Application of high-pressure water jet technology and the theory of rock burst control in roadway

This paper puts forward using high-pressure water jet technology to control rock burst in roadway, and analyzes the theory of controlling rock burst in roadway by the weak structure zone model. The weak structure zone is formed by using high-pressure water jet to cut the coal wall in a continuous and rotational way. In order to study the influence law of weak structure zone in surrounding rock, this paper numerically analyzed the influence law of weak structure zone, and the disturbance law of coal wall and floor under dynamic and static combined load. The results show that when the distance between high-pressure water jet drillings is 3 m and the diameter of drilling is 300 mm, continuous stress superposition zone can be formed. The weak structure zone can transfer and reduce the concentrated static load in surrounding rock, and then form distressed zone. The longer the high-pressure water jet drilling is, the larger the distressed zone is. The stress change and displacement change of non-distressed zone in coal wall and floor are significantly greater than that of distressed zone under dynamic and static combined load. And it shows that the distressed zone can effectively control rock burst in roadway under dynamic and static combined load. High-pressure water jet technology was applied in the haulage gate of 250203 working face in Yanbei Coal Mine, and had gained good effect. The study conclusions provide theoretical foundation and a new guidance for controlling rock burst in roadway.

高温高压实验揭示俯冲带蛇纹岩熔融行为与高镁岩浆成因

近年来一些研究在岛弧岩浆中发现了蛇纹岩组分,这表明俯冲至弧下的蛇纹岩不仅为地幔楔提供流体,而且可以通过部分熔融参与岛弧岩浆形成。然而,蛇纹岩在地幔楔中的熔融行为及其在俯冲带物质循环中的作用仍未进行深入研究。因此,本研究选择3种蛇纹岩样品:蚀变原岩分别为二辉橄榄岩(SE2)和方辉橄榄岩(SE3)的天然蛇纹岩,以及模拟含有大量滑石的合成蛇纹岩样品(SEQ),在700~1300℃和4 GPa的温度压力条件下进行了模拟实验,限定了蛇纹岩的熔融温度,分析了实验产生的熔体成分。研究发现,不同类型蛇纹岩的固相线存在显著差异,SE3、SEQ和SE2蛇纹岩的固相线分别为900~960℃、960~1100℃以及1150~1200℃。这3种蛇纹岩的固相线均高于俯冲板片上表面的温度,要求蛇纹岩通过底辟作用进入地幔楔以发生部分熔融。根据实验结果,本研究认为SE2和SEQ蛇纹岩可以在地幔楔底部相对较低的温度条件下(960~1100℃)即发生熔融,产生科马提质岩浆;而在上覆地幔楔更高温度条件下(>1200℃),SE2蛇纹岩可以发生更广泛、更高程度的部分熔融,产生玻安质岩浆。

新型红外非线性硒镓钡多晶的合成与提纯研究

硒镓钡晶体(BaGa_(4)Se_(7),BGSe)是目前广受关注的一种新型红外非线性晶体。本文分别采用双温区法和高压辅助法合成硒镓钡多晶原料,并设计大温度梯度快速提纯方法对合成后的多晶料进行提纯。通过粉末X射线衍射仪(XRD)、电感耦合等离子体质谱仪(ICP-MS)和X射线能谱仪(EDS)对提纯前后的BGSe多晶的物相组成和杂质浓度进行了表征。X射线衍射谱与理论模拟图谱结果一致,无杂峰;ICP-MS等测试结果表明,提纯后晶锭中的Fe、Al等金属杂质以及O杂质含量均得到明显降低。本工作可为高品质单晶生长提供原料基础。

