To ensure rapid and safe railway tunnel crossing coalrich
stratum without gas outburst, the outburst prevention specification of 〖WT５《TNR#I》〗Technical
Code for Railway Tunnel with Gas〖WT５《TNR》〗 (2019) and the technological
characteristics of rotary jet grouting pile are investigated. In addition, a
new construction method for rapid outburst prevention of rotary jet grouting
pile is proposed based on the blocking and releasing method. First, the
proposed method is studied with respect to the advance comprehensive gas
outburst prevention and tunnel face gas outburst prevention. Second, a case
study is performed on the gas outburst prevention of Oujiawan highgas tunnel on XuyongBijie railway, and a
multischeme design of the pile diameter and the number
of gas release holes is developed for the proposed method. Finally, the
proposed method is compared with the traditional gas drainage method from the
perspectives of construction cost and time. The results reveal the following:
(1) The highstrength jet grouting pile reinforces the
geological structure of the coal seam on the contour lines of the gas outburst
prevention area, isolates the coal outside the enclosure pile, and cuts off the
way of coal and gas outburst extending the pile. (2) The gas outburst
prevention range can be significantly reduced by releasing gas through
geological drilling holes inside the enclosure pile. (3) Compared with the
traditional gas outburst prevention methods, the number of releasing holes
inside the enclosure pile and the total length of geological drilling holes of
the recommended method are reduced by 4/5~ 2/3 and 13%~22%, respectively, and
the construction cost is increased by only 1.7% ~10.5%, which is safe and
efficient.
YANG Yurong
,
HUANG Hongting
,
YAN Qixiang
,
LI Ruilin
,
TANG Junlin
. Outburst Preventive Construction of Rotary Jet
Grouting Enclosure Pile for Railway Tunnel Crossing Gas and CoalRich Strata[J]. Tunnel Construction, 2022
, 42(7)
: 1300
-1307
.
DOI: 10.3973/j.issn.2096-4498.2022.07.018
