A Study of the Relationship between Rock Music and the Counterculture Movement

In the 1960 s, America has entered a new historical period with recession in economy and increasingly bad social problem. Besides, Civil Rights Movement and women rights movement have been led by black people and women for equal rights.With the development of these movements, the counter-cultural movement came into being, and the movement which represented a significant period in post-war youth cultural history was caused by the impending readjustment of social structure during the transition from industrial to post-industrial society in the 1960 s. American white middle class youth were disillusioned with the way their parent culture controlled the society and had no desire to become caught up in the machinery of social power themselves.The counter-cultural constituted a direct attack on the part of white middle class youth against the dominant ideological machinery set in place and maintained by its parent culture, and its influence has been maintained to the modern times. Except for the liberation of sex and drug, the most important symbol of the counter-culture is rock music. There is a close relationship between the counter-cultural movement and rock music. During the mid to late 1960 s rock music became a centrally significant medium for the dissemination of a range of social-political issues in counter-cultural movement. The period from the mid-1960 s to the early 1970 s represented the first time that popular music, a mass cultural form, had become a centrally significant medium for the dissemination of a range of sociopolitical issues, from US involvement in the Vietnam war to the Civil Rights Movements, to the rejection of western political and cultural ideology. As Eyerman and Jamison^([1])point out:‘Movement ideas, images,and feelings were disseminated in and through popular music and, at the same time, the movements of the times influenced developments, in both form and content, in popular music'.

An estimation model for the fragmentation properties of brittle rock block due to the impacts against an obstruction

Mountain hazards with large masses of rock blocks in motion – such as rock falls, avalanches and landslides – threaten human lives and structures. Dynamic fragmentation is a common phenomenon during the movement process of rock blocks in rock avalanche, due to the high velocity and impacts against obstructions. In view of the energy consumption theory for brittle rock fragmentation proposed by Bond, which relates energy to size reduction, a theoretical model is proposed to estimate the average fragment size for a moving rock block when it impacts against an obstruction. Then, different forms of motion are studied, with various drop heights and slope angles for the moving rock block. The calculated results reveal that the average fragment size decreases as the drop height increases, whether for free-fall or for a sliding or rolling rock block, and the decline in size is rapid for low heights and slow for increasing heights in the corresponding curves. Moreover, the average fragment size also decreases as the slope angle increases for a slidingrock block. In addition, a rolling rock block has a higher degree of fragmentation than a sliding rock block, even for the same slope angle and block volume. Finally, to compare with others' results, the approximate number of fragments is estimated for each calculated example, and the results show that the proposed model is applicable to a relatively isotropic moving rock block.

Investigation on fracture models and ground pressure distribution of thick hard rock strata including weak interlayer

Dynamic disasters,such as rock burst due to the breaking of large area stiff roof strata,are known to occur in the hard rock strata of coal mines.In this paper,mechanical models of the fracturing processes of thick hard rock strata were established based on the thick plate theory and numerical simulations.The results demonstrated that,based on the fracture characteristics of the thick hard rock strata,four fracture models could be analyzed in detail,and the corresponding theoretical failure criteria were determined in detail.In addition,the influence of weak interlayer position on the fracture models and ground pressure of rock strata is deeply analyzed,and six numerical simulation schemes have been implemented.The results showed that the working face pressure caused by the independent movement of the lower layer is relatively low.The different fracture type of the thick hard rock strata had different demands on the working resistance of the hydraulic powered supports.The working resistance of the hydraulic powered supports required by the stratified movements was lower than that of the non-stratified movements.

基于Rockfall数值模拟的危岩体运动规律分析

危岩体发育过程具有渐进性,失稳过程具有突变性和强致灾性,危岩崩塌灾害是山区公路工程建设及运营过程中普遍存在的突发性重大安全隐患,前期预测和分析危岩体落石运动特征可为危岩体治理提供参考。本文以兴义环高某特大桥桥台上方的危岩体为例,通过现场调查研究,分析危岩特征,采用Rockfall数值软件模拟危岩落石运动轨迹、落石终点水平位置,分析落石速度及其能量大小。结果表明:危岩体W5发生崩塌后,有大部分落石到达桥面,且在到达桥面时仍有较大动能和转动速度,会对桥面造成严重撞击和破坏,威胁和影响行车安全。建议对危岩体进行防护或加固,以保障公路建设运营安全。

