2012 年6 月30 日新疆新源-和静MS 6. 6地震序列震源机制解

利用CAP方法反演了2012年6月30日新源-和静Ms6.6地震序列震源机制解.反演得到Ms6.6地震节面Ⅰ的参数为:走向299°,倾角68°,滑动角164°;节面Ⅱ的参数为:走向35°,倾角75°,滑动角23°;P轴方位角166°,倾角5°,T轴方位角258°,倾角26°;矩震级Mw为6.3;矩心深度为21km.此次地震序列破裂优势方向为NWW,倾角以60°～90°为主,滑动角以±180°±30°为主;P轴方位的优势取向为近NS向,T轴优势取向为近EW向.初步分析表明,主震节面Ⅰ为发震断层,是走向为NWW、近乎直立的左旋走滑断层.此次6.6级地震震源断错性质和主压应力方向以及序列P轴优势方位与震源区周围构造应力场特征基本一致.     

用CAP方法研究重庆荣昌2014年2月23日M_L3.8地震震源机制

利用CAP(cut-and-paste)法反演2014年2月23日重庆荣昌ML3.8地震震源机制,得到MW震级为3.04,节面Ⅰ走向46°、倾角44°、滑动角74°,节面Ⅱ走向247°、倾角48°、滑动角104°,P轴方位147.25°、仰角-2.09°,T轴方位46°、仰角-78.76°,表明该地震是带走滑分量的逆冲型地震。CAP测定的这次ML3.8地震的震源深度为3km,在油气的储层内,震源机制解中节面Ⅱ走向、倾角与震中附近的一条深度为1700m以下走向为SW230°倾向NW,倾角约45°的"腹底"逆断层基本一致。震中位于荣昌天然气田,附近有几口废水回注深井,曾发生大量的注水诱发地震。本次地震亦有可能是在区域主应力场的作用下,注水后岩石的孔隙压发生变化触发了盆地盖层内"腹底"断层活动的结果。     

利用CAP法研究重庆荣昌2014年2月23日ML3.8地震震源机制

利用CAP(cut-and-paste）法反演2014年2月23日重庆荣昌ML3.8地震震源机制,得到震级MW为3.04,节面Ⅰ走向46°、倾角44°、滑动角74°,节面Ⅱ走向247°、倾角48°、滑动角104°,P轴方位147.25°、仰角-2.09°,T轴方位46°、仰角-78.76°,表明该地震是带走滑分量的逆冲型地震。CAP测定的这次ML3.8震源深度为3km,在盖层内,震源机制解中节面Ⅱ走向、倾角与震中附近的一条深度为1700m走向为SW230°倾向NW,倾角约45°的“腹底”逆断层基本一致。震中位于荣昌天然气田,附近有几口废水回注深井,曾发生大量的注水诱发地震。本次地震亦有可能是在区域主应力场的作用下,注水后岩石的孔隙发生变化触发了盖层内“腹底”断层活动的结果。     

Design and Application of Underground Mine Paste Backfill Technology

This paper reviews the design and application of paste backfill in underground hard rock mines used as ground support for pillars and walls, to help prevent caving and roof falls, and to enhance pillar recovery for improved productivity. Arching after stope filling reduces vertical stress and increases horizontal stress distribution within the fill mass. It is therefore important to determine horizontal stress on stope sidewalls using various predictive models in the design of paste backfill. Required uniaxial compressive strength (UCS) for paste backfill depends on the intended function, such as vertical roof support, development opening within the backfill, pillar recovery, ground or pillar support, and working platform. UCS design models for these functions are given. Laboratory and backfill plant scale designs for paste backfill mix design and optimization are presented, with emphasis on initial tailings density control to prevent under-proportioning of binder content. Once prepared, paste backfill is transported (or pumped) and placed underground by pipeline reticulation. The governing elements of paste backfill transport are rheological factors such as shear yield stress, viscosity, and slump height (consistency). Different models (analytical, semi-empirical, and empirical) are given to predict the rheological factors of paste backfill (shear yield stress and viscosity). Following backfill placement underground, self-weight consolidation settlement, internal pressure build-up, the arching effect, shrinkage, stope volume, and wall convergence against backfill affect mechanical integrity. An erratum to this article can be found at     

