Study On Monitoring And Optimization Of Supporting Structure Of Deep Foundation Pit For Xisi Subway Station On The 4th Line

Monitoring on supporting system of a deep foundation pit is significant to engineering construction. Dynamic information from the monitoring is very useful to the adjustment of construction process and the optimization of supporting structure.The monitoring system of the deep foundation pit for Xisi station on the 4th line of Beijing subways is introduced in this paper, and the deformation of the supporting piles, the horizontal displacement of the supporting structure and axial force of inner supporting girders are obtained from the monitoring data. According to these data, the dynamic states of the supporting system may be clearly distinguished and the construction of supporting system may be adjusted and optimized. There are mainly two parts in this paper:1. Analysis and process of monitoring dataThe key points of this part are as follows:(1) Varying law corresponding to deformation of supporting pile, horizontal displacement of supporting structure and axial force of girder in different excavation stage.(2) Varying law corresponding to deformation of supporting pile, horizontal displacement of supporting structure and axial force of girder in different construction position.(3) Analysis for abnormal phenomena corresponding to deformation of supporting pile, horizontal displacement of supporting structure and axial force of girder.2. Discussion on optimization of supporting structure.Because the supporting piles are finished before excavation of foundation pit, the optimization is mainly focused on the adjustment of inner supporting girders. The reduction in the amount of inner supporting girders should be considered to optimize the supporting structure.