综放开采技术及合理架型的发展趋势外文文献翻译

英文原文The developing trend of fully mechanized mining and caving technology and the rational supportsAbstract:This paper summarized the outstanding achievements of Yankuang on the areas of long wall top coal caving technology (LTCC). Analysis and research have been done through site tests on the characteristics of dynamic movement of supports at coal face, the caving breakage, power transmission regulations and the existing problems in four leg low level shield supports. The paper recommends a new type support, which can further improve the relationship between supports and wall rock, and also prospects the future development of LTCC technology.Keywords: LTCC;The relationship between the supports of LTCC and wall rock;The prospects of new typeLTCC is a mining method with high efficiency and productivity, which is most suitable for thick coal seams with appropriate conditions. It is widely adopted due to its high productivity, high efficiency, low cost, safety and reliability. Its technical advantage has been transformed to cost advantage.Since Yankuang Group introduced the LTCC through audacious practice, its coal face output was raised from 1 Mt to 6.4 Mt and its mining efficiency has been increased by 7.2 times compared with slicing mining. Achievements of Yankuang took a lead to the overall progress of caving technology and equipment and made a great contribution to the development of the coal industry of China.However, through mining practices of many years, we found that there are still disadvantages in the four leg low level shield supports, which restricts at a certain extent the further development and improvement of LTCC technology. This paper explores the developing trend of LTCC technology, especially the development of rational supports.The general situation of the LTCC technology in Yanzhou GroupCovering Yanzhou Coal Field and Jining Coal Field, Yanzhou mining area includes six extraordinary large scaled modern minesNantun, Xinglong-zhuang, Baodian, Dongtan, Jier, Jisan and two mines of thin seams. The main seams are No.3 seam with average thickness of 8.5 m, Upper No.3 seam with average thickness of 5.25 m and Lower No.3 seam with average thickness of 4.1 m.The technical development of Yanzhou Mining area experienced two stages-conventional mining (before1979), mechanized mining (1979 1991) and entered into the stage of LTCC from 1992. The output from LTCC has been increasing rapidly and its characters and achievements are as follow.The output from LTCC increasing rapidlyIn 1992, there was only 0.53 coal face using LTCC technology in Xinglongzhuang Mine in Yanzhou Mining area with annual production of 530,300 t, which was 5.7% of the production from mechanized mining of the company. By 2002, the coal face using LTCC was increased to 9.27 from 7 mines and the production reached 33.634 Mt, which accounted for 92.64% of the production from mechanized mining of the whole company. In 10 years, the production from LTCC has increased 62.4 times. Please refer to the Figure 1.Figure 1 Indication of output in Yanzhou mining area from 1992 to 2002Unit production from LTCC increasing at a big marginThe rapid development of LTCC in Yazhou mining area enabled the unit production to increase at a big margin. In 2002, by using “Ninth-five” domestic equipment, the highest unit production reached 541,000 t/m, 2.1 times of the highest production from mechanized mining. Please refer to the Figure 2.Figure 2 Output of per working face in Yankuang in different periods of equipmentsA group level of world LTCC teams with high efficiency and high productivityThe development of LTCC has built a group of world class