To investigate
the stress distribution characteristics of the compression zone formed by endanchored
prestressed anchor bolts in the surrounding rock of tunnels, the response of
the surrounding rock under the action of a single prestressed bolt is analyzed
using laboratory tests and numerical simulations. The ABAQUS software is used
to explore the radial stress distribution patterns in the surrounding rock of a
horseshoeshaped tunnel anchored by bolt groups with
various prestresses, lengths, and bolt spacings. The results reveal the
following: (1) The compression zone formed by endanchored
prestressed bolts primarily concentrates in the unanchored section of the
surrounding rock. By contrast, the anchored section experiences a tensile
stress concentration due to the shearing effect of the anchors. (2) With
increasing anchorage length, the compression zone noticeably decreases; when
full anchorage is conducted, a compression zone is formed only within a very
small range near the bearing plate, limiting the diffusion effect of prestress.
(3) The thickness of the continuous compression zone formed by a group of
prestressed anchors considerably increases as the bolt spacing decreases. However,
it shows less variation with increasing anchor length. (4) A continuous
compression zone is more likely to form by short anchors within their range,
whereas it cannot be formed by long anchors within their range, thereby
limiting the effectiveness of stress diffusion.
ZI Xin
,
WANG Bo
,
YU Wei
,
ZHONG Guanfeng
. Distribution Characteristics of Prestressed Field of
EndAnchored Bolts[J]. Tunnel Construction, 2023
, 43(10)
: 1750
-1759
.
DOI: 10.3973/j.issn.2096-4498.2023.10.011