掺氢天然气高压管道小孔泄漏及扩散特性

通过现有的天然气管道运输掺氢天然气,可大幅降低氢气运输成本。为了评估掺氢天然气管道泄漏的风险,综合高压管道小孔泄漏模型和高斯羽流模型,考虑射流初始动量导致的抬升高度,将高斯羽流模型计算结果与已有实验数据进行对比,并分析了掺氢天然气管道发生单个小孔竖直向上喷射泄漏后,掺氢比、管道压力、风速和泄漏孔直径对泄漏气体导致的爆炸危险区域范围的影响规律。结果表明,高斯羽流模型计算结果与实验数据比较吻合;甲烷危险区域最大距离与掺氢比近似呈线性负相关,氢气危险区域最大距离与掺氢比近似呈线性正相关;甲烷和氢气危险区域最大距离与管道压力近似呈线性正相关,与风速近似呈抛物线型负相关,与泄漏孔直径近似呈正相关。

高参数高压差流量调节无死区控制阀的研究与应用

目前高参数高压差控制阀广泛采用迷宫式和多级套筒式结构,由于迷宫片的工艺结构因素(每一碟片流道间均存在轴向上的高度)和多级套筒式(笼罩式)开孔布局等情况,均存在流量控制调节死区问题,即控制阀的流量特性曲线不是连续变化的。通过对套筒式(笼罩式)节流元件进行大量研究和模拟试验,在流量调节控制无死区方面有所创新和突破,解决了控制类阀门内件等关键零部件设计的重大问题。经多家用户长期使用,证明该控制阀具有调节性能好、无调节死区、工作可靠等特点。

混合模式搜索差分进化算法研究及其在高压容器概率优化中的应用

为求解高压容器的概率优化问题,提升差分进化算法的收敛速度,提出一种基于模式搜索算法的混合差分进化算法。该算法在差分进化算法的后期,引入模式搜索算子,以当前群体最优点作为模式搜索算子的基点进行模式搜索。仿真结果表明该混合算法收敛速度明显要优于差分进化算法。最后建立高压容器的概率优化设计模型,利用混合算法求解高压容器优化问题的确定型优化模型及概率优化模型,结果表明概率优化模型的优化结果更合理可靠。

The Influence of SST Warm-water Region and ITCZ in the North-West Pacific Ocean on the Northeast Cold Vortex and the Subtropical High

By using the monthly mean grid data of NCAR/NCEP reanalysis at 500 hPa geopotential height from 1958 to 1997,the relationship between the Northeast cold vortex and the western Pacific subtropical high was analyzed.The influence of the sea surface temperature(SST) and outgoing longwave radiation(OLR) on the Northeast cold vortex and subtropical high was studied.As was shown in the results,in summer,there was a positive correlation between the Northeast cold vortex and the subtropical high,and an anti-phase relationship existed between the threshold characteristic line of GMS-SST=28 ℃ and the height index of the Northeast cold vortex and the subtropical high.With the gradual northward moving of the threshold characteristic line,the subtropical high was weakening,and the Northeast cold vortex was increasing and strengthening.

近距离煤层群卸压瓦斯联合抽采技术研究及应用

为解决煤层回采过程中下临近层卸压瓦斯涌入采场空间造成瓦斯超限问题,以平煤股份八矿己_(15)-15050工作面为研究对象,分析采动作用下煤层顶底板裂隙发育规律,确定了基于定向钻进技术的近距离煤层卸压瓦斯联合抽采方案。结果表明:(1)研究区域内己_(15)煤层顶板上部55.80 m,底板下部19.71 m范围内均有裂隙产生;(2)底板拦截钻孔抽采浓度均超过90%,单孔最大纯量为163.12 m^(3)/d;(3)采用联合抽采方案时,应优先将拦截钻孔布置在高位孔孔底附近来弥补前期抽采能力不足。

