Phase 1 of
Guiyang rail transit line 3 involves the construction of a shield tunnel that
extends from the College of Agriculture Guizhou University station to the Huaxi
Park station, passing beneath the Huaxi river with complex geological
conditions. The abovewater geological exploration cannot
be implemented in this river because it is a water source protection area. In
this study, a specialized geological exploration probe capable of launching and
receiving lowfrequency of the electromagnetic wave
crosshole CT scans is introduced to overcome this
obstacle. This innovative probe reduces the operating frequency range from 8~64
MHz to 2~4 MHz while
enhancing the power of the spark seismic source in the acoustic wave crosshole CT launching probe from 2 500 J to 5 000 J. This adjustment
enables the execution of crosshole CT test at a
maximum distance of 54 m and the mutual verification between the
electromagnetic wave crosshole CT and the acoustic wave
crosshole CT results. By adopting comprehensive
exploration technology based on the use of ultralong
distanc electromagnetic wave crosshole CT and acoustic
wave crosshole CT technology, as well as mutual
verification of exploration holes, boreholes have been successfully implemented
in Huaxi river water source areas. The distribution of weak rock and soil
layers involved in the shield tunnel has been identified, providing reasonable
suggestions for the design and construction.
JIANG Yiping
,
CHEN Hongsheng
,
LI Luyao
,
ZHU Xiaohui
,
YANG Zhenggang
,
SONG Xiaoqing
,
CAO Zhendong
. Comprehensive Exploration Technology for Metro Shield
Tunnel Crossing Underneath Water Source in Karst Area[J]. Tunnel Construction, 2023
, 43(9)
: 1541
-1548
.
DOI: 10.3973/j.issn.2096-4498.2023.09.011
