張小樓煤礦1.5Mta新井設(shè)計【含CAD圖紙+文檔】,含CAD圖紙+文檔,張小樓,煤礦,mta,設(shè)計,cad,圖紙,文檔 翻 譯 部 分 英文原文 Mine gas drainage and outburst control in Australian underground coal mines Naj Aziza, Dennis Blackb and Ting Rena a School of Civil, Mining & Environmental Engineering, University of Wollongong,NSW 2522, Australia b PacificMGM, Mining and Gas Management Consultants, Wollongong,Australia (www.pacificmgm.com.au) Abstract:Australia produces both black and brown coal and is the world’s fourth largest producer of black coal, after China, USA and India. Australian underground coal mines operate under controlled safety codes. The establishment of the mine safety management system, including the 1994 outburst management plan, contributed to a significant improvement in mine safety leading to non-fatality in outburst related incidences since 1994. The management of outburst risk, as a part of the overall safety and health management system is described. Also discussed are the introduction of outburst threshold limit values and the desorption rate index which forms the basis for determining safe mining conditions along with the “Authority to Mine” process The measures taken and lessons learned from safe mining of Australia’s outburst prone mines represent an opportunity for improved mining safety in other countries, such as China. The role of the Australian Coal Association Research Program, which supports research in critical are as such as outburst risk control and management, is also discussed. Keywords: Mine, Gas, Outburst, Mine safety management, Threshold limit values, Risk management 1.Introduction Australia produces both black and brown coal and is the world’s fourth largest producer of black coal, after China, USA and India, and the fifth largest producer of brown coal, after Germany, Russia, Turkey and USA. In 2009, Australia produced approximately 346 Mt of saleable black coal from 451 Mt of total raw coal production, and approximately 68 Mt of brown coal [1][2]. Almost 98% of Australian black coal production is sourced from the two eastern states of New South Wales (NSW) and Queensland (QLD) while brown coal is produced mainly in Victoria, with 98% coming from the Latrobe Valley. All of the brown coal production is utilised within Victoria for power generation. In 2009, Australia supplied 29% of global black coal export market, and has been the leading exporter of black coal since 1984. Black coal is Australia’s principal export commodity, generating A$55 billion in revenue for the nation last year. Australia produces and exports both metallurgical and thermal coal in approximately equal proportions. The majority of Australia’s metallurgical (coking) coal is produced in Queensland, while New South Wales produces predominantly thermal (steaming) coal. The Australian coal mining industry directly employs approximately 30 000 people and indirectly supports the employment of a further 100 000 people who provide services to the coal industry. Coal seam gas