The support deformation risk of tunnel in red beds in
west Yunnan is high, and the construction speed of singletrack
small crosssection tunnel is low because of space
limitations. The geological conditions of red beds in west Yunnan include
purplishred mudstone and sandstone, developed joint
fissures, and moderate surrounding rock strength. Accordingly, a boomtype roadheader is adopted in a small crosssection
tunnel of the pilot heading of Xiuling tunnel on DaliRuili
railway in red beds in west Yunnan. An indepth study
is conducted on the feasibility and design parameters of the boomtype roadheader, and it is compared with the drill and blast method
in terms of cost, schedule, and quality. The results show the following for the
boomtype roadheader: (1) Suitability for tunnels with
moderate surrounding rock strength, broken surrounding rocks, developed joints
and cracks, and insufficient underground water. (2) It mildly disturbs the
surrounding rock of red beds in west Yunnan; thus, the system bolt for primary
support can be eliminated, and the steel frame spacing can be increased. (3)
Superiority to other methods in red beds in west Yunnan in terms of
construction speed, especially for Grade Ⅳ surrounding
rock, the boring speed can be improved by approximately 67%. (4) A higher early
capital investment than the drill and blast method, with excavation cost per
unit of approximately 4~5 times that of the drill and blast method.
ZHU Tingyu
,
WANG Huanlong
,
SONG Zhilai
,
LUO Maolin
,
ZHANG Lei
. Application of BoomType Roadheader in RedBed Tunnel in West Yunnan[J]. Tunnel Construction, 2021
, 41(3)
: 458
-466
.
DOI: 10.3973/j.issn.2096-4498.2021.03.015