2015年新疆皮山6.5级地震序列震源机制特征分析

利用新疆区域数字地震台网波形资料,采用CAP方法反演了2015年7月3日新疆皮山6.5级地震主震及部分M_S≥3.6余震的震源机制解和距心深度。研究结果显示,皮山6.5级地震主震最佳双力偶解节面I：走向290°/倾角55°/滑动角96°;节面Ⅱ：走向101°/倾角35°/滑动角82°,最佳矩心深度16km,表明该地震是一次逆冲型事件。通过反演部分M_S≥3.6余震的震源机制解发现,早期余震的破裂方式与主震较为一致,随着时间的推移余震震源机制出现走滑型和正断型,表明早期余震的破裂受主震影响较大,随着序列的发展变化,后期震源区应力场可能出现一定程度的调整。统计皮山6.5级地震序列P轴方位发现,优势方位为NNE向,与该区域构造应力场方向较为一致。结合地震序列的震源机制及他人精定位结果和震源区地质构造情况,初步解释了导致此次地震的原因。     

低应变测试中需要注意的几个问题

低应变反射波法是目前国内外使用最广泛的一种基桩无损检测方法。本文就测试前准备工作、耦合剂的选择和盲区确定三个方面进行了总结和分析,提出了合理的建议。     

Development of a high modulus paste fill using fine gold mill tailings

Summary In the mining industry today there is some caution about using fine tailings as a backfill material. Traditionally, hydraulic backfill has only used the coarse fraction of tailings, excluding the fines by a classification process. With the development of paste fill, the percentage of fine tailings being sent underground has increased, but still remains low due to the high percentages of sand and gravel which usually make up these fills. Sand and gravel have been added to paste fills to aid pumpability and to increase fill strength and stiffness. This leaves the remainder of fine tailings destined for surface disposal. The main focus of this paper is to evaluate what effect the addition of fine gold mill tailings in the form of agglomerated tailings pellets has on the strength and stiffness characteristics of a total tailings paste fill. The purpose is to create a high modulus fill which is made up entirely of fine tailings. A constant slump design of 20 cm (8 in) was used for each mix. Various binder dosages, curing periods and combinations of pellet to tailings ratio were studied. Raw fill slump and density, and cured fill compressive strength and modulus of elasticity were also examined. Results from the above study indicate that agglomerated tailings paste fill (ATPF) has superior strength and stiffness characteristics. Compressive strengths were enhanced while the modulus of elasticity values was tripled when compared to total tailings paste fills of the same binder content and consistency. ATPF minimizes the surface disposal of tailings and maximizes the utilization of fine tailings underground as a useful backfill material.     

Geotechnical properties of cemented paste backfill from Cannington Mine,Australia

Paste fill is the newest form of backfill material in the spectrum available to international mines and is made from full mill tailings. Tailings have an effective grain size of approximately 5 μm and are combined with a small portion of binder and water to make paste. It is deposited into the voids created by mining which are referred to as stopes. The empty voids are approximated as vertical rectangular prisms, with plan dimensions of 15–40 m and heights of 100 m or more. Backfilling of mined stopes provide an increased level of local and regional stability to the ore body, as well as providing a suitable and economic dump of mining related waste. Paste is a relatively new technology in the mining industry and a review of the physical properties and mechanical fill behaviour was considered pertinent.     

2016年1月21日青海门源MS6.4地震震源机制解及发震构造初步探讨

采用CAP（Cut and Paste）方法反演了2016年1月21日青海门源M_S6.4地震的震源机制解,其最佳双力偶解节面I走向339°,倾角49°,滑动角111°：节面Ⅱ走向129°,倾角45°,滑动角68°,矩震级M_W5.92,矩心震源深度约为9 km,地震破裂类型为逆冲型地震。结合余震序列展布及震区的活动构造特征,判定发震断层面为节面I,推测此次地震的发震断裂为冷龙岭断裂。     

2013年7月22日岷县漳县6.6级地震序列震源机制解及其特征分析

针对2013年7月22日甘肃岷县漳县发生的M_s6.6地震序列,采用CAP(Cut and Paste)方法反演了岷县漳县6.6级地震及部分强余震的震源机制解。结果显示,6.6级主震最佳双力偶解节面I走向189°,倾角51°,滑动角142°;节面II参数走向305°,倾角61°和滑动角46°,主震为逆冲兼走滑型,矩心震源深度均为7km;8次M_s≥3.0余震震源机制解向NE倾的节面II的优势倾角约为52°,表现出逆冲分量大的特性。结合震区的活动构造、余震及烈度分布,判定节面II代表了相应地震的发震断层面,地震序列震源机制的特性反映了与临潭一宕昌断裂带相似的活动特征,分析认为,岷县漳县6.6级地震的发生与临潭-宕昌断裂的活动可能存在一定的相关性。