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1. Force analysis: The foundation bolts of the skirt base are used to withstand tensile stresses when the tower resists overturning. The bolts located at the outermost positions in the direction of the wind and earthquakes experience the greatest forces, while the forces on the bolts in other locations decrease accordingly. Once the foot bolt under the greatest stress yields due to overload, the load carried by the other bolts will be redistributed, preventing the entire tower from collapsing immediately. Therefore, the foundation bolts of the skirt base are primarily designed to withstand tensile stresses caused by wind loads or seismic loads. For H/D>5, that is, for towers covered by the main text of NB/T 47041, the maximum tensile stress on the bolts shall be checked in accordance with standard 7.13.2. However, for towers with H/D ≤ 5, the shear stress of the foundation bolts shall be checked in accordance with Appendix E.4 of NB/T47041. For the foundation bolts of the saddle, shear and tensile stresses under seismic load conditions should be considered. When the horizontal seismic force resulting from seismic loads exceeds the static friction force between the base plate and the foundation, the shear stress on the foundation bolts caused by these seismic forces must be calculated; simultaneously, the tensile stress on the foundation bolts due to lateral overturning moments also needs to be calculated. Generally, the overturning moment caused by seismic loads is often not sufficient to pose a risk of toppling for horizontal containers. Therefore, the anchor bolts of the saddle are primarily designed to withstand the shear stress caused by seismic loads. The tensile and shear stresses of the foundation bolts shall be checked in accordance with 7.8.3 of NB/T47042. For the foot bolts of the ear mounts, tensile and shear stresses under wind load and seismic load conditions must be taken into account. When calculating the tensile stress on these foot bolts, the combined severe conditions resulting from equipment installation (at which time the internal components and insulation are not installed, resulting in the lowest weight of the equipment) and wind load should be considered. The highest tensile stress occurs on the windward side, where the bending moment is greatest; thus, the foot bolts experience the most stress, and there is a high risk that the ear mounts could topple over. Therefore, the foundation bolts of the ear seats are primarily designed to withstand tensile stresses caused by wind loads. Since the standards for ear-type supports do not include provisions for checking foot bolts, reference can be made to section 8.1 of \"Chemical Vessels\" in the Comprehensive Book on Chemical Equipment Design. The foundation bolts for the legs are not mentioned in the literature; reference can also be made to section 8.2 of \"Chemical Vessels\" in the Comprehensive Book on Chemical Equipment Design. The function of the foot bolts of the legs is to prevent the container from toppling under the action of horizontal forces and external moments; when the container is empty, the vertical load is minimal, making toppling most likely. The tensile stress of the anchor bolts under the combined action of the minimum vertical load, maximum horizontal force, and external torque should be checked. If the vertical load on the container itself is large enough, and there is no tensile stress in the anchor bolts (with a value of negative or zero), anchor bolts should still be installed for fixation. 2. Allowable stress of foundation bolts It is well known that the safety factor for the allowable stress of bolt materials used for pressure-sealing purposes, such as flanges, is much higher than that for foundation bolts; in other words, bolt materials used for pressure-sealing have a lower allowable stress. The biggest difference between the two is that if one of the flange bolts yields, it will be impossible to redistribute the load among the other bolts; instead, this will directly lead to the failure of the flange seal. In fact, all flange bolts share the load evenly; if one bolt yields, it means that all bolts have yielded as well. The allowable stress values for anchor bolts in standards such as GB 150, ASME, and EN vary; see the table below. The authors of the literature believe that, due to differences in materials and engineering experience across countries, there is no need to worry about which standard is conservative and which one is overly aggressive. The commonly used materials for foundation bolts are Q235 from GB/T 700 \"Carbon Structural Steel\" and Q345 from GB/T 1591 \"Low-Alloy High-Strength Steel\".