淮北煤矿大口径排水孔施工技术          下载免费PDF全文

耿洪州  叶礼明 《探矿工程》1994,(4):30-32

着重论述了淮北煤矿大口径排水钻孔的施工方法及成井工艺。采用满眼钻具防斜，确定上、中、下扶正器安装的最佳位置，利用喷射钻进提高钻进效率，利用管底逆止阀浮力塞解决下管及注浆的难题。  相似文献   

Development of fluid conduits in the auriferous shear zones of the Hutti Gold Mine, India: evidence for spatially and temporally heterogeneous fluid flow   总被引：1，自引：0，他引：1  

Jochen Kolb  Amanda Rogers  F. Michael Meyer  Torsten W. Vennemann 《Tectonophysics》2004,378(1-2):65-84

The gold mineralization of the Hutti Mine is hosted by nine parallel, N–S trending, steeply dipping, 2–10 m wide shear zones, that transect Archaean amphibolites. The shear zones were formed after peak metamorphism during retrograde ductile D₂ shearing in the lower amphibolite facies. They were reactivated in the lower to mid greenschist facies by brittle–ductile D₃ shearing and intense quartz veining. The development of a S₂–S₃ crenulation cleavage facilitates the discrimination between the two deformation events and contemporaneous alteration and gold mineralization. Ductile D₂ shearing is associated with a pervasively developed distal chlorite–sericite alteration assemblage in the outer parts of the shear zones and the proximal biotite–plagioclase alteration in the center of the shear zones. D₃ is characterized by development of the inner chlorite-K-feldspar alteration, which forms a centimeter-scale alteration halo surrounding the laminated quartz veins and replaces earlier biotite along S₃. The average size of the laminated vein systems is 30–50 m along strike as well as down-dip and 2–6 m in width.Mass balance calculations suggest strong metasomatic changes for the proximal biotite–plagioclase alteration yielding mass and volume increase of ca. 16% and 12%, respectively. The calculated mass and volume changes of the distal chlorite–sericite alteration (ca. 11%, ca. 8%) are lower. The decrease in δ¹⁸O values of the whole rock from around 7.5‰ for the host rocks to 6–7‰ for the distal chlorite–sericite and the proximal biotite–plagioclase alteration and around 5‰ for the inner chlorite-K-feldspar alteration suggests hydrothermal alteration during two-stage deformation and fluid flow.The ductile D₂ deformation in the lower amphibolite facies has provided grain scale porosities by microfracturing. The pervasive, steady-state fluid flow resulted in a disseminated style of gold–sulfide mineralization and a penetrative alteration of the host rocks. Alternating ductile and brittle D₃ deformation during lower to mid greenschist facies conditions followed the fault-valve process. Ductile creep in the shear zones resulted in a low permeability environment leading to fluid pressure build-up. Strongly episodic fluid advection and mass transfer was controlled by repeated seismic fracturing during the formation of laminated quartz(-gold) veins. The limitation of quartz veins to the extent of earlier shear zones indicate the importance of pre-existing anisotropies for fault-valve action and economic gold mineralization.  相似文献   

高渗压下水岩相互作用试验研究   总被引：1，自引：0，他引：1  

黄润秋  徐德敏 《工程地质学报》2008,16(4):489-494

新研发的岩石高压渗透试验仪以静态伺服阀为主要控制元件,在脱离计算机控制条件下可使试样进水端水压保持不变。出水端水压采用调速阀控制,实现了高渗透压力下长时间的水-岩相互作用试验研究。在此基础上,提出了水-岩作用渗透液体不同时段各离子浓度变化的分析方法,并容易得到不同时段试样渗透性变化规律。为研究水-岩作用对岩石强度的影响,按基本相同条件,对该试样及未经长期水-岩渗流作用同一岩性试样进行了高渗压下的常规三轴试验,提出以试样临近破坏时的有效侧向应力大小进行强度分析,并按上述实际所加侧向压力大小及有效侧向压力大小,进行了常规饱水三轴压缩试验。试验得出,所研究蚀变岩在高渗压下水-岩作用结果与常温、常压条件测试结果类似,蚀变岩与库水的水化学反应微弱,对其自身岩体的渗透性及力学性质影响均较小。  相似文献   

液化地层震动沉管桩施工对策     

赵以龙 《中国煤田地质》2007,19(A01):67-67,77

南京某综合办公楼桩基工程采用震动沉管桩，由于该区地层的粉砂层存在不同端阻力分界面，因上层长时间的震动，下层粉砂层发生液化，导致桩尖与沉管脱离，桩管内出现水泥浆：为此在施工中采用活瓣桩尖，并用0．5m^3的砼封底，有效地解决了桩管冒浆问题。  相似文献   

