A box type duct with circumferential obtuse angle connection. Unit plates respectively located on the upper, lower and two side surfaces are spliced in the circumferential direction to form a unit pipe section, and the unit pipe sections are spliced in the axial direction to form a box type duct; wherein the unit plate is an arc-shaped corrugated plate arched to the outside of the box type duct, and the adjacent unit plates form an obtuse angle of circumferential connection. The cross section of the duct is in an approximately rectangular box shape, so the utilization ratio of clearance of the duct is high; the unit plate adopts an arc-shaped structure, and by utilizing the pipe-soil joint stressing principle, the strength and bearing capacity of the overall structure are maximized; and the box type duct adopts flat flange or angle steel flange connection in the circumferential direction.

A box type duct with circumferential obtuse angle connection. Unit plates respectively located on the upper, lower and two side surfaces are spliced in the circumferential direction to form a unit pipe section, and the unit pipe sections are spliced in the axial direction to form a box type duct; wherein the unit plate is an arc-shaped corrugated plate arched to the outside of the box type duct, and the adjacent unit plates form an obtuse angle of circumferential connection. The cross section of the duct is in an approximately rectangular box shape, so the utilization ratio of clearance of the duct is high; the unit plate adopts an arc-shaped structure, and by utilizing the pipe-soil joint stressing principle, the strength and bearing capacity of the overall structure are maximized; and the box type duct adopts flat flange or angle steel flange connection in the circumferential direction.

A fire resistant tunnel expansion joint system for installation between substrates of a tunnel. The system includes a fire protection barrier applied at a predetermined thickness to the substrates and a fire resistant tunnel expansion joint. The tunnel expansion joint includes a core and a fire retardant infused into the core. The core is configured to define a profile to facilitate the compression of the tunnel expansion joint when installed between the substrates. The fire protection barrier and the fire resistant tunnel expansion joint are each capable of withstanding exposure to a temperature of at least about 540 C. or greater for about five minutes.

A method configured to be executed by a system controller. The method includes obtaining a first metric from a first sensor installed in a first underground vault of a system of interconnected underground vaults, and obtaining a second metric from a second sensor installed in a second underground vault of the system. The first and second underground vaults are in fluid communication with one another via one or more connections. The method also includes locating a gas source based at least in part on one or both of the first and second metrics, and performing an action. The action includes identifying the gas source to one or more users and/or altering a rate of atmospheric turnover in at least a portion of the system.

A method configured to be executed by a system controller. The method includes obtaining a first metric from a first sensor installed in a first underground vault of a system of interconnected underground vaults, and obtaining a second metric from a second sensor installed in a second underground vault of the system. The first and second underground vaults are in fluid communication with one another via one or more connections. The method also includes locating a gas source based at least in part on one or both of the first and second metrics, and performing an action. The action includes identifying the gas source to one or more users and/or altering a rate of atmospheric turnover in at least a portion of the system.

A gas storage system for storing compressed gas, and method for constructing the system, are described. The system includes a borehole having a first borehole portion and a second borehole portion. An inflatable balloon is arranged within the second borehole portion. An upper support member, mounted on top of the inflatable balloon, is configured for anchoring the inflatable balloon to a sealing material filling the first borehole portion. A lower support member is arranged at the bottom of the inflatable balloon. The system includes an inlet gas pipe for filling the inflatable balloon from the gas compressing system and an outlet gas pipe for releasing the compressed gas. A compacted filling material is placed within a gap formed between the inflatable balloon, the upper support member, the lower support member, and an inner surface of the second borehole portion. One or more filling material pipes extend along the borehole to the gap for providing a filling material thereto.

A gas storage system for storing compressed gas, and method for constructing the system, are described. The system includes a borehole having a first borehole portion and a second borehole portion. An inflatable balloon is arranged within the second borehole portion. An upper support member, mounted on top of the inflatable balloon, is configured for anchoring the inflatable balloon to a sealing material filling the first borehole portion. A lower support member is arranged at the bottom of the inflatable balloon. The system includes an inlet gas pipe for filling the inflatable balloon from the gas compressing system and an outlet gas pipe for releasing the compressed gas. A compacted filling material is placed within a gap formed between the inflatable balloon, the upper support member, the lower support member, and an inner surface of the second borehole portion. One or more filling material pipes extend along the borehole to the gap for providing a filling material thereto.

A fire resistant tunnel expansion joint system for installation between substrates of a tunnel. The system includes a fire protection barrier applied at a predetermined thickness to the substrates and a fire resistant tunnel expansion joint. The tunnel expansion joint includes a core and a fire retardant infused into the core. The core is configured to define a profile to facilitate the compression of the tunnel expansion joint when installed between the substrates. The fire protection barrier and the fire resistant tunnel expansion joint are each capable of withstanding exposure to a temperature of at least about 540 C. or greater for about five minutes.

Described herein are apparatus, systems and methods useful in forming vertical structures.

Described herein are apparatus, systems and methods useful in forming vertical structures.