WO2012017409A1

WO2012017409A1 - A monitoring apparatus, and a support means

Info

Publication number: WO2012017409A1
Application number: PCT/IB2011/053485
Authority: WO
Inventors: Andries Lottering; Elrond Bishop; Francois Pieterse; Paul Stracy Wootten; Steven Paul Mason
Original assignee: Azuravax (Proprietary) Limited
Priority date: 2010-08-04
Filing date: 2011-08-04
Publication date: 2012-02-09
Also published as: WO2012017410A2; WO2012017410A3

Abstract

This invention relates to a monitoring apparatus and to a support means comprising at least some of the components of the monitoring apparatus. The monitoring apparatus comprising at least an attachment member configured to facilitate the monitoring apparatus being attachable to, or in contact with, a support means; an electrical strain gauge to measure stress or strain experienced by the support means; and indicator means to indicate at least unsafe strain associated with the support means measured by the strain gauge. The apparatus also conveniently comprises a processor to control at least the indicator means in response to receiving electrical signals measured by the electrical strain gauge.

Description

A MONITORING APPARATUS, AND A SUPPORT MEANS

BACKGROUND OF THE INVENTION

THIS invention relates to a monitoring apparatus and a support means, for use in, for example, in a mining application.

One of the problems facing the mining industry, as well as opencast mining and civil industry, although not necessarily limited thereto, is incorrectly installed or unsafe support means, in particular support means for example, cable anchors, roof bolts, or the like, installed in mine rock strata, for example, ceilings, floors or walls of mines.

It will be appreciated that in the mines, the abovementioned support means provide structural support to the rock strata which in turn reduces rock movement and subsequent potential for rock collapse. However, cable anchors or roof bolts are sometimes not properly installed within rock strata in mines in accordance with predetermined specifications, prescribed by safety standards for the particular mine and circumstances. This jeopardises the safety of those mining sites and it follows that these incorrectly installed cable anchors or roof bolts are unsafe and worse still are difficult to detect. In particular, it is difficult to detect increasing or decreasing loads on these cable anchors or roof bolts, often at great peril.

Similarly, cable anchors or roof bolts installed in dangerous rock strata, for example, shifting rock strata are also unsafe and difficult to detect.

With the unsafe cable anchors and/or roof bolts, what follows is a mining environment which is vulnerable to cave in, rock slides, or the like often with devastating human and economic losses.

Although attempts, have been made to address this issue, it is difficult to determine, in a convenient and more reliable manner, whether or not a cable anchor or a roof bolt is/was correctly/safely installed and also in accordance with predetermined safety standards. Further, it is difficult to determine if the cable anchor or rock bolt installed in rock strata is experiencing load stress there from.

It follows that it is an object of the present invention to address the abovementioned problem and also to address the abovementioned difficulties, and in doing so address a need to provide a safer mining environment.

SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a monitoring apparatus comprising: an attachment member configured to facilitate the monitoring apparatus to be operatively attachable to, or in contact with, a support means; a strain gauge to measure stress or strain experienced by the support means; and indicator means to indicate if at least unsafe stress or strain associated with the support means is measured by the strain gauge.

The strain gauge may comprise an electrical strain gauge configured to generate an electrical signal in response to a variation in stress or strain experienced by the support means.

The monitoring apparatus may advantageously comprise, or may be in communication with, a processor which may be configured to: receive the electrical signal from the strain gauge indicative of the stress or strain which the support means is experiencing; compare the received electrical signal with one or more predetermined thresholds or threshold ranges stored in a memory to determine if the support means is experiencing one or more of a dangerous condition, a strata unstable condition, and a stable condition; and transmit to the indicator means, a corresponding dangerous condition signal, strata unstable condition signal, or a stable condition signal depending on the comparison step respectively.

The indicator means may comprise one or both of a visual indicating means and audio indicating means configured to be operated in response to receiving one or more of the dangerous condition signal, strata unstable condition signal, and a stable condition signal respectively.

The visual indicating means may comprise one or more lights (e.g., Light Emitting Diodes (LEDs), particularly a multiple colour changing LED) such that the dangerous condition signal, the strata the unstable condition signal, and the stable condition signal is configured to operate the lights LED/s accordingly. Different colours of the LED/s may conveniently correspond to the different condition signals. In this way the apparatus may visually indicate at least a dangerous strain condition of the support means and a safe strain condition of the support means.

The audio indicating means may be a speaker, siren, horn, or the like.

The indicator means may conveniently comprise a communication means configured to transmit one or more of the dangerous condition signal, strata unstable condition signal, or a stable condition signal from the monitoring apparatus. The communication means may be configured to send the respective signals wirelessly, or via a hard wired network to other monitoring apparatuses, or a control center/interested party. The communication means may be configured to transmit a Short Message Service (SMS) message to a mobile communication device/s of an interested party indicative of the respective condition signal. It will be appreciated that only some of the condition signals may be transmitted in this fashion. In this way, interested parties may be alerted if there are any potential problems in the support means and the strata to which the support means is attachable to as will be described below.

In any event, the attachment member may comprise a body having a recessed portion in which the strain gauge is disposed such that the strain gauge is configured to measure stress or strain experienced by the support means by measuring the stress or strain experienced by the body of the attachment member substantially at the recessed portion.

The body of the attachment member may define a circumferentially extending recessed portion such that the attachment member has a substantially hourglass-like profile.

The attachment member may conveniently define an axially extending hole to accommodate an anchor member of the support means, in use. The attachment member may define the axially extending hole with a shape and dimension to fit snugly to the support means, particularly an anchor member thereof.

The support means may typically comprise one or more of a cable, cable anchor, bolt, roof bolt, anchor bolt and screw attachable to strata. The support means may be anchored in strata, wrapped around strata, or the like. In any event, the support means may typically be under tension such that stress or strain in the support means is associated with the stress or strain in the strata to which the same is attached. The support means may be disposed relative to the strata being monitored such that the stress or strain in the strata is transmitted to the support means which correspondingly experience stress or strain.

