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中文题目：西沟四矿5.0Mt/a新井初步设计外文题目：WEST DITCH FOUR MINE5.0MT/A NII PRELIMINARY DESIGN附录A1 煤层赋存规律1.1地质构造对煤层的影晌区内以近东西走向正断层和北西南东向断层为主，北东一南西向断层不太发育.褶曲一般规模不大，多为中、小型褶曲.断层对二煤层的赋存和后期开采都有很大影响，它们破坏了煤层的连续性和完整性，限制了矿井建设规模和生产能力，增加了矿井煤柱报失，增多了矿井生产不安全因素等等.由于断层影响，区内除东西两端断层稀疏且落差不大的地段之外，不易建设大型矿井.但从另一方面分析，断层对本区二:煤层开采也造就了一些有利条件，如魏碧断层与牛店断层之间，断层组合形成地垒，在此条带内煤层埋探变浅，利于中小型矿井开发由于井筒浅无疑对节省建井投资，提高生产效益都是极其有利的。1.2煤层的厚度及其变化规律区内二:煤层最小厚度为0.5厚度20余米，一般厚度为7m.其厚度变化总配规律是以超化一三李一线北西一侧增厚，如米村井田煤层平均厚度达11.27m，该线南东- 4m,沿该线向煤层厚度由6m到8.5m, -般7m左右.由北西向南东方向煤层由厚变薄规律十分明显.这一方向恰与原始沉积坳笔轴向垂直，苟堂井田位于原始沉积坳陷的南东边缘，而米村井田则位于坳陷的斜坡地带故而，由北西向南东煤层变薄.可见本区煤厚变化主要是受沉积环境所控制。此外，后斯构造变动对煤厚变化亦有一定影响，现今的密县向斜，总的看来是西窄东宽，相对之下西端较为紧闭，东端更为宽缓，反映出向斜西端两翼盛力比东端较为剧烈，煤层受挤压应为作用产生塑性流动，由两翼向轴部运移，造成煤层增厚，而向斜东端由于两翼受力较小所以两翼与轴部煤厚变化不大，次一级的褶曲和发育在向斜背景上的断层，对煤厚的种现象在超化煤矿西采区、白碧煤矿、苟堂煤矿等处表现十分明显.断层对煤厚的影响，仅限于断层带的两侧，滑动构造对煤厚的影响，与滑体的滑动方向、构造面的陡缓以及煤层倾角大小有关，一般情况下与滑动方向相对的一侧煤层增厚，而另一侧变薄，滑体中央煤层往往被切割破坏不复存在一般都是局部的，多呈带状分布，背斜的鞍部，向斜的槽部为厚煤带，两翼为薄煤带. 1.3煤层的埋藏深度由于本区地处篙箕台隆区东部，受篙山、箕山上升隆起的牵动，地势西高东低东西高差300余米，风化剥蚀作用十分强烈，含煤组段上覆地层，均遭严重剥蚀除向斜中央尚有部分出露外，其余各处残存甚少.再者如上述断层的抬升，滑构造的影响等，煤层埋藏深度普遍变浅;如超化以南目前生产矿井证实，二，煤层埋深不超过150m，现在生产矿井井筒一般多为50-v 80rn.超化以北最大井筒深度也不超过200m.，就:a1=:7煤层开采创造了有利条件，然而，本区东部与新郑县交界处，因向斜向东倾伏，加之地势低平，第三、第四系沉积尽度加大，而使二;煤层埋深急剧增大，最大埋深达400m以上 1.4煤层变质及煤种分布规律据所得资料，煤挥发分产率(V)说明二:煤的变质程度.笔者收集了矿区各井的原煤挥发分产率的数据，择其要者介绍如下:矿区南部平陌井田为14.71，苟堂并田为15.51;中部龙台井田为14.10%，裴沟井田为14.25%，王庄井田为11.90%梁沟井日为11.38%，任岗井田为11.29%;北部芦沟井田为9.27，三李井田为7.48% .上述数据不难看出，本区由南而北二;煤原煤挥发分产率逐渐减少，最南部的苟堂井田叱最北部的三李井田原煤挥发分产率高两倍以上，并由此证明本区二、煤的变质程度由南北逐渐曾高，与成拐寸应本区煤种变化由南而北由贫煤变为无烟煤.笔者调查研究了矿区内所有井田，截止目前未发现有岩浆活动及其他引起煤层变质因素和证据，为本区二:煤层的变质作用类型当属深成变质作用.2 煤层的主要开采技术条件2.1煤层结构和原煤灰分 本区二:煤层中，魏奢断层以南一般无稳定研石层存在，多属简单结构煤层.魏碧断层以北煤层中研石层逐渐增多，如芦沟井田二:煤层中研石多达6层，其中最厚的一层达1.55m,研石岩性为粉砂质泥岩及泥岩.三李井田二:煤中歼石岩层多达8 10层，可见越往北煤层结构越复杂.究其原因与当时沉积环境直接有关，由于越往北越靠近当时沉积坳陷中心，泥炭层堆积速度不能与沉降速度经常保持一致所致.2.2煤层顶底板岩性及厚度2.2.1顶板伪顶岩性为炭质泥岩，其厚度大多为3-8m，很少超过10m，回采过程中随煤层垮落而垮落直接顶岩性为粉砂质泥岩及粉砂岩，厚度为0.7 - 2m，个别井田直接顶厚度可达4-6m放顶时即自行垮落;二:煤的老顶为中厚层状中一细粒长石石英砂岩，层面上富含炭屑及白云母片，其厚度4-20m，一般多为8 -15m，放顶时不易垮落，多半在周期性来压时才垮落，个别需用放炮切顶放落.2.2.2底板煤底板几乎全为粉砂质泥岩，北部个别矿井煤层底板中夹有粉砂岩，底板岩石中富含植物化石碎片，菱铁矿结核亦较多，该区底板粉砂质泥岩厚度，矿区南部一般为3.84一 6m，中部7- 9m，北部粉砂质泥岩夹粉砂岩厚度10-20m(三李井田厚达24.9m),底板岩石多具遇水变软、膨胀之特性，易使巷道变形、底鼓.2.3水文地质条件密县矿区地形特征，总的看来为三面环山向东开阔和倾斜的箕形盆地，南、北西三面寒武系、奥陶系、石炭系碳酸盐岩大面积分布出露、裂隙、溶洞发育，易于接受大气降水，形成良好补给条件.区内地质构造为一复式向斜，其南北两侧分别为荟萃山一风后岭和五指岭一碧背斜.向斜轴迹一线即为本区的集水线，因地形特征与构造形态基本一致，所地表的集水线与地下的汇水线也基本上是一致的，此线呈近东西向由超化一大魏继续向东进人新郑县境内，地表逞流及地下逞流受地形条件和地质构造、岩层产状控制，在本区表现十分明显.煤系地层下伏的寒武、奥陶、石炭三个系碳酸盐岩裂隙、溶洞中，由于上述良好的补给、逞流条件而储水，成为本区三大强含水层.由于受地形和地质构造控制，本区地下水总体流向是由西向东，各个块段因受具体条件影响，流向有所偏转，如向斜北翼地下水流向偏向南东，南翼则稍向北东偏转，但汇流向斜中央后依然向东，荡然而去.综观全区，据地形、构造差异，补给、逞流、埋藏条件不同，本区水文地质特征可划分为三大块段，简介如下:(见附图)2.4 瓦斯煤尘与自燃煤层瓦斯含量随深度增加而增加，据目前生产矿井揭露、实测，矿井相对瓦斯涌出量，一般情况下，埋深小于100m的矿井为2.68-6.81m/t,埋深在150m左右的矿井为一15m，埋深大于200m的矿井相对瓦斯涌出量大于15m/t.煤的煤尘具有爆炸性，爆炸指数为0.77-22.94%.二:煤层煤质松软，井下采掘和运输程中极易破碎产生煤尘，必须加强扑尘工作，以防止爆炸事故发生.具有自燃性，1957年天仙庙煤矿、1958年火石岗煤矿、1972年超化煤矿、1981年刘碧煤矿、1990年王村煤矿等都发生过井下煤层自燃，今后开采过程中对此必须严加防范.3特殊煤层采煤方法可行性分析不稳定煤层的开采，历来是采矿工作者的棘手问题。迄今为止，国内外尚没有一种采煤方法能适应各种不稳定煤层的开采。究其原因，是因为不稳定煤层的地质条件复杂，煤层赋存不规则、无规律，煤层厚度和倾角变化难以预测。受地质构造影响的不同，造成了不稳定煤层赋存状况的多样性，有的煤层厚度变化大，有的是倾角变化大，有的则二者兼有之。就形成这些变化的原因而论，有的为原始沉积而成，有的则是后期火成岩侵入或地质构造影响造成的。因此很难找到一种采煤方法能解决几种不同特征的不稳定煤层的开采问题。因此，针对矿井的具体情况，试验研究合适的采煤方法对提高不稳定煤层资源采出率具有普遍意义。3.1 不稳定煤层特征不稳定煤层又称不规则复杂煤层或难采复杂煤层。其不稳定和复杂有二方面:一是赋存状况不稳定，表现为厚度、倾角、煤质以及煤层结构等要素的变化;二是煤层的地质构造复杂，表现为煤层受褶曲、断层、岩浆岩入侵等影响。一般情况下，不稳定煤层主要是指厚度变化大的煤层。因为煤层厚度变化对开采的影响最大，而且最为常见。其煤层不稳定的成因主要有以下几种:(1)由于煤层形成时地壳不均衡沉降造成的;(2)泥炭沉积基底不平造成的;(3)河流或海流冲蚀造成的;(4)地质构造挤压造成的;(5)由于石灰岩地层岩溶塌陷或火成岩侵入造成的。但是，煤层厚度的变化往往不是单一地由某一种原因造成，而是由两种或几种原因综合作用的结果。在同一矿井的不同煤层或同一煤层的不同部位，引起厚度变化的原因也可能不同，有些地方可能是原生沉积造成的厚度变化，而另一些地方则可能是后期地质构造形成的厚度变化。根据济宁二号煤矿井田地质报告可知，“特殊煤层”的形成是河流冲蚀和地质构造挤压综合作用的结果，属于煤层厚度的后生变化。3.2 不稳定煤层开采技术难题 主要是煤层在厚度方面的不稳定，给矿井生产带来严重影响主要有三个方面:(l)影响采区巷道布置当人们根据己知地质资料在采区内布置好巷道后，却由于煤层厚度变化较大，给巷道布置带来困难。如原为分层开采的厚煤层，一旦煤层变薄只能单一煤层开采;或原为单一煤层开采的，由于煤层变厚而被迫改为分层开采，都需要重新调整巷道布置。(2)影响计划产量在存在不稳定煤层的矿区，如果工作面的回采巷道己经掘好，因为煤层变薄造成可采煤量减少，这不仅使原来的生产计划不能完成，还使许多已开掘进巷道发挥不了作用。影响工作面回采率不稳定煤层厚度变化造成工作面回采率下降是对矿井最严重的影响。在正常开采过程中，由于遇到煤层厚度变薄造成局部不可采的面积损失，和局部变厚造成丢顶煤或底煤的厚度损失。因此，对于不稳定煤层，为了减少资源损失，应根据煤层厚度变化采取对策，在采区回采前应对煤厚进行探测，力求掌握厚度变化规律，以减少它对生产的不利影响。所以，不稳定煤层开采的主要技术问题，是如何根据煤层厚度变化选择合理的采煤方法，提高工作面回采率。3.3 不稳定煤层采煤现状对于缓倾斜、倾斜不稳定厚煤层的开采，国内外主要采用的方法有以下三种方法:(l)分层下行开采分层下行开采是开采不稳定厚煤层应用最为广泛的方法。在煤层较厚的局部地区，对煤层进行分层，布置走向或倾斜长壁工作面，用综采、普采或炮采工艺自上而下顺序开采。但由于煤层厚度的变化大，分层厚度及工作面大小常受影响，导致工作面的产量、效率和回收率普遍偏低，同时也不适应综合机械化开采的要求，难以达到高产高效。(2)恒底分层开采恒底分层开采方法将回采工作面沿底板布置，先沿底板回采第一分层，上方顶煤和顶板自然垮落。顶煤和顶板经过一段时间活动稳定后再沿底板布置，回采第二分层;并用同样的方法顺序采完各个分层。但恒底分层开采的条件是上部煤层垮落后能够胶结为再生煤层，对煤层条件要求高，且最后分层工作面由于垮落顶板影响，煤质灰分高。(3)一次采全厚放顶煤开采一次采全厚放顶煤采煤法，能够很好地解决缓倾斜不稳定厚煤层的开采问题该法是沿厚煤层的底板布置回采巷道，在采用走向长壁采煤方法回采底层煤的同时放顶煤，一次采全厚。它具有巷道布置简单、效率高、产量大、生产安全、回采率高等优点。我国在开采厚煤层中先后有炮采放顶煤采煤法、普通机采放顶煤采煤法和综采放顶煤采煤法等。一次采全厚放顶煤采煤法的工作面始终沿底板推进，这样煤层厚度变化不会影响工作面的正常生产，只影响煤层生产能力，并不影响煤的损失量，即不存在丢顶煤和丢底煤的问题。在煤层厚度变化较大的厚煤层中采用放顶煤采煤法比分层开采可以取得较高的采出率。所以，此方法被认为是解决缓倾斜不稳定厚煤层开采的最好方法。对于急倾斜不稳定厚煤层的开采，由于其具有特殊性，如果采用倾斜分层开采会因厚度变化而丢失煤炭;如果采用水平分层开采，工作面长度将随煤厚变化而变化，不利于工作面管理;当采用机械化开采时，要使工作面成为等长必然造成走向方向上的煤炭损失。因此，开采急倾斜不稳定厚煤层一般采用仓储式放顶煤采煤法。对于较薄不稳定厚煤层开采，目前国内有少数矿井采用轻型放顶煤支架进行综采放顶煤开采，工作面年产量一般为70一100万t。3.4“特殊煤层”采煤技术可行性研究根据国内外不稳定煤层的开采技术现状，结合“特殊煤层”的厚度及煤层赋存特点，可以采用的采煤方法有普通综采、常规放顶煤、大采高综采、轻型放顶煤。3#煤层现有配套设备开采特殊煤层，普通综采和常规放顶煤开采都不可避免造成资源损失;而大采高综采和轻型放顶煤都需要投入新的设备不具可行性。本着充分利用已有设备的原则，考虑在“特殊煤层”工作面选用放顶煤液压支架，回采方式根据煤层厚度的变化确定一次采全厚或放顶煤开采。4 巷道放顶煤采煤法的特征与研究4.1 巷道布置及生产系统回采巷道的布置要与回采工艺相适应。作为采煤方法的核心一回采工艺的改进，必然导致巷道布置的改革，而巷道布置的改进，又将为充分发挥回采效能提供条件。国外二十世纪六十、七十年代就开始出现了壁式放顶煤工艺，七十年代后期我国长壁工作面放顶煤工艺才得到一定的发展。然而，要在急倾斜中厚一厚煤层煤层中实现放顶煤开采，由于不具备长壁工作面的条件，也就不能运用壁式放顶煤工艺，这就必然导致巷道放顶煤工艺的改革。因此，放顶煤巷道的布置，是解决急倾斜中厚一厚煤层乃至突出煤层放顶煤开采的关键技术之一。其他相关巷道的布置，遵循采准巷道布置一般原则，并充分利用己有的采准巷道。急倾斜煤层巷道放顶煤是在一个采区内沿倾斜方向按照一定的标高(15一30米划分若干个区段，在每个区段的下部布置放煤巷道，放煤巷道的两端分别与采区内的进回风系统相联，构成全负压通风系统。所有的工艺和工序都在放煤巷道内进行，顶煤开采在巷道内侧帮全长内以一定间距布置放煤小眼，利用矿山压力作用或辅以爆破松动的方法，使巷道上方顶煤破碎，堆于采场，临时支撑顶、底板。