To investigate the spatial variability of a sandlayer
groutingreinforced body based on the water bleeding
effect of cement slurry, experiments are conducted and the concept of
attenuation rate of sandgrouting performance as well
as the simplified equation of spatial distribution of attenuation rate is
proposed. Accordingly, stability analysis is performed on a tunnel′s groutingreinforced body undercrossing sand layer by using a finite element simulation method. The
crown settlement and water inflow of the tunnel are used as indices to evaluate
the tunnel stability and validate the necessity of considering the spatial
variability as well as the influence of the thickness of the reinforcement ring
and the watercement ratio of the cement slurry on the
tunnel stability. The results show that: (1) The watercement
ratio has a significant influence on the spatial distribution of the groutingreinforced body performance. When the watercement
ratio is ≥ 1.2, the performance of the groutingreinforced body is nonlinearly distributed spatially. In addition,
the compressive strength and deformation modulus at the bottom are
significantly higher than those at the top. Furthermore, the performance of the
groutingreinforced body is negatively correlated with
the height of the position. However, when the watercement
ratio is ≤1.0, the impact of the water bleeding effect
on the groutingreinforced body performance can be
ignored. (2) When the watercement ratio is ≥1.2, the crown settlement and water inflow of the tunnel obtained by
considering the spatial variability are both significantly larger than when
ignoring the spatial variability and considering the spatial variability of the
groutingreinforced body is of vital importance. (3)
Finally, the crown settlement and water inflow of the tunnel present nonlinear
characteristics with the change of the thickness of the groutingreinforced body ring. These two indices decrease with the increasing
thickness, and the decreasing rate significantly declines when the thickness of
the groutingreinforced body ring is extremely large;
this is unfavorable to economic consideration. (4) The increase in the watercement ratio is unfavorable to the control of the crown settlement
and water inflow of the tunnel. In addition, a lower watercement ratio should be chosen in the sand grouting engineering under
the premise of infiltration.
ZHANG Xiaoying
,
WENG Xianjie
,
YANG Pei
,
HUANG Changxin
,
FAN Wensheng
,
ZHANG Lianzhen
. Stability Analysis of Tunnel′s
SandLayer GroutingReinforced Body Considering Spatial Variability[J]. Tunnel Construction, 2023
, 43(6)
: 968
-979
.
DOI: 10.3973/j.issn.2096-4498.2023.06.007
