# A Comprehensive Review of Open Caisson Modeling Technology: Current Practices and Future Prospects
## 4 Advances in Computational Modeling Method
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Using COMSOL Multiphysics 5.3, in the excavation process, researchers [75] investigated rigidity and the settlement of the retaining wall deformation. They also conducted a comparative study with monitoring data collected from the excavation of a deep foundation pit in Shanghai. In order to investigate the impact of caisson structure dimensions on internal forces during the early sinking phase, [PERSON] et al. [76] created a 3D finite element method (FEM) model for soil-structure interaction. Furthermore, [PERSON] et al. [77] examined the impact of excavation on the sinking process of open caissons using numerical simulations based on FEM. [PERSON] et al. [78] used both physical model testing and numerical simulations in Plaxis \({}^{\text{3D}}\) to carry out an extensive investigation into the stress and deformation properties of anchor caisson foundations on sandy soils. A thorough examination of the mechanics behind the interaction between soil and structure was also included in the study. To more precisely model installation impacts, [PERSON] et al. [79] used sophisticated kinematic and continuous three-dimensional numerical approaches in a different investigation. These methods used the normal Lagrangian finite element (FE) approach and the large deformation finite element (LDFE) method, respectively, to integrate coupled interactions between the excavation and penetration processes. However, there were considerable time constraints and high computational expenses involved with both approaches. [PERSON] et al. [80] examined how deep excavations behaved close to flexible retaining walls, using the numerical tool Plaxis \({}^{\text{3D}}\) to evaluate how wall depth, excavation depth, and bending rigidity affected the retaining structures' mechanical reaction. Through numerical simulation using ABAQUS, [PERSON] et al. [81] analyzed the deformation characteristics and stress distribution of the caisson structure and surrounding soil. The reliability of the finite element model was validated by field monitoring data collected during the construction process that confirmed the strong correlation between simulation and monitoring data. [PERSON] et al. [82] also employed ABAQUS for simulation of laboratory-scale caisson models by changing base dimensions and embedment depth while holding other factors constant. The results revealed that lateral load resistance increased with both parameters. Using the numerical code Plaxis \({}^{\text{3D}}\), [PERSON] et al. [83] validated and extended the work of conducted by [PERSON] et al. (2019) which utilized a geotechnical centrifuge to estimate the depth-dependent distribution of soil movements induced throughout shaft  
Figure 11: Illustration of various types of numerical modeling approaches. construction. Numerical modeling is divided into three distinct calculation phases, as shown in Figure 12: (a) the phase of consolidation; (b) the phase of pre-excavation; and (c) the phase of excavation. During the first phase, the speswhite kaolin clay employed in the centrifuge test is over consolidated by applying uniform vertical load of up to 500 kPa, followed by the establishment of the gravity-induced stress profile. This step was performed to replicate the test conditions of CR500 carried out by [PERSON] et al. (2019) [70]. To avoid soil displacement during soil removal, the excavation support system which included a basement and a cylinder liner, was constructed in the physical model during the pre-excavation phase (Figure 12b). In order to simulate this phase, which was carried out quickly in tests, very rigid elements (whose dimensions are shown in Figure 12c) were activated, and the interior clay elements were removed. The largest displacements occur at the shaft wall. These displacements were primarily horizontal and were most significant at a depth of nearly 0.6 times the shaft diameter. Beyond a distance of 1.5 times the shaft diameter (which corresponds to 30 m), the displacements become negligible.