破碎煤体及其上覆顶板垮落研石利用自重近似水平状态下移，并且沿放煤巷道走向全长通过放煤管理制度将放煤小眼上部松散的煤体均匀放出，放煤巷道实际上是在松散煤体的保护下的一种沿空留巷68一5刃。因此，巷道放顶煤采煤法综合应用了综采放顶煤开采理论6。一62和急倾斜煤层沿空留巷理论是放顶煤技术和沿空留巷技术的综合运用。4.1.1 放顶煤巷道的布置根据放煤巷道的作用及布置的基本要求，放煤巷道的布置，除考虑放顶煤的技术要求外，还要综合考虑掘进、维护、安全施工、通风及运输等因素。它可布置于煤层顶板、底板、煤层和半煤岩中，既可单巷布置，也可双巷布置。根据煤层赋存特点和顶底板岩性以及放煤巷道的生产要求，对放煤巷道布置的7种方式进行分析(见图一1):煤层底板紧贴煤层布置岩巷的方式(图a)。采用这种方式，巷道围岩较稳定，同时不受上方冒落煤、研的冲击，巷道好维护;放煤口布置在巷道的侧帮，易于实现低位放煤，且能形成连续放煤口，有利于控制顶煤。但岩巷施工困难;对于突出煤层经常有揭煤问题;对于倾角大的煤层， 煤层中布置巷道的方式(图b)。放煤巷道沿煤层顶板布置，掘进较容易，掘进费用较低:放煤口安放在支架靠底板侧，且布置一个放煤眼，能实现低位多口均衡放煤;能处理放煤过程中出现的问题(如大研堵口、顶煤的二次成拱等)。但易受上方冒落煤研的冲击及放煤过程中的动压影响。煤层顶板岩石中的布置方式(图c)。顶板岩巷能实现低位多口均衡放煤;能理放煤过程中出现的问题(如大研堵口、顶煤的二次成拱等);但易受上方冒落煤研的冲击及放煤过程中的动压影响;破坏了顶板岩层的完整性，不利于采空区的岩层控制;掘进难度大，掘进费用高。 半煤岩巷布置方式(图d)。这种方式部分吸收了全底板岩巷的优点，同时也解决了巷道施工中经常揭煤的问题;但半煤岩巷掘进工序复杂，且成巷较困难。全煤斜巷联系的布置方式(图e)。将放煤巷道提高一个标高，放煤生产与其他工序分开，有利于运煤巷道的维护和生产的正常进行;还有探煤的作用;但多掘进一条巷道，掘进率高、成本增加;顶煤放出后运输机增加;全煤巷道的维护工作量大。半煤斜巷联系的双巷布置方式(图f)。将运煤的巷道布置在岩层中，既有利于本区段生产的正常运行，又有利于下区段回风用;煤层巷道根据巷道准备程度和生产进度，可一次掘出，也可分段掘出，可以起到探煤的作用;但整个巷道的施工成本增加，增加了揭煤的次数，在突出煤层中不利于安全生产。石门联系的煤岩巷道布置方式(图g)。将放煤作业的巷道布置在煤层内，运输巷道布置在底板岩层内，且在同一水平内，两条巷道用石门联系，煤巷能起工作面开切眼的作用，且煤巷超前岩巷施工，能解决石门揭煤和岩巷定向问题，在突出煤层中有利于巷道施工和采煤生产;运煤的巷道布置在岩层中，既有利于本区段生产的正常运行，又有利于下区段回风;但运输环节多，增加了运输设备;巷道的施工成本高;不能形成连续放煤口，脊背煤损增大。 综上所述，为减少巷道的工程量，节约巷道的施工成本，在单一中厚一厚煤层的条件下，单巷优于双巷;为避免巷道掘进时的揭煤，煤层巷道和半煤岩巷优于顶、底板巷道。由此可见煤层中布置放煤巷道的方式和半煤岩巷布置放煤巷道的方式均可取。考虑放煤口布置、巷道维护、放煤过程中大块堵口处理、顶煤不冒落的强制措施实施、煤层顶、底板的维护等问题以及通风安全等问题，煤层巷道布置方式优于半煤岩巷布置方式;半煤岩巷布置方式的问题在于半煤岩巷掘进施工工序复杂，成巷困难;对于煤层中布置放煤巷道的方式，通过改进巷道支护结构且实现支护结构的整体化，巷道的维护状况能得到改善。从实现放顶煤工艺来看煤层中布置巷道的方式(贴顶板布置)很容易实现放顶煤工艺，将壁式放顶煤工艺转化为巷道放顶煤工艺，这是在急倾斜中厚一厚煤层，甚至突出煤层中实现放顶煤工艺的技术关键之一。 以上巷道布置方式中，对于单一簿、中厚一厚煤层，一般采用单巷布置较经济，而对于单一厚一特厚煤层，由于巷道放顶煤工艺的局限性，为发挥放顶煤的优越性，因此，在巷道布置上采用双巷布置形式，从巷道的施工成本、巷道维护、放煤作业及放煤过程中的堵口和顶煤不冒落等问题的处理，以及顶煤下放后的运输等方面考虑，全煤斜巷联系的布置方式(图e)可以优先考虑。4.1.2 放煤巷道的断面形状与支护我国巷道支护存在的主要问题是:相当一批巷道(主要是采准巷道)支架的可缩量与巷道围岩的变形量不相适应，造成支架损坏严重，巷道维护困难，需多次翻修，维护费用很高，影响煤矿的安全和生产。据不完全统计，原煤炭部的统配煤矿至少有60%支架的可缩量与围岩变形量不相适应。如开滦矿务局1980年开拓巷道的维修量为2.6%，准备巷道的维修量为53.5%，回采巷道的维修量达106.7%。由此，采准巷道支护改革的方向就是要使支架的型式、结构和力学特性与巷道围岩的变形情况相适应，改善巷道的维护状况。己经在放顶煤实际生产过程中应用的巷道断面形状有:梯形、半圆拱形、三心拱形等，如图2-2所示，支架受力状况分析。放煤巷道在掘进和放煤过程中，所承受的压力呈动态变化。第一阶段，放煤支架受到煤体的挤压作用;第二阶段，放煤小眼开掘后，煤体的变形能得到释放，支架压力暂时减小，但随着顶煤的垮落，压力逐渐增大;第三阶段，随着放煤的进行，顶板由于失去支撑而缓慢下沉，此时，支架将承受来自顶板变形而产生的附加应力。如图2-3所示。因此，要求支架具有较大的承载能力。支架类型。由于放煤巷道的服务时间相对较短，一般2-3个月，且巷道支护的作用不只是维护巷道的稳定，因此而是选用便于回收的金属支架。在支护方案选择时不考虑锚、喷等永久支护方式，我国矿用支护型钢主要有U型钢和矿用工字钢两种，U型钢是为制造可缩支架而设计的，矿用工字钢过去多用于制造刚性金属支架，90年代以来，由于研制了专门的可缩性连接件，或对矿工钢刚性支架进行某些改造，成功地使用了矿工钢可缩支架。根据放煤巷道的矿压显现特点，和现场的实际应用情况，可用于放煤巷道支护的主要有以下6种支架:矿用工字钢刚性支架，矿用工字钢梯形可缩支架，U型钢半圆拱可缩支架，三心拱直腿可缩支架，三心拱曲腿可缩支架，多铰摩擦可缩支架。4.1.3 放顶煤小眼的布置 为较好地解决布置在煤层中的放煤巷道支架的稳定性，确保放煤生产的正常进行，关键在于让巷道处于一定范围的实体煤中，或至少要求巷道上方一定范围的煤体是不运动的。为此，在一定厚度的煤体中设计一放煤小眼，既保护放煤巷道的正常生产，又使放煤作业控制在一定范围内。 放煤小眼位置参数(开口位置、小眼倾角、小眼长度以及放煤小眼的间距等)。随煤层厚度的变化而变化，根据试验和工业实验的结果，开在煤层中低位放煤小眼的 放煤小眼开挖后，其扰动给围岩带来了影响: (1)放煤巷道的顶部和两帮扎脚处出现塑性区，放煤小眼的顶煤处出现塑性区，在巷道的下帮扎脚处和放煤小眼的顶煤处出现塑性破坏: (2)从位移矢量图上可以看出，顶煤的位移主要在靠煤层底板的方向，有利于顶煤的破碎下放，同时也是巷道支护要重点考虑的部位; (3)放煤小眼开挖后，放煤巷道周边的垂直主应力发生变化，其主应力分最大值布在巷道靠顶板的肩部和放煤小眼的上部。4.1.4 放煤口的参数及开启方式 放煤作业是在沿煤层走向的水平区段煤层巷道中进行，放煤口设在巷道靠煤层底板一侧。开口为分高位、中位、低位三种。高位放煤口回采率低，低位放煤口回采率高。高位放煤口由于其位置较高，因而操作困难。又由于支架上部冒落的松散煤体的运动影响，支架处于不稳定状态，维护条件差，尤其是一旦将放煤口放空，由于煤流的冲击，威胁巷道的安全;同时高位放煤粉尘浓度大，恶化工作环境。由此可见，高位放煤无论从经济指标，还是从技术操作、安全、环境等方面均劣于低位放煤口。考虑到工程实际中运输机设于巷道的底板上，一般情况下，放煤口最低的位置要高出运输机顶面100毫米。放煤口尺寸越大，放煤越顺利，放煤时不会发生大块煤堵塞现象，放煤速度快，放煤损失小，回收率高。一般放煤口最小尺寸，根据放出体最大块度的3倍左右的原则确定，同时，考虑放煤小眼施工的需要，适当增大放煤小眼尺寸。放煤口的开启方式，可采用机械插板和人工插板两种方式，操作简便。衡量放煤机构性能好坏的标准是:不易堵塞放煤口;放煤速度快;二次破煤能力强;尽可能使松散顶煤都有机会从放煤口放出;开闭灵活;操作维修方便等等。目的是有利于高产，提高顶煤回收率，降低顶煤含研率。 4.1.5放顶煤采煤法的生产系统 巷道放顶煤采煤法对采区巷道的布置和生产系统没有特别的要求，与其他采煤的巷道布置相比，该采煤方法对巷道布置和生产系统的要求最简单、系统运行成本最低。现场工业试验研究中，进行了多种类型的巷道布置和生产系统，有从采区准备巷道开始到回采巷道的布置，也有利用原有巷道布置和生产系统进行巷道放顶煤研究，有利用原有巷道系统在最后一个区段进行巷道放顶煤研究。巷道放顶煤采煤法只在每个区段的下部布置一条放煤巷道，放煤巷道的两端分别与采区内的进、回风系统相联，构成全风压通风系统，所有的工艺和工序都在放煤巷道内进行，如图2-8所示。4.2 巷道放顶煤采煤法的安全技术放顶煤开采与其他采煤工艺相同，都将受到煤层自燃、瓦斯、煤尘、水以及其他灾害影响。在多次巷道放顶煤的工业性试验中对巷道放顶煤开采的安全技术进行了大量研究与实践，特别是瓦斯和煤层自燃等方面取得了一些重要进展。4.2.1 瓦斯防治 煤冒落和下放过程中，可能因顶板和顶煤不能及时冒落而留有空洞或空隙，瓦斯大量解析涌向有空洞或空隙的区域，而造成瓦斯大量积聚，这将成为一大安全隐患。为此，巷道放顶煤开采中对瓦斯积聚问题重点采取两项措施，即通过放煤制度让顶煤均衡下移和加强放煤巷道的通风。直至目前还未发生由于采取放顶煤开采而引起的瓦斯超限、瓦斯突出和瓦斯爆炸等事故。4.2.2 煤尘防止 巷道放顶煤产生的煤尘是一个重要的安全问题。巷道放顶煤产生的煤尘源主要是放煤口，目前主要采用喷雾降尘措施，在放煤口和各运输机机头处装上喷头，实行人工喷雾降尘。今后应积极探索煤层注水降尘技术。4.2.3 煤层自然发火防治巷道放顶煤采煤法具有产量高的特点，因此，其工作面回采的时间相对较短，在试验和推广的几个工作面的煤层均有自然发火特征，经过生产试验的检验，未见有发火的情况，其主要原因是巷道上部的顶煤在放出之前一直处于惰性状态，没有氧化的条件，加之，生产时间较短，没有煤层氧化的时间。因此，巷道放顶煤采煤法有利于抑制煤层自然发火。5 柔掩支护采煤法5.1 巷道布置岩石底板巷掘反眼到见煤点，向同一方向掘进若干条煤巷上山(即溜煤斜坡)，各上山之间用若干条煤层斜坡联络，煤层斜坡间距为20 30 m，与斜坡的坡度均为230，形成回采条件.在边界溜煤斜坡上向反方向掘进安装柔掩护工作面，其它溜煤斜坡与柔掩工作而掘透，见图1. 5.2 柔掩侧放煤技术为了有效地回收煤炭资源，提高回采率，本工作面进行侧放煤技术一次采全高.对急倾斜厚层柔掩侧向放顶煤开采技术而言，其工艺包括爆破落煤(对硬煤部分)、移架、侧向放煤(软煤部分)和运煤等工艺. 1)利用扒煤原则使柔掩工作面支架的下肢逐步扬起，并在下肢上每米打一根木支撑来保证支架的稳定，沿工作面伪倾走向每隔5 m布置一个侧放煤口，宽2m，并在放煤口挡好封塘木，见图6. 2)工作面每推进三循环(即溜煤斜坡下推6. 3m便开始在沿着工作面靠实体煤一侧煤帮部开一放煤口，进行一次侧放煤.第一轮放煤将煤量放出60%。6生产中主要问题及处理方法6.1 支架挂顶或啃底问题如支架已挂顶阻碍了支架下放，可用打眼放炮崩去顶板岩石，并使嵌入顶板一端的下放步距大于另一端.控制下放步距，架子恢复正常;如支架已啃底阻碍了支架下放，可用打眼放炮崩去底板岩石，并使嵌入底板一端的下放步距大于另一端.控制下放步距，架子恢复正常，见图7a, b. 6.2 窜矸问题发生窜研事故的处理方法:把窜研处的空洞用笆片或木料堵上，并采取相应的措施，使支架在下一循环下放时落实在顶底两帮的煤台上.若为钢梁间窜研，可根据具体情况，用笆片、木料或型钢插堵并用铁丝固定.如果架端空洞面积较大除用笆片、木料堵塞外，还可以每间隔一定距离用木梁或点柱支撑。6.3 顶底板凸起不平问题当支架上肢切到顶板或遇到顶板突然凸起时，支架落架困难.此时，采用的处理方法先用千斤顶向底板方向顶架，然后打一加强支柱支撑下肢，再用煤电钻破掉凸出的顶板，漫慢落架使支架达到正常工作状态.当支架下肢切到底板突然凸起时，先用千斤顶向顶板方向斜顶支架上肢，使下肢离开底板，然后用加强支柱支撑上肢，再用煤电钻破掉凸起的底板，或用导链拉下肢，x慢落架，使之进入正常支护状态。