Research on application of rockmass breaking and inversion stress distribution by MS monitoring in Iongwall face

Brought forward the conception of conventional MS monitoring, and described the different monitoring ranges of frequencies and magnitude about earthquake and conventional MS monitoring and MS monitoring in detail. The monitoring results received by the Polish ARAMIS M/E monitoring system and the monitodng instrument designed by the author＇s research group in the same colliery show that the events amount received by conventional MS monitoring instrument which is only about 1/20 of the MS monitoring events, and it can only describe violent activity in larger range and be only applied to monitor hard and thick surrounding rock under mine. Meanwhile the small scale and high precision MS monitoring instrument can receive a lot of low rock fracturing signals, which can actualize the rock movement inversion and precisely descdbe 4-D changes of stress fields, and depend on the observed results we can determine the upper limits of mining and describe S-shaped strata spatial structure and high stress field in Iongwall face surrounded by two sides mined areas.

动水作用下岩体裂隙中颗粒运动规律的试验研究

动水作用下岩体裂隙中的颗粒运动是引起渗透破坏的常见原因。针对天然岩石裂隙的随机性与隐蔽性,采用三维Weierstrass-Mandelbrot分形函数构建随机裂隙通道,并采用3D打印方法获得透明裂隙模型实体,使用微流体控制仪开展动水作用下颗粒在裂隙中的运动试验,分析裂隙粗糙程度、颗粒粒径与裂隙开度的比值(简称粒径隙宽比)、渗流水压力对颗粒在裂隙中起动、运移的影响规律,进而推断岩体裂隙发生渗透破坏的可能性。研究结果表明:颗粒在岩石裂隙中的运动规律与裂隙粗糙程度、水压力、颗粒粒径隙宽比3个因素有关。裂隙粗糙程度越大,或颗粒粒径隙宽比越大,颗粒越不容易开始运动,即裂隙发生渗透破坏的可能性越低。同时,水压力是颗粒运动的主导因素,颗粒粒径隙宽比对颗粒运动的影响与水压力有关。存在一特定水压力临界值,未达到该水压力时,颗粒粒径隙宽比对平均运动速度的影响不明显,超过该水压力后,影响程度显著增大,且该临界水压力值的大小与裂隙粗糙程度有关,裂隙越粗糙,临界水压力越大。

大红山铁矿露天——地下联合开采岩移发展规律研究

地下开采产生的地表移动会影响邻近露天采场边坡的稳定性。以大红山铁矿露天—地下联合开采为例,采用微震、地表开裂观测等多种方法进行岩移监测和数据分析,探究了地下开采引起的岩体移动与地表开裂规律。首先,对历史监测数据进行了整理和分析,包括地表塌陷和裂缝的发育情况。其次,针对地下开采过程中的围岩变形特点,开展微震数据分析,获取了岩体损伤破坏信息。同时,结合矿山地质资料,统计数据得出了陷落角的变化范围。结果表明:大红山铁矿露天—地下联合开采,岩体移动发展阶段可划分为:冒落及地表贯通的岩移阶段、陷落区充分发展的岩移阶段、F2断层影响的陷落角非对称发育阶段、废石充填与深部开采下的岩移阶段。西北部陷落角发育范围为75°~81°、东南部陷落角发育范围为65°~82°。研究可为类似地质及工程条件矿山岩移发展规律分析提供一定参考。

