Abstract: Dome A in Antarctica is known as one of the best ground-based observatory sites in the world. Nevertheless, the particular geographical positioning of Dome A and the harsh local climatic conditions that prevail on the site necessitated the overcoming considerable transportation and construction challenges in building the tower on the 3000-m weak snow foundation. To ensure that the tower meets the requisite precision conditions for accurate telescope observations, it is essential that the structure of the tower be designed and optimized in accordance with the permissible value of the foundation bearing pressure. In this study, the strength of the snow foundation was gauged and analyzed through field experiment, and the root mean square value of foundation strength was determined as 1.962 MPa. Based on the analysis, the tower was designed and optimized to satisfy the requirements of a 2-m-class telescope, including the stiffness and the displacement of the top under a wind speed of 10 m·s⁻¹. After optimizing the tower structure, the maximum stress of the tower was 11.059 MPa, and the maximum stress on the snow foundation was only 0.133 MPa. Linear pressure was applied on the tower to simulate 10 m·s⁻¹ wind pressure, and the maximum displacement of the tower in that direction was 0.04 arcsec. The analyses revealed that the tower can meet the requirements of telescope observations, and inform the future use of the large-scale, high-precision telescopes and other large-scale equipment at Dome A.

Key words: snow foundation, steel structure tower, Antarctica, structure optimization