Comparative Study On The Design And Monitoring Of Anchor Supporting Pile Structure In Deep Foundation Pit Engineering

With the rapid development of China’s economy in the recent decades, and with the increasing construction of middle high-rise buildings and underground engineering in modern cities, deep foundation pit has been used extensively. Because supporting pile structure in deep foundation pit costs too much, we nee to do a further research about design theories and methods of deep foundation pit to lower the cost while ensuring safety. Anchor supporting pile structure is a new kind of supporting pile structure which is used widely in deep foundation pit in recent years, especially in deep foundation pit which has a narrow and complicated surrounding. It makes best use of the advantages of both pre-stressed anchor and supporting pile, makes supporting structure stressed more reasonably and makes construction easier comparatively. This paper takes Dacheng Plaza in Zhang Jianggang as an example, analyses several calculating methods adopted in anchor supporting pile in deep foundation pit, makes a comparative analysis between the results of internal forces and deformation of supporting pile and the field monitoring results during construction, and assesses and puts forward some suggestions on the design methods.This paper mainly deals with the following issues:1. Elaborating the basic theories of supporting pile design and new tendencies of relevant fields.2. Placing emphasis on analyzing some key points in analysis and calculation of anchor supporting pile structure, such as the stressed theory of anchor supporting pile, soil pressure calculation method and determination of calculation parameters, etc.3. In the analysis and calculation, dividing the excavating and pre-pressed processes into several parts, calculating and analyzing the changes of the internal forces and deformation of supporting pile structure between two anchors in accordance with excavation.4. Analyzing how well calculating results of several commonly-used supporting pile design match and choosing a better one.5. In the design methods used extensively at present, the internal force of supporting pile calculated by adopting elastic resistance method "c" and the monitoring result seem to be more practical, while the internal force of supporting pile by adopting "m" method is too conservative. In terms of horizontal displacement of supporting pile, the displacement value by adopting the "m" method and triangle soil pressure is close to reality.