Disclosed is a method for designing parameters of an advance stress relief hole in a rockburst source zone of a construction tunnel in deep-seated hard rocks, including S1: classifying rockbursts in the TBM tunnel in the deep-seated hard rocks; S2: identifying a potential rockburst source zone of the TBM tunnel in the deep-seated hard rocks; S3: developing a scheme design and effect evaluation method for the parameters of the advance stress relief hole; S4: performing analysis to find a pattern in the parameters of the advance stress relief hole and optimizing the design; and S5: determining an optimal scheme for arranging the stress relief hole in accord with engineering practice.

A platform, system, and method for simulating critical rock collapse of surrounding rock in underground engineering includes: four vertically arranged reaction walls defining a square reaction space, and a base mounted at a lower end opening of the wall; and a row of horizontally arranged stress loading plates at a side of each wall close to the reaction space, and a reaction beam above this space, where the reaction beam, the stress loading plate, and the base define a loading space, and the loading space is configured for placement of a surrounding rock simulation block to be tested; the stress loading plate capable of moving horizontally in a direction of the reaction wall, and the reaction beam capable of moving in a vertical direction, so as to load the surrounding rock simulation block; and the stress loading plate and the reaction beam being driven by linear motion units for movement.

A platform, system, and method for simulating critical rock collapse of surrounding rock in underground engineering includes: four vertically arranged reaction walls defining a square reaction space, and a base mounted at a lower end opening of the wall; and a row of horizontally arranged stress loading plates at a side of each wall close to the reaction space, and a reaction beam above this space, where the reaction beam, the stress loading plate, and the base define a loading space, and the loading space is configured for placement of a surrounding rock simulation block to be tested; the stress loading plate capable of moving horizontally in a direction of the reaction wall, and the reaction beam capable of moving in a vertical direction, so as to load the surrounding rock simulation block; and the stress loading plate and the reaction beam being driven by linear motion units for movement.

Known georeferencing techniques require input in the form of manually-chosen anchor points or dense surveyed data. The present invention is an improved method and system for georeferencing underground geometric data. The method comprises (a) visiting at least two control points; (b) obtaining information about each of the at least two control points using scanning means; (c) recording the information about the at least two control points into a computer processor; and (d) performing a best-fit transformation to the recorded information. Preferably, the scanning means comprises laser scanners and at least two radio-frequency identification (RFID) tags. However, other technologies, such as retro-reflective LIDAR targets, Wi-Fi access points or bar codes and a bar code reader may also be used. In addition, sonar, radar, flash LIDAR, MEMS LIDAR, or any other similar technology could be used.

A pressure control apparatus includes a main line section and a branch line operably joined to and extending from the main line section. A housing around the branch line has a first wall and a second wall opposed to the first wall, and a first opening is in the first wall. A plug is operably positioned in the branch line, and the plug has a first position that prevents fluid flow through the branch line and a second position that permits fluid flow through the branch line. A loop extends from the plug, and a lever pivotally connected to the second wall and extending through the loop and the first opening in the first wall positions the plug to the first and second positions.

There is described an interior positioning system for tracking spatial position of communication devices within a remote location. The interior positioning system generally has: a radio frequency network distributed through said remote location; beacons spaced-apart from one another throughout said remote location and powered by said radio frequency network, each beacon locally emitting a corresponding beacon identifier which when received by a nearby communication device is communicated over said radio frequency network by said communication device; and a tracking controller being communicatively coupled to said radio frequency network, said tracking controller stored thereon tracking data associating each of said beacon identifiers to respective spatial coordinates, and instructions that when executed perform the steps of: receiving said beacon identifier communicated over said radio frequency network by said communication device, and determining spatial coordinates of said communication device by cross referencing said received beacon identifier to said tracking data.

A support system, an excavation arrangement, and a process of supporting an object are disclosed. The support system includes a weight-bearing device and a camming mechanism positioned below the weight-bearing device. A downward force on the weight-bearing device at least partially secures the camming mechanism to opposing surfaces. The excavation arrangement includes a borehole, a support system positioned within and secured to the borehole, and an object positioned on and supported by the support system. The process includes positioning and securing the support system and positioning the object on the weight-bearing device.

The present disclosure provides an artificial dam of a distributed coal mine underground reservoir and its constructing method. The artificial dam comprises a support layer (10), an anti-seepage layer (20), and a concrete structure layer (30) that are successively formed in an auxiliary roadway (1) from inside to outside, the concrete structure layer (30) being embedded into a security coal pillar (2) and/or surrounding rock (3) around the auxiliary roadway (1). Because the concrete structure layer (30) is embedded into the security coal pillar (2) and/or the surrounding rock (3) around the auxiliary roadway (1), the artificial dam is combined to the security coal pillar (2) to together form a dam for an underground reservoir. Due to multi-layer design, anti-seepage performance and structural strength of the dam can meet the water storage requirements of the underground reservoir.

The present disclosure provides an artificial dam of a distributed coal mine underground reservoir and its constructing method. The artificial dam comprises a support layer (10), an anti-seepage layer (20), and a concrete structure layer (30) that are successively formed in an auxiliary roadway (1) from inside to outside, the concrete structure layer (30) being embedded into a security coal pillar (2) and/or surrounding rock (3) around the auxiliary roadway (1). Because the concrete structure layer (30) is embedded into the security coal pillar (2) and/or the surrounding rock (3) around the auxiliary roadway (1), the artificial dam is combined to the security coal pillar (2) to together form a dam for an underground reservoir. Due to multi-layer design, anti-seepage performance and structural strength of the dam can meet the water storage requirements of the underground reservoir.

Described are a test apparatus and a test method for the wetted perimeter of coal seam water injection. In the test apparatus, a columnar insulator is provided between an upper electrode and a lower electrode, circular insulating tapes are located at the outer edges of the upper electrode and the lower electrode, a circular reverse osmosis membrane is provided at the middle of the circular insulating tape, the upper electrode, lower electrode, circular insulating tapes and circular reverse osmosis membrane form an enclosed chamber which is filled with solid sodium chloride, and cotton yarns are packed among the upper resin backing plate, lower resin backing plate, circular insulating tapes and the inner walls of water permeable perforated pipes. The upper electrode is provided with an electrode lead which passes through the columnar insulator, the lower electrode and the lower resin backing plate and goes out from the tail connecting end.