# Force Analysis of Circular Diaphragm Wall Based on Circular Cylindrical Shell Theory
###### Abstract  
In order to make up for the shortcomings of existing theory calculation methods for circular diaphragm walls, an alternative calculation method was developed with a clear concept based on the circular cylindrical shell theory and superposition principle in elasticity and named the circular cylindrical shell theory calculation method (CCSTCM). We took the north anchorage circular foundation pit of G3 Tongling Yangtze River Highway and Railway Bridge as an example and calculated and analyzed it by the proposed CCSTCM, finite element numerical simulation method (FENSM) and site monitoring. As a result, we obtained the radial displacement, circumferential stress and vertical bending moment of the circular diaphragm wall, and then summarized their regularities. By researching the results of the CCSTCM (TCR), the results of the FENSM (NSR) and the results of the site monitoring (SMR), the following conclusions could be drawn: the numerical calculation model established was reasonable; the variation trends of the data curves of the TCR were highly similar to those of the NSR and SMR; and the TCR were slightly larger than the NSR but slightly smaller than the SMR, and closer to the SMR in general. Finally, the proposed CCSTCM was proven to be correct and applicable and could be used in similar circular diaphragm wall projects. circular cylindrical shell theory; circular diaphragm wall; radial displacement; circumferential stress; vertical bending moment +
Footnote †: journal: Applied  
depths based on the analytical solution of internal force and displacement of circular diaphragm walls, and they discussed the pattern of the internal force, which changed with the body characteristics. [PERSON] et al. [17] established a functional to solve the displacement of the circular diaphragm wall based on the basic three-dimensional elasticity equations of cylindrical shells under the action of axial symmetric loads. They obtained the solution equations of the displacement function with the variational principle by introducing a single Fourier series as the trial function of displacement and put forward the Ritz method of the circular diaphragm wall after finally combining it with the boundary conditions. Some scholars use the numerical simulation method to research the mechanical response of only the circular foundation pit (e.g., [PERSON] et al., 2002; [PERSON] et al., 2008; [PERSON] and [PERSON], 2014; [PERSON] et al., 2017) [18; 19; 20; 21]. Some scholars adopt the site monitoring method to study the mechanical response of circular foundation pits and compare the field monitoring data with the existing research results or the theoretical calculation results, so as to provide reference experience and methods for the design and construction of circular ground walls (e.g., [PERSON] and [PERSON], 2013; [PERSON] and [PERSON], 2015; [PERSON] et al., 1999; [PERSON] et al., 2007; [PERSON] et al., 2019) [1; 22; 23; 24]. Some scholars utilize the site monitoring method and numerical simulation method at the same time to study the mechanical response of circular foundation pits, in order to compare and analyze the results from the two methods and make the conclusion more convincing (e.g., [PERSON] et al., 2023; [PERSON] et al., 2010; [PERSON], 2014; [PERSON] et al., 2015; [PERSON] et al. 2022) [25; 26; 27; 28]. However, it is difficult to set the material parameters of the model and the contacts between different parts accurately when the numerical simulation method is utilized, and the calculation cost is also very large. The parameters in the numerical calculation model are different for different construction sites, and therefore the parameters chosen should not be identical. The calculation process may not converge for these complex models. The site monitoring method has a hysteresis quality and the monitoring instruments and process are easily interfered with by external factors, such as temperature and mechanical load, which leads to some errors in the monitoring data obtained.