In certain example embodiments, the support means may form part of the strata, for example, a pillar. In this example embodiment, the monitoring apparatus is typically be configured to abut the strata (e.g. the pillar) or an intermediate member disposed between the strata and the monitoring apparatus so as to determine the stress-strain experienced by the strata.

The strain measured by the strain gauge may be the stress or strain experienced by the support means, particularly the anchor member, e.g. cable anchor, anchor bolt, or roof bolt, in use.

The strain may be positive or negative strain, or tensile strain or compressive strain respectively, experienced by the cable anchor or roof bolt experiencing tensile or compressive stresses associated with the strata to which the same is attached to.

The attachment member may be operatively disposed between a cable tension collette claw and a dome plate of the cable anchor such that, in use, the strain gauge is configured to measure positive and negative strain transmitted between the cable tension collette claw and the dome plate. The attachment member may comprise a head portion receivable in a suitable recess of the dome plate, and a base portion defining a recess for receiving the cable tension collette claw, in use.

The strain gauge may be directly disposed onto a shaft of the anchor member. However, in one example embodiment the strain gauge may be attachable to an attachment member which in turn may be operatively attachable to the support means.

It will be appreciated that the strain gauge may be configured to measure stress in the support means (Primary Stress) by experiencing stress in the attachment member (Secondary Stress) which is operatively connected to the support means.

According to a second aspect of the invention, there is provided a support means comprising: an anchor member to anchor the support means to different strata; a strain gauge operatively connectable to the support means to measure stress or strain experienced by at least the anchor member; and indicator means to indicate if at least one or more of at least a safe or unsafe stress or strain is measured by the strain gauge.

The support means comprises one or more of a cable, cable anchor, bolt, roof bolt, and screw.

The strain measured by the strain gauge may be the stress or strain experienced by the cable anchor, or roof bolt, in use. The strain may therefore be positive or negative strain, or tensile strain or compressive strain respectively, experienced by the cable anchor or roof bolt experiencing tensile or compressive stresses. The strain gauge may be directly disposed onto a shaft of the anchor member; or attachable to an attachment member which in turn may be operatively attachable to the support means.

The attachment member may comprise a body having a recessed portion in which the strain gauge is disposed, wherein the strain gauge is_. configured to measure strain when the attachment member, and hence the support means, experiences strain.

In a preferred example embodiment, the strain gauge, or attachment member as the case may be, may be operatively disposed between a cable tensioner or collette claw and a dome plate of the cable anchor such that, in use, the strain gauge is configured to measure positive and negative strain transmitted between the cable tensioner or collette claw and the dome plate.

The audio indicating means may be a speaker, siren, horn, or the like.

The strain gauge is an electrical strain gauge configured to generate an electrical signal in response to a variation in strain experienced by the support means.

The support means may comprise, or may be communicatively coupled to, a processor which may be configured to: receive electrical signals from the strain gauge indicative of the strain which the support means is experiencing; compare the received electrical signals with one or more predetermined thresholds or threshold ranges stored in a memory to determine if the support means is experiencing one or more of a dangerous condition, a strata unstable condition, and a stable condition; and transmit, to the indicator means, a corresponding dangerous condition signal, strata unstable condition signal, or a stable condition signal depending on the comparison step respectively.

According to a third aspect of the invention, there is provided a system comprising a plurality of monitoring apparatuses and/or support means as hereinbefore described disposed in a particular monitored area.

The particular monitored area may be a mine.

According to a fourth aspect of the invention there is provided a method of operating a mine, the method comprising: installing one or more of the monitoring apparatuses and/or support means as hereinbefore described in a mine; and monitoring the installed monitoring apparatuses and/or support means.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a schematic drawing of part-sectional side view

(including a functional block diagram of a processor) of an installation of the monitoring apparatus/support means in accordance with an example embodiment;

Figure 2 shows a partial section of a portion of the monitoring apparatus of Figure 1 at A-A; Figure 3 shows a schematic drawing illustrating a system in accordance with an example embodiment;

Figure 4 shows a flow diagram of a method in accordance with an example embodiment;

Figur 5 shows a flow diagram of a method of installing the monitoring apparatuses of Figure 1 and 2 in accordance with an example embodiment;

Figure 6 shows a flow diagram of a method of obtaining monitoring apparatus calibration information in accordance with an example embodiment;

Figure 7 shows a workflow diagram of a method of installing the monitoring apparatuses in accordance with an example embodiment;

Figure 8 shows a workflow diagram of a method of commissioning monitoring apparatuses in accordance with an example embodiment;

Figure 9 shows a workflow diagram of a method of monitoring and reporting events in accordance with an example embodiment;

Figure 10 shows a use case diagram for emergency configuration, monitoring and response for emergencies in accordance with an example embodiment;

Figure 11 shows an emergency response plan workflow diagram for monitoring officers in accordance with an example embodiment; Figure 12 shows a define risk/emergency level workflow diagram for mine engineers in accordance with an example embodiment;

Figure 13 shows a control room user emergency response workflow diagram for a control room user;

Figure 14 shows a manage users workflow diagram in accordance with an example embodiment;

Figure 15 shows a flow/workflow diagram of collection of monitoring calibration information and data storage;

Figure 16 shows a part section, exploded perspective illustration of some of the components of the monitoring apparatus/support means, in an installation, substantially corresponding to the monitoring apparatus illustrated in Figure 1 , bar a few minor differences;

Figure 17 shows a part section, perspective view of an assembled monitoring apparatus of Figure 16;

Figure 18 shows a perspective illustration of the monitoring apparatus in accordance with an example embodiment disposed on a roof of a mine;

Figure19 shows another example embodiment of the monitoring apparatus in accordance with an example embodiment, in use in a different application; and

Figure 20 shows a high level flow diagram of another method in accordance with an example embodiment. DESCRIPTION OF PREFERRED EMBODIMENTS

In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of an embodiment of the present disclosure. It will be evident, however, to one skilled in the art that the present disclosure may be practiced without these specific details.

