In this study, a case study
is conducted on the Chongqing-Kunming
high-speed railway crossing underneath the Changshui
airport, and the automatically monitored data in real-time
of the airport surface displacement are used to analyze the lateral and
longitudinal settlement patterns of the surface caused by the construction of
the cantilever boring machine method. The results show the following: (1) The
overall temporal evolution of surface settlement manifests in three distinct
phases: gradual fluctuation, accelerated development, and stabilization. The
rapid development of surface settlement concentrates in the interval after the
upper bench passes through the monitoring point and before the lower bench
passes through the monitoring point. (2) The modified Peck′s formula is more effective in characterizing the distribution of
lateral surface settlement caused by the cantilever boring machine
construction. The final settlement of the surface is 7.3 to 25.0 mm, the strata
loss ratio is in the range of 0.16% to 1.01%, the lateral impact range is 4.0D to 5.3D (D is the span of the tunnel excavation),
with the most unfavorable area concentrated in the range of 1.3D on either
side of the tunnel, where requires particular monitoring. (3) The unfavorable
conditions, including the diagonal intersection of the upper existing airport
cargo access road, hidden cavities, and rock production, result in a shift in
the distribution of surface settlement troughs in some sections to the right.
(4) A notable discrepancy is observed in the extent of strata loss and surface
settlement attributable to the various excavation phases, the strata loss rate
associated with the excavation stages of upper and lower benches, as well as
the invert arch, exhibits a descending order, with the respective proportions
accounting for 81.3%, 17.0%, and 1.7% of the total settlement. (5) The
longitudinal settlement pattern demonstrates that the longitudinal final
settlement curve of the surface exhibits a pattern of increase initially and
then decrease. The longitudinal influence of surface settlement resulting from
tunnel excavation ranges from 3.2D to6.0D, with a
corresponding variation of 1.3D to 2.3D ahead of the excavation and 1.4D to 3.9D behind.
FENG Shangze
,
DING Zude
,
GUO Yongfa
,
DING Wenyun
,
LIU Zhengchu
,
WANG Changyu
. Surface Settlement Pattern
Caused by Excavation of a Cantilever Boring
Machine Under an Airport[J]. Tunnel Construction, 2024
, 44(S2)
: 319
-328
.
DOI: 10.3973/j.issn.2096-4498.2024.S2.031
