Study On The Application Of The Innovative Pre-stressed Support System For Xuzhou Ruyi Plaza Deep Foundation Pit

Along with urbanization process increases day by day,urban underground engineering presents a larger development trend.Different from the simple form of foundation pit support in the last century,nowadays,under the premise of meeting the strength requirements,the foundation pit excavation is becoming more and more strict.especially in the case which has a large number of existing buildings around the underground works,it is necessary to strictly control the deformation of the foundation pit structure.Concrete supports and steel supports commonly used in foundation pit support have their own advantages and disadvantages.Concrete support is good at deformation controling,but the construction period is long,and it is not convenient to disassemble.The steel support has a short installation time,short construction period and convenient removal,but the deformation control is not as good as concrete support.At the same time,neither is convenient to transport soil.Prestressed fish web beam can control deformation effectively,and has other advantages,such as easy installation and demolition,short construction period and convenient excavation.The advantages are obvious in the foundation pit support engineering of large underground projects,but less research than traditional support.In this paper,the deformation control and stress of prestressed fish web beam are studied by numerical calculation and corresponding actual engineering field test results,and a design scheme that can be referenced for practical engineering in the future will be provided.Through the analysis of Midas/GTS numerical simulation software,the maximum displacement of the pre-stressed fish web structure is 28.26 mm,the maximum horizontal displacement is 14.7mm,the maximum surface settlement is 9.6mm,and the maximum axial force is 5896 kN.The maximum horizontal displacement of the subway tunnel near the foundation pit is 2.32 mm due to excavation.The maximum vertical displacement is 5.343 mm.The calculated displacement and the measured displacement deformation in the field are within the alarm value range,which verifies the reliability of the calculation model and the results,and provides reference experience for the future foundation pit design.Figure 66 table 14 reference 57...