晋城岳城矿地面采动区井井位优选与抽采寿命研究

为了降低晋城岳城矿工作面U型通风造成的上隅角瓦斯聚集,提高采动与采空区煤层气地面井抽采井产量及抽采寿命,在借鉴成庄矿、寺河矿和赵庄矿等地面采动试验井研究及工程示范的基础上,以晋城岳城矿煤层气地质条件为工程设计依据,提出并优化地面采动区井位尽量靠近巷道位置处、大井眼地面钻井工艺、优化井身结构等设计方案。现场试验证明:部分采动区井通过避开采动应力卸载区及原位煤层高应力区优化布井,开采中包含3个阶段即卸压区抽采、新采空区抽采、老采空区抽采,达到了延长抽采井寿命的目的;但仍有部分采动区井在回采工作面推过井口后,煤气层抽采量迅速衰减至不产气,抽采寿命只包含两个阶段即卸压区抽采、新采空区抽采甚至仅卸压区抽采一个阶段。研究表明,优化后的大井眼钻井工艺及三开割缝套管井身结构设计对保持采动区井井身稳定,延长抽采寿命,保证采动区井产气运移通道畅通,提高抽采率起到了一定效果;采动区井煤气层抽采量和该井井筒位置至回风巷距离存在明显的负相关关系。岳城矿采动、采空区井基本不存在速敏效应,在井筒与裂隙带沟通良好的前提下,应选用大功率抽采设备抽采,可以有效扩展压降漏斗区域,其抽采影响半径水平方向可延伸至500 m以上。岳城矿地面采动区抽采取得了较好的效果,可在相似条件的煤矿区推广应用。      

Structure and late quaternary activity of the northern Owens valley fault zone, Owens valley, California

The Fish Springs fault is a primary strand in the northern end of the Owens Valley fault zone (OVFZ). The Fish Springs fault is the northwest strand in a 3-km-wide left echelon step of the OVFZ which bounds the Poverty Hills bedrock high. The Fish Springs fault strikes approximately north-south, dips steeply to the east, and is marked by a prominent east-facing scarp. No other faults in the OVFZ have prominent east-facing scarps at the latitude of Fish Springs, which indicates that the Fish Springs fault has accommodated virtually all of the local late Quaternary vertical displacement on the OVFZ.

The Fish Springs fault exhibits normal dip slip with no measurable lateral slip. Vertical displacements of a Late Pleistocene (0.314 ± 0.036 Ma, 2σ) cinder cone and of an overlying Tahoe-age (0.065–0.195 m.y.) alluvial fan are 76±8 m and 31±3 m, respectively. The maximum vertical 3.3. m. Two nearly equal vertical displacements of the active stream channel in the Tioga-age fan total 2.2. m. Vertical displacement of a stream terrace incised into the cinder cone is 1.2 ± 0.3 m. The minute amount of incision into that terrace indicates that uplift of the terrace probably occurred during the 1872 Owens Valley earthquake.

Three displacements of 1.1 ± 0.2 m each apparently have occurred at the Tioga-age fan since the midpoint of the Tioga interval, allowing an average recurrence interval of 3500 to 9000 years. Based on the age and displacement of the cinder cone, the average late Quaternary vertical displacement rate is 0.24 ± 0.04 mm/yr (2σ). At this rate, and assuming an average vertical displacement of 1.1 ± 0.2 m per event, the average recurrence interval would be 4600 ± 1100 years (2σ). The recurrence interval for the Fish Springs fault is similar to that for a strand in the southern part of the OVFZ which also ruptured in 1872.

Right-lateral, normal oblique slip characterizes the OVFZ. The location of the Poverty Hills bedrock high at a left step in the north-northwest-striking fault zone is consistent with the style of slip of the zone. The pure normal slip on the north-striking Fish Springs fault and the alignment of local cinder cones along north-striking normal faults indicate that the late Quaternary maximum horizontal compression has been oriented north-south at the north end of the OVFZ. Data from southern Owens Valley indicate a similar stress regime there. Late Quaternary slip on the OVFZ is consistent with north-south maximum horizontal compression.     

