## 1 Introduction  
In recent years, with the rapid development of cities, underground space has been developed and utilized, and the construction of tunnels has greatly alleviated urban traffic congestion on the ground. Due to the imperfection of space planning in the early stage of underground space development, tunnel construction often needs to cross existing pipelines. The construction of a new shield tunnel will disturb the surrounding soil layer and endanger existing buildings (structures), which also complicates the balance between the new shield tunnel construction, the existing buildings (structures) and the subsurface environment. In particular, with the vigorous development of super-large-diameter shields in recent years, the impact of super-large-diameter shields on existing buildings (structures) and the corresponding accident prevention technology need to be studied urgently. Shield tunneling may lead to stratum loss and changes in the internal forces of the rock and soil, resulting in the deformation and displacement of the rock, soil ([PERSON] [1], [PERSON] [2], [PERSON] et al. [3], [PERSON] et al. [4]) and surrounding buildings (structures). Therefore, many researchers have studied the influence of rock and soil mass ([PERSON] et al. [5], [PERSON] et al. [6], [PERSON] et al. [7]), surface ([PERSON] et al. [8], [PERSON] et al. [9], [PERSON] et al. [10], [PERSON] et al. [11], [PERSON] et al. [12], [PERSON] et al. [13]) and adjacent building ([PERSON] et al. [14], [PERSON] et al. [15], [PERSON] et al. [16], [PERSON] et al. [17], [PERSON] et al. [18]) deformation on subsurface construction ([PERSON] et al. [19], [PERSON] et al. [20]), based on the study of the mechanical properties of rock and soil mass ([PERSON] et al. [21; 22]). Similarly, when a shield tunnel passes existing tunnels, railways, and pipelines, the displacement of the surrounding rock and soil will adversely affect the existing buildings (structures). Therefore, on the basis of studying the influence of shield construction on the surrounding rock and soil, researchers have mainly used physical model experiments and finite element analysis to analyze the spacing effect of new tunnels under existing tunnels ([PERSON] et al. [23], [PERSON] et al. [24], [PERSON] et al. [25]) and the influence of shield construction on the displacement, stress ([PERSON] et al. [26], [PERSON] et al. [27], [PERSON] et al. [28], [PERSON] et al. [29]) and deformation of existing tunnels ([PERSON] et al. [30], [PERSON] et al. [31], [PERSON] et al. [32]). With the rapid development of urbanization and the surge in demand for rail transportation, super-large-diameter shields are the mainstream direction of urban underground space development at present; most of the current research focuses on small- and medium-diameter shields (<6 m), but super-large-diameter shield research is becoming more common. In the process of shield construction, causing disturbance to the surrounding rock and soil mass is inevitable, leading to the risk of the destruction of the original underground structures. To ensure the safety of constructing a new tunnel and the operation of the existing structures, it is necessary to implement measures for accident prevention and control. At present, the commonly used prevention and control measures are grouting reinforcement, isolation piles and diaphragm walls. According to the partitioning effect and economic considerations of these prevention and control measures, isolation piles are often selected for partitioning. During foundation pit excavation and shield construction, isolation piles are often used to protect the surface ([PERSON] et al. [33], [PERSON] et al. [34]), adjacent buildings ([PERSON] et al. [35; 36]) and pile foundations ([PERSON] et al. [37]). In recent years, isolation piles have gradually been adopted in shield construction to protect existing subway lines ([PERSON] et al. [38], [PERSON] et al. [39]), but there are relatively few studies on this practice.