represents a potentially significant risk to the safety and productivity of underground mines. Ineffective control and management of coal seam gas increases the risk of creating conditions that may result in either a coal and gas outburst or a methane and coal dust explosion. Poor gas management may also lead to general body gas concentrations exceeding statutory limits necessitating the cessation of production activities within the affected area. Over 730 outbursts have occurred in Australian mines since 1895. Table 1 lists both fatal and other incidents related to coal seam gas explosions and gas outbursts. Such incidents have shaped coal mine legislation and operating practices and provide the motivation to develop and maintain safe working conditions and operating practices. Many of the leading Australiancoal mining companies now strive for “Zero Harm” and significant resources are dedicated to achieving this goal. Australian mining now relies on the use of Safety and Health Management Systems (SHMS) that identify hazards and other potential risks present at individual mines and requires the development of management plans and operating procedures that detail the process to identify and assess hazards and implement appropriate controls to reduce risks to as low as reasonably achievable. The management of the Mine/Colliery is required to reduce and minimise the risks associated with outbursts in development panels and on longwall faces. This aim is achieved by the drainage of inseam gas to reduce in situ content to below defined Threshold Limit Values (TLV) and implementing a system of measurement and assessment of outburst risk prior to authorising mining activities to take place in any part of the mine. Table 1: Gas explosions and outburst incidents in Australia 2.Outburst Risk Management The Outburst Management Plan (OMP) [6] is an integral part of a mine’s SHMS and is developed and maintained to effectively control the risks associated with the outburst hazard. An example of a typical relationship between the OMP and other components of the mine SHMS is illustrated in Fig. 1. The prime objective of the Mine/Colliery OMP is to facilitate exploratory inseam drilling and gas drainage with the aim of reducing in situ coal seam gas contents, in all areas of the mine where development and longwall operations (and subsequent longwall extraction) are to be carried out.Reducing the pressure and content of gas within the coal seam through focussed gas drainage has beenproven in Australia to be the most effective control to ensure that the risk of an outburst (or other release of dangerous quantities of noxious or flammable gas) is minimised and allows normal mining operationsto be carried out. In exceptional circumstances, where conditions within the coal seam prevent effective gas drainage, the OMP makes allowance for alternate mining procedures to be used, under strictly controlled and considered circumstances. In all circumstances the