# Study of the Effect of Cutting Frozen Soils on the Supports of Above-Ground Trunk Pipelines
## 2 Materials and Methods  
The stability of above-ground trunk pipelines in permafrost soils poses a significant scientific and engineering challenge [25; 26; 27]. The supports and sections of the pipelines are subjected to varying loads depending on the depth and seasonality of ground freezing [28; 29; 30; 31; 32]. When selecting the supports, it is crucial to conduct thorough calculations, taking into account the soil type, temperature, and the support's ability to protect the pipeline from the impact of frost heave forces [33; 34; 35; 36; 37]. The design of the selected supports, particularly their size, and number, must meet the operational reliability requirements of above-ground trunk pipelines in conditions of continuous permafrost. The utilization of either pile or above-ground supports during construction must be substantiated through technical calculations. Pile foundations, being situated at depths beneath the ground, are prone to incurring defects, hence it is imperative to consider the soil characteristics when constructing these supports. The choice of the type of pipe support to be employed is directly influenced by the soil conditions. The stability of the design position for an above-ground pipeline is contingent upon the precise selection of support structures. In regions characterized by continuous permafrost, calculating the load exerted on the ground during the process of frost heave and determining the soil fracture stress is crucial in ensuring a dependable pipeline system [38; 39; 40]. Considering the existing structures of above-ground pipeline supports employed in permafrost soils, we have two types: fixed and movable supports. A fixed pipeline support is comprised of an additional pipe that is attached to the support surface, equipped with an angle adjustment device, and layered with thermal insulation. The main pipeline is installed on a sub-frame using a pre-manufactured pipe with the appropriate diameter [41]. On the other hand, a movable support consists of a pile, on which the pipeline base is secured through springs. To counteract the effects of frost heave, a measuring bar is utilized to fix the pile's movement. This type of support allows for the regulation of pipeline stresses, thereby increasing the pipeline's service life [42; 43; 44; 45]. However, the process of frost heave is not uniform, and as a result, these supports do not completely counteract the displacements caused by uneven frost heave forces. Additionally, the lack of a rigid connection between piles can result in pile deflection and the collapse of the supports. Therefore, the objectives of this study can be summarized as follows:  
1. The first step is to design a trunk pipeline support and pipeline support device, taking into account the advantages and disadvantages of existing proposed devices. 2. The second step is to perform numerical simulations to determine the spatial position of the pipeline support structure based on its fracture stress in frozen bloated soil, obtained from cutting the ground under a specified load on the support structure. 3. The third step is to conduct numerical simulations to estimate the loads that the proposed devices can withstand during their operation and the forces required to maintain the stability of the pipeline support structure. The numerical model will use the soil characteristics obtained from the results of the single-plane shear method on the freezing surface as input data. To validate the proposed pipeline support design and numerical modeling, an experimental study is necessary. This study will encompass the following components:  
* Single-plane shear tests along the freezing surface
* Uniaxial compression tests
* Triaxial compression tests
* Comparison of the obtained loads with the actual position of the pipeline support structure in space
* Calculation of the loads taken by the proposed devices during their operation and the forces needed to maintain a stable position of the pipeline support structure.