Referring to Figures 1 , 2 and 16 to 18 of the drawings where a monitoring apparatus in accordance with an example embodiment is generally indicated by reference numeral 10. The monitoring apparatus 10 may conveniently be attachable to a support means 11 , for example, a cable anchor, roof bolt, or the like. For ease of explanation, reference will now be made to the example embodiment of the monitoring apparatus 10 being attachable to the cable anchor 11 for use in a mining application.

Although the description will be given with the support means comprising a cable anchor, it will be appreciated that for brevity, the term "support means" in this specification will be understood to also include any means which is disposed relative to the strata being monitored such that the stress or strain in the strata is transmitted to the support means which correspondingly experiences stress or strain. As will be mentioned below, the support means may conveniently comprise elements of the monitoring apparatus 10 or in other words the monitoring apparatus 10, more accurately parts thereof, may be integral with the support means.

Also discussed below it the example embodiment where the support means is portions of strata, e.g., pillars of the strata.

The cable anchor 11 , or components thereof, may be constructed of substantially ferrous material. The cable anchor 11 comprises an elongate cable or anchor member 12 which facilitates anchoring or installing the cable anchor 11 to rock strata 13, for example, a roof of a mine. It will be appreciated that, depending on the mining application, the member 12 may be a ferrous cable or tendon which axially extends through the cable anchor 11. In other example embodiments, the member 12 may be a solid rod extending axially through the anchor 11. Also, the cable 12 need not necessarily be considered as part of the cable anchor 11 , though it is described as such in this specification for ease of explanation.

It will be noted that the cable 12 may typically be cropped as illustrated in Figure 16.

The cable anchor 11 further comprises a dome plate 28 and a cable tensioner or cable tension collette claw 26. In use, the monitoring apparatus 10 is axially located along the cable 12 between the dome plate 28 and a cable tension collette claw 26. It will be appreciated that in certain example embodiments, the cable anchor 11 may be understood to only include the cable or anchor member 12.

The monitoring apparatus 10 comprises at least one strain gauge 14 or Optical Fibre Bragg grating strain measuring device (more may possibly be employed) operatively connectable to the cable anchor 11 to measure strain associated with or experienced by the anchor 11 , or at least a part thereof. The strain measured by the gauge 14 may be positive or negative strain, or tensile strain or compressive strain respectively, experienced by the cable anchor 11. It will be appreciated that in some instances, the strains or stresses measured by the monitoring apparatus 10 may be related to, or at least indicative of, the condition of the rock strata 13 to which the cable anchor 11 is attached.

In one example embodiment, the strain gauge 14 or Optical Fibre Bragg grating strain measuring device, may be directly attachable to a portion of the anchor 11 , for example, the cable 12 by way of an adhesive, friction, or the like. However, in a preferred example embodiment, the monitoring apparatus 10 comprises an attachment member 20 to which the strain gauge 14 is attachable. It follows that the attachment member 20 is attachable to the cable anchor 11 , in particular, between the dome plate 28 and a cable tension collette claw 26 such that, in use, the strain gauge 14 is configured to measure strain or stress transmitted between the cable tension collette claw 26 and the dome plate 28 (may be positive and negative strain). It will be appreciated that the strain gauge 14 may be configured to measure stress in the cable anchor 11 (primary stress) by experiencing stress in the attachment member 20 (secondary stress) which is operatively connected to the anchor 11.

The attachment member 20 may comprise a barrel-like body having a substantially cylindrical shape with an axially extending hole to accommodate the cable 12, substantially snugly. The attachment member 20 defines a recessed portion 22 such that the attachment member 20 defines shoulders 24 which flank the recessed portion 22. In a preferred example embodiment, the recessed portion 22 extends circumferentially around an outer surface the attachment member 20 such that the attachment member 20 has a substantially hourglass-like profile. This shape of the attachment member 20 advantageously enables the apparatus 10 to more accurately measure stress and or strain as described herein.

At least the attachment member 20 may be constructed of a high quality stainless steel. The member 20/the material from which the member 20 is constructed from may be heat treated enabling more accurate measurements of stress and/or strain as discussed below.

The strain gauge 14 is operatively attachable to the attachment member 20, in the recessed portion 22. The gauge 14 may be integrally formed with the attachment member 20 or may be adhesively or frictionally attached thereto, or attached by means of screws, bolts, etc. In addition, the strain gauge 14 may be disposed at a portion of the attachment member 20 in the recessed portion 22. However, the strain gauge 14 may be located wraparound fashion within the recessed portion 22 of the attachment member 20. The attachment member 20 may comprise a head portion and a base portion shaped and dimensioned to be attachable to the cable anchor 11. In particular, the head portion of the member 20 may be shaped and dimensioned to be attachable to the dome plate 28, and the base portion of the attachment member 20 may be shaped and dimensioned to be attachable to the cable tension collette claw 26, in use. The head portion may be a bulbous head portion receivable in a suitable recess in the dome plate 28. Similarly, the base portion may comprise a recess to receive the tensioner 26.

It will be understood that the strain gauge 14 is typically an electrical strain gauge configured to generate an electrical signal in response to a variation in strain experience by the cable anchor 11. The generated electrical signal conveniently varies in response to different stress or strain levels experienced by the cable anchor 11.

To this end, the strain gauge 14 may comprise a metallic foil pattern which is housed by an insulated flexible backing, or a strain sensing optical fibre (known as the Optical Fibre Bragg Grating Sensor). As the cable anchor 11 , and hence the attachment member 20, is deformed due to strain (either tensile or compressive), the foil is resultantly deformed as well thereby varying its electrical resistance or conductance. It will be appreciated by those skilled in the art that the strain gauge 14 may also be configured to vary electrical capacitance, inductance, or the like in response to different strain levels.