teams with high efficiency and high productivity represented by Xinglongzhuang Team and Dongtan Mine Team. In 1995, the LTCC team in Xinglongzhuang Mine reached the record-breaking production of over 3 Mt/a and became the first team with annual production of over 3 Mt in China. In 1998, the LTCC team of Dongtan Mine achieved annual production of 5 Mt and in 2002 yield a record of 6.07 Mt by using domestic mining equipment. Also, the LTCC team of Xinglongzhuang achieved 6.4 Mt by using “Tenth-five” auto-controlled hydraulic pressure valve equipment in 2002. In 2003 the production from three teams will break 6 Mt and reach the top level in the world. Table 1 shows the status of the teams and the equipments.Table 1 The condition and equipment of high performance coal facesParameters of coal face“Ninth-five”domestic equipment in Dongtan Mine“Tenth-five” auto-controlled hydraulicpressure valve equipment in Xinglongzhuang MineThe length of coal face (m)220300Strike length of coal face (m)24002000Seam slope angle ()0 100 11Average seam thickness (m)5.87 10Seam hardness(f)2.22.3Drawing ratio1.11.87HydraulicsupportsZFS6200/18/35ZFS6800/18/35End supportZTF6500/19/32ZTF7000/19/32ShearerMGTY-400/900-3.3DFront conveyorSGZ-960/750SGZ-1000/1200Rear conveyorSGZ-900/750HSGZ-1200/1400Stage loaderSZZ-1000/400SZZ1200/525CrusherPLM-3000PLM3500StrapSSJ1200/3200SSJ1400/34000The mining scale continuously expending and the production consolidating at a high degreeThe six minesXinglongzhuang, Baodian, Nantun, Dongtan, Jier and Jisan have formed a production pattern of “one mine, one shaft, one coal face or two faces” with a production capacity of 5 10 Mt/a. In 2003, Jisan Mine will produce a record 10 Mt, which will be the highest level of vertical shaft in China. The expected 2003 output of the main mines of Yankuang is shown by Table 2.Table 2 The expected output of main pit in 2003MineDesigned capacity (10,000 t)Expectedproduction of 2003(10,000 t)Nantun240450Xinglongzhuang300710Baodian300690Dongtan400820Jier400600Jisan5001000The existing problems of four leg low level hydraulic shield supportsThe four-leg low level hydraulic shield support plays an important role in LTCC and it is widely used at the coal faces of LTCC nationally. However, the production practice showed that some problems still exist such as its complicated structure and control system, big size, low hardness of main parts, and the slow relocation speed. Especially, the pressure at front and rear supports are not even, the utilization rate of working pressure at the end leg is low, and the support frame is broken easily. These restrict the production.The site study on the bearing characteristics of the four leg low level shield supportThe site tests on the mines of Yanzhou mining area showed that affected by the caving procedure, the support bearing has following characteristics during dynamic movement:When the support reaches its initial supporting point, the working pressure increases slightly. When the caving starts the working pressure at both front and rear legs decreases and the working pressure at the rear leg drops most. Just before the caving finishes it drops further and even to zero. 46.3% drops to over 20 MPa, 32.7% drops to below 20 MPa, 8.5% drops to below 10 MPa and 12.5% drops to 0 MPa. Results are shown by Figure 3.In Xinglongzhuang Mine, 16.6% of the working pressure of the rear leg drops to below 20 MPa, 18.7% drops to below10 MPa and 64.7% drops to zero. After the caving finishes, the working pre-ssure at rare leg increases gradually in 10 to 30 minutes and is raised to about 2 10 MPa in general.The average support strength before caving is 0.51 MPa, and it is 0.47 MPa after caving. The strength is lowered after the caving.The load-bearing situation of the LTCC support at other minesThe load-bearing situations at Yaoqiao Mine of Datun Coal and Power Company, Quantai Mine of Xuzhou are the same in general.The status of support damageSupport damages always occur at the faces. 