When slurry shield boring in high permeability
stratum, a large amount of slurry will be lost, which would cause difficult
formation of filter cake and even instability of excavation face. The addition
of coarseparticle materials can effectively improve the forming effect of
filter cake. In order to explore the influence of the addition of coarseparticle materials on the formation of filter cake, the vermiculite
with small density is selected as coarseparticle
material to carry out slurry permeation and membrane formation test in selfmade slurry permeation experiment equipment by changing its particle
size and content. The filtrate loss and filtercake
forming time are taken as evaluation indices to analyze the influence of
particle size and content on film forming effect, and a rational particle size
range of coarseparticle materials is proposed. The
experimental results show that: (1) The average formation pore diameter D0〖TX-〗 has reference significance for the addition of coarseparticle materials; the coarseparticle
materials with particle size of D0〖TX-〗/2~2D0〖TX-〗 is conducive to the formation of filtercake,
and with the increase of the particle size of coarseparticle
materials, the filmforming effect increases first and
then decreases. (2) When the content of coarseparticle
materials is between 20% and 40%, the larger the content of coarseparticle material, the better the film forming effect, but as the
content continues to increase (larger than 40%), the effect weakens. (3) When the content of coarseparticle materials is between 20% and 60%, the influence of the
particle size of coarseparticle materials is greater
than that of the content, and the increase of particle size will weaken the
gain effect brought by the content. (4) It is suggested that the selection of
the particle size of coarseparticle materials should
be mainly considered in practical engineering.
ZHANG Yujie
,
WANG Yuan
,
WANG Zhikui
,
FENG Di
,
LIU Sijin
,
XU Shujun
. Influence of Particle Size and Content of Coarseparticle
Materials on Filmforming
Effect of Slurry in High Permeability Formation[J]. Tunnel Construction, 2020
, 40(7)
: 1004
-1010
.
DOI: 10.3973/j.issn.2096-4498.2020.07.009