The monitoring apparatus 10 may comprise a cover 16 removably attachable to the attachment member 20, for example, slidably attachable to the attachment member 20. The cover 16 may be colour coded for different load sets or strains. In addition, in use, the cover 16 covers the recessed portion 22 thereby to advantageously protect the electronic components of the monitoring apparatus 10 which is conveniently disposed in the recessed portion 22. The cover 16 may provide a watertight seal with the member 20. The body of the attachment member 20 may be encased in silicon epoxy, for example, to seal in the strain gauge 14 and other electronics, if any, before fitment of the cover 16.

The monitoring apparatus 10 also comprises indicator means 30 to indicate at least one or more of at least a safe or unsafe strain measured by the strain gauge 14. The indicator means 30 may comprise visual indicating means, audio indicating means, tactile indicating means or the like. In a preferred example embodiment, the indicator means 30 may comprise one or more light emitting diode/s (LED/s) to visually indicate at least a dangerous strain condition of the cable anchor 11 and a safe strain condition of the cable anchor 11. In Figures 16 to 18, the indicator means 30 is illustrated to include one colour changing LED which may change colours according to the different condition signals as will be described below.

The apparatus 10 may advantageously comprise a communication means configured to transmit a suitable signal from the apparatus 10 in response to at least one or more of at least a safe or unsafe strain being measured by the strain gauge 4 in a manner that will be described below.

It will be understood that in assembly of the components mentioned above, the attachment member 20 with the cover 16 is located along the cable 12 (which is fixed to the strata 13) between the dome plate 28 and the tensioner or tension element 26 such that the cable is received in the hole of the member 20. The tension element 26 is then forced toward the direction of the strata 13 such that the head portion of the member 20 is lodged in the dome plate 28 and the member 26 is snugly received in the recess of the base portion of the member 20 thereby tensioning the cable anchor 11. The cable anchor 11 is further tensioned until an associated mechanical tension indicator 27 (Figure 16) or optionally the indicator means 30 indicates that the cable has been correctly tensioned. Although the indicator 27 may indicate that the cable anchor 11 is correctly tensioned, the present invention seeks to monitor the same as the conventional indicators 27 are not very accurate.

To this end, the monitoring apparatus 10 advantageously comprises, and/or may be communicatively coupled to, a processor 32. The strain gauge 14 and indicator means 30 may be coupled to the processor 32 via a connecting cable 34. However, this connection may be a wireless connection, for example, Bluetooth, infra red, some other radio frequency, or the like. The processor 32 may be attachable to the strata 13 adjacent the monitoring apparatus 10 or cable anchor 11. In other, more sophisticated example embodiments, the processor 32 may be integral with the monitoring apparatus 10.

The processor 32 may be housed in a housing 33 which may also be attached to the strata 13 adjacent the cable anchor 1 , as illustrated in Figure 18.

In any event, processor 32 may conveniently comprise main memory, and/or hard disk drive, which carries a set of instructions to direct the operation of the processor 32. It is to be understood that the processor 32 may be one or more microprocessors, controllers, or any other suitable computing apparatus, resource, hardware, software, or embedded logic.

The processor 32 may be configured to receive electrical signals from the strain gauge 14 indicative of the strain which the cable anchor 11 is experiencing. It follows that the processor 32 comprises, or may be in communication with, an ADC (analogue to digital converter) to convert the received electrical signals from the strain gauge 14 to a useable digital format.

The processor 32 is then configured to compare the received electrical signals, typically in digital format, with one or more predetermined critical threshold values or threshold ranges to determine if the cable anchor 11 is experiencing one or more of a dangerous condition, a strata unstable condition, and a stable condition. This comparison steps performed by the processor 32 will be described in greater detail below. However, it will be appreciated that the thresholds or ranges may be determined experimentally for different strain gauges. Also, the determination by the processor 32 may be done in a plurality of different ways for example by having a look-up table, or the like. It follows that the processor 32 may be configured to allow for remote setting and programming of the apparatus 10.

The threshold critical values or ranges for at least the stable and dangerous conditions may comprise threshold values or ranges for both positive or negative strain measured by the monitoring apparatus 10, these may correspond to the tensile or compressive stresses or strain (including bending or anchor slippage) experienced by the cable anchor 11. The threshold values and ranges may be data bands and may relate to slippage of the support means in the strata 13.

The processor 32 is also configured to transmit, to at least the LEDs 30 a dangerous condition signal, strata unstable condition signal, or a stable condition signal depending on the determination of the abovementioned comparison. It will be understood by those skilled in the art that the steps performed by the processor 32 may be carried out by discrete components.

It follows that the LEDs 30 may be operated according to the condition signal. This also could be done in a number of ways, for example, if the there is a stable condition signal, i.e. the strain associated with the cable anchor 11 is within an acceptable range, the LED/s 30 will be green in colour (there may be dedicated colour coded LEDs for the different conditions, however, there may be one LED which may be operated to glow in a range of colours). Similarly, the LEDs 30 will have different colours for the other conditions, for example, orange for strata unstable condition, and red for dangerous strain condition. Though mine workers, etc. will know the respective colour signals indicated by the LEDs 30, a dangerous condition signal may cause the LED/s 30 to flash, an audible alarm signal to activate, or a warning message to be transmitted as this condition may result in greatest damage as it would indicate that the cable anchor 11 is experiencing a great deal of strain, or lack thereof as the case may be.

It will be understood by those skilled in the art, that the monitoring apparatus 10 may be integrated into the cable anchor 11 , or any other support means. To this end, the cable anchor 11 may be adapted to be integral with the monitoring apparatus, or the cable anchor 11 may be manufactured to include one or more elements of the monitoring apparatus 10 integral therewith. It follows that the invention extends to a support means integral with one or more components of monitoring apparatus 10, for example the strain gauge, indicator means, and processor, and even the attachment member 20 as hereinbefore described. It will be appreciated that these variations will not detract from the invention as disclosed herein as the description of the monitoring apparatus 10 may extend to the support means with substantially some of the elements of the monitoring apparatus 10 integral therewith. Also, the monitoring apparatus may conveniently be retrospectively attached to existing cable anchors or roof bolts to indicate strain experienced by the same.