四川茂县周场坪滑坡发育特征与变形监测分析

位于四川茂县南新镇的周场坪滑坡是一大型古滑坡,曾于1982年发生大规模快速复活,目前滑体半堰塞岷江。野外地质调查表明,周场坪滑坡在平面上呈不规则长舌形,长约850 m,滑体前后缘高差约350 m;在剖面上发育3级滑动,钻探揭露滑带埋深以50~70 m为主,推测潜在失稳滑坡体积为1 500×10 ⁴~2 000×10 ⁴ m ³。周场坪滑坡在平面上分为4个变形区,在滑体中后部和前缘坡脚发育大量拉裂缝与下错陡坎,拉裂缝宽度以0.2~3.0 m为主,陡坎下错高度2~10 m。在野外调查和钻探分析的基础上,对该滑坡开展了地表位移(GNSS)、深部蠕滑变形(钻孔测斜仪)和雨量等监测。监测分析表明,目前周场坪滑坡后缘变形速率达0.80 m/a,中部和前缘分别为0.69 m/a和0.51 m/a,呈推移式滑动变形,整体向NW310°方向滑动;地表位移速率在监测期内基本在1~3 mm/d之间波动,波动主要受降雨量影响,且略滞后于降雨量;滑移加速度基本在0~6 mm/d ²范围波动。ZK2钻孔测斜仪监测数据表明,滑坡在80 m深度内主要沿2层滑带蠕滑,其中浅层滑带埋深在22 m左右,深层滑带埋深在46 m左右,滑移速率在0~5 mm/d范围波动。综合研究认为,周场坪滑坡目前处于缓慢变形的深层蠕滑中,其变形速率受降雨和河流侵蚀等因素的影响,在极端内、外动力条件下,可能会加速滑动,并再次整体复活,造成堵塞岷江等危害。     

开封市垃圾场污染物运移模拟与控制

在对开封市某典型垃圾场进行野外调查的基础上,应用Visual Modflow建立了该垃圾场污染场地的水流和溶质运移耦合模型并进行数值模拟预测,预测了20年后该污染场地垃圾渗滤液污染羽运移范围、途径及方式等特点。模拟了应用防渗墙和抽水井两种方式控制地下水污染的措施和方案,并利用计算机模型对污染控制的效果进行了模拟分析。模拟结果表明,模拟初期污染羽覆盖了3个抽水井,污染羽前缘距离村庄688 m。模拟20年后污染羽已经覆盖了7个抽水井,其中浓度超标井有3口,污染羽前缘距离村庄605 m。建议在加强污染物监测的同时协助开展其他的污染控制措施,进一步控制污染羽的扩散。     

垃圾填埋场抽水试验及降水方案设计

垃圾填埋场中的渗滤液水位过高会引发一系列环境和稳定问题,工程上可用竖井抽水降低渗滤液水位。通过在填埋场现场进行抽水试验,确定垃圾土的渗透系数和抽水影响半径,在此基础上对填埋场降水的瞬态流问题进行有限元模拟,分析了抽水井口径和间距对填埋场降水的影响,提出了降水方案的设计步骤和方法。抽水试验表明,现场垃圾的渗透系数约为3.6×10-4cm/s,抽水影响半径约为20m。数值分析表明,井径的变化对于降水效果影响不大,而合理选择抽水井间距对降水十分关键。进行抽水方案设计时,应首先根据工期和降水幅度要求计算井间距,按井的出水速度选择水泵,再根据水泵确定井径,最后根据井径和过滤层形式确定钻孔尺寸并选择钻机。     

地面防治水钻探技术在双系煤层 上覆采空区积水治理中的应用

针对双系煤层上覆采空区积水对下部煤层开采构成的威胁,提出在地面布置钻孔,穿越上部多层采空区,施工探放水孔与大直径抽水井的防治水钻探技术。采用该技术在大同矿区上覆侏罗系采空区的积水治理实践表明,地面探放水孔能够实现采空积水区与下部石炭系开采煤层巷道的贯通式放水,大直径抽水井可实现超大流量的采空区积水抽放,施工的9个地面探放水累计疏放采空区积水398.1万m3,5个大直径抽水井累计抽排采空区积水200余万立方米,取得了较好的贯通式放水和抽排效果。介绍了地面探放水孔与大直径抽水井钻探技术在同煤集团同忻矿上覆侏罗系采空区积水治理中的应用,可为其它类似开采条件的矿井上覆采空区积水治理提供参考。     