80% of the damages are caused by the hauling resulting of the rear leg at the broken cylinder by the connecting pin. In Face 4326 of Xinglongzhuang Mine alone 98 pillars were replaced during production.The results of the above mentioned site tests show:It is popular at the faces that the working pressure of rear leg is less than that of front leg. The difference of the working pressure between front and rear leg is caused by the characteristics of the LTCC technology. The structure of supports is damaged at a large number because of the change of barycenter of the supports during caving.Since the pressure on the four-leg shield supports is not even, the supports cannot function fully to uphold the roof so that supports can be damaged heavily at large roof weighting. Yanzhou experienced three times that the supports were heavily damaged in a large area 28 supports were broken at Baodian Mine, 23 supports were broken at Dongtan Mine and 36 supports were broken at Jisan Mine.From the above mentioned, it is clearly explained that the supports with “high working pressure” are not necessarily the supports with high reliability.The characteristics of the top coal damageFrom the statistics of site tests on the falling angle it can be learned that the caving angle is relevant to the mechanic characters of the top coal. Under different mechanic conditions, the falling situation is shown by Figure 4. Figure 4 Relation between caving angle of top coal and the strength of seamIt can be learned that the harder the top coal is, the smaller the caving angle is; and vice versa the softer the top coal is, the bigger the caving angle is.When top coal is hard seam and 90, the pressure from old roof to direct roof and top coal is minor and the main pressure is from direct roof and top coal.As the top coal is soft and loose at shearing area, the pressure from upper stratum cannot be transferred effectively to the supports, which makes the composite force point shift to the coal rib so that the working pressure at rear leg drops rapidly or even to zero. Thus the working pressure of front leg is larger than that of the rear leg. This phenomenon can explain the reason that the working pressure of the support at mid-hard coal or soft coal faces is relatively small.The suggestion of two leg low level shield supportsIt can be learned from the site tests and theoretical analysis that there is a special relationship between the supports of LTCC and wall rock. The good relationship should be shown by a sound control over the top coal, the good working status of supports, and its role to accelerate the advancing of the face and raise the efficiency and productivity. Therefore, it is imperative that the four leg hydraulic shield supports which are popular in China at moment should be transformed to two leg shield supports which can be better applied in the low level caving and more suitable for the support and wall rock relations.Based on the characteristics of the relationship between supports and wall rock, the new type supports should have the following characteristics to be applied to high performance caving:To be able to solve the problem of the shift of composition force point of support load caused by the advancing of the caving line at the face. The forward-inclined leg adopted by the support strongly upholds the front end of the roof