Engineered mine seal
View Patent ↗A method for designing and fabricating a mine seal includes determining an initial thickness for a mine seal based on a predetermined underground opening, developing and solving a numerical model for response of the mine seal upon application of a blasting pressure, and determining whether the mine seal meets predetermined design criteria. A mine seal having a minimum seal thickness may be fabricated after determining the mine seal meets the predetermined design criteria.
1. A method for designing and fabricating a mine seal, the method comprising:
determining an initial thickness for a mine seal based on a predetermined underground opening dimension;
developing a numerical model for response of the mine seal upon application of a blasting pressure;
solving the numerical model using a processor;
simulating the response of the mine seal to the blasting pressure using the processor;
determining yielding condition and safety factor of the mine seal based on material failure criteria;
determining whether the mine seal meets predetermined design criteria utilizing the numerical model, wherein the predetermined design criteria comprises:
absence of tensile failure at a center of an inby side of the mine seal;
minimum average Mohr-Coulomb shear safety factor along a middle line of a larger span interface of 1.5;
minimum average interface plug shear safety factor of 1.5; and
minimum seal thickness of about 50% or greater than a short span of the underground opening dimension;
increasing the initial thickness of the mine seal in the numerical model and solving the numerical model until a minimum seal thickness meeting the predetermined design criteria is determined.
2. The method of claim 1 , further comprising:
determining constitutive behavior of material used for the mine seal based on laboratory test results.
3. The method of claim 1 , wherein the material failure criteria is established using Mohr-Coulomb strength criterion and tensile strength criterion.
4. The method of claim 1 , further comprising:
fabricating a mine seal having a minimum seal thickness that was determined to meet the predetermined design criteria.
5. The method of claim 1 , wherein the initial thickness for the mine seal is calculated by the equation
T
ini
=
P
×
D
L
F
×
W
×
H
×
S
F
2
(
W
+
H
)
×
τ
shear
wherein P is a blast pressure (psi), DLF a dynamic load factor, W is a width of the underground opening, H is a height of the underground opening, SF is a safety factor of interface between the mine seal and surrounding rock strata, and τ shear is a shear strength of the mine seal against the surrounding rock strata.
6. A computer-implemented method for designing and fabricating a mine seal, the method comprising:
determining an initial thickness for a mine seal based on a predetermined underground opening dimension;
developing a numerical model for response of the mine seal upon application of a blasting pressure;
solving the numerical model using a processor; and
determining whether the mine seal meets predetermined design criteria utilizing the numerical model, wherein the predetermined design criteria comprises:
absence of tensile failure at a center of an inby side of the mine seal;
minimum average Mohr-Coulomb safety factor along a middle line of a larger span interface of 1.5;
minimum average interface plug shear safety factor of 1.5; and
minimum seal thickness of about 50% or greater than a short span of the underground opening, and
wherein solving the numerical model using the processor comprises:
calculating stress-strain to detect material yielding;
identifying a minimum seal thickness meeting the predetermined design criteria;
changing an entry height of the predetermined underground opening dimension; and
changing an entry width of the predetermined underground opening dimension.
7. The method of claim 6 , further comprising:
increasing the initial thickness of the mine seal in the numerical model and solving the numerical model until a minimum seal thickness meeting the predetermined design criteria is determined.
8. The method of claim 6 , further comprising:
fabricating a mine seal having a minimum seal thickness that was determined to meet the predetermined design criteria.
9. The method of claim 7 , further comprising:
fabricating a mine seal having the minimum seal thickness that was determined to meet the predetermined design criteria.
10. The method of claim 6 , wherein the initial thickness for the mine seal is calculated by the equation
T
ini
=
P
×
D
L
F
×
W
×
H
×
S
F
2
(
W
+
H
)
×
τ
shear
wherein P is a blast pressure (psi), DLF is a dynamic load factor, W is a width of the underground opening, H is a height of the underground opening, SF is a safety factor of interface between the mine seal and surrounding rock strata, and τ shear is a shear strength of the mine seal against the surrounding rock strata.