长白山天池火山地热系统——岩浆囊与隐伏高温地热资源

长白山天池火山是晚新生代中心喷发式复合型层状火山,全新世以来发生过多次大规模喷发,与深部岩浆热扰动活动相关的构造地震、地表形变、温泉气体组份等均显示该火山仍可能再次喷发,是我国东部潜在的高温地热资源区。长白山天池火山周边地下水十分丰富,具有形成高温水热活动的岩浆囊热源。为探索地壳浅层隐伏的高温地热资源,本文在野外考察基础上,利用地热学方法,计算了该区地层结构与热状态,分析了地表下的火山地热系统。结果表明:长白山天池火山区地下2 km深处的温度在66—110℃之间,12 km深处的温度在313—417℃之间;该区居里面深度较浅,平均深度为12.7 km,居里点温度为375℃,其中长白山天池火山喷发中心和望天鹅火山喷发中心为居里面上隆区;在人工地震基底速度约束下,通过沉积地层重力反演发现,在约3.5—5.5 km深度处存在密度梯级高压带,该高压带与12 km深度处的岩浆囊之间的区域是形成隐伏高温地热资源的有利区域。

盾构穿越大金山破碎带超高压开仓换刀施工风险管控措施

盾构带压开仓换刀一直是盾构施工风险管控的重难点,文章以穿越大金山破碎带超高压开仓换刀为例,从停机原因分析、超高压确认、开仓前准备及开仓换刀作业过程管控等多方面分析高埋深、高水压带压开仓换刀的各类浆体材料配合比、注浆量、注浆压力和气体检测、空压机监控、循环水温度监控等控制要点,可为同类盾构施工情况提供参考借鉴。

Upper Limit for Rheological Strength of Crust in Continental Subduction Zone:Constraints Imposed by Laboratory Experiments

The transitional pressure of quartz coesite under the differential stress and highly strained conditions is far from the pressure of the stable field under the static pressure. Therefore, the effect of the differential stress should be considered when the depth of petrogenesis is estimated about ultrahigh pressure metamorphic (UHPM) rocks. The rheological strength of typical ultrahigh pressure rocks in continental subduction zone was derived from the results of the laboratory experiments. The results indicate the following three points. (1) The rheological strength of gabbro, similar to that of eclogite, is smaller than that of clinopyroxenite on the same condition. (2) The calculated strength of rocks (gabbro, eclogite and clinopyroxenite) related to UHPM decreases by nearly one order of magnitude with the temperature rising by 100 ℃ in the range between 600 and 900 ℃. The calculated strength is far greater than the faulting strength of rocks at 600 ℃, and is in several hundred to more than one thousand mega pascals at 700-800 ℃, which suggests that those rocks are located in the brittle deformation region at 600 ℃, but are in the semi brittle to plastic deformation region at 700-800 ℃. Obviously, the 700 ℃ is a brittle plastic transition boundary. (3) The calculated rheological strength in the localized deformation zone on a higher strain rate condition (1.6×10 -12 s -l ) is 2-5 times more than that in the distributed deformation zone on a lower strain rate condition (1.6×10 -14 s -1 ). The average rheological stress (1 600 MPa) at the strain rate of 10 -12 s -1 stands for the ultimate differential stress of UHPM rocks in the semi brittle flow field, and the average rheological stress (550-950 MPa) at the strain rate of l0 -14 - 10 -13 s -l stands for the ultimate differential stress of UHPM rocks in the plastic flow field, suggesting that the depth for the formation of UHPM rocks is more than 20-60 km below the depth estimated under static pressure condition due to the effect of the differential stress.

低渗稠油高压降黏驱高黏阻滞带形成机制与主控因素——以胜利油田王152油藏为例

化学降黏剂驱已在胜利油田深层低渗稠油中开展了初步先导试验,但试验表明井间存在高黏阻滞带,降低了地层渗流能力。因此,借助降黏剂驱岩心流动实验,结合必要的测试分析,剖析低渗稠油降黏驱高黏阻滞带形成机制与主控因素。结果表明,大排量高压注入降黏剂会在驱替前缘形成高黏阻滞带,影响驱替压力传导、降低驱油效果。该高黏阻滞带形成核心机制在于:(1)高压注入增加低孔压区域有效应力,地层孔喉受到挤压损害渗流能力;(2)高压快速降黏剂驱时,轻质组分优先流出,重质组分滞留、堆积、压实从而堵塞细小孔隙,形成高黏稠油沉聚的高饱和度油墙;(3)高压注入降黏剂会加剧其指进窜流,驱替前缘易形成W/O乳状液,增大混合流体的黏度。由此,对于低渗稠油油藏降黏驱开发,应采取多轮次温和注入降黏剂的开发模式,渐进式建立注采井间稠油整体驱动,进而有效规避稠油高黏阻滞带的形成,提高降黏剂驱油效果。