intent of the OMP is to maintain the protection provided to employees and the operation. The OMP applies to all employees of the Colliery who are engaged in development mining, longwall mining, gas drainage or associated tasks and any other parties associated with the application of the OMP. It covers the strategies associated with prediction and prevention techniques as well as methodologies associated with the protection of personnel and the operation from the effects of an outburst. If a coal seam is identified to be outburst prone, it is a requirement for the Mine/Colliery operating in such coal seam to develop and operate in accordance with an outburst management plan (OMP). This plan has been developed to address the risk of a gas induced outburst. The OMP’s prime operational objective is to carry out effective in-seam drilling and gas drainage, sufficiently in advance of development mining, in order to reduce in situ seam gas contents to below the normal mining thresholdsand allow mining to be carried out under normal conditions. The main elements of the plan include Prediction, Prevention and Protection (Control). 2.1 Prediction There are several factors that are accepted as the key parameters associated with outburst prediction.The geological structures of coal, excessive gas content and ground tectonic stresses are the key factors.In general, geological structures are likely to be the location of any outbursts. Geological structures are considered to present an increased risk of outburst as such structures may create stress concentrations and create a barrier that results in a high gas pressure differential. The detection of geological structural anomalies ahead of mining is achieved by in-seam drilling and the nature of the anomalies are subsequently elaborated through the use of various geophysical logging methods such as 2D and 3D seismic surveys, and the use of other technologies such as radio imaging and radar. Other methods of gas outburst prediction tools include the prediction indices [7] and using tube bundle and/or real time gas monitoring systems to detect the gas concentrations throughout the mine. In each mine the mine geologist will be responsible for the collection, analysis (with regard to outburst potential) and maintenance of the data; the mine surveyor [8] will be responsible for a drill log summary sheet for each in-seam borehole drilled within the Colliery for the purpose of exploration,structure prediction core sampling or gas drainage and plot any anomalies recorded by drillers onto the Surveyors plan, independent of the geological interpretation of that data. The gas drainage engineer willestablish documented standards and assessments for drilling of in-seam boreholes, connecting the drainage holes to the gas drainage system in the mine, and the monitoring of gas flows from boreholes, and maintenance of the gas drainage system to maximise effectiveness and the safe means of clearing a borehole suspected of being blocked. Other responsibilities of the mine geologist, the surveyor and the gas drainage engineer are described in the New South Wales Department of Mineral Resources OMP [6]. 