The invention relates to a similar material for simulating
expansive soil tunnel surrounding rock in a
model test and a preparation method thereof. According to the similar material, clay and
bentonite, which pass through a 4.75mm
sieve, serve as main raw materials, the materials are proportioned by a weight part ratio according to different expansion levels, weak
expansive soil is prepared from 100 parts of clay and not less than 2 and less than 10 parts of
bentonite, medium
expansive soil is prepared from 100 parts of clay and not less than 10 and less than 22 parts of
bentonite, strong expansive soil is prepared from 100 parts of clay and not less than 22 and less than 30 parts of bentonite, water is added to the
mixed materials, and compaction molding is carried out so as to prepare the similar material. According to the similar material and the preparation method, expansive soil with different
free expansion ratios can be prepared so as to carry out the
model test, so that the mechanical and deformation characteristics of the expansive soil surrounding rock can be met, the raw materials can be obtained locally, the operation is simple and convenient, and the
resource utilization ratio is increased.