Influence of Sea Level Pressure on Inter-Annual Rainfall Variability in Northern Senegal in the Context of Climate Change

This study examines the inter-annual variability of rainfall and Mean Sea Level Pressure (MSLP) over west Africa based on analysis of the Global Precipitation Climatology Project (GPCP) and National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) Reanalysis respectively. An interconnection is found in this region, between Mean Sea Level Pressure (MSLP) anomaly (over Azores and St. Helena High) and monthly mean precipitation during summer (June to September: JJAS). We also found that over northern Senegal (15°N - 17°N;17°W - 13°W) the SLP to the north is strong;the wind converges at 200 hPa corresponding to the position of the African Easterly Jet (AEJ) the rotational wind 700 hPa (corresponding to the position of the African Easterly Jet (AEJ) coming from the north-east is negative. In this region, the precipitation is related to the SLP to the north with the opposite sign. The Empirical Orthogonal Functions (EOF) of SLP is also presented, including the mean spectrum of precipitation and pressures to the north (15°N - 40°N and 50°W - 25°W) and south (40°S - 10°S and 40°W - 0°E). The dominant EOF of Sea Level Pressures north and south of the Atlantic Ocean for GPCP represents about 62.2% and 69.4% of the variance, respectively. The second and third EOFs of the pressure to the north account for 24.0% and 6.5% respectively. The second and third EOFs of the pressure to the south represent 12.5% and 8.9% respectively. Wet years in the north of Senegal were associated with anomalous low-pressure areas over the north Atlantic Ocean as opposed to the dry years which exhibited an anomalous high-pressure area in the same region. On the other hand, over the South Atlantic, an opposition is noted. The wavelet analysis method is applied to the SLP showings to the north, south and precipitation in our study area. The indices prove to be very consistent, especially during intervals of high variance.

横风桥隧区域列车突出隧道时的瞬态气动特性

基于横风作用下高速列车流场的非定常特性,建立了横风-列车-桥隧模型进行仿真计算,并通过1∶8列车动模型试验验证数值方法的准确性。随后研究横风条件下列车突出隧道时,隧道内外瞬态气动压力、气动荷载变化及流场特性,揭示了横风-列车-隧道之间的相互作用机理。研究结果表明:随着横风风速的增大,压力逐渐减小,但压力随时间的变化规律相似;横风对隧道出口处及隧道外监测点处的压力梯度有明显的影响,对于隧道内的监测点几乎没有影响;随着横风风速增大,隧道外背风侧正压峰值随风速增大略有减小,迎风侧正压峰值基本保持不变,背风侧负压峰值减小速率大于迎风侧;横风对列车突出隧道运行过程的压力波动影响有限,在横风风速为20 m/s时,隧道外界流场影响隧道内气动压力的范围不超过20 m。同种横风条件下,迎风侧、背风侧监测点处压力时程变化规律不相同,压力梯度峰值出现的位置也不同,且位于列车同侧越靠近地面的监测点处压力峰值及压力梯度峰值绝对值越大;横风下,气流经过车-桥系统时,在桥底部、列车背风侧顶部及底部发生明显的流动分离现象,导致隧道外车体两侧的压差大于隧道内车体两侧压差。