The invention described herein may be used with de-bonded or conventional chemical grouted anchor bolts. In the former, it will be appreciated that the cable 12 may typically define a thin plastic sheath encasing the same.

In installation, a hole is drilled in the strata 13, and the cable 12 is inserted therein and operated to secure the same therein. Grout material is then introduced around the cable 12 in a conventional fashion. The dome plate 28, monitoring apparatus 10 and tensioner 26 are then operated to tension the cable as hereinbefore described.

For de-bonded anchor bolts, the measurements by the apparatus 10 is relatively accurate due to the plastic sheath separating the cable form the grouting material substantially along the length of the hole. The present monitoring apparatus may be configured to measure stress and strain from a few kilograms to a few tons.

In any event, because of the far reaching monitoring implications of monitoring apparatus 10, and support means as hereinbefore described, it follows that the invention extends also to a monitoring network indicated by reference numeral 40 in Figure 3.

The monitoring network 40 comprises a monitoring system 42 for at least a mining application, wherein the monitoring system 42 may comprise a plurality of components or modules which correspond to the functional tasks to be performed by the system 42. In this regard, "module" in the context of the specification will be understood to include an identifiable portion of code, computational or executable instructions, data, or computational object to achieve a particular function, operation, processing, or procedure. It follows that a module need not be implemented in software; a module may be implemented in software, hardware, or a combination of software and hardware. Further, the modules need not necessarily be consolidated into one apparatus but may be spread across a plurality of apparatuses, for example, in the network 40.

In particular, the system 42 comprises a receiver module 44 configured to receive strain data indicative of strain in one or more of a plurality of monitoring apparatuses 10 disposed on cable anchors 11 within strata of a particular area in a mine. The strain data may be received via a communication network 43 from the monitoring apparatus 10. The strain data may comprise strain measurements from the strain gauge 14, as determined by the processor 32 as hereinbefore described. Instead, or in addition, the strain data may comprise the conditions determined by the processor 32 as hereinbefore described.

The system 42 may comprise the monitoring apparatuses 10. However, the system 42 may merely be in communication with the monitoring apparatuses 10 to at least receive measurements from the strain gauges 14. In this regard, it will be noted that the system 42 and the monitoring apparatuses 10 may comprise communication means which are matched (e.g., an antenna, or wireless modem housed in the housing 33) to enable communication via the communication network 43. Although the communication network 43 may conveniently be a radio frequency, WiMAX, or Bluetooth network, the communication network 43 could comprise hard wired networks, for example, electric cable or fibre optic cable networks. The network 43 could also be a telecommunication network, a wireless telecommunication network, a packet-switched network and may form part of the Internet. Instead, the communications network 43 may be a circuit switched network, public switched data network, or the like.

It will be appreciated that the system 42 may comprise the processor 32 as hereinbefore described, in which case, the strain data received may comprise the raw electrical signals measured by the plurality of strain gauges 14 and the processor 32 may process the signals as previously described. However, in a preferred example embodiment, the receiver module 44 may be configured to receive strain data from the processors 32 of respective cable anchors 10 or monitoring apparatuses, for example, wirelessly via the network 43 indicative of the aforementioned conditions. As previously mentioned, the monitoring apparatus 10 may comprise a wireless communication means such as an RF transmitter, a GSM modem, or the like to enable communication with the receiver module 44, for example, via the communication network 43.

In a preferred example embodiment, the network 43 may be a "leaky feeder" system using RS 485 protocol. The processor 32 may be communicatively coupled to the leaky feeder system (may be a hardwired connection or a wireless connection) to transmit data to the receiver module 44. Leaky feeders are cables that can emit radio frequencies. They're like coaxial cables which carry a signal from one endpoint to another. Instead of covering the cable in a solid copper shield, a leaky feeder has small gaps in the shielding to let the signal through. The gaps create a limited wireless radio network environment. Line amplifiers and repeaters boost the signal at regular intervals along the cable to make up for signal loss. They can receive radio signals from the cable and transmit data back. The data can include voice, video and computer data. It is via this leaky feeder system that the system 42 may be configured to remotely control processors 32 and hence monitoring apparatuses 10.

Instead, or in addition to the leaky feeder system, the network 43 may be an optic fibre based communication system.

In any event, the system 42 comprises a mine monitoring management module 46 configured to generate an alarm signal at least if the received strain data (comprising a received condition from the processor 32 in certain example embodiments) is indicative of a dangerous strain in one or more of the cable anchors 11 (to which the monitoring apparatuses 10 are attached). The dangerous strain may be over tension or slack in tension, in the cable anchor 11. The alarm signal may comprise generating a visual, audible, tactile alarm, an alarm message or signal (e.g., a text or SMS, Short Message Service, message, or the like) for transmission to a contact person, for example, a safety or monitoring center (e.g., a control room mentioned below), site or mine manager/engineer, safety officer, etc. The alarm signals and/or messages may be transmitted to receiver/communication modules incorporated into miner's helmets which in turn may trigger visual, audible, or tactile alarms thereon to alert miners that there is a hazardous situation in the location of the mine in which they are in. In this regard, the system 42 may be configured to optionally track locations of miners in the mine by way of the helmets. In any event, it will be understood that this is useful to enable a wide scale evacuation if a predetermined number of cable anchors 11 are indicating dangerous strain levels or if inspection is needed at a particular location in the mine.

Each monitoring apparatus 10 may have a unique identifier or code associated therewith to identify the same. The module 46 may make use of the unique identifiers to keep a record of which area in the mine a particular monitoring apparatus 10 is located. This conveniently allows for remote management of the monitoring apparatuses 10, in addition to the visual indication provided on the apparatus 10 of the previously mentioned conditions.

