant effect on the moderating effect of internal force redistribution of extraction column structure and the deformation control beam vertical pumping column, comparing with Concrete beam enlarging section method, prestressed beam method and additional web column method. When the nunmber of demolished columns is small, the above several underpinning for the seismic performance of the overall structure has tiny effect.The paper provides a certain reference value for related engineering in future on the framework of rules underpinning the comparison between before and after stress. Meanwhile, this paper also has some deficiencies and needs to improve further.