附录B1The existing conditions of coal seam1.1the influence of geologic structure on coal seamArea near East-West faulting and North West to South East to the North East to South West of faults, fault less development. Fold the general size, as small fold, fault on two coal seam hosting and later exploitation has great influence, they destroy the continuity of coal seam and integrity, limit mine construction scale and production capacity, increase of coal pillar loss, increased the mine production safety factor and so on. Due to the influence of fault zone in addition to the eastern and western ends of fault, sparse and drop small lot, is not easy to build large mine. But on the other hand, analysis, fault on the region two: Coal mining are created some favorable conditions, such as the Wei Bi fault and bovine shop between fault, fault combination forming Horst, the band on the shallow buried coal seam, for small mine development due to build wells wellbore shallow undoubtedly save investment, improve production efficiency is extremely advantageous.1.2 coal seam thickness and variation regularityDistrict Two: a minimum thickness of 0.5coal seam thickness of 20meters, the general thickness of 7m. whose thickness changes in total distribution rule is to use super one three Li line north west side of thickening, such as Mickey Mukai Da the average coal seam thickness of 11.27m, the line south east -4m, along the line to the coal seam thickness from 6m to8.5m, - like about 7m. From North West to south east direction of coal seam by thinning rule is very clear. This direction exactly with the original sedimentary depression pen is vertical to the axial direction, if don Ida is located in the southeast edge of original sedimentary depression, while Mimura Ida is located in the depression slopes are, from North West to South East. The thin coal bed District of coal thickness change is mainly affected by the sedimentary environment control. In addition, after this tectonic movement on thickness variation of coal also have certain effect, the county syncline, look always is the narrow East wide, in contrast the western end of relatively closed, at the eastern end of more lenient, reflects the Western flanks of syncline Sheng is more intense than the easternmost, seam shall be produced by extrusion of plastic flow, the flanks of the axial part migration, causing coal thickening, and Eastern flanks syncline due to less force so both wings and shaft of coal thickness change is not big, the second level of the fold and development the background on the fault of coal thickness, the kind of phenomenon in Chaohua Coal Mine, coal mine, in the West District of white green careless hall coal department performance obviously. Fault on coal thickness influence, restricted to both sides of the fault zone, sliding structure on coal thickness effects, and landslide sliding direction, structure surface corrosion and steep dip angle of coal seam on the size, in general and the sliding direction of the side opposite to the coal seam thickness, and the other side is thin, smooth central seam is often cutting damage does not exist in general are more local, the zonal distribution of anticline syncline, saddle, the grooves for the thick coal belts, two thin coal.1.3the buried depth of coal seamsBecause the district is located in the loop platform uplift area in the East, by the mountain, mountain uplift skip rise affect, low-lying West High East East elevation 300meters, weathering and denudation is very strong, coal group of overlying strata, were severely eroded except syncline central still the part exposed outside, the rest remaining everywhere little. Furthermore as the fault uplift, slip structure influence, embedding depth of coal seam is generally shallow; such as ultra to South at present mine production confirmed, two, the buried depth of coal seam less than 150m, now the production of mine shaft generally is 50-v80rn. of the largest north shaft depth is not more than200m., will: a1=:7coal mining has created favorable conditions, however, the eastern part of this district and Xinzheng county at the junction, to the east by plunging syncline, and low-lying, third, Quaternary sedimentary try to increase, to two; the buried depth of coal seam increase sharply, most buried depth of 400m above1.4of coal metamorphism and the coal distributionAccording to the data obtained, the coal volatile matter ( ( V ) two: degree of coal metamorphism. The author collected in each well of coal volatile yield data, those who choose it to introduce as follows: southern area level street Ida 14.71, Gou church and field15.51; central dragon station Ida 14.10%, Pei channel Ida 14.25%, Zhuang Jingtian king11.90% beam ditch day is 11.38%, gang Ren Ida11.29%; northern Polo Ida 9.27, three Li Jingtian7.48%.The data is not difficult to see, the area from south to North in two; coal coal volatile yield decreased gradually, the most southern Gou church Ida most of the northern three Li Jingtian coal volatile yield of more than two times, and it is proven that this area two, metamorphic degree of coal from the South gradually was high, and turn should this area coal changes from south to north by lean coal into coal. The author investigated the mine all mine field, up to now not found magma activity and other factors cause of coal metamorphism and evidence, for the district two: coal metamorphic types is plutonic metamorphism.The main conditions of mining technology in 2 coal seam of2.1coal seam structure and raw coal ashThe district two: coal seam, Wei to fault south of general stability research layer exists, more simple structure coal seam fault to the north of Wei country coal layer increased gradually, such as Marco Polo Ida Ni: Institute of stone coal with as many as 6 layers, wherein the thick layer of up to 1.55m, grind stone is composed of silt medium mudstone and shale. Three Lee Ida Ni: coal gangue rock up to8 10, visible farther north coal seam structure is more complex . The reason for this was directly related to the depositional environment, farther north closer when sedimentary depression center, peat layer stacking velocity and settling velocity by Chang Baochi.2.2 coal seam roof and floor and thicknessFalse