The module 46 may allow operators to view the status of the monitoring apparatuses 10 and associated cable anchors 11 , preferably in real-time. In this regard, the module 46 may comprise or may form part of a SCADA (Supervisory Control and Data Acquisition) system and may comprise an HMI (Human Machine Interface), GUI (Graphical User Interface), etc. The module 46 may be located off-site from the mine and may be accessed, for example, via a secure web portal or website. However, nothing stops the module 46 from being located or accessible at the mine (on-site, e.g., at the control room) to enable the plurality of monitoring apparatuses 10 in the mine to be monitored. In addition to monitoring, the module 46 may allow operators to calibrate or program each monitoring apparatus 10 (as identified by their associated unique identifier) remotely to adjust strain thresholds, to activate or deactivate the apparatuses, to add one or more conditions for generating signals, or the like. It will be appreciated that the remote programming capabilities of the system 42 conveniently removes the need for operators to go physically to each particular monitoring apparatus 10 to adjust or program the same.

It follows that the modules 46, 48 and the database 50 may only be accessible by authorised users or operators who have to log-in to use the modules and the database. The system 42 may therefore comprise a security module (not shown) to enable only registered or authorised users to access the modules 46, 48 and the database 50.

The system 42 may further comprise a memory database 50 to store data, for example, strain data, strain data history, any graphs or plots generated (discussed below), contact data for those to contact in case of an alarm signal being generated, etc. This stored data may be accessed off-site, and conveniently allows for analysis of strata conditions, and at least gives information regarding the condition of rock strata up till the point when a particular rock surface collapses, if/when this occurs. The database 50 advantageously comprises map data indicative of the area being monitored, e.g., the mine.

The system 42 also preferably comprises a data processing module 48 configured to process received strain data to at least generate plots, graphs, or the like, indicative of at least strata movement, or the like. The module 48 may conveniently assist geologists, scientists, and engineers, etc. an opportunity to study at least the pattern of strata movement in the mine. It follows that rock strata movement or rock strata conditions may be inferred from the strain measurements obtained via the plurality of monitoring apparatuses 10. The module 48 is conveniently accessible through SCADA systems.

The module 48 may be configured to render a map of the mine using stored map data indicating the position and status of each monitoring apparatus 10 (and associated cable anchor 11) disposed within the mine, according to the unique identifiers. This will conveniently provide a user with a visual indication of the exact locations of all the monitoring apparatuses 10 and their conditions. For example, if a particular apparatus 10, which is identified by a particular unique identifier, generates a dangerous condition signal, a corresponding light will flash on the rendered map at the location which the particular monitoring apparatus 10 is located. Lights on the map may be colour coded depending on the status of the strain measured monitoring apparatuses 10 in a similar fashion as hereinbefore described.

By selecting one or a group of monitoring apparatuses 10 on any level in the mine, the module 48 may be configured to chart the strain values over time.

Referring now to Figure 19 of the drawings where another example embodiment of a monitoring apparatus in accordance with an example embodiment is generally indicated by reference numeral 100. The monitoring apparatus 100 is very similar to the monitoring apparatus 10 and for this reason no in depth explanation will be given therefor. In particular, the apparatus 10 is configured to be attachable to a cable 112 via a cable connector 114 which is in turn wrapped around a pillar or column 113. It will be appreciated that any stress or strain experienced by the strata (pillar 113) will be transmitted to the cable 112 and hence the apparatus 100 which may indicate if there is a dangerous stress or strain in the pillar 113 in a similar manner as hereinbefore described. In this regard, an important element of the present invention is the determination of stress or strain in strata from measuring stress or strain associated with a support means attachable to the strata.

It will be appreciated that in some example embodiments, the monitoring apparatus is typically be configured to abut the strata (e.g. the pillar 113) directly or via an intermediate member disposed between the strata and the monitoring apparatus so as to determine the stress-strain experienced by the strata.

In any event, those skilled in the art will understand that depending on the application, there may be overlap between the apparatus 10 and system 42.

Example embodiments will now be further described in use with reference to Figures 4 to 15, and 20. The example methods shown in Figures 4 to 15, and 20 are described with reference to Figures 1 to 3, and 16 to 19, although it is to be appreciated that the example methods may be applicable to other apparatuses and systems (not illustrated) as well.

Referring now to Figures 4 of the drawings where a flow diagram of a method in accordance with an example embodiment is generally indicated by reference numeral 60.

Cable anchors 11 , or roof bolts for that matter, are typically used in mining applications to support roofs, side walls, or foot walls of mines. In this regard, in use, a monitoring apparatus 10 as hereinbefore described is operatively connected between a dome plate 28 and a cable tension collette claw 26 of the cable anchor 11 with a cable 12 axially extending there through to the rock strata 13 to which the anchor 11 is attached. The cable tension collette claw 26 is then tensioned to a correct tension (and hence the cable anchor 11 to a correct tension) by way of a hydraulic hand pump. In this regard, an advantage of the present invention is that once the correct tension has been reached, the monitoring apparatus 10 will generate a stable condition signal to visually indicate (e.g., by way of the LED 30) that the correct tension has been reached, wherein the correct tension corresponds to the safe tension condition or the cable anchor 11. For example, in a dark underground mine, all correctly tensioned cable anchors will have green LEDs on to indicate the same.

Once the apparatus 10 is fitted, the fitting crew will log on to the system 42 and assign attributes to each apparatus 10, including the mapping of the apparatus's location. Once completed, the system 42 will send a notification to a mine engineer who will be responsible for reviewing the information, assigning critical threshold values and approving the installation. At this point the apparatus is commissioned as will be touched upon below.

The system 42 records and logs data received from all commissioned monitoring apparatuses 10.

The method 60 therefore comprises continuously measuring or receiving, at block 62, strain experienced by the cable anchor 11 by way of the strain gauge 14 of the monitoring apparatus 10 as hereinbefore described.

The method 60 then comprises analysing, at block 64, the measured strain to determine if the measured strain associated with the anchor 11 is indicative of one or more of a dangerous condition, strata unstable condition, and a stable condition. The method 60 further comprises generating and/or transmitting, at block 66, a corresponding dangerous condition signal, strata unstable condition signal, or a stable condition signal depending on the comparison step respectively an indicating signal.

