Analysis of the effect of underground storey supplement of multiple excavation methods under different foundation forms

Xiaotong He ¹ Zhibin Zhong ¹ Wei Li ² Yongli Zheng ² Shangheng Huang ¹ Baoxian Liu ³ Zhile Shu ^4* Tao Li ⁵ Jie Li ¹

• ¹ Chengdu Construction Third Construction Engineering Co, chengdu, China
• ² Chengdu Construction Group Co, chengdu, China
• ³ Chengdu Technological University, chengdu, China
• ⁴ School of Emergency Management, Xihua University, Chengdu, China
• ⁵ Chengdu University of Technology, Chengdu, Sichuan Province, China

With the accelerated process of urbanization, urban land is nearly saturated and the contradiction between people and land is increasing. The development of underground space has become an important measure for solving the three major crises of urban population, resources and environment, and is an important way for cities to take the road of sustainable development. Therefore, in this paper, the effects of excavation method and drag-and-replace on underground storey supplement of 3×3 frame structures under different foundations are investigated through model tests and combined with numerical simulations. The results show that the top slab removal in concentric square slab tray replacement is the most unfavourable working condition when the foundation is an independent foundation. In cruciform slab draglines, the uneven settlement of non-equal-span frame structures is greater than that of equal-span frame structures, and its final settlement is positively correlated with the span size. The methods of central shaft soil excavation and surround island type soil excavation are more effective in the application of free-standing foundations. In the strip foundation, the deformation of the strip foundation in the pile-wall type of buttress is mainly concentrated in the contact part with the buttress pile and the middle area of the frame. The ring-shaped reserved core soil body earth excavation method is more effective in the layered excavation in the buttressing of strip foundation piles. On this basis, corresponding measures are proposed, which can be used as certain reference for the project.