roof lithology carbonaceous mudstone, whose thickness is 3-8m mostly, rarely more than10m, the process of mining coal seam with caving and collapse of direct roof lithology is silty mudstone and siltstone, thickness of 0.7-2m, individual mine thickness of immediate roof caving is up to 4-6m to collapse; two: the old coal top is bedded in a fine-grained feldspathic quartz sandstone, level with charcoal and Muscovite film, the thickness of 4-20m, the general number of8 -15m, caving is not easy to collapse, mostly in periodical pressure is falling, the individual need of blasting cut top drop.2.2.2 substrateCoal floor almost entirely of silty mudstone, northern individual coal seam floor with siltstone, floor rock rich in fossil plant debris, siderite concretions also more, the bottom silty mudstone thickness, the southern area of3.84 is generally a6m, middle7-9m, northern silty mudstone intercalated siltstones thickness 10-20m ( three Li Jingtian up to 24.9m thick), floor rock with water softening, swelling properties, easy to make, deformation of roadway floor heave.2.3hydrogeological conditionCounty mining area terrain feature, look always is surrounded on three sides by the east open and tilt of the dustpan shaped basin, South, North West three Cambrian, Ordovician, Carboniferous carbonate rocks in large area of distribution of exposed, fissure, cave, easy to accept the atmospheric precipitation, forming a good supply conditions.The geological structure is a compound syncline, the two sides of the South as a blend of mountain ridge and ridge anticline fingers after a synclinal axis trace line. Is this area sets waterline, because of the terrain features and structural configuration are basically the same, the surface water and underground water collection department also basically is consistent, this the line is near East-West by ultra big Wei Jixu to the East into Xinzheng County, according to flow underground to flow and surface topography and geological structure, strata occurrence and control, in this area is very obvious. Coal formation Lower Cambrian, Ordovician, Carboniferous System in three to fractured carbonate rock, cavern, due to the good supply, according to flow conditions and water storage, into the area of the three strong aquifer.Due to topographic and geologic structure control, the groundwater flow is generally from west to East, each block due to specific conditions, to be deflected, such as syncline North Wing groundwater flow towards the East, the south is slightly north east deflection, but the bus still to East Central syncline, all go.In the region, according to the terrain, structural difference, recharge, flow, be buried in different conditions, the hydrogeological characteristics can be divided into three parts, introduction is as follows: ( see Figure )2.4of coal dust and gas and spontaneous combustionCoal seam gas content and increased with increasing depth, according to the current production mine, mine to expose the measured, relative gas emission, in general, buried depth of less than 100m mine for2.68-6.81m/t, at the depth of about 150m of mine for a15m, buried depth is less than200m mine relative gas emission in coal dust explosion is greater than 15m/t., explosion index for0.77-22.94%. two : coal coal is soft, underground mining and transportation process easily broken produce coal dust, dust work must be strengthened, in order to prevent the explosion accidents. With spontaneous combustion,1957beecheyana Temple coal mine, coal mine fire of 19581972, Shek Kong in Chaohua coal mine of Liu Bi coal mine, on 1981,1990in Wangcun coal mine all happened in the spontaneous combustion of coal seam, mining process we must guard against.3special seam mining method feasibility analysisUnstable coal seam mining workers, all through the ages is a thorny problem. To date, there is no coal mining method can adapt to all kinds of unstable coal seam. Investigate its reason, because the unstable coal seam with complex geological conditions of coal seam occurrence, irregular, irregular, coal seam thickness and angle changes unpredictably. The influence of different geological structure, causing unstable coal seam situation of diversity, some variation in thickness of coal seam, there is the inclination change, or some combination of the two. On the formation of the reasons for these changes is concerned, some for the original depositional, some is late the igneous rock intrusion or geological structure effect. Therefore, it is very hard to find a mining method can solve several different characteristics of the unstable coal seam of. Therefore, according to the specific conditions of the mine, the mining method test research suitable to improve the unstable coal seam mining rate of universal significance.3.1 unstable coal seam characteristicsUnstable coal seam is also called irregular coal seam with complex or difficult mining coal seam with complex. The instability and complex has two aspects: one is the occurrence state of instability, manifested as thickness, angle, coal quality and coal seam structure and other factors change; two coal seam with complex geological structure, coal seam fault fold, as by magmatic intrusion, influence. In general, the unstable coal seam mainly refers to the large thickness variation of coal. Because of the variation in thickness of coal seam on the mining impact is the biggest, and most common. The seam is not stable main reason has the following kinds:(1) as the seam formed crustal uneven subsidence caused by;(2) a deposition substrate unevenness caused by peat;(3) the erosion caused by river or sea;(4) the geological tectonic compression caused by;(5) as the