TY - CONF AU - Yan, F. AU - Jing, X.P. AU - Lin, G.P. AU - Lu, A.Z. AU - Qiu, J. AU - Xing, Y.L. AU - Xu, G. AU - Xu, Z.G. AU - Zhang, Y.S. AU - Zhou, N.C. ED - Jaski, Yifei ED - Den Hartog, Patric ED - Jaje, Kelly ED - Schaa, Volker R.W. TI - The Design and Prototype Test for the Tunnel Foundation of High Energy Photon Source J2 - Proc. of MEDSI2020, Chicago, IL, USA, 24-29 July 2021 CY - Chicago, IL, USA T2 - Mechanical Engineering Design of Synchrotron Radiation Equipment and Instrumentation T3 - 11 LA - english AB - High Energy Photon Source (HEPS) is being built in China with challenging beam stability requirements. To fulfil the 25 nm ground motion restriction on the storage ring tunnel slab, two prototype slabs with different design schemes were constructed on the HEPS site. The first scheme adopted a 1 m reinforced concrete with replace-ment layer of a 1 m sand & stone underneath. The second scheme employed an extra 5 m grouting layer below the previously mentioned two layers. A series of tests had been carried out. The prototype slab with grouting layer is testified to have comparable vibration level with the bare ground, which is under 25 nm without traffic inside the HEPS campus, while the vibration level is amplified a lot on the other prototype slab. However, it is hard to make the grouting layer homogeneously under the kilo-metre-scale tunnel and besides the cost is unacceptable for 5 m grouting with such a large scale. The finalized design is fixed to be a 1 m reinforced concrete slab and 3 m replacement layer underneath using plain concrete. In this paper, the details of the prototype slab test results will be presented. PB - JACoW Publishing CP - Geneva, Switzerland SP - 141 EP - 144 KW - storage-ring KW - ground-motion KW - site KW - photon KW - emittance DA - 2021/10 PY - 2021 SN - 2673-5520 SN - 978-3-95450-229-5 DO - doi:10.18429/JACoW-MEDSI2020-TUPA12 UR - https://jacow.org/medsi2020/papers/tupa12.pdf ER -