There is no relevant normative guidance for the
construction deformation control of the super-large-span flat underground cavern with a span greater than 50 m.
Therefore, the theoretical analysis and numerical simulation methods are used
to study the deformation control standards for large-span
caverns based on an actual project. To assess the stability of a large-span cavern, the surrounding rock strain is used as a rock mass
strength index. The settlement-span ratio is proposed
as the deformation control standard, and a correlation between cavern crown
settlement and rock
mass ultimate strain ε is proposed. Furthermore, the
deformation control standards applicable to each excavation stage are proposed,
and the classification management method for deformation control standards is
developed. The results show the following: (1) The allowable settlement
deformation of a large-span cavern is related to the
geometry of the cavern and the strength characteristics of surrounding rocks.
(2) Regarding the excavation scheme of partial excavation and reserved rock
pillar for the case study of the large-span cavern, the
deformation of the cavern mainly occurs in the large-span
cavern stage.
TAO Lianjin
,
HUANG Linkun
,
SHI Cheng
,
ZHANG Naijia
. Deformation Control Standards for Super-Large-Span Flat Underground Cavern[J]. Tunnel Construction, 2022
, 42(1)
: 9
-15
.
DOI: 10.3973/j.issn.2096-4498.2022.01.002