Steps 64 and 66 may be conducted by the processor 32 or optionally the system 42 as hereinbefore described. In this regard, the signals transmitted in step 66 may cause the LEDs to flash or be operated, or both (e.g., a dangerous condition signal may cause a red LED 30 to flash), a siren to be operated, a message to be sent to an operator as hereinbefore described with reference to the system 42 of Figure 3.

In Figure 5, when an operator, user, or the like of the system 42 receives a message from a monitoring apparatus 10 that is not part of the existing system, 42 (e.g., a new apparatus 10 with a new identifier), the system 42 is configured to trigger an event to collect calibration parameters for the newly detected monitoring apparatus 10 and verify that the monitoring apparatus 10 is in fact part of the present system 42. The collection of calibration data for the monitoring apparatus 10 is illustrated in Figure 6. It will be appreciated that in Figure 6, the listener service may correspond to the receiver module 44 of the system 42. It will be appreciate that the illustrated web service may form part of the system 42 and the illustrated application and calibration information databases may for part of the database 50.

It will be understood that the system 42 will auto detect the new apparatus 10 on the network (see Figure 7). The system 42 will automatically obtain the calibration information for new apparatuses 10. It will be understood that the newly added apparatuses 10 will be available to assign attributes and map locations too. An installation team will log in to the system 42 via the module 46 and map the location of the apparatuses 10 they have installed. Additional attributes can be captured such as; Shaft Number, Shaft Depth; Sensor distance from mine shaft, Anchor location such as Side Wall; Floor; or Roof, Rock Material, Cable Tension, Cable Length, Apparatus Type,

On completion of the mapping and attribute capture process, a notification will be sent to the mine engineer or responsible person to review the information, assign critical threshold values and commission the apparatus 10. It will be noted that the mine engineer is be required to, login and review the map and set the critical threshold values of strain which each monitoring apparatus 10 in the system 42 should use. Once this task has been completed and the work approved, the apparatus 10 is said to be commissioned as illustrated in the flow diagram of Figure 8.

A monitoring apparatus 10 may only be commissioned by the mine engineer. This presupposes the following for each commissioned apparatus 10;

• The apparatus 10 has been installed

• The apparatus 10 is working and communicating on the network 43

• The apparatus 10 has been mapped

• The apparatus 10 has calibration parameters

• The apparatus 10 has critical threshold values assigned

• The above information has been reviewed and approved by the mine engineer.

On commissioning of an apparatus, the system will generate a commission log for each apparatus 10.

Referring to Figure 9 of the drawings, an authorised user, for example, a control room user will login to the system 42 by way of the security module, particularly to access one or more of the modules 46, 48, or the database 50.

The user will select a shaft of the mine which they desire to monitor which will bring up a floor plan / schematic with the location of each of the different monitoring apparatuses 10. The monitoring apparatuses 10 will be colour coded by the status of each apparatus 10 with respect to the strain measured respectively thereby relative to the threshold values, for example as hereinbefore described. In this way, not only are alarms generated by the system 42, but the general condition of the mine, particularly rock strata therein, may be monitored remotely.

In the event of an emergency conditions (e.g., dangerous conditions), referring now to Figure 10 to 13 of the drawings, the system 42 is configured to initiate an automated response as a result of the dangerous condition signal received by one or more monitoring apparatuses 10.

The control room user will be notified of a change in risk level by way of the module 46 as hereinbefore described. The system 42 will automatically identify and flag all concerned mine sections for him to evaluate and monitor closely.

The system 42 will provide the user with a pre-defined list of steps or tasks to follow depending on the type of risk level. The system 42 should be able to audit these activities and record information indicative of the same in the database 50 once the tasks have been completed.

Figures 11, 12, and 13 illustrates emergency response workflow associated with safety officers, mine engineers, and control room users (may be on site or offsite) respectively. At least the former two have to log in to use the system 42 as hereinbefore described. The control room user typically is alerted of a dangerous condition via the receiver module 44 if the monitoring apparatus/s determines a dangerous condition and sends a dangerous signal to the receiver module 44 which causes some sort of alarm to be raised.

Referring to Figure 14, it will be noted that the module 46, or even the security module, may be configured to allow certain authorised users to allow or restrict other users from using and/or accessing certain functionalities of the system 42. The module may also allow a certain authorised user to edit details etc. associated with a particular user or themselves.

In Figure 15, it will be appreciated that the system 42 is configured to store a range of information associated with commissioned monitoring apparatuses 10 in the database 50. The system 42 therefore conveniently keeps a complete audit trail/log in the database 50 of system 42 activities for auditing purposes. In addition to the previously mentioned information which is stored, the database 50 also stores information indicative of the registered users, and the emergency tasks to be done in the event of one or more emergency conditions.

Referring now to Figure 20 of the drawings where a flow diagram of another method in accordance with an example embodiment is generally indicated by reference numeral 70.

The method 70 comprises identifying, at block 72 by way of module 48, strain data received from a particular monitoring apparatus 10 in the area being monitoring by way of a unique identifier associated with the particular monitoring apparatus 10 as hereinbefore described.

The method 70 then comprises associating and/or corresponding, at block 74 also by way of module 48, the identified strain data with map data stored in the database 50 by way of the unique identifier associated with the particular monitoring apparatus 10. As previously mentioned, the map data may be associated with the area being monitored

The method 70 finally comprises generating, at block 76 by way of the module 48, corresponding graphical representations of stress and strain, associated with the strata of the area being monitored, on the map data as previously described.

It will be understood that the abovementioned monitoring apparatus, support means, and system and associated methods need not be utilised exclusively in the mining environment, although described with reference thereto merely by way of an example. In this regard, the invention may find particular use in any application in which support members are anchored into strata, for example, in civil engineering applications such as bridges, tunnels, or the like. In this regard, the strata to which the support means are attached need not be rock and may be ferrous strata, cement, brick, or the like. It follows that the support means may extend to bolts, or any other members which undergo tensile and compressive strains or stresses and a need exists to indicate and monitor the same. In this regard, these variations of application of the present invention need not detract from the scope and/or spirit of the present invention.