strata of limestone karst collapse or igneous intrusion cause.However, changes in thickness of coal seam are often not only by one reason, but by two or several reasons for the result of the comprehensive effect of. In the same mine different coal seam or the same coal seam thickness change caused by different parts, the reasons may also be different, some places may be the primary sedimentary thickness variation, and another some of place may be a late geological formation thickness variation.According to the Jining No. two coal mine geological reports that, a special seam is the formation of river erosion and tectonic extrusion combined action result, belonging to the coal seam thickness of the epigenetic changes.3.2 unstable coal seam mining technology difficult problemIs the main coal seam in thickness is not stable, to mine production brings serious influence mainly has three aspects:( L ) effect of roadway arrangementWhen people according to the known geological data in the mining area roadway layout within the well, but due to the coal seam thickness change is bigger, to the roadway layout difficult. As for the thick seam slicing mining of thin coal bed, once only a single seam mining; or for single coal seam mining of coal seam thickness, due to forced to slicing mining, will need to adjust the layout of roadway.(2) effects of planned outputIn the presence of the unstable coal seam mining, if the roadway has been dug out, because the coal seam thinning caused the mineable coal quantity reduction, which not only makes the original production plan cant finish, also make a lot of excavation roadway can not play a role in.The influence of working surface stoping rateUnstable coal seam thickness change caused by mining in working face of coal mine is the most serious decline in the rate of effect. In the normal mining process, encountered due to coal seam thickness thinning caused by local mining area loss, and local variable thickness caused by lost top coal or bottom coal thickness loss. Therefore, the unstable coal seam, in order to reduce the loss of resources, should be based on the coal seam thickness change and Countermeasures in the mining area, mining before the deal with coal thickness detection, and strive to grasp the change of thickness, to reduce it to produce adverse effects. Therefore, the unstable coal seam mining the main technical problems of coal seam thickness change, is how to choose reasonable mining method, improve the working surface stoping rate.3.3unsteady coal seam conditionFor gently inclined, inclined unstable thick seam mining at home and abroad, the main method used has the following three kinds of methods:( L ) stratified downward miningStratified down mining unstable thick seam mining is the most widely used method. In coal-bed thicker parts of coal, stratified, arranged to or inclined long wall working face with fully mechanized mining, mining, or blasting mining technology in top-down sequence mining. But as a result of changes in thickness of coal seam thickness is large, and size of working surface often affected, resulting in the output, and recovery efficiency is generally low, but also can not adapt to the requirement of comprehensive mechanized mining, difficult to achieve high yield and high efficiency.(2) constant bottom slicing miningConstant bottom slicing mining method in mining working face layout along the bottom, along the first floor above the first layer mining, top roof and top coal caving in nature. The top coal and roof over a period of time after the activity stability along the base plate arranged in layers, second; and a method of using same order picking various stratification. But the constant bottom slicing mining upper coal seam condition is falling behind to cementation for regeneration of coal seam, coal seam conditions, and the last layer working face with caving roof coal with high ash.(3) a mining full-seam coal caving miningA mining full-seam caving mining method, which can solve the gently inclined and unstable thick seam mining problems the method is along the thick coal seam floor roadway layout, in the long wall mining method to bottom coal mining and caving coal mining, a full thickness. It has a roadway layout simple, high efficiency, large output, production safety, high recovery rate. China has successively in mining thick coal seam blasting mining caving method, the ordinary machine mining caving top coal mining and fully mechanized top coal caving mining. A mining full thickness of top coal caving mining method for working face advancing along bottom, such changes do not affect the thickness of coal seamThe normal production, affects only the coal production capacity, does not affect the coal loss, there is no lost of top coal and lost the bottom coal problem. In the coal seam thickness change large and thick coal seam with caving mining method can achieve higher recovery rate. Therefore, this method is considered a solution to gently inclined and unstable thick seam mining in the best way. For steeply inclined unstable thick seam mining, due to its particularity, if using the sloping clices mining for coal thickness change and loss; if the horizontal slicing mining, working face length will vary with the coal thickness change, is not conducive to the working face; when using mechanized mining working face, to make be equal to direction will inevitably cause the coal loss. Therefore, the mining of steep inclined unstable thick seam generally use the storage type caving mining method.For thin instability thick coal bed mining, the mine employed a few light caving support for fully mechanized top coal caving miningAccording to the domestic