Large Scale Mass Movements Triggered by the Kashmir Earthquake 2005,Pakistan

The SPOT image analysis in Muzaffarabad Azad Kashmir,northwest Himalayas,Pakistan reveals that the Kashmir earthquake 2005 triggered a number of coseismic mass movements along the hanging wall block of the Muzaffarabad Fault.The Neelidandi and Langarpura rock falls have been identified as two major reactivated mass movements with an estimated volume of 3.1 × 106m3and 5.76 × 106m3,respectively.The Neelidandi and Langarpura mass movements were initiated during earthquake in the direction of northwest-southeast extension and northeastsouthwest directed thrusting,respectively.The Neelidandi rock fall occurred in sheared cherty dolomites and limestones of the Cambrian Muzaffarabad Formation,whereas the Langarpura rock fall occurred in alternating clays,shales,claystones,siltstones and sandstones of the Miocene Murree Formation.These rock units along the fault are highly fractured and jointed.The geotechnical maps and geological longitudinal profiles show the relationship between the geometrical characteristics and mechanism of these mass movements.Their characteristics were analyzed according to the role of topographic,seismic,geological and tectonic factors.The steep topography,sheared rocks,lithology,coseismic uplift and strong ground shaking of the hanging wall block along Muzaffarabad Fault facilitated the gravity collapse of these mass movements.

基于非线性弹性地基梁的地下矿山充填开采覆岩移动规律研究

为了研究地下金属矿充填开采覆岩移动规律,以盘龙铅锌矿采场作为研究对象,建立非线性弹性地基梁力学模型,开展了不同采场结构参数、顶板厚度、原岩应力及充填体配比对于覆岩移动的影响研究。研究发现5个因素对于覆岩移动的影响从强到弱依次为充填体配比、采场结构参数、顶板厚度、原岩应力,提高充填体配比是控制覆岩位移的关键。通过采用Flac3D数值模拟方法计算不同充填体配比下覆岩移动值,将数值模拟分析结果与力学理论计算结果进行对比,二者差异率在3%~9%之间,从而验证了力学模型计算结果的可靠性。基于研究结果,提出地下矿山充填开采覆岩沉降控制技术,并将其应用于工业试验。研究成果可为类似矿山进行岩层控制提供借鉴。

峡谷区公路桥隧衔接段危岩运动模拟及轻量化防护预警体系探讨

深切峡谷区公路桥隧衔接段危岩落石极为普遍,具有高陡、面广量大、致灾随机性强等特点,存在识别难、绕避难、防治难、养护难等诸多工程难题,使得现有防护措施面临巨大挑战。以巫溪隧道出口危岩为例,采用无人机倾斜摄影测量技术建立山体高精度三维模型,快速准确识别危岩及其分布,利用RockFall及CRSP-3D软件模拟落石运动特征。结果表明:1)落石以自由飞落、滚动、弹跳为主;2)无防护工况下落石最大弹跳高度大于70 m,最大冲击能量9000 kJ,主被动防护工况下,仍有10%的高位落石破网而出;3)LS-DYNA模拟显示,冲击作用下柔性棚洞可拦截破网落石,棚洞各构件处于弹性状态,但拱架基础在低能落石冲击下易破坏。基于此,提出深切峡谷区桥隧衔接段突发型及渐进型危岩落石全寿命周期轻量化预警防护体系,以实现“高能易修、中能无害、低能零损”的防护预警目标。

近距离煤层重复采动覆岩破坏规律及“两带”发育高度分析

为研究近距离煤层重复采动下覆岩破坏规律与“两带”发育高度,预防工作面开采过程中由导水漏风通道引起的工作面顶板漏水、采空区自燃等各种安全事故,以鄂尔多斯市某煤矿为工程背景,采用井下窥视法和数值模拟对近距离煤层开采后覆岩破坏规律以及“两带”发育高度进行分析,揭示了规律形成的原因。研究结果表明:在近距离煤层重复采动影响下,“两带”发育高度远超过上煤层开采,下煤层推进80 m时裂隙带最大发育高度为88 m,与地表贯通形成导水漏风通道;初次采动与重复采动时的裂采比分别为19.33、29.33;裂隙带的发育呈台阶式上升,阶段间的变化表现为激跳形式;覆岩的破坏表现为“拱形→帽形→马鞍形→外O内蝶形”;数值模拟及拟合公式所预测的“两带”发育高度与实测值之间误差率为1%左右,验证了预测的准确性,可为相似工作面的开采以及相似工程提供借鉴。

