The present invention disclose a tunnel profile element (10, 20A, 20) comprising a lightweight body constituted by foam glass panels sprayed with unbroken polyurea layer providing a fire resistant coating, and which is providing increased mechanical integrity of the tunnel profile element (10, 20A, 20).

The frost-resistant assembled initial support structure of the tunnel for supporting a surrounding rock includes a bearing layer, an elastic compressible structure and an inflatable airbag. A gap space is formed between the bearing layer and the surrounding rock, and the inflatable airbag and the elastic compressible structure are provided in the gap space; and the inflatable airbag after being inflated and the elastic compressible structure jointly fill up the gap space. A construction method includes providing the bearing layer in the tunnel, and forming the gap space between the bearing layer and the surrounding rock; providing the inflatable airbag and the elastic compressible structure in the gap space; and inflating the inflatable airbag and filling up the gap space with the inflatable airbag and the elastic compressible structure.

The frost-resistant assembled initial support structure of the tunnel for supporting a surrounding rock includes a bearing layer, an elastic compressible structure and an inflatable airbag. A gap space is formed between the bearing layer and the surrounding rock, and the inflatable airbag and the elastic compressible structure are provided in the gap space; and the inflatable airbag after being inflated and the elastic compressible structure jointly fill up the gap space. A construction method includes providing the bearing layer in the tunnel, and forming the gap space between the bearing layer and the surrounding rock; providing the inflatable airbag and the elastic compressible structure in the gap space; and inflating the inflatable airbag and filling up the gap space with the inflatable airbag and the elastic compressible structure.

A system for re-tensioning mine roof channels includes a roof plate having a first side, a second side positioned opposite the first side, and a sidewall extending therebetween, where the first side is configured to engage a surface of a mine roof, and where the sidewall defines a radially extending slot configured to receive a mine roof bolt. The system also includes a spacer having a first side, a second side positioned opposite the first side, and a sidewall extending therebetween, with the first side of the spacer configured to engage with the second side of the roof plate, and the sidewall defining a slot configured to receive a mine roof bolt, and a nut having a first side, a second side positioned opposite the first side, a sidewall therebetween, and a threaded opening, with the sidewall defining a radially extending slot configured to receive a mine roof bolt.

A method for calculating an earth pressure load on a tunnel includes the following steps: (1) taking interaction between external soil and a tunnel structure in an actual operation condition as an earth pressure load acting on the tunnel structure; (2) establishing a physical model for the tunnel structure; (3) designing, on the basis of the physical model for the tunnel structure, a plurality of structural loads in different operation conditions to obtain a plurality of different structural deformations; and (4) drawing an inference according Betti's theorem, and establishing a physical model for an original structure, such that a load on the original structure, namely an earth pressure load on the tunnel, can be directly calculated according to a load-deformation relationship of the physical model and deformation of the original structure. The above method can determine distribution and size of an actual earth pressure load on a tunnel.

A fractured roof 110 mining method entry-side anti-collapsed structure, one working face of the 110 mining method corresponds to one roadway but without retaining any coal pillar, the roadway retains an entry after the previous working face implements mining top-cutting pressure release, and a roof of the roadway is arch-shape, directional cutting is conducted on one side of the roadway, and the cutting angle is between 15-20 degrees. One working face corresponds to one roadway but without retaining any coal pillar when underground mining is conducted, which can save resources and improve recovery rate of mining. And, the roof of the roadway of the retained entry is arch-shaped, which can improve safety and ensure safety of the coal mining working face. In addition, a cutting angle is 15-20 degrees, which can effectively determine a roof caving direction after top-cutting and reduce affect to the retained entry.

A fractured roof 110 mining method entry-side anti-collapsed structure, one working face of the 110 mining method corresponds to one roadway but without retaining any coal pillar, the roadway retains an entry after the previous working face implements mining top-cutting pressure release, and a roof of the roadway is arch-shape, directional cutting is conducted on one side of the roadway, and the cutting angle is between 15-20 degrees. One working face corresponds to one roadway but without retaining any coal pillar when underground mining is conducted, which can save resources and improve recovery rate of mining. And, the roof of the roadway of the retained entry is arch-shaped, which can improve safety and ensure safety of the coal mining working face. In addition, a cutting angle is 15-20 degrees, which can effectively determine a roof caving direction after top-cutting and reduce affect to the retained entry.

A polymer mesh for skin control in hard rock mining conditions is provided. The polymer mesh is manufactured using a knitted or woven design that further includes one or more pairs of solid cut-resistant bands. The bands are positioned in pairs, each band in a pair having a width of at least about 2.5 and being generally parallel with the other band. The bands are spaced from one another at a distance of between about 1.5 and about 4 to create a reinforced aperture between the bands. One or more reinforcement bolts are installed within the aperture with the bands on opposing sides of each bolt buffering the edges of the steel plates associated with the bolts to prevent the plates from tearing the polymer mesh.

An infrared ray radiated from a region of a surface of an object to which a coating film (20) of a coating material is provided is detected by an infrared sensor (42). The coating film (20) includes a porous ceramic particle (22) and a binder (24), and the ceramic particle (22) includes a compound represented by a compositional formula of any of A.sub.aR.sub.bAl.sub.cO.sub.4, A.sub.aR.sub.bGa.sub.cO.sub.4, R.sub.x, Al.sub.yO.sub.12, and R.sub.xGa.sub.yO.sub.12. Here, A is one or more elements selected from a group consisting of Ca, Sr, and Ba, and R is one or more elements selected from a group consisting of rare earth elements. Also, a is equal to or greater than 0.9 and equal to or less than 1.1, b is equal to or greater than 0.9 and equal to or less than 1.1, c is equal to or greater than 0.9 and equal to or less than 1.1, x is equal to or greater than 2.9 and equal to or less than 3.1, and y is equal to or greater than 4.9 and equal to or less than 5.1. A porosity of the ceramic particle (22) is equal to or greater than 20% and equal to or less than 40%.

Disclosed are a fireproof material, a fireproof plate, a fireproof wall structure for tunnels and a construction method. The fireproof material includes the following components in weight ratio: 20-35 parts of aluminosilicate; 10-25 parts of calcium carbonate; 5-15 parts of magnesium oxide; 5-15 parts of silica; 20-40 parts of a binder; and 5-10 parts of a curing agent, the binder includes at least one of lithium silicate, potassium silicate and sodium silicate in combination with at least one of quartz sand and industrial sugar; and the curing agent is at least one of lithium oxide and magnesium oxide. In the preparation, firstly forming the mixture of aluminosilicate, magnesium oxide and silica into particles at 900 C.-1250 C., and then mixing the particles with calcium carbonate, the binder and the curing agent, and then pouring same into a forming mold and heating and pressing to form the fireproof material.