近海码头大圆筒基床夹泥的砂砾挤扩灌浆桩加固法     

何开胜  童旭东  周荣官  汪成明 《岩土力学》2005,26(Z1):193-197

针对长流油气码头海上重达千吨以上的大圆筒码头基床夹泥引起倾斜的工程问题,研究提出了砂砾挤扩灌浆桩的 加固新方法,并进行了加固设计、现场施工和质量检测。检测结果表明,挤入淤泥和粉土中的纯砂砾柱平均直径达到55～ 82 cm,28 d龄期时水泥砂砾灌浆体取芯的抗压强度达到4.3～11.4 MPa。工程竣工使用1年状态良好,表明砂砾挤扩灌浆桩的提出和应用取得圆满成功。  相似文献   

改进型袖阀管注浆在黄河冲积层地基加固中的应用          下载免费PDF全文

孙艳  辛强  陈佃浩  张学正 《山东国土资源》2021,37(9)

袖阀管注浆是建筑地基加固工程中常用的手段。但是,传统的袖阀管设备存在密封圈和袖阀管内壁之间贴合不密实而易导致注浆压力偏小的缺点。本文对传统袖阀管设备进行改进,并依托济南市某黄河冲积层地区建筑地基加固工程,进行改进型袖阀管的注浆效果试验研究。结果显示,改进型袖阀管在济南黄河冲积层地区建筑地基加固中应用效果良好。与传统型袖阀管相比,改进型袖阀管的最大注浆压力提高了1.3倍,注浆时间节省了22%。采用改进型袖阀管后,浆液骤降和孔口返浆几率大大降低,密封圈与袖阀管管壁跑浆的问题得到彻底解决。  相似文献   

大型换流站阀厅结构地震响应弹塑性分析   总被引：1，自引：0，他引：1  

韦文兵  吴轶  蔡健  杨春  唐冬  陈寅 《地震工程与工程振动》2011,31(5):113-120

利用有限元方法对带悬挂阀的阀厅结构进行地震响应弹塑性分析,研究不同场地土条件、不同地震动作用对阀厅结构以及悬吊设备地震响应的影响.研究结果表明:阀厅结构在纵向和三向地震作用下存在较明显的扭转效应;三向地震输入时,吊杆产生的拉力约为单向输入的2倍;悬吊设备竖向地震响应大于水平地震响应,大震下悬吊设备竖向加速度约为水平向的...  相似文献   

基于多变量非线性DAE子系统模型的同步发电机励磁汽门综合控制     

陈蓓玉  岳华  屠壮 《南京气象学院学报》2020,12(4):515-520

同步发电机励磁汽门综合控制由多变量非线性DAE子系统模型来描述.本文扩展了非线性常微分方程系统的反步控制方法,研究了其镇定控制问题.首先若被控系统的向量相对阶存在,那么可通过一个微分同胚和反馈控制实现系统的解耦和等价转化.然后基于等价系统,利用反步方法设计其镇定控制器,使得整个闭环系统渐近稳定.最后基于MATLAB进行了仿真,仿真结果验证了本文所提方法的有效性.  相似文献   

Phytoplankton,especially diatoms,in the gut contents and feces of two plantivorous cyprinids—Silver carp and bighead carp     

Xie Ping  Liu Jiankang 《中国海洋湖沼学报》1994,12(4):308-315

In order to clarify whether the planktivorous silver carp and bighead carp can collect phytoplankton as small asCyclotella(<20 μm) in Donghu Lake, studies on phytoplankton in their gut contents and feces were made in 1990. The fish were cultured in both net cage in Donghu Lake and aquaria with the lake water. Past the intestine, the average valve diameter ofCyclotella changed little. The average ratio of empty frustule ofCyclotella to totalCyclotella in the foregut contents of the fishes were 1.8–1.9 times higher than that in the lake water, but changed little from foregut to feces. The aquarium experiment showed that both carps could collect particles as small as 8–10 μm, which was obviously narrower than the distance between their gill rakers. Probably, secretion of mucus plays an important role in collecting such small particles.  相似文献   

CTG-200型全液压工程钻机的研制与应用          下载免费PDF全文

邱华  彭儒金  戴圣海 《探矿工程》2017,44(11):50-55

本文针对目前市场上工程钻机施工过程中存在工艺适应性差、钻进效率低、能耗较高等问题,介绍了一种采用负载反馈系统的新型全液压工程钻机——CTG-200型工程钻机。其具有适应强、节能降耗、钻进行程长、起拔能力大及自动卸扣等优点。野外地质勘探结果表明,CTG-200型全液压工程钻机履带行走平稳,性能稳定,操作简单,给进辅助时间少,钻具提升速度快,拆卸钻具及多角度孔位施工方便快捷,很好地解决了工程施工过程中难以克服的问题。无疑,全液压工程钻机是解决当今钻探市场对钻机高效与节能环保需求的一个新的发展方向。  相似文献