2.2 Prevention This is related to the effectiveness of gas drainage coupled with gas flow monitoring, and regular core sampling, so that the mine manager is always aware of the seam gas and structural environment into which the mine is about to develop or extract. Prevention of outburst during mining of development roadways is achieved by the deployment of gas drainage in reducing seam gas contents to below the appropriate threshold value for the composition of the prevailing seam gas. Both prediction and prevention form the input into the Authority to Mine (ATM) process which, upon completion, will determine the mining methodology to be used to develop each roadway or sequence of roadways and extract longwall panels. 2.3 Protection or Control This is offered to development operators by way of routine training in outburst awareness, the identification of outburst warning signs and use of first response rescue and escape equipment, the provision of that equipment in the development panel at all times and the ability to suspend mining and initiate an inspection at any time should outburst warning signs be observed. Various systems and measures, which contribute to control/or protection from outbursts to include: l Ground destressing, which includes stress relief drilling, stress relief mining, inducer shot firing and gas drainage, l The use of OMPs[6], l Hydraulic fracturing; a method that has increasing application both for UIS and SIS operations, l Pulse infusion shot firing, l Water infusion. Pulsed infusion shot firing and water infuse are not generally used in Australia. Fig. 1 Mine safety management system 3.Authority to Mine (ATM) The prediction and prevention provisions are designed to develop a clear picture of the conditions prevailing ahead of development panels and to reduce the seam gas content to below the threshold value corresponding to the seam gas composition prevailing in that area. The data generated as a result of the prediction and prevention provisions provide the input into the Authority to Mine process. The method of working will be decided for each set of circumstances by using the available and recognized outburst decision making flowchart” [6]. The Outburst Risk Review Team (ORRT) will be responsible for and manage the ATM process.The ATM will be co-authorised by the mine manager, undermanager-in-charge and the gas drainage engineer. ORRT is a group responsible under the OMP to review data relevant to outburst risk at the mine and to manage mining activities through the ATM process. The group normallyconsists of mine manager, gas drainage engineer or ventilation coordinator, undermanager-in-charge, gas drainage engineer, mine geologist, workforce representative and development coordinator. The mine manager, undermanager-in-charge