and foreign coal seam mining technology status, combined with special coal seam thickness and coal seam occurrence characteristics, can be used in coal mining method in fully mechanized top coal caving, ordinary routine, large mining height fully mechanized coal mining, light caving coal. Existing equipment3# coal seam mining special coal seam, fully mechanized top coal caving mining in ordinary and routine will inevitably cause the loss of resources; and the large mining height fully mechanized coal mining and light caving coal requires new equipment not feasible. In the full use of the existing equipment principle, considered in the special coal seam working face of selection of caving coal hydraulic support, mining mode according to the coal seam thickness changes identified a mining full-seam or caving coal mining.4roadway caving mining method of characteristics and research4.1roadway arrangement and production systemRoadway layout and mining process is adapted to. As the core of a coal mining method improvement of mining technology in roadway layout, will inevitably lead to the reform, and the roadway layout improvement, and to bring into full play the mining effectiveness condition. Abroad in twentieth Century sixty, seventy time begin to appear the wall caving technology, our country of seventy time later period of long wall working face with caving technology got certain development. However, in steep medium thick coal seam in the realization of a thick seam caving coal mining, because they do not have the long wall working face condition, also cannot use the wall caving technology, this will inevitably lead to the roadway caving technology reform. Therefore, caving roadway layout, is the solution of inclined medium thickness and a thick coal seam outburst coal seam with caving mining is one of the key technologies. Other roadway layout, mining roadway layout follows the general principle, and make full use of the existing workings.Caving in steep seam is in a mining area along the tilt direction according to a certain elevation of30 meters (15divided into several sections, each section is arranged in the lower part of caving roadway caving roadway, and both ends are respectively connected into the area within the air return system, constitute the full negative pressure ventilation system. All the technology and processes are in caving coal laneways, top coal mining in roadway inside help full length in a certain spacing arrangement of coal mine by using slim hole, pressure or supplemented by blasting method, the roadway above the top coal broken, heap in stope roof, floor, temporary support. Broken coal and its roof caving grind stone by the dead weight approximate level down, and along the caving roadway to full-length by coal management system will be placed coal slim upper loose coal body is uniformly released, caving roadway in loose coal body is actually under the protection of a roadway along gob (685 blade. Therefore, the roadway caving mining method applied in the fully mechanized top coal caving mining theory (6. A62 and steeply inclined seam roadway along goaf is the theory of top coal caving technology and retaining roadway along Goaf Technology Integrated use.4.1.1caving roadway layoutAccording to the caving roadway function and requirements of the layout, caving roadway layout, besides considering the top coal caving technology requirements, but also integrated into the excavation, maintenance, construction safety, ventilation and transportation factors. It can be arranged in the roof, floor, coal and coal rock, either a single roadway layout, you can also double roadway layout. According to occurrence characteristics and top and bottom slate and caving roadway production requirements, of caving roadway layout of the7kinds of means to undertake an analysis (see Figure1): close to the coal rock roadway in coal seam floor layout manner ( figure a ). In this way, the roadway surrounding rock is stable, at the same time from top caving coal, development impact, roadway maintenance; put a coal inlet is arranged on the side of roadway caving, easy to realize, and can form a continuous caving mouth, facilitates the control of top coal. But the rock roadway construction difficulty; for outburst coal seam often uncovering coal seam in large inclination,Seam roadway layout manner ( Figure B ). Caving roadway layout along coal seam roof, driving easier, driving costUsing low caving coal export: put on the bracket on the side of the base plate, and arranged a caving eye, can achieve more balanced low caving coal; coal caving process can handle problems ( such as Dayan and plugging, the top coal of two arch etc. ). But vulnerable to top caving coal research impact and caving process in dynamic pressure effect.The arrangement of the roof rock ( Figure C ). Roof rock lane to achieve more balanced low caving coal; energyCoal caving process problems ( such as Dayan and plugging, the top coal of two arch etc.); but vulnerable to top caving coal research impact and caving process in dynamic pressure effect; destroyed the roof rock integrity, not conducive to the goaf drivage difficulty big, strata control; the high cost of driving. Half coal rock roadway layout manner ( Figure D ). This partial resorption of the whole bottom Lane slate advantages, but also solve the roadway is often used in the construction of uncovering coal in question; but in half coal rock roadway complex procedure, and a lane is difficult.Full coal inclined roadway connection arrangement ( Figure e ). The caving roadway to improve an elevation, coal production and other processes separately, in favor of coal roadway maintenance and normal