Da Silva Castro, J. Ducourtieux, S. Fan, Z. Lepage, F. Nadji, A. Tavakoli, K. JACoW Publishing Geneva, Switzerland 2673-5520 978-3-95450-250-9 10.18429/JACoW-MEDSI2023-THPPP038 English 332-334 dipole storage-ring lattice synchrotron alignment Contribution to a conference proceedings 2024 2024-07 https://doi.org/10.18429/JACoW-MEDSI2023-THPPP038 https://jacow.org/medsi2023/papers/thppp038.pdf After two decades since its establishment, the SOLEIL Synchrotron facility needs to adapt to follow new scientific fields that have emerged since. After the Conceptual Design Report (CDR) phase for the facility Upgrade, the SOLEIL teams have been working for several months on the Technical Design Report (TDR). The ¿SOLEIL Upgrade¿ project is called ¿SOLEIL II¿ and is divided into several sub-projects. Among these sub-projects, one concerns storage ring Girders that will support all magnets of the new Lattice. These 86 Girders, each one supported by 2 plinths, must ensure an excellent degree of vibration stability. Before obtaining a final design for these Girders, a significant amount of study work has already been carried out (design, finite elements simulations, sub-assembly prototyping, dynamic measurements, tests, etc.). To validate the concepts, a fully equipped prototype girder was launched into manufacturing. In this contribution the preliminary studies and the ongoing investigations on SOLEIL II girder design will be presented.