Subway Station Monitoring And Analysis Of Deep Foundation To Support Engineering

The thesis has studied on force and deformation of protective structures of deep foundation pit considering step braced excavation. It has adopted the combination of three methods: field monitoring, theoretical research, and numerical modeling, on the ground of engineering of support of deep foundation pit in the No.3 Line of Guangzhou Subway and on the basis of thorough analysis on lots of relevant research at home and abroad. The main jobs and conclusion include:1. The suitable field monitoring schemes were established, through analysis of the monitoring data, the distribution trend of the displacement of pile stem, the internal forces and supporting forces in construction were mastered. Compared the monitored data with the controlling standard, well-development of construction went on.2. The relevant theories and methods of the simulation of excavation process by Finite Element Analysis were carefully studied, the calculation method about supporting force were analyzed. The control value of supporting figrce on this project were confirmed.3. Applying with the PLAXIS, a sort of huge geotechnical engineering software, the numerical modeling during the actual excavation process on this test engineering have been done. In terms of contrast analysis of this result and the field test results, The correctness of the new-built model and the properness of adopted parameters were validated. The distribution trend of displacement of the pile stem and the internal force, supporting force on deep foundation pit considering step braced excavation were analyzed through numerical analysis, the influence on the displacement of pile stem and internal forces caused by supporting system and foundation pit dewatering were probed.4. A comparative complete support pile structure optimization system was established, and construction processes were reasonably optimized.5. Adopting SAP84, a structure Finite Element Analysis software, the numeric simulation of internal forces, displacement of support pile and steel supporting force in construction has been carried out. Contrast analysis with the calculated result of criterion in this field, technical support for data analysis and early-warning system in field monitoring was provided.