Three kinds of excavation blind area pretreatment
methods are proposed to improve the applicability of the various cutterheads
driven using central shaft, eccentric shaft swing, and planetary wheel of the
existing noncircular tunnel boring machine(TBM) in composite strata. These
methods include smalldiameter rock drilling combined
with soil backfilling, hard rock pipe jacking combined with pipe joint soil
backfilling, and blind hole host back combined with soil backfilling. These
methods are developed based on the geological conditions of rock strength,
range, and length in the noncircular tunnel and are
successfully applied in the exit and entrance sections of a metro project.
Moreover, a synchronous excavation system for multirotating
cutterheadintegrated excavation blind area treatment
devices is analyzed to achieve successful onetime
excavation of noncircular TBM in composite strata. To
further improve the excavation process, two kinds of excavation blind area
treatment devices are designed and validated using the finite element method.
These devices include the swing milling head and milling drum and are applied
to a rectangular pipe jacking project in composite strata. Finally, excavation
data is analyzed, and the driving parameters of the swing milling head and
milling drum equipment are obtained. This new solution for the construction of
noncircular tunnels in composite strata has the
potential to greatly improve the efficiency and safety of tunnel excavation
projects.
LIU Jiao
,
JIA Lianhui
,
FAN Lei
,
DONG Yanping
,
YUAN Zheng
.
Key Technologies of Excavation Blind Area Treatment
for NonCircular Tunnel
Boring Machine in Composite Strata
[J]. Tunnel Construction, 2023
, 43(2)
: 345
-353
.
DOI: 10.3973/j.issn.2096-4498.2023.02.016