含水溶洞对采煤工作面覆岩移动的影响规律

含水溶洞的存在使得煤层覆岩移动规律具有特殊性。为了研究含水溶洞对煤层覆岩移动的影响,以贵州松南煤矿作为工程背景,利用FLAC 3D进行数值模拟研究,对比分析溶洞有无含水作用下煤层覆岩移动规律。研究发现:随着采煤工作面的推进,含水溶洞围岩裂隙和煤层顶板裂隙不断扩展,当工作面推进至与溶洞水平距离小于10 m时,溶洞围岩裂隙和顶板裂隙贯通,形成导水裂隙;含水溶洞煤层开采情况下,溶洞围岩变形下沉量相较于无水情况增加了37.24%,随着推进距离的增加,溶洞靠近采空区侧底角出现明显的下沉现象,溶洞右帮出现向内挤压现象,溶洞围岩和煤层顶板应力集中区和破坏区逐渐贯通;相比于无水情况,覆岩运移在含水条件下得到加强,其中最大曲率增大了0.88 mm/m^(2)、最大水平变形增大了1.81 mm/m。建议该矿采煤工作面与溶洞水平距离需大于10 m。

“三下”采煤下某煤矿E2307工作面地表岩移规律研究

为系统掌握综放开采条件下地表移动变形规律和机理,某煤矿于2018年初建立了E2307综放工作面地表岩移观测站,结合工作面具体概况,在对现场进行实地观测和资料分析的基础上,结合理论分析、数值模拟计算,求取了某煤矿特定地质采矿条件下的岩移参数和岩移角值,揭示了该矿厚松散层综采放顶煤条件下地表沉陷变形规律,为某煤矿今后开展村庄下、水体下、铁路下、公路下采煤以及合理留设保护煤柱提供了科学依据,同时丰富了我国“三下”采煤关于综放开采沉陷领域研究成果。

营盘壕煤矿深部多煤层开采地表移动变形规律及最优错距研究

鄂尔多斯东胜煤田为侏罗系含煤地层,诸多深部矿区2-2煤层和3-1煤层全区可采,并且煤层间距较小。以营盘壕煤矿为地质原型,通过FLAC3D和UDEC数值模拟软件构建研究区域数值模型,围绕2-2煤层和3-1煤层开采引起的地表移动变形及应力场演化规律进行研究。结果表明:多煤层重复采动将引起沉陷盆地中心投影向下煤层采空区方向移动,进而逼近煤层初采中心投影,并最终越过之;两煤层连续开采后,地表最大下沉值小于两煤层单独开采最大下沉值之和,煤层复采下沉系数小于初采下沉系数;煤柱错距与地表移动参数关联密切,错距系数与地表下沉系数、水平移动系数和主要影响角正切分别呈对数正态函数、凹抛物线和凸抛物线函数关系,并且与宽深比作为共同因子对煤层初采及复采表征参数的比值产生耦合影响;另外,同时随着错距的增大,地表沉陷盆地范围先减小后增大的趋势发展,水平移动近盆地等值线由椭圆形向梭子形演化;综合卸压错距经验公式、地表损伤程度及煤柱卸压效果确定的研究区域多煤层开采最优错距为30 m。

上行开采煤层减损的工作面合理布设位置研究

以枣泉煤矿五分区1煤的上行开采问题为背景,为了达到1煤的减损目的,借鉴协调减损开采的思想,采用相似模拟、数值计算的研究方法,确定了沿煤层倾向先期开采煤层工作面之间的相对布设位置和范围。采用下沉、水平移动、倾斜、曲率、水平变形5个指标,对1煤的移动变形程度和均匀性进行了评价。结果表明:当工作面在合理布设范围之内时,可以促使遗留煤柱位置处1煤进一步充分下沉,移动变形指标均达到该地质采矿条件的最均匀程度,可以有效抵消由于遗留煤柱影响而引起的待上行开采煤层的变形不均问题,使多次采动成为上行开采的有利条件,达到1煤的减损目的。

