## 1 Introduction  
The distribution of buried pipeline networks in cities is very complex, and includes a large-scale lifeline system. The excavation of a foundation pit may lead to a large deformation of adjacent pipelines, and, in several cases, even lead to water and gas leakage. Once this happens, the urban lifeline will be under serious threat, causing a great loss of lives and property. Therefore, research on the settlement deformation of nearby buried pipelines affected by deep excavation is an important work with regard to foundation pits [1, 2, 3]. So far, the analysis methods for the settlement deformation of buried pipelines mainly include the theoretical analysis method, numerical simulation method, model experiment method, and field test method [4]. However, in the past, because very limited data regarding excavation-induced buried pipeline deformation are available for analysis, as a consequence, the study of the settlement displacement of buried pipelines still relies heavily on theoretical analysis and numerical simulation. For the past several decades, several researchers have tried to establish a strict mechanical model for obtaining an analytical solution to buried pipeline deformation in order to evaluate the safety of pipelines [2, 3, 4, 5]. At present, theoretical analysis methods primarily rely on two mechanical models, one of which is the Winkler model, and the other is the Pasternak model [6]. [PERSON] [7] proposeda theoretical formula forecasting the ground surface caused by tunnel excavation based on a larger number of field test data, and provided a reference for the deformation theory of buried pipelines. After, under the framework of the Winkler model, some analytical solutions for buried pipeline deformation based on the different boundary conditions and load conditions were researched by different scholars, such as [PERSON] et al., [PERSON] et al., and [PERSON] et al., who have been developing simplified calculated models and analyzing different influence factors on settlement displacement [3; 8; 9]. The Winkler model is mostly used in the above research, but this model ignores the shear stress in the soil and cannot describe the continuity of soil deformation very well. To overcome these shortcomings, in recent years, [PERSON] et al., [PERSON] et al., and [PERSON] et al. used the Pasternak model to derive the calculated mechanics model of pipe-soil separation, and also proposed a new analysis method for buried pipeline deformation by excavation [10; 11; 12]. [PERSON] et al. [13] also proposed an analytical solution for the response of two neighboring pipelines to tunneling based on the Pasternak model, which not only spreads the analysis method to a wider extent, but also enriches the evaluation methods for pipeline safety. In the above research works, a prominent problem is the lack of empirical analysis. These methods mainly focus on theoretical analysis, less on empirical analysis, and the empirical analysis of the data is also not enough. As a result, the accuracy of these methods is limited, which also limits their popularization and application. Another common research method in buried pipeline settlement deformation is numerical simulation, including the finite element method, finite difference method, and discrete element method. Previously, [PERSON] et al. [14] proposed a principle of horizontal movement caused by shallow buried pipelines during excavation and backfilling, and established an elasticity mechanical model to analyze the mechanical state of buried pipelines. [PERSON] et al. [15] used the finite element method to investigate the settlements of nearby buildings and buried pipelines induced by excavation, focusing particularly on the influence factors of settlement. [PERSON] et al. [16] studied the mechanical behavior analysis of a buried pipeline underground overload, using a general-purpose finite element programmer. [PERSON] et al.