独山子背斜的几何学运动学数字模拟

独山子背斜位于准噶尔盆地南缘西段,是北天山逆冲推覆带在前陆盆地山前形成的断层相关褶皱。本文以横跨背斜的过井地震剖面为蓝本,用钻井数据、相邻地震剖面和地表形态为约束,运用断层相关褶皱模型对独山子背斜进行几何学定量分析,以建立合理的与实际接近的构造模型; 提取构造特征参数进行基于Trishear模型的运动学定量模拟,选取与实际数据吻合度最高的构造形态为独山子背斜的最佳几何模型。模拟数据表明:独山子背斜为前翼呈三角剪切的断层传播褶皱; 背斜变形从喜马拉雅山晚期更新统(Q_1-3)沉积期间开始形成并生长,平均推覆速率为0.18 mm/a; 全新统沉积期间(Q₄)推覆活动强度达到最大值,平均推覆速率为 4.64 mm/a。形成独山子背斜所需的总推覆位移量为5 600 m左右,第四纪期间的平均推覆速率约为0.19 mm/a。     

Quaternary Activity of the Monastir and Grombalia Fault Systems in the North‒Eastern Tunisia (Seismotectonic Implication)

The Monastir and Grombalia fault systems consist of three strands that the northern segment corresponds to Hammamet and Grombalia faults. The southern strand represents Monastir Fault also referred to as the Skanes-Khnis Fault. These NW-trends are observed continuously in the major outcropping features of north-eastern Tunisia including both the Cap Bon peninsula and the Sahel domain. Along the Hammamet Fault, the north-eastern strand of Grombalia fault system, left lateral drainage offset of amount 220 m is found in Fawara valley. To the South, the left lateral movement is occurred along the Monastir Fault based on 180 m of Tyrrhenian terrace displacement. Field observations supported by satellite images suggest that the Monastir and Grombalia fault systems appear to slip mostly laterally with components of normal dip slip. Assuming the development of the stream networks during the Riss-Würm interglacial (115000–125000 years) and the age of the Tyrrhenian terrace (121 ± 10 ka), the strike slip rates of the Hammamet and Monastir faults are calculated in the range of 1.5–1.8 mm/yr. There vertical slip rates are estimated to be 0.06 and 0.26 mm/yr, respectively. These data are consistent with the displacement rate in the Pelagian shelf (1–2 mm/yr) but they are below the convergence rate of African-Eurasian plates (8 mm/yr). Our seismotectonics study reveals that a maximum earthquake of Mw = 6.5 could occur every 470 years in the Hammamet fault zone and Mw = 6–every 263 years in the Monastir fault zone.     

非卫生垃圾填埋场渗滤液污染防治对策研究

针对非卫生垃圾填埋场环境污染问题,以某垃圾填埋场为例,通过 WHI UnSat Suite软件 HELP模块计算不同填埋条件下渗滤液渗漏量。利用GMS模拟了该垃圾场中心抽水条件下污染物迁移变化规律。结果表明,简单地表防渗条件下,渗滤液渗漏量为现状条件下的50%,增铺 HDPE土工膜后,渗漏量可减少99%。卫生填埋渗滤液仅为现状条件下的3.6＆#215;10-3倍。当抽水量为2000 m3/d时,Cl-浓度呈明显下降趋势,由84 mg/L降至80.1 mg/L。     

2008年汶川地震同震滑移特征、最大滑移量及构造意义

2008年汶川地震（M_s8.0）形成了迄今为止空间上分布最为复杂、长度最大的逆冲型同震地表破裂带。沿约275km长的地表破裂带的同震滑移及其最大滑移量的确定,对认识和理解汶川地震地表破裂过程及其变形机制具有重要意义。我们沿地表破裂带进行了详细的滑移特征考察及其同震位移测量,发现沿映秀-北川破裂带分布南北两个滑移峰值区段,南段以深溪沟-虹口破裂段为中心,以逆冲为主伴随右旋走滑运动为特征,最大垂直位移量为6.0～6.7m,北段以北川破裂段为中心,以右旋走滑为主伴随逆冲运动为特征,最大垂直位移量为11～12m,南北两滑移峰值区段所代表的两次地表破裂事件与地震波数据反演结果一致。通过对北川段破裂带的精细地形剖面测量,以及地震前后对比,在北川县曲山镇沙坝村一组获得该破裂段的最大右旋水平位移为12～15m,最大垂直位移为11～12m,这是目前世界上一次地震产生的最大同震垂直位移,最大斜向滑移量为14～17m,为整个汶川地震地表破裂最大滑移量,是汶川地震的宏观震中。北川破裂段高角度的地震断裂、逆冲断裂面的倒转作用以及具最大滑移量的强烈变形作用是北川县城遭受到最强的地表破坏和地质灾害的主要原因。具有走滑量和逆冲量近一致（走滑水平位移/逆冲垂直位移比值为1）的斜向逆冲作用可能是山脉快速隆升的重要机制。