超深超高压裂缝性致密砂岩气藏气井不稳定压力分析

对于超深超高压裂缝性致密砂岩气藏,综合考虑孔缝并存、离散裂缝与连续介质裂缝并存、应力敏感效应及3个物性分区的影响,建立裂缝性致密砂岩气藏气井不稳定压力模型,采用Pedrosa变换、摄动变换、Laplace变换等方法求解模型,通过编程绘制不稳定压力典型曲线;根据不稳定压力典型曲线特征划分流动阶段,对影响因素进行敏感性分析。结果表明:复杂气藏压裂井渗流过程划分14个典型流动阶段;存在应力敏感效应时,导数曲线中后期位置更高;钻遇离散裂缝长度越长,Ⅰ区缝网系统线性流等阶段的导数曲线位置越低;流度比主要影响相应拟径向流和窜流等阶段的压力导数曲线。各区储容比越小,相应窜流阶段压力导数曲线上的凹子越深;各区窜流系数越小,相应窜流阶段压力导数曲线上的凹子出现时间越晚。该结果为超深超高压裂缝性复杂气藏试井解释提供支撑。

高压流体条件下叶蛇纹石摩擦特性及其对俯冲带慢滑移事件的启示

为了探讨在俯冲带构造加载环境中叶蛇纹石矿物的摩擦力学性质,我们使用叶蛇纹石作为实验样品,开展了高压流体条件下的摩擦滑动实验研究.实验在气体介质的高温高压三轴实验系统中进行,实验中的有效正应力为30 MPa,孔隙流体压力为100 MPa,温度范围为100~500℃.实验过程中为了得到叶蛇纹石摩擦强度系数的速度依赖性,我们将轴向加载速率在1.0μm·s^(-1)、0.2μm·s^(-1)和0.04μm·s^(-1)之间进行切换.实验结果发现在实验温度范围内叶蛇纹石的摩擦强度系数随着温度的升高表现出系统的降低趋势,摩擦系数从100℃的0.81降低到500℃的0.41.在高于300℃的温度条件下,叶蛇纹石的剪切力学曲线表现出显著的位移弱化现象.在300℃的温度条件下,叶蛇纹石在0.2~1.0μm·s^(-1)的加载速率范围内表现出速度强化的摩擦行为,而在0.04μm·s^(-1)的加载速率下表现为速度弱化.在100~200℃以及400~500℃的温度条件下皆表现为速度强化.我们的实验研究表明在俯冲带地幔楔附近的高压流体条件和低有效正压力环境下,叶蛇纹石矿物可以促成慢滑移现象,但是其背后的物理机制可能与已有的认知(不稳定的摩擦滑动由叶蛇纹石脱水过程所控制)不同.这为我们探讨俯冲带慢滑移现象的物理过程和机制提供了新的思路.

破碎带地层盾构隧道建造关键问题

断层破碎带是引起盾构隧道施工灾害的关键因素之一,其形态各异、岩性复杂以及高渗透性,都极易导致隧道涌水、塌方等施工灾害,给隧道安全高效掘进带来了巨大挑战。总结分析断层破碎带的形成机理,包括破碎带地层的形成原因、破碎带地层的岩体性质及其与盾构施工安全之间的内在联系。重点介绍了近年来盾构隧道穿越破碎带所面临的刀具磨损、开挖面稳定控制、同步注浆质量控制、衬砌外水土压力确定、破碎带地质预报和地层处理等方面问题。结果表明:断层破碎带岩体破碎,黏聚力低,渗透系数从10^(-5)~10^(-3)cm/s不等,且含水率较高;对于高水压断层破碎带管片结构防水应采取防、排结合,以排为主、以防为辅;含断层破碎带盾构隧道工程建设应做好断层破碎带的综合超前地质预报,将传统的地质分析法、超前钻孔法等与新型探测技术、数字技术相结合。研究结果可为盾构隧道穿越断层破碎带提供借鉴与指导,对进一步提高中国隧道及地下工程建设水平有着积极意义。

江苏省东海县毛北金红石矿区中-北矿段矿体地质特征及成因初探

通过对矿区进行勘查工作,对矿床地质条件、控矿因素及成因进行总结研究。矿区位于苏北超高压变质带,岩浆活动强烈,基底地层为海州群变质岩系。本次工作共发现十条工业矿体,矿床赋存于榴辉岩中,成矿期后矿床受断层切割,使岩(矿)体不连续,走向及倾向发生明显变化。根据赋矿榴辉岩岩体结构构造不同分为块状榴辉岩及云母榴辉岩,前者较后者含矿性相对较好。金红石矿物颗粒主要呈浸染状分布于石榴子石、绿辉石等矿物粒间,矿石中金红石含量区间在1%~6%。榴辉岩的成因已有定论,经历了四个变质阶段,而对榴辉岩相峰期变质的温度及压力的认识观点不一,但不可否认的是本矿床属深成岩浆变质矿床。

