Study on Permanent-temporary Combined Support Technology for Deep and Shallow Pit in Open Cut Tunnel of Subway
In a deep foundation pit of open cut tunnel of a subway,the main line of the track is shared with the entrance and exit line of the foundation pit,due to their different functions,there is a large height difference between the bottom of the two foundation pits.Through the design of row pile support during the transition of deep and shallow foundation pit,the rein-forced concrete crown beam is applied at the top of pile,and the transverse concealed beam is set in the bottom plate of shal-low pit,the crown beam is connected and anchored with the diaphragm wall to form a frame structure,some of the support-ing structure is permanent-temporary combined;and bored piles are respectively installed in the foundation of deep and shallow pit,and cement mixing piles are used to reinforce the foundation of shallow pit,so as to change the mechanical properties of soil,to improve the strength of the base and the anti-overturning ability of the structure.According to the analysis of monito-ring data,it is shown that the technical parameters of soil around foundation pit are stable and the changing values are within the allowable range,this technology is helpful to solve the problems of deep and shallow foundation pit support.
subway pitopen-cut methodfoundation pit supportfoundation reinforcementtube well dewatering
万方数据
维普