and gas drainage engineer are responsible for approving an ATM. 4.Threshold Limit Values (TLV) Following the last outburst related fatality in Australia, which occurred at West Cliff Colliery, Illawarra Coalfield, Sydney Basin, on 25th January 1994, the NSW Department of Mineral Resources (DMR) issued a directive to all mines operating in the Bulli seam detailing actions to be implemented to prevent further outburst related fatalities. Arguably the most significant of these actions was the stipulation of limits on seam gas content prior to mining, known as outburst Threshold Limit Values (TLV). Fig shows the Bulli seam TLV prescribed by the DMR [9]. The TLV varied linearly based on gas composition, decreasing from a maximum in CH4 rich conditions to a minimum in CO2 rich conditions. The Level 1 TLV indicates the maximum gas content limit for normal mining above which outburst mining procedures must be followed. The Level 2 TLV indicates the maximum gas content limit for outburst mining above which mining must only be undertaken using remote operated equipment, with all personnel remaining clear of the outburst risk zone. Fig. 2 Prescribed Bulli seam Outburst Threshold Limits [9] Williams and Weissman [10] introduced the concept of using the rate of gas desorption from crushed coal, during Q3 testing, known as Desorption Rate Index (DRI), to determine TLV applicable to coal mines operating in coal seams other than the Bulli seam. The test involved measuring the volume of gasemitted from a 200 g sub-sample of coal material after crushing for 30 seconds and extrapolating the result to the total gas content (QM) of the full core sample to determine the DRI of the full coal sample (Williams, 1996 [11] and Williams, 1997 [12]). The data presented in Fig, which represents data collected from the 386 panel at West Cliff Colliery [12] demonstrate a strong correlation between QM and DRI for both CO2 rich and CH4 rich coal samples. The relationship was assumed by Williams and Weissman [10] to be representative of all Bulli seam conditions. As shown in Fig.3, the Bulli seam TLV of 9 m3/t (100% CH4) and 6 m3/t (100% CO2) correspond to a common desorbed gas volume of 900 mL. From this assessment, Williams and Weissman concluded that the QM value corresponding to a DRI of 900, based on a unique QM-DRI relationship determined specifically for each mine and coal seam, represent the TLV applicable to that coal mine. Fig. 3 QM relative to DRI for CO2 and CH4 rich coal from 386 panel [12] 5.Conclusions The stringent guidelines under which the Australian underground coal mines operate demonstrate that coal mining can be achieved safely. China and other high coal producing countries with abundance of coal reserves may consider the use of SHMS’s and OMP’s similar to those being used in Australia. In the present era of advanced knowhow and technology there is no reason why underground coal miningcannot operate totally free from injuries and fatalities. This is a great challenge that must not be ignored.  