露天转地下挂帮矿崩落法开采边坡安全防控技术研究

露天转地下过渡期崩落法开采挂帮矿,会引起边坡的岩移和陷落,威胁露天矿的安全生产。以大孤山铁矿为工程背景,分析边坡岩移机理,得出挂帮矿持续冒落跨度为临界冒落跨度的1.25~1.65倍,第一分段进路布置在矿体厚度大于3.3l的位置,能够保证露天开采的安全。研究陷落散体所需的回采体积,得出回采体积先随着保安矿柱宽度的增加而减小,后又随着保安矿柱宽度的增加而增大,当保安矿柱的宽度为88.45 m时,所需回采体积最小。采用散体滑落试验,得出了防护坝设置在露天坑底的上一个台阶,保证了露天开采的安全。研究成果能够实现大孤山铁矿露天转地下过渡期的产能衔接和安全生产,对于矿山的未来发展具有重要意义。

基于离散元法的反倾边坡动力破坏模式及分区研究

在地震作用下,一旦诱发反倾路堑边坡的失稳破坏,将对高速公路的安全运行带来不可估量的损失。为研究反倾边坡的动力响应特征,利用UDEC离散元软件模拟了Scavia反倾边坡模型在双向地震作用下的位移过程,分析了块体的运动模式。结果表明:在双向地震作用下,反倾边坡各岩块从稳定状态到滑出坡体的运动状态是相互转换的,靠近坡体后缘岩块运动状态的相互转换更为剧烈;根据块体的运动状态,可以分为3个区域,其中位于坡体前端的岩块主要经历“滑动—倾倒—滑动-倾倒”的状态变化,坡体中部则在滑动-倾倒与滑动状态之间相互转换,且转换速度慢,而坡体后缘岩块运动模式为“滑动—倾倒—滑动-倾倒—滑动”状态,其中滑动-倾倒状态到滑动状态相互转换,且转换速度快。

高强度重复开采覆岩与地表移动机理

为了给神东等大型煤炭生产基地生态修复和“三下”开采提供理论和技术支持,以实测方式为基础,深入研究了高强度重复开采地表移动特征和机理。分别对老采空区下开采、工作面隔离煤柱下开采、跨老采空区和隔离煤柱下开采这3种工况布设地表移动观测线,开展快速密集监测,采集了丰富的地表移动数据。结合井下推进过程,通过数据分析,获得了不同时期下沉和水平移动值,绘制了地表移动曲线时序图。研究表明:隔离煤柱对地表下沉的发展过程具有阻碍性、带动性和活化性等特征,水平移动方向对井下推进方向具有追随性等现象。据此建立了高强度重复采动条件下形成的块体岩层结构模型,分析了块状岩体在井下推进过程中平衡—旋转平移—再平衡的运动过程,揭示了地表移动实测曲线形态背后的岩层移动机理。研究成果可为该矿区或类似矿区开采沉陷预计模型建立和生态环境修复治理提供参考。

考虑采空区压实度的端面顶板稳定性数值模拟

为研究不同采空区压实度条件下端面顶板稳定性,通过PHASE 2D有限元软件建立高刚度和低刚度2个采空区数值模型,研究端面顶板下沉规律、支承压力分布特征及端面顶板塑性区演化。研究结果表明,当采空区刚度为250 MPa时,开采前后直接顶下沉量最大值分别为90 mm和109 mm;当采空区刚度为600 MPa时,开采前后直接顶下沉量最大值分别为43 mm和74 mm;当采空区刚度由250 MPa增大至600 MPa时,工作面支承压力峰值由7.3 MPa降低为6.8 MPa;增大采空区刚度后,工作面端面顶板塑性区范围降低了44.3%。因此,有效提高采空区刚度能提高端面顶板稳定性,从而降低端面冒顶发生的概率。

厚煤层开采上覆岩层移动与应力分布特征研究

厚层顶板的垮落常对综放工作面前方的煤岩体造成冲击,为防治厚煤层开采引发的冲击地压灾害,了解工作面开采的安全稳定性,利用FLAC^(3D)建立了李楼煤矿1301工作面三维采动模型,获得了随工作面推进覆岩移动与应力分布特征,理论计算了厚表土地层侧向支承压力,对回采面整体的安全性进行分析。结果表明:采空区上覆岩层的运动随工作面的推进逐步向上发展,当工作面推采至400 m时,上覆岩层运动高度达到最大;工作面超前支承压力的影响范围和应力的集中程度随工作面的推采逐渐增加,当工作面推采至工作面见方时,超前支承压力的应力达到60 MPa,应力的峰值距工作面的距离约为70 m。