US 2025/0164371 A1 · WATER FILLING AND DRAINAGE TEST METHOD AND DEVICE FOR PREFABRICATED CRACK-CONTAINING REINFORCED CONCRETE LINING PRESSURE TUNNEL

Abstract

Disclosed in the present invention is a water filling and drainage test device and method for a prefabricated crack-containing reinforced concrete lining pressure tunnel. The test device comprises a cylindrical barrel, a reinforced concrete lining containing prefabricated cracks, surrounding rock, geotechnical cloth, a front flange, a rear flange, and a monitoring instrument. The surrounding rock is proximate to an inner wall of the cylindrical barrel, and the reinforced concrete lining containing the prefabricated cracks is inside of the surrounding rock; and the front flange and the rear flange are fixed at two ends of the cylindrical barrel. The test device is used for carrying out a water filling and drainage test on the pressure tunnel, and observing the change in the width of the prefabricated cracks and the conditions of the pressure tunnel.

A water filling and drainage test device for reinforced concrete lining pressure tunnel with prefabricated crack, comprising:

a cylindrical body, a reinforced concrete lining with a prefabricated crack, a surrounding rock, a geotextile, a front flange, a rear flange, and monitoring instruments;
wherein the cylindrical body is a rigid metal cylinder, and a wall thickness dthreshold of the cylindrical body satisfies the following requirements:
d
t
⁢
h
⁢
r
⁢
e
⁢
s
⁢
h
⁢
o
⁢
l
⁢
d
≥
1.05
d
(
1
)
wherein dthreshold and d are a design value and a standard value (m) of the wall thickness of the cylindrical body, respectively, and dis determined by the following formula:
d
=
r
s
(
1
-
σ
s
t
-
p
t
σ
s
t
+
p
t
)
(
2
)
wherein rs is an outer diameter (unit:
m) of the cylindrical body, σst is a ultimate tensile strength (unit:
MPa) of steel used for the cylindrical body, and Pt is a design head of a pressure tunnel (unit:
MPa);
wherein the surrounding rock abuts against an inner wall of the cylindrical body, the reinforced concrete lining with prefabricated crack is provided on an inner side of the surrounding rock, and the front flange and the rear flange are respectively fixed to both ends of the cylindrical body to form a closed internal water loading cavity capable of being filled and drained;
wherein the monitoring instruments include a crack gauge configured to monitor a change in a width of the crack during the filling and draining process, a reinforcement meter, a strain gauge, an osmometer, and a soil pressure gauge that are each configured to monitor an operation condition in the pressure tunnel, and the monitoring instruments are provided in an inner wall of the crack, in the reinforced concrete lining, and between the reinforced concrete lining and the surrounding rock;
wherein the geotextile is laid between the surrounding rock and the reinforced concrete lining, and a thickness of the geotextile is configured such that a circumferential stress σθ and a circumferential strain εθ of the reinforced concrete lining with the prefabricated crack satisfy the following relationship:
σ
θ
⁢
1
<
σ
θ
<
σ
θ
⁢
2
(
3
)
ε
θ
⁢
1
<
ε
θ
<
ε
θ
⁢
2
(
4
)
wherein σθ1 and εθ1 are respectively a circumferential stress and a circumferential strain of an outer wall of the reinforced concrete lining with the prefabricated crack under rigid constraint;
wherein σθ2 and εθ2 are respectively a circumferential stress and a circumferential strain of the lining when the outer wall of the reinforced concrete lining with the prefabricated crack is a free boundary;
wherein σθ1, εθ1, σθ2 and εθ2 are respectively determined with the following formulas:
σ
θ
⁢
1
=
1
-
2
⁢
υ
r
2
-
1
b
2
1
-
2
⁢
υ
a
2
+
1
b
2
⁢
p
crack
(
5
)
ε
θ
⁢
1
=
(
1
-
2
⁢
υ
)
⁢
(
1
+
υ
)
E
⁢
1
r
2
-
1
b
2
1
-
2
⁢
υ
a
2
+
1
b
2
⁢
p
crack
(
6
)
σ
θ
⁢
2
=
a
2
⁢
b
2
⁢
p
crack
b
2
-
a
2
⁢
1
r
2
+
a
2
⁢
p
crack
b
2
-
a
(
7
)
ε
θ
⁢
2
=
1
E
[
(
1
+
υ
)
⁢
a
2
⁢
b
2
⁢
p
crack
b
2
-
a
2
⁢
1
r
2
+
(
1
-
υ
)
⁢
a
2
⁢
p
crack
b
2
-
a
2
]
(
8
)
wherein pcrack is an estimated value of internal water pressure (unit:
MPa) when a pressure tunnel lining cracks;
a is an inner diameter of the reinforced concrete lining with the prefabricated crack, b is an outer diameter of the reinforced concrete lining with the prefabricated crack, and r is a distance from any point in the reinforced concrete lining with the prefabricated crack to a center thereof,
v is a Poisson's ratio of a material of the reinforced concrete lining with the prefabricated crack;
and
E is an elastic modulus of the material of the reinforced concrete lining with prefabricated crack.

257 more elements

Water filling and drainage test method and device for prefabricated crack-containing reinforced concrete lining pressure tunnel

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Water filling and drainage test method and device for prefabricated crack-containing reinforced concrete lining pressure tunnel

Life of this patent

Abstract

Claims7