Origin of the deep fluids in the paleosubduction zones in western Tianshan:Evidence from Pb-and Sr-isotope compositions of high-pressure veins and host rocks

Fluids in the deep subduction zones play an important role in crust-mantle ex-change related to the subduction process. Identification of fluids origin, internal or external, can help us to evaluate the contribution of crust materials to mantle during this process. High-pressure veins, which developed in the western Tianshan HP-metamorphic belt extensively, are the direct products of the fluids in subduction zones. In western Tianshan, high-pressure veins and host rocks have overall Pb- and Sr-isotope compositions. At t = 340 Ma, the high-pressure metamorphic time, the ratios of 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb and 87Sr/86Sr of high pressure veins are 17.122―18.431, 15.477―15.611, 37.432―38.689 and 0.70529―0.70705, and are 17.605―17.834, 15.508―15.564, 37.080―38.145 and 0.70522―0.70685 for host rocks. However, high-pressure veins show a much larger variation in Pb-isotope composi-tions than host rocks. Plots of samples are distributed roughly along a line parallel to and far away from the Northern Hemisphere reference line (NHRL) on the plot of 206Pb/204Pb vs 207Pb/204Pb. On the plot of 206Pb/204Pb vs 208Pb/204Pb, plots of data are distributed nearby mid-ocean-ridge basalts (MORB) area or along a line parallel to and not far away from NHRL, which shows that the data plots are farther away from MORB and ocean island basalts (OIB) areas on the plot of 206Pb/204Pb vs 207Pb/204Pb than on the plot of 206Pb/204Pb vs 208Pb/204Pb. The compositions of Pb- and Sr-isotopes of these high-pressure metamorphic rocks are between that of enriched mantle 1(EMI) and of sediments or upper crust. A notable characteristic can be seen from plots of Pb-isotope ratio vs Pb-isotope ratio and 206Pb/204Pb vs 87Sr/86Sr that array of plots shows an evident tendency of mixture of two end members. Ratios of Rb/Ba, Ce/Pb, Nb/U and Ta/U of high-pressure veins and host rocks are between that of OIB or MORB and that of conti-nental crust, which indicates that continental crust materials probably have been incorporated into the rocks. The fluids in the paleosubduction zones in western Tianshan are mixtures of two sources, one originating from the devolatilzation of the host rocks with protolithes similar to ocean basalts from enriched mantle 1 (EMI), the other from the dehydration of subducted sediments.

Early Mesozoic mantle-crust transitional zone in eastern Inner Mongolia: Evidence from measurements of compressional velocities of xenoliths at high pressure and high temperature

Compression wave velocity Vp has been measured on 10 representative rock samples from the Early Mesozoic granulite and mafic-ultramafic cumulate xenoliths population from the Harqin area of the Inner Mongolia Autonomous Region (for short Inner Mongolia) as an aid to interpreting in-situ seismic velocity data and investigating velocity variation with depth in a mafic lower crust. The experiments have been carried out at constant confining pressures up to 1 000 MPa and temperatures ranging from 20 to around 1 300℃, using the ultrasonic transmission technique. After corrections for estimated in situ crustal pressures and temperatures, elastic wave velocities range from 6.5 to 7.4 km · s-1, indicating that they are components of the Early Mesozoic crust-mantle transitional zone. Combining with previous experimental data, we have also reestablished the Early-Mesozoic continental compression velocity profile and compared it with those of the present and of the different tectonic environments in the world. The result shows that it is similar to the velocity pattern of the extensional tectonic area, providing new clues to the Mesozoic continental structure of the North China Craton.