Abstract:Based on the underground public car channel in the international residential area of Hengqin New Area, the problems faced by the construction of foundation pit for the channel are analyzed. The geotechnical Lizhen software and MIDAS/GTS software are used to carry out the three-dimensional modeling according to the actual supporting situation of the foundation pit, and then the corresponding simulation calculation is carried out according to the actual excavation conditions. The numerical simulation results are analyzed, and are verified and compared with the actual monitoring data, which provides the checking calculation and proof for the reliability of cast-in-situ pile and internal support system. When the soil is excavated, the soil deformation is mainly moving towards the free surface after excavation. When the excavation depth is small, the soil deformation is small. With the continuous excavation of the foundation pit, the deformation of the soil towards the free face is also increasing, and gradually presents a large deformation in the middle, in which the part with the largest deformation is near the bottom of the foundation pit, which is consistent with the deformation characteristics of the soil of the internal support structure. The maximum horizontal displacement of soil is about 14.98 mm, which is far less than the maximum allowable value of 39.52 mm, which indicates that the foundation pit after supported is in a safe and stable state. Through the design of SMW method support and open caisson support in foundation pit scheme, the support design and key construction technology of foundation pit are analyzed, and the monitoring technology in the construction of foundation pit is studied, which can provide a certain reference for the similar projects.
