Elevation monitoring apparatus includes an enclosed base reference station (10) a 2000 m long, elongate housing (11) extends along the length of a traverse. A pair of conduits (12, 13) are filled with air (14) and water (15) respectively and extend through the elongate housing (11). 200 differential piezo pressure sensors (16) are spaced at 10 m intervals along the pair of conduits (12, 13) and are selected to sense the pressure difference between the respective fluids (14, 15). A dedicated microprocessor (17) associated with each pressure sensor (16) collects and distributes pressure difference data over a CANbus compatible network comprising twisted pairs (20) extending to the base reference station (10). A main data processor (21) relates the data to form a database of elevations. A modem (24) and antenna (23) outputs the data to remote management. A precision GPS unit (25) monitors the base reference elevation to assure the reference standard.

Disclosed is a method for rock burst prevention by active support reinforcement and active pressure relief. The method comprises the following steps: A. rating a burst tendency based on a comprehensive index method: determining a zone as a general risk region or a mediate risk region by using a comprehensive index method; B. predicting a burst risk region and determining pressure relief borehole parameters in real time by using a drill cuttings method: determining borehole parameters of the general risk region and the mediate risk region; C. drilling holes after determining arrangement patterns of large-diameter pressure relief boreholes according to different burst risk levels; D. forming a coal wall-bolt-grouting hole sealing support reinforcement system through a roadway support system; and E. monitoring a pressure relief effect of the support reinforcement system: until a required effect of preventing bursts by pressure relief is achieved while the support is reinforced. The present invention can not only achieve an effect of preventing rock bursts by pressure relief but also enhance the integrity of a coal wall in a roadway excavation process, thereby achieving the objective of rock burst prevention by active support reinforcement and active pressure relief.

A monitoring and forewarning method for coal-rock dynamic disasters based on an electromagnetic radiation and an earth-sound monitoring includes the following steps: (1) calculating the weighted average value of research parameter P(t) during a time period according to the monitoring data collected by the electromagnetic radiation and the earth-sound monitoring system in real time; (2) calculating D(t), the deviation value of P(t); (3) calculating |D(t)| as the deviation threshold value, the average value of |D(t)| during period of normal mining of the working surface; (4) calculating D.sub.S, the number of times that D(t) is greater than |D(t)| in one day; (5) normalizing D.sub.S to obtain the monitoring and forewarning index ; (6) forewarning the hazard state of dynamic disaster of the working surface in real time according to and forewarning method, determining hazard level.

The invention discloses an integrated manufacturing system and method for a small-deformation self-diagnosis shield segment, wherein the designed installation process saves time and effort, and all the sensing modules are provided inside the segment without disturbing the space outside the segment. Integration of all the deformation self-diagnosis shield segments is achieved by comprehensively monitoring inclination, displacement, strain, pressure and temperature of the shield segments via five monitoring modules. At the same time, the obtained data is uploaded to a database, and various contents are displayed in real time according to indication information input by a user.

Systems and methods are described for monitoring a condition of a mine roof using a longwall mining system. A plurality of powered roof supports is controlled to apply an adjustable support pressure on a mine roof. A condition of the mine roof is monitored based on the adjustable support pressure applied to the roof by a respective actuator of each powered roof support. In some implementations, the condition of the mine roof is monitored by generating and analyzing a graphical pressure map based on the adjustable support pressure applied by each powered roof support and a relative position of a shearer moving across the mine face. In some implementations, roof collapse events are detected based on temporally similar changes in the adjustable support pressure applied by multiple adjacent powered roof supports as indicated by the graphical pressure map.

A sensor assembly for a rock bolt, wherein the rock bolt includes a central rod, a split tube and a wedge anchor assembly fitted around the central rod, a rock plate, and a nut for attachment to an outer end of the central rod. The sensor assembly includes a distance sensor, a bracket for attaching the distance sensor to an outer portion of the split tube, an elongate spacing member configured to be fitted around the split tube between the nut and the rock plate to keep the nut and the rock plate spaced apart. The spacing member has an opening extending along at least a portion of the length thereof, the opening being sized large enough to allow movement of the bracket along a portion of the length of the spacing member with the distance sensor attached to the outer portion of the split tube by the bracket.

The present invention provides a full-roadway full-process full-cross-section deformation monitoring device and a monitoring method thereof, which are applicable to the field of roadway surface deformation monitoring. A monitoring station is deployed utilizing an anchor rope, a supporting frame and a rotary laser measuring device are connected via a threaded sleeve at the tail end of the anchor rope, the rotary laser measuring device can rotate and drive a laser range finder to rotate, the data of a plurality of cross sections can be measured at the same time with one monitoring station, the data is processed by computer programming, so that the measurement data is converted into coordinates in a three-dimensional coordinate system, and thereby full-roadway full-process full-cross-section digital imaging is realized. The monitoring method attains high measuring accuracy, involves very low artificial error, supports intuitive observation of dynamic roadway deformation condition, can provide accurate warning for roof pressure condition, and provides a technical guarantee for safety of the downhole workers.

A monitoring device and method for monitoring a longwall mining system having a roof support, the roof support including a pressure sensor to determine pressure levels of the roof support during a monitoring cycle. Pressure information is obtained for the roof support. An electronic processor then determines whether the pressure information is indicative of a first type of pressure failure of the roof support and whether the pressure information is indicative of a second type of pressure failure of the roof support. An alert is generated in response to determining that the pressure information is indicative of at least one selected from the group consisting of the first type of pressure failure and the second type of pressure failure.

The present invention provides a full-roadway full-process full-cross-section deformation monitoring device and a monitoring method thereof, which are applicable to the field of roadway surface deformation monitoring. A monitoring station is deployed utilizing an anchor rope, a supporting frame and a rotary laser measuring device are connected via a threaded sleeve at the tail end of the anchor rope, the rotary laser measuring device can rotate and drive a laser range finder to rotate, the data of a plurality of cross sections can be measured at the same time with one monitoring station, the data is processed by computer programming, so that the measurement data is converted into coordinates in a three-dimensional coordinate system, and thereby full-roadway full-process full-cross-section digital imaging is realized. The monitoring method attains high measuring accuracy, involves very low artificial error, supports intuitive observation of dynamic roadway deformation condition, can provide accurate warning for roof pressure condition, and provides a technical guarantee for safety of the downhole workers.

A process for locating underground markers, including: transmitting signals through the ground between markers in the ground; and determining locations of the markers based on the transmitted signals.