中文翻譯 澳大利亞井工煤礦的瓦斯抽放技術(shù)與瓦斯突出控制技術(shù) Naj Aziza, Dennis Blackb and Ting Rena 臥龍崗大學(xué)土木工程學(xué)院采礦與環(huán)境工程系, NSW 2522 ,澳大利亞 太平洋地區(qū)煤炭開采與瓦斯管理戰(zhàn)略部，臥龍崗, 澳大利亞 摘要:澳大利亞是世界上僅次于中國、美國及印度的第四大煙煤與褐煤的生產(chǎn)基地。澳大利亞煤礦井下工作必須嚴格遵守安全規(guī)則。煤礦安全管理制度的建立，包括1994年頒布的顯著提高煤炭瓦斯突出的非致死率的瓦斯突出管理措施。本文描述了做為安全和衛(wèi)生管理制度的重要的一部分的突出危險管理制度。本文還討論了突出閥限值的引進利用及煤礦管理系統(tǒng)在確定安全開采條件過程中形成的瓦斯解析率指數(shù)。澳大利亞的有突出危險性的煤礦為保證煤礦的安全開采采取的防突措施及治突的經(jīng)驗教訓(xùn)為其他國家的煤炭安全開采提供了一個范本，例如中國。一向支持在關(guān)鍵領(lǐng)域的研究例如突出危險控制和管理的澳大利亞煤炭工業(yè)協(xié)會研究規(guī)劃部所起的作用也被提及。 關(guān)鍵詞：煤礦，瓦斯，突出礦井的安全管理，閾限值，風(fēng)險管理 1.引言 澳大利亞是僅次于中國、美國及印度的世界第四大煙煤生產(chǎn)基地及僅次于德國、俄羅斯、土耳其和美國的世界第五大褐煤生產(chǎn)基地。2009年澳大利亞從451萬噸原煤中生產(chǎn)約346萬噸可供銷售的煙煤和約68萬噸褐煤。幾乎98％的澳大利亞煙煤來源于東部兩個州新南威爾士（NSW）和昆士蘭州（QLD），而褐煤生產(chǎn)主要集中在維多利亞州，全國98％的褐煤出自拉特羅布山谷，維多利亞州的電能幾乎全部由褐煤生產(chǎn)而來。 2009年，澳大利亞出口的煙煤占世界出口市場29％，并從1984年開始一直牢牢占據(jù)著煙煤出口市場的龍頭地位。煙煤是澳大利亞的主要出口能源商品，去年澳大利亞煙煤出口獲利55億美元。澳大利亞生產(chǎn)和出口的冶金和動力煤比例大致相等。大多數(shù)澳大利亞的冶金（煉焦）煤產(chǎn)自昆士蘭州，而新南威爾士州主要生產(chǎn)動力（汽）煤炭。澳大利亞約30萬人直接從事煤炭開采業(yè)，煤炭衍生行業(yè)間接為100萬人澳大利亞人民提供就業(yè)機會。 煤層瓦斯是影響井工煤礦安全生產(chǎn)的潛在重大隱患。煤層瓦斯管理和控制不利，將會增加煤與瓦斯突出及瓦斯和煤塵爆炸等災(zāi)害的發(fā)生機率。惡劣的煤層瓦斯管理水平，將可能會使工作區(qū)瓦斯超限，導(dǎo)致煤礦不得不停止生產(chǎn)進行整改。自1895年以來，澳大利亞全國發(fā)生超過730次瓦斯突出災(zāi)害。表1列出了澳大利亞發(fā)生過的瓦斯爆炸和煤與瓦斯突出事故。這些事故促使煤炭法規(guī)及煤炭作業(yè)規(guī)范的形成，并為尋找更安全的工作條件和不斷完善操作規(guī)范提供了源源不斷的動力?，F(xiàn)在許多技術(shù)領(lǐng)先的澳大利亞煤礦公司在實現(xiàn)高產(chǎn)高效的同時爭取“零傷害”，并致力于實現(xiàn)這一目標。 現(xiàn)在，澳大利亞礦業(yè)依靠使用的安全健康管理系統(tǒng)（SHMS）來確定各個煤礦危害等級及其他潛在災(zāi)害。詳盡的管理計劃和作業(yè)規(guī)程可以用來確定和評估災(zāi)害發(fā)生狀態(tài)，并及時采取措施將災(zāi)害降到最低。 礦山/煤礦的管理要減少或盡量減少在已開拓巷道和回采工作面發(fā)生與瓦斯突出有關(guān)的災(zāi)害。以下兩種措施實現(xiàn)了該目的： 通過瓦斯預(yù)抽排放技術(shù)使煤層瓦斯含量降到閾限值（TLV）以下； 在進行任何開采活動前需對煤礦各個部位進行突出危險性的測量和評估。 表 1澳大利亞歷年突出事故匯總表 發(fā)生煤礦 時間(年) 深度(m) 死亡人數(shù)（個） 突出 氣體 突出煤量（t） Metropolitan 1895 425 CH4混CO2 200 Metropolitan 1896 425 3 礦井瓦斯 Metropolitan 1926 400 2 CO2 Metropolitan 1954 425 2 CH4、CO2 140 Metropolitan 1961 425 CH4 90 North Bulli 1911 370 CH4、CO2 300 Coal Cliff 1961 450 CH4、CO2 1 Corrimal 1967 400 CH4 2 Appin 1966 520 CH4 50 Bulli 1972 380 CH4 60 West Cliff 1977-1993 460 CO2 100 Collinsville 1954-1978 220 300 C.C.C.P 1978 280 CH4 400 Leichardt 1975 370 CO2 25 Tahmoor 1985 1 CO2 500 South Bulli 1991 3 CH4 West Cliff 1994 1 CH4 300 Central 2001 400 CH4、CO2 Brimestone/ Oakdale 1992-1995 CH4、CO2 60-80 Kemira 1980 CH4、CO2 10 Tower 1981-2000 CH4 1-80 Appin 2010 CH4 2.突出危險管理 突出管理計劃（OMP）是煤礦安全健康管理系統(tǒng)（SHMS）的組成部分，可以幫助研究開發(fā)能夠有效控制與突出相關(guān)的的災(zāi)害的措施，并確保它能順利實施。圖1詳細說明了突出管理計劃（OMP）與煤礦安全健康管理系統(tǒng)（SHMS）各部分之間的關(guān)系。 突出管理計劃（OMP）最初的目的是研究利用鉆孔技術(shù)和瓦斯的流動性進行瓦斯抽放進而將煤層瓦斯含量降到安全水平以下?，F(xiàn)在OMP已在礦井各個領(lǐng)域廣泛應(yīng)用，無論是開拓還是回采作業(yè)。在澳大利亞通過集中瓦斯抽放進而降低煤層瓦斯壓力和含量，可以有效的控制瓦斯突出（或其他的有毒或可燃氣體的大量釋放），并將突出危險性降到最低，進而允許礦井進行正常的采礦作業(yè)。在特殊情況下，由于煤層的特殊條件影響，瓦斯抽放很難取得理想效果，在考慮實際情況和采取嚴格措施后，OMP會采用備用采礦工序。無論在什么情況下OMP的目的是保護工人和設(shè)備的安全。OMP與礦山的所有人員有關(guān)，無論是從事掘進、回采、瓦斯抽放及其它相關(guān)工種的工作人員還是從事OMP服務(wù)與應(yīng)用的相關(guān)人員。它涵蓋了瓦斯突出的預(yù)測與預(yù)防技術(shù)策略，以及保護工作人員和機器免受突出災(zāi)害影響。 