production; and the exploration of coal role; but many boring a tunnel, tunneling rate is high, cost increases; top coal caving coal roadway after transport increased; the maintenance workload.Half coal inclined shaft linked dual roadways layout ( Figure f ). The coal roadway layout in rock formation, is conducive to the section of the normal operation of production, and is helpful for return air in coal roadway section; according to the tunnel preparation and production progress, once unearthed, also can be segmented out, can play the role of coal; but the entire roadway construction costs, increase the number of uncovering coal in outburst coal seam, which is not good for the safe production.Shimen coal rock roadway layout manner ( Figure g ). Put coal roadway layout in operation in coal transportation, roadway layout in floor strata, and at the same level, two tunnels in Shimen coal mine working face, can play the role of open-off cut, and the coal lane ahead of rock roadway construction, can solve the Shimen coal and rock drift directional problem, in outburst coal seam in favor of roadway construction and production of coal mining; coal roadway layout in rock formation, is conducive to the section of the normal operation of production, and is advantageous to the next section return; but the transport link is much, increase of transportation equipment; tunnel construction cost is high; can not form a continuous caving coal exports, coal loss. Increase. To sum up, in order to reduce roadway engineering quantity, save the roadway construction cost, in a single thick thick coal seam conditions, single lane is superior to double lane; in order to avoid tunnelling when uncovering coal seam roadway, and half coal rock roadway, better than the top floor roadway. Thus in the coal seam caving roadway layout manner and half coal rock roadway layout caving roadway are desirable. To put a coal inlet is arranged, roadway maintenance, coal caving process in bulk blocking treatment of top coal caving, not compulsory measures implemented, roof, floor maintenance problems and ventilation issues such as safety, coal seam roadway arrangement mode is better than that of half coal rock roadways layout; half coal rock roadways layout problem is half coal rock roadway construction process is complex, difficult for coal seam roadway; layout of caving roadway, through improving the roadway supporting structure and the realization of bracing structure, roadway maintenance status could be improved. From the view of coal seam top coal caving process layout of roadway way ( paste roof arrangement ) is easy to achieve the top coal caving process, the wall top coal caving technology into roadway caving process, which is in the inclined medium thick and thick coal seam outburst coal seam, even in the realization of key technology of caving coal technology.Above the roadway layout, for a single book, in the thick of a thick coal seam, generally using a single lane layout is economy,But for a single thick coal seam, the roadway caving technology limitations, to play the top coal caving superiority, therefore, in the roadway layout using double roadway layout, construction cost from the roadway, roadway maintenance, operation and top coal caving coal in the process of blocking and top coal caving treatment of such problems, as well as the top coal after devolution transport and other aspects, the coal inclined lane contact arrangement ( Figure E ) priority.4.1.2caving roadway cross section shape and supportThe roadway supporting in the main problems are: quite a number of roadway (mainly workings ) bracket can be shrinking and the roadway surrounding rock deformation does not suit, causing serious damage to support, tunnel maintenance difficulty, need much renovation, maintenance costs are high, affecting coal mine safety and production. According to incomplete statistics, Ministry of raw coal in the coal mines at least 60% bracket may be shrinking and surrounding rock deformation does not suit. As the Kailuan Mining Bureau 1980roadway repair capacity of 2.6%, the amount of preparation roadway repair53.5%, actual mining roadway repair amounted to 106.7%. Thus, mining roadway support the direction of reform is to make the bracket type, structure and mechanical properties and the surrounding rock deformation case is adapted, improvements in roadway maintenance status.Has been in the top coal caving in the production process of the actual application of tunnel cross section shape: trapezoidal, arched, with three centers, as shown in figure 2-2,The support stress state analysis. Caving roadway in tunneling and caving process, the pressure in a dynamic change. The first phase, caving support in coal body by squeezing effect; the second stage, caving is excavated, coal deformation can be released, the support pressure is reduced temporarily, but with the top coal caving, pressure increases gradually; the third stage, with the coal, roof due to loss of support and slowly sinking, at this point, the stent will suffer from a roof deformation and additional stress generated by. As shown in figure 2-3. Therefore, requires that the holder has large bearing capacity.Frame type. As a result of caving roadway business hours are relatively short, generally 2-3 months, and the roadway supportNot only maintain the roadway stable, thereforeBut selection facilitates the recovery of metal stent. The support scheme selection does not consider the anchor, spray and other permanent support form, our country mining support steel mainly U type steel and mining I-beam two, U steel for manufacturing retractable support and design, mine I-steel past for making a rigid metal