Study on characteristics of ground connecting wall and surface deformation during excavation of subway foundation pit in soft soil area
Miao Lei-Qiang
Hebei Academy of Building Research/Hebei Construction Engineering Quality Inspection Center Co., Ltd
Ying Zhi-Chao
CHN Energy Xinshuo Railway Co.,Ltd
DOI: https://doi.org/10.59429/pest.v6i4.8427
Keywords: Soft soil area; Diaphragm wall; Excavation of foundation pit; Surface settlement; Deformation characteristics
Abstract
In order to deeply explore the deformation mechanism and response mechanism of the retaining structure and the surrounding soil during the excavation process of the subway in the soft soil area of Suzhou, the construction project of the foundation pit of 8 metro stations in the area was selected, the foundation pit construction projects of 8 metro stations in the area was selected, and the evolution of underground continuous wall displacement and surface settlement was researched during excavation by arranging monitoring points. The results show that, the horizontal displacement curve in the depth direction of diaphragm wall is similar to the “bow” type during excavation, and the trend of “bow” type increases with the increase of excavation depth. The maximum horizontal displacement of the whole foundation pit is located at the midpoint of the long side, and it slowly moves down during excavation, and finally tends to be stable. The maximum horizontal displacement is about 0.6-0.8 of the excavation depth, and the maximum horizontal displacement is 0.1%-0.3% H. During the excavation of foundation pit, the surface settlement increases, and the overall deformation is “concave”, with the maximum value of 0.014%~0.326% of the excavation depth. The maximum horizontal wall displacement and maximum surface settlement are linearly distributed with the excavation depth of the foundation pit, and the maximum surface settlement is also positively correlated with the maximum horizontal wall displacement. The maximum horizontal displacement of the wall is 0.54~1.14 times of the maximum surface settlement. The influence of the horizontal wall insertion on the horizontal displacement of the maximum wall is significant, and the influence on the maximum surface settlement is not strong.
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