## 3 Numerical Simulations
### Simulation Scenarios  
The upper boundary is set as a free boundary to match the actual construction situation. The model is set to be vertical in the Z-axis direction, so the pile foundation model is set to be vertical in the XY-axis direction, the pipeline model is set parallel to the Y-axis, and the constraints are set in the XY-axis direction, and for the ground, the constraints are set in all three directions, and the nodes of the side boundaries are applicable to the free field conditions. The basic assumptions for modeling are as follows:  
* The pipelines are considered as equal diameter and equal wall thickness fittings, without considering the effect of the joint fittings, and the constitutive relations are considered as linear elastic materials;
* The soil is considered as a continuous linear elastomer in a porous medium and the Mohr-Coulomb damage criterion is applied (asymmetric solver is chosen);
* There are no contact surface units between the pipeline and the soil, and the two are considered to be in close contact with each other, without misalignment. The reason for using the FLAC3D finite element simulation software in this paper is that the software is specifically designed for geotechnical engineering. It has significant advantages in dealing with complex geological conditions and deformation issues. In regard to this area of expertise, it boasts high computational efficiency, especially when handling large geological models. The downside is that it is relatively difficult to master and its application in non-geotechnical fields is limited. The Griddle processed mesh model is imported into the FLAC3D software, the structural units are grouped and assigned values, the gravity conditions and contact surface parameter conditions are given and the environment is initialized, followed by adding monitoring information. Finally, additional pile foundation loads are simulated, and the number of operations is 80,000 [22]. In an attempt to minimize the impact on oil pipelines during pile foundation construction, this paper will explore the role of rotary drilling [23] (as shown in Figure 4) in controlling construction impacts. The rotary drilling method of piling is a method of piling that is carried out using a specialized rotary drilling rig, as shown in Figure 5. The rotary drilling rig, through its power system, drives the rotation of the rotary drill rod and drill bit. The drill bit is chosen based on the design requirements and its suitability for the local geological conditions, which includes single spiral, double spiral and flat drill bits. As it rotates, the drill bit slices and fractures the soil, which is then extracted from the ground via the drill rod's rotating and lifting actions. To prevent hole collapse, the rotary method additionally employs steel casings, thereby further minimizing the vibrational impact. In contrast with the traditional impact drilling method that employs a hammer to continuously strike the ground at frequencies of 20-50 Hz, the vibrational and stress impacts induced by rotary drilling rigs are considerably lower than those produced by impact drills. Nonetheless, the rotary method has its drawbacks, such as reduced efficiency in hard or stone-containing soil layers and potential damage to the drill bit. Furthermore, when considering construction costs, rotary drilling rigs tend to be more expensive. This method involves the use of mechanical equipment with a drill bit to excavate a pile hole through rotary drilling into the ground, in which a reinforcing cage is then placed, and