如果煤層經(jīng)鑒定后為易突出煤層，則該煤層的開拓和回采應(yīng)嚴格按照突出管理計劃（OMP）中規(guī)定的作業(yè)規(guī)程執(zhí)行。這個計劃就是為減少突出引發(fā)的瓦斯災(zāi)害而設(shè)計的。OMP首要的目標是實施有效的煤層鉆孔瓦斯抽放措施，使煤層在開采前將煤層瓦斯含量降低到瓦斯閾限值以下，以便進行正常安全的回采作業(yè)。該計劃的主要內(nèi)容包括預(yù)測、預(yù)防和保護（控制）。 2.1預(yù)測 以下是幾個參數(shù)被公認為是預(yù)測突出有的關(guān)鍵參數(shù)，它們是煤炭的地質(zhì)結(jié)構(gòu)、氣體含量過高和地面構(gòu)造應(yīng)力場。一般情況下，地質(zhì)構(gòu)造處往往容易發(fā)生突出災(zāi)害，地質(zhì)構(gòu)造往往會增加突出發(fā)生的幾率，這種構(gòu)造往往會產(chǎn)生應(yīng)力集中，阻礙瓦斯流動造成局部地區(qū)高瓦斯壓力。礦山地質(zhì)構(gòu)造異常檢測是通過在煤層鉆井利用各種地球物理測井方法來確定構(gòu)造的異常性質(zhì)，如通過二維和三維地震勘探，或使用如無線電成像和雷達探測等其他技術(shù)。其它的瓦斯突出預(yù)測方法包括包括預(yù)測瓦斯指數(shù)和使用管束和/或?qū)崟r氣體監(jiān)測系統(tǒng)檢測到整個礦井的瓦斯?jié)舛取? 各個煤礦的礦井地質(zhì)工作者負責(zé)收集、分析（有突出危險性的數(shù)據(jù)）和整理保存數(shù)據(jù)；礦山測量員負責(zé)確定鉆孔日志，為取得構(gòu)造核心有代表性的樣本品巖石或為進行瓦斯抽放而在各個煤層中鉆孔勘探，并將勘探數(shù)據(jù)記錄匯總，對構(gòu)造異常現(xiàn)象作出解釋。瓦斯抽放技術(shù)人員負責(zé)建立一套鉆孔標準和評價體系，建立完整的礦井的瓦斯抽放體系和鉆孔瓦斯流量的動態(tài)監(jiān)測體系，維護好瓦斯抽放體系使其達到最佳經(jīng)濟效益并可安全方式處理堵塞鉆孔。在新南威爾士州礦產(chǎn)資源OMP部對煤炭地質(zhì)工作人員、測量員和瓦斯抽放技術(shù)員的其他職責(zé)有詳細說明。 2.2預(yù)防 有效的瓦斯抽放、氣體流量的動態(tài)監(jiān)測和定期核心取樣與預(yù)防突出有緊密聯(lián)系，因此礦井管理人員一定了解各煤層煤層氣的分布狀態(tài)及其地質(zhì)構(gòu)造情況，事實證明最有效地降低瓦斯突出可能性的措施是，通過鉆孔進行瓦斯抽放，使煤層瓦斯含量降低到閾限值以下。 將預(yù)測結(jié)果和預(yù)防措施輸入到ATM系統(tǒng)中，ATM系統(tǒng)將會確定煤層采煤方法、巷道掘進方法和巷道掘進順序。 2.3保護/控制 煤礦工人要經(jīng)常接受突出演習(xí)訓(xùn)練，通過訓(xùn)練，工人須牢記突出危險發(fā)生前兆，要確保突出發(fā)生時第一反應(yīng)是使用救命和逃生設(shè)備，煤礦要有實時監(jiān)控回采區(qū)段的的設(shè)備，并且當發(fā)現(xiàn)明顯突出前兆發(fā)生時，該監(jiān)測系統(tǒng)要隨時立即切斷回采區(qū)段所有設(shè)備的電源，使設(shè)備停機，以確保安全。 突出災(zāi)害發(fā)生時有以下幾條保護措施和方法： l 減小應(yīng)力集中，包括鉆孔釋放應(yīng)力、開采解放層、誘導(dǎo)應(yīng)力釋放和瓦斯抽放等等； l OMP系統(tǒng)的推廣應(yīng)用； l 水力壓裂法； l 脈沖輸液開槍射擊煤壁； l 注水； 脈沖輸液開槍射擊煤壁和注水這兩種方法未在澳大利亞推廣應(yīng)用。 3.煤礦管理系統(tǒng)（ATM） 預(yù)測和預(yù)防突出主要是在區(qū)段回采前將煤層瓦斯含量降到閾限值（TLV）以下，將預(yù)測和預(yù)防突出所得的結(jié)果輸入到煤礦管理系統(tǒng)（ATM）中，ATM系統(tǒng)會通過現(xiàn)有的突出決策流程圖為每種獨特的開采條件制定一套適合的采煤方法。突出危險性評審小組（ORRT）將負責(zé)管理ATM流程。ORRT是OMP下設(shè)的通過利用ATM系統(tǒng)專門負責(zé)審查與礦井突出危險性相關(guān)的數(shù)據(jù)及控制煤層活動。本小組一般由礦長、瓦斯抽放工程師、通風(fēng)協(xié)調(diào)員、井下負責(zé)人、煤炭地質(zhì)工程師和職工代表組成。礦長，井下負責(zé)人和瓦斯抽放工程師負責(zé)審批ATM所得結(jié)論。 4.閾限值（TLV） 自1994年1月25日，澳大利亞悉尼盆地伊拉瓦拉煤田西崖煤礦發(fā)生導(dǎo)致工人死亡的瓦斯突出事故后，新南威爾士州礦產(chǎn)資源部（DMR）發(fā)出指令各煤礦加強管理，研究新技術(shù)以降低瓦斯突出事故所帶來的災(zāi)害。并規(guī)定了可采煤層的瓦斯含量即閾限值（TLV），圖2是DMR繪制的一幅關(guān)于煤層閾限值（TLV）示意圖。從圖中可以看出閾限值（TLV）呈線性,橫軸代表氣體成分(CO2)，豎軸代表瓦斯含量。隨著 CH4含量的減少氣體成分中CO2含量逐步增加。TLV 1表明正?；夭蓵r所允許的瓦斯含量臨界值，超過該值，就需要預(yù)先采取防突措施。TLV 2表明正常掘進時所允許的瓦斯含量臨界值，超過該值時，必需采用遠程遙控機械作業(yè)，相關(guān)人員要撤離到安全區(qū)內(nèi)。 在第三季度測試時威廉姆斯和韋斯曼提出利用了煤破碎時瓦斯釋放率即解吸率指數(shù)（DRI）來確定煤層的TLV。將一塊重200g的煤巖樣本完全破碎，30秒后測量其釋放的瓦斯量，推算出完整巖心樣品的瓦斯含量（QM），進而確定瓦斯解吸率指數(shù)（DRI）。 圖3所顯示的數(shù)據(jù)是從西崖煤礦386工作面實測收集而來。從圖中可以看出CO2 含量豐富和CH4含量豐富的煤樣QM和DRI表現(xiàn)出很強的相關(guān)性，威廉姆斯和韋斯曼假設(shè)這種關(guān)系是布利煤層條件最好的表示。正如圖3所示，布利煤層的TLV線9m3/t（100％的CH4）和6m3/t（100％的CO2）對應(yīng)一個共同的解吸率指數(shù)900毫升。  圖1瓦斯含量與TLV關(guān)系圖 圖2瓦斯含量與解吸率的關(guān)系 5.結(jié)論 在嚴格的指導(dǎo)監(jiān)督下，澳大利亞的煤礦實現(xiàn)了安全，高效生產(chǎn)目的。中國和其他產(chǎn)煤大國應(yīng)試著采用參考澳大利亞開發(fā)自己的SHMS和OMP系統(tǒng)。在目前先進技術(shù)條件下，井工煤礦完全可以實現(xiàn)0傷亡目標，實現(xiàn)這個目標需克服重重挑戰(zhàn)。