A method is to excavate main roadways in the upper and lower parts separately and an inclined intake roadway in the central part of the mine and pre-excavate an inclined seam roadway as the first mining face at the boundary on one side of the mine. Staring from the mine boundary, the retreating mining shall be carried out on the first mining face strip by strip with belt conveyors arranged in the upper main roadway and assistant conveying devices in the lower main roadway and inclined intake roadway; the open-off cut of the first mining face shall be built on the underside of the upper main roadway at the boundary of the mine to carry out the downward inclined mining on the strike and along the inclination.

An underwater traffic tunnel that includes a body immersed in water, a connector, and a ventilation system. The body comprises a first cavity for providing a passage space and a second cavity located below the first cavity. The second cavity is in communication with water; the connector connects the body and the water bottom and is used to resist buoyancy, and the ventilation system is in communication with the first cavity and extends above the water surface; the body of the present invention is safely immersed in water, and a vessel can navigate freely above the body; the second cavity is in communication with water and is not easy to be overturned by seawater; the connector resists buoyancy; the ventilation system can prevent damage by external forces through deformation and movement, and an escape system can be activated in emergency situations.

A conduit segment casting mold system includes at least one inner mold; at least one outer mold configured as at least two outer mold sections of opposed shapes that define a cavity between the at least two outer mold sections that is sized to at least partially enclose the at least one inner mold, each of the at least two outer mold sections including a respective mating surface, each of the at least two outer mold sections including at least one hole sized to receive a cable, and the at least one hole of a particular one of the at least two outer mold sections is aligned with the at least one hole of another particular one of the at least two outer mold sections when the mating surfaces of the particular one and the another particular one of the at least two outer mold sections are mated; and a mold base.

Provided is a blower installed at a manhole opening, with which it is possible to facilitate an entry or an exit of a worker or an import or an export of an article. The present invention provides a ventilation system comprising a frame and a single or a plurality of airflow generation means arranged at the frame, a direction of an airflow is adjusted so that the airflow generated from the airflow generation means flows along with a virtual axis penetrating a virtual surface which the frame is regarded as to periphery, and the airflow flows while swallowing up the surrounding air of the virtual axis, and an air volume more than two times of total fluid volume of the airflow is generated.

Provided is a blower installed at a manhole opening, with which it is possible to facilitate an entry or an exit of a worker or an import or an export of an article. The present invention provides a ventilation system comprising a frame and a single or a plurality of airflow generation means arranged at the frame, a direction of an airflow is adjusted so that the airflow generated from the airflow generation means flows along with a virtual axis penetrating a virtual surface which the frame is regarded as to periphery, and the airflow flows while swallowing up the surrounding air of the virtual axis, and an air volume more than two times of total fluid volume of the airflow is generated.

A conduit segment casting mold system includes at least one inner mold; at least one outer mold configured as at least two outer mold sections of opposed shapes that define a cavity between the at least two outer mold sections that is sized to at least partially enclose the at least one inner mold, each of the at least two outer mold sections including a respective mating surface, each of the at least two outer mold sections including at least one hole sized to receive a cable, and the at least one hole of a particular one of the at least two outer mold sections is aligned with the at least one hole of another particular one of the at least two outer mold sections when the mating surfaces of the particular one and the another particular one of the at least two outer mold sections are mated; and a mold base.

A split air cabin ventilation system for construction of tunnel inclined shafts, including a first air cabin and a second air cabin which are both in a hollow closed structure with an air inlet end and an air outlet end respectively at both sides. The two air outlet ends are arranged away from each other. An end of the split air cabin is provided with an air inlet, and the other end is provided with an air outlet. The air inlet is connected to an air source, and the air outlet is connected to the air inlet ends of the first and second air cabins, respectively. The air inlet end of the first air cabin is connected to another air source.

A ventilation system for an underground mine includes a blowing curtain, a passive regulator in a shape of an airfoil and an airflow ventilation source. The passive regulator is positioned in the air path adjacent a discharge end of the blowing curtain.

A control system for use during a tunnel fire includes: measurement means 100.sub.1 to 100.sub.n installed in each of a plurality of management sections assigned in a tunnel, and for measuring one or both of a gas concentration and a smoke concentration in the management section using a light signal; and control means 102 for identifying a management section which includes a fire point, and controlling blowing means 101 capable of changing an air volume, based on one or both of the gas concentration and the smoke concentration measured by one or more measurement means installed in one or more management sections located downstream of the identified management section.

A control system for use during a tunnel fire includes: measurement means 100.sub.1 to 100.sub.n installed in each of a plurality of management sections assigned in a tunnel, and for measuring one or both of a gas concentration and a smoke concentration in the management section using a light signal; and control means 102 for identifying a management section which includes a fire point, and controlling blowing means 101 capable of changing an air volume, based on one or both of the gas concentration and the smoke concentration measured by one or more measurement means installed in one or more management sections located downstream of the identified management section.