The invention as hereinbefore described provides a convenient way to indicate the correct tension of the cable anchors or roof bolts, as the case may be. Also, the invention provides an indication of possible strata movement/condition of the rock strata to which the cable anchors (with the monitoring apparatuses attached) are installed. In this regard, the invention provides a convenient way to easily discriminate between safe or unsafe cable anchors and safe and unsafe rock strata.

The system described herein provides an complete system for monitoring safe and unsafe support means, and stable and unstable rock strata. This resultantly addresses the need to facilitate providing a safer mining environment thereby at least to curb human losses and also economic losses as a result of rock falls etc. caused by incorrectly installed/unsafe cable anchors, roof bolts, or the like and unsafe rock strata.

Claims

1. A monitoring apparatus comprising: an attachment member configured to facilitate the monitoring apparatus to be operatively attachable to, or in contact with, a support means; a strain gauge to measure stress or strain experienced by the support means; and indicator means to indicate if at least unsafe stress or strain associated with the support means is measured by the strain gauge.

2. A monitoring apparatus as claimed in claim 1 , wherein the strain gauge comprises an electrical strain gauge configured to generate an electrical signal in response to a variation in stress or strain experienced by the support means.

3. A monitoring apparatus as claimed in claim 2, the monitoring apparatus comprising, or communicatively coupled to, a processor configured, the process being configured to: receive the electrical signal from the strain gauge indicative of the stress or strain which the support means is experiencing; compare the received electrical signal with one or more predetermined thresholds or threshold ranges stored in a memory to determine if the support means is experiencing one or more of a dangerous condition, a strata unstable condition, and a stable condition; and transmit to the indicator means, a corresponding dangerous condition signal, strata unstable condition signal, or a stable condition signal depending on the comparison step respectively.

4. A monitoring apparatus as claimed in claim 3, wherein the indicator means comprises one or both of a visual indicating means and audio indicating means configured to be operated in response to receiving one or more of the dangerous condition signal, strata unstable condition signal, and a stable condition signal respectively.

5. A monitoring apparatus as claimed in claim 3, wherein the indicator means comprises a communication means configured to transmit one or more of the dangerous condition signal, strata unstable condition signal, or a stable condition signal from the monitoring apparatus.

6. A monitoring apparatus as claimed in claim 1, wherein the attachment member comprises a body having a recessed portion in which the strain gauge is disposed such that the strain gauge is configured to measure stress or strain experienced by the support means by measuring the stress or strain experienced by the body of the attachment member substantially at the recessed portion.

7. A monitoring apparatus as claimed in claim 6, wherein the body of the attachment member defines a circumferentially extending recessed portion such that the attachment member has a substantially hourglass-like profile.

8. A monitoring apparatus as claimed in claim 1 , wherein the attachment member defines an axially extending hole to accommodate an anchor member of the support means, in use.

9. A monitoring apparatus as claimed in claim 8, wherein the support means comprises one or more of a cable, cable anchor, bolt, anchor bolt, roof bolt, and screw attachable to strata such that stress or strain in the support means is associated with the stress or strain in the strata to which the same is attached.

10. A monitoring apparatus as claimed in claim 9, wherein the strain is positive or negative strain, or tensile strain or compressive strain respectively, experienced by the cable anchor or roof bolt experiencing tensile or compressive stresses associated with the strata to which the same is attached to.

11. A monitoring apparatus as claimed in claim 10, wherein the attachment member is operatively disposed between a cable tensioner or collette claw and a dome plate of the cable anchor such that, in use, the strain gauge is configured to measure positive and negative strain transmitted between the cable tensioner or collette claw and the dome plate.

12. A monitoring apparatus as claimed in claim 1 , wherein the monitoring apparatus is configured to abut strata directly or via an intermediate member thereby to determine the stress-strain experienced thereby.

13. A support means comprising: an anchor member to anchor the support means to strata; a strain gauge operatively connectable to the support means to measure stress or strain experienced by at least the anchor member; and indicator means to indicate if at least one or more of at least a safe and unsafe stress or strain is measured by the strain gauge.

14. A support means as claimed in claim 13, wherein the support means comprises one or more of a cable, cable anchor, bolt, roof bolt, and screw.

15. A support means as claimed in claim 13, wherein the strain gauge is directly disposed onto a shaft of the anchor member; or attachable to an attachment member which in turn is operatively attachable to the support means.

16. A support means as claimed in claim 15, wherein the attachment member comprises a body having a recessed portion in which the strain gauge is disposed, wherein the strain gauge is configured to measure strain when the attachment member, and hence the support means, experiences strain.

17. A support means as claimed in claim 13, wherein the strain gauge is an electrical strain gauge configured to generate an electrical signal in response to a variation in strain experienced by the support means.

18. A support means as claimed in claim 17, wherein the support means comprises, or is communicatively coupled to, a processor which is configured to: receive electrical signals from the strain gauge indicative of the strain which the support means is experiencing; compare the received electrical signals with one or more predetermined thresholds or threshold ranges stored in a memory to determine if the support means is _vexperiencing one or more of a dangerous condition, a strata unstable condition, and a stable condition; and transmit, to the indicator means, a corresponding dangerous condition signal, strata unstable condition signal, or a stable condition signal depending on the comparison step respectively.

19. A support means as claimed in claim 18, wherein the indicator means comprises one or both of a visual indicating means and audio indicating means configured, to be operated in response to receiving. one or more of the dangerous condition signal, strata unstable condition signal, and a stable condition signal respectively.

20. A support means as claimed in claim 18, wherein the indicator means comprises a communication means configured to transmit one or more of the dangerous condition signal, strata unstable condition signal, or a stable condition signal from the monitoring apparatus.