support, since 90 time, the development of special retractable connector, or the steel rigid support some transformation, successfully used by miners steel yieldable support.According to the caving roadway mine pressure behavior characteristics, and the scene of the actual application, can be used for caving roadway mainly has the following 6 kinds of support: Mine I-steel rigid support, mine I-steel trapezoidal retractable support, U steel semicircular arch retractable support, three centered arch straight leg retractable bracket, three heart arched legs retractable support, multiple joint friction yielding support.4.1.3caving coal slim arrangementTo solve the layout in the coal seam by caving roadway support stability, ensure the normal production of coal, is a key that the roadway at a range of entities in coal roadway, or at least demand above the range of coal body is not in motion. Therefore, in a certain thickness of coal caving coal slim design, both to protect caving roadway in normal production, and make the caving operation is controlled in a certain range.Coal slim position parameters ( opening position, angle, length and slim slim coal slim spacing etc.). With the coal seam thickness change, according to the test and industrial experiment results, open in the coal seam caving and small eyesCoal is the disturbance to the surrounding rock after excavation, impact:(1) caving roadway roof and two help at the foot of plastic zone, the top coal caving is appeared in the plastic zone, the roadway for foot binding and top coal caving is appeared in the plastic failure:(2) from a displacement vector can be seen, the top coal displacement is mainly on coal seam floor in direction, is conducive to the top coal broken down, but also the roadway to focus on the site;(3) is placed after the excavation of coal caving roadway, surrounding the vertical stress changes, the main stress maximum cloth in the roadway near to the roof caving coal at the upper part of the shoulder and slim.4.1.4coal export parameters and opening modeCaving is operating in the horizontal section along the seam to seam roadway in coal roadway, located in the mouth by coal seam bottom side. The opening for the high, median, low three. High coal export recovery rate, low caving coal export recovery rate is high. High coal export because of its high position, and the operation difficulty. Because the upper part of the bracket falling movement effect of loose coal body, bracket is in an unstable state, maintenance condition is poor, especially once the coal export vent, as the coal flow impact, threaten tunnel safety; at the same time discharging coal dust concentration, the deterioration of working environment. Thus, the high coal from economic indicators, or from the technical operation, safety, environment and other aspects are inferior to low caving coal export. Considering the practical engineering conveyer in roadway floor, under normal circumstances, coal export lowest position above the conveyor top surface 100mm.Coal export of the large size, top coal caving more smoothly, does not occur when large coal blockage, coal discharge speed, coal loss is small, high recovery rate. General coal export minimum size, maximum size according to emit about 3 times to determine the principles, at the same time, considering the coal slim construction needs, increasing coal slim size.Coal export of open mode, can adopt mechanical plug board and artificial board in two ways, simple operation. A measure of caving mechanism performance of the standard is good or bad: not easy to block caving coal export coal caving; speed; two coal breaking ability; as much as possible to make the loose top coal caving opportunities from outlet; flexible opening and closing; convenient maintenance and repair etc. Purpose is conducive to high yield, improving top coal recovery ratio of top coal with research, reduce the rate of.4.1.5caving mining method of production systemRoadway caving method for mining roadway layout and production system has no special requirements, and other mining roadway layout, the coal mining method for roadway layout and production system requirements of the most simple, the system operation cost minimum. Industrial experiment study, carried out various types of roadway layout and production systems, from preparation roadway to roadway layout, but also the use of the existing roadway layout and production system for roadway caving study, the use of the existing roadway system in the last section of roadway caving study. Roadway caving method in each section of the lower part provided a caving roadway caving roadway, and both ends are respectively in the return air system in mining area, connected, form a full wind pressure ventilation system, all the processes and procedures are in caving coal laneways, as shown in figure 2-8.4.2roadway caving mining method of security technologyCaving coal mining and other mining technology, will be subject to spontaneous combustion of coal, gas, coal dust, water and other disasters. In times of roadway caving industrial test on roadway caving mining safety technology for a lot of research and practice, especially the gas and coal seam spontaneous combustion has made some important progress.4.2.1gas prevention and controlCoal caving and the decentralization process, possibly because of top roof and top coal caving and can not be left empty or void,Gas analysis to large holes or voids in the region, caused by the gas accumulation, which will become a big hidden trouble of safety. Therefore, roadway caving mining on gas accumulation point to take two measures, namely thr
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