bar. The force at roof bar towards top coal is of high level, which helps to maintain the roof complete and prevent roof fall. A complete and simple-structured roof bar should be applied.The rear part should have big space for fully caving at the rear part of roof bar.The height of support should not only satisfy the requirements for ventilation and passengers, but also the rational mining to caving ratio to have the height of mining and caving compatible. The supporting strength should be able to meet the requirements of strong weighting from caving face. Single-row leg with simple system is suitable for electronic hydraulic control and easy relocation of supports to enhance the productivity.The front end of the base of the two-leg shield support is usually bigger than the four-leg support so that base device should be applied.The height of roof control of two-leg support is 600 700 mm less than the four-leg support so that the supporting strength is greatly enhanced.The prospects of the application of support of new typeStudy and development of new type support to match LTCC technology and the application of two- leg shield support in LTCC are key factors to further improve the overall technical level and have a realistic significance. Two-leg low level shield support is new development and trend in LTCC method. The successful development of this new type will inevitably promote the development of the technology and another innovation in coal mining history.中文译文综放开采技术及合理架型的发展趋势摘要：本文总结了兖矿集团在综放开采技术上的突出成就，通过现场实测，分析研究了综放工作面支架承载的动态变化特征、顶煤破坏和传力规律以及四柱支撑掩护式低位放顶煤支架存在的问题，提出了进一步改善支架与围岩关系的新架型，展望了放顶煤开采今后的发展趋势。关键词： 综采放顶煤，支架与围岩关系，新架型综采放顶煤开采技术是开采适应条件的厚煤层并实现高产高效最有效的采煤方法，它以产量高、效率高、成本低、效益好、安全可靠等主要特点被普遍应用，它以技术优势已转化为成本优势。兖矿集团自1992年采用低位综采放顶煤技术以来，大胆实践和创新，使工作面年产量由100万t逐步提高到640万t，回采工效比分层综采提高了7.2倍。带动了我国放顶煤开采技术及装备水平的整体进步，为煤炭工业的发展做出了重大贡献。但是，通过多年的现场实践发现，四柱支撑掩护式低位综采放顶煤支架还存在一些不足，在一定程度上制约了综放技术的进一步发展和提高。本文以兖矿集团综放开采的生产实践为基础，探讨了综放开采技术尤其是在合理架型方面的发展趋势。一、综放开采技术在兖矿集团的发展概况兖州矿区包括兖州煤田和济宁煤田，现有南屯、兴隆庄、鲍店、东滩、济二、济三六对特大型矿井和北宿、杨村两对薄煤层矿井。主采煤层有3煤（平均厚度8.5m）、3上煤（平均厚度5.25m）和3下煤（平均厚度4.1m）。兖州矿区采煤工艺技术的发展，在经历了普采（1979年以前）、综采（19791991年）两个发展阶段之后，从1992年起进入综放发展时期，综放产量快速增长，主要标志和成果有以下几个方面。1.综放产量快速增长1992年兖州矿区仅有兴隆庄矿0.53个综放工作面，产量53.03万t，占全公司综采产量的5.7%，到2002年综放工作面已增加到7个矿的9.27个，产量达到3363.4万t，占全公司综采产量的92.64%，10年间综放产量提高了62.4倍。如图1所示。2.综放工作面单产大幅度提高兖州矿区综放开采的快速发展，使工作面单产水平大幅度提高。2002年，综放工作面采用“九五”国产设备最高单产达到54.1万t月，是综采最高单产的2.1倍。如图2所示。图1 兖州矿区19922002年产量指标图2 兖州矿区不同装备时期的工作面3.创建了一批具有国际一流水平的高产高效综放队高产高效综放开采技术的发展，创建了以兴隆庄矿和东滩矿综放队为代表的一批具有国际一流水平的高产高效综放队。1995年兴隆庄矿综采一队首先突破年产300万t，成为全国第一个年产超过300万t的综放队；1998年东滩矿综采队实现了年产500万t，2002年东滩矿综采队采用国产设备创年产607万t，兴隆庄矿综采队采用“十五”电液自动化控制的综放工作面创年产640万t，双双突破600万t。2003兖矿年预计将有三个综采队年产突破600万t，其中济三煤矿综采队年产将突破660万t，连续9年创国内外综放生产最好水平。表1为高产高效综放队开采工作面和设备情况。4.矿井规模不断扩大，生产高度集中兴隆庄、鲍店、南屯、东滩、济二、济三6对立井矿井已经形成了年产5001000万吨“一矿一井一面或两面”的生产格局，济三矿在2003年将创年产1000万t的全国立井开采最高水平。兖矿集团主要矿井2003年预计产量见表2。表1 2002年高产高效工作面基本条件及设备配置情况序号工作面参数东滩矿“九五”国产设备兴隆庄“十五”电液控制设备1工作面长度（m）2203002工作面走向长度（m）240020003煤层倾角（）010 0114煤层平均厚度（m）5.87105煤层硬度（f）2.22.36采放比1.11.877液压支架ZFS6200/18/35ZFS6800/18/358端头支架ZTF6500/19/32ZTF7000/19/329采煤机MGTY-400/900-3.3DSL30010前部运输机SGZ-960/750SGZ-1000/120011后部运输机SGZ-900/750HSGZ-1200/140012转载机SZZ-1000/400SZZ1200/52513破碎机PLM-3000PLM350014皮带机SSJ1200/3200SSJ1400/34000表2 兖矿集团主要矿井2003年预计产量序号单 位矿井设计能力（万t）2003年预计产量（万t）1 南屯矿2404502 兴隆庄矿3007103 鲍店矿3006904 东滩矿4008205 济二矿4006006 济三矿5001000二、四柱支撑掩护式低位放顶煤液压支架存在的问题四柱支撑掩护式低位放顶煤液压支架在综放开采中发挥了重要作用，在全国综放工作面被广泛应用。但是生产实践表明，该架型还存在结构和控制系统复杂，体积庞大，主要结构件强度低，移架速度慢等问题。尤其是支架承载存在支架前后柱受力不均，后柱工作阻力利用率低，支架结构件易损坏等现象，制约了生产发展。1.四柱支撑掩护式低位放顶煤支架承载特性的实测研究兖州矿区各矿对主采煤层综放工作面的实测显示，受放煤工序的影响，支架承载具有以下动态变化特征：(1) 在升架达到初撑力之后，支架的工作阻力呈微增阻状态。当支架开始放煤时，前后柱的阻力都开始下降，但后柱下降幅度大。在放煤即将结束时后柱的阻力进一步下降，甚至降为零。其中阻力降低至20MPa以上的占46.3%，降低至20M