用管棚实现超前支护的实践   总被引：2，自引：0，他引：2  

王东鸣 《四川地质学报》2002,22(Z1):34-35

介绍在隧道严重塌方段，采用管棚实现一次20m超前支护的实践经验。  相似文献   

砂钻的双管冲击内管取心工艺     

李树海 《黄金地质》2002,8(2):58-61

为提高砂矿勘查的施工效果，将取样内管立在套管钻头的内台肩上，冲击钻进1个回次后，将内管提升至地面采集样品。套管及内管分别采用φ152和127mm的地质钢管。钻头用35CrM钢锻造，内径大于110mm。吊锤重量300kg。一般孔内故障用抽筒、吊锤和劈刀即可排除。采集的样品基本保持原生结构。只要严格按照规程施工，钻孔的各项指标均能满足地质要求。  相似文献   

高密度电法在金矿找矿中的应用   总被引：6，自引：1，他引：6  

王文龙  杨拴海  张慧玉  马德锡  肖力  陈瑞林 《黄金地质》2002,8(3):53-56

以岩（矿）石的导电性和激电效应差异为基础，沿测线同时布设几十到几百根电极，仪器按选定的供电，测量排列方式自动采集电位值，并进行滤波，地改，计算等处理，可探测深度在150m以上的电阻率和充电率的精细结构，用以推断精细的地质和电子型导电矿物结构，在不同地区，不同类型的已知金矿床的试验表明，高密度电法异常与矿体在空间位置上十分吻合，在未知区，在异常区施工QZ14-2钻孔，发现了地下38m的盲矿体，取得了满意的试验和找矿效果。  相似文献   

城市地下管线普查数据处理系统设计     

张国林 《测绘与空间地理信息》2002,25(3):50-51,56

主要阐述一套比较完善的城市地下管线外业普查数据处理系统的实现过程。  相似文献   

钻孔灌注桩设备及机具选择与设计     

丁兴敏  卢予北 《地质与勘探》1995,31(6):54-57

在收集大量资料基础上，根据多年实际经验结合国内现有设备，提出了不同情况下合理选择设备的原则，对灌浆导管、灌浆装置和钻头设计，提出了新的看法和改进措施。  相似文献   

The effects of drag reduction by ribbons attached to cylindrical pipes   总被引：1，自引：0，他引：1  

S. H. Kwon  J. W. Cho  J. S. Park  H. S. Choi 《Ocean Engineering》2002,29(15):1945-1958

This study proposes a drag reduction device that uses three ribbons attached 120 degree apart to vertical pipes. Experiments were conducted in a circulating water channel to investigate the effects of the ribbon length and the direction of the flow on various current velocities. Drag on a vertical cylinder was measured by a resistance dynamometer. Flow visualizations were conducted using laser sheet beams. Laser Doppler Velocimetry (LDV) was used to measure the velocity field in the wake. This experiment demonstrates that attached ribbons can be used to reduce the drag force on vertical pipes for various directions of incoming flows. The ribbon-type device is very simple and easy to fabricate for field applications. The results are promising for the application to offshore structures.  相似文献   

A study of spar buoy floating breakwater     

Nai-Kuang Liang  Jen-Sheng Huang  Chih-Fei Li 《Ocean Engineering》2004,31(1):43-60

A floating breakwater produces less environmental impact, but is easily destroyed by large waves. In this paper, the spar buoy floating breakwater is introduced with a study on the wave reflection and transmission characteristics and mooring line tension induced by the waves. Mei (The Applied Dynamics of Ocean Surface Waves, Wiley, New York (1983) 740 p) proposed a theoretical solution for the reflection and transmission coefficients as the wave propagates through a one-layer slotted barrier. For a multiple-layer fence system, the analytical solution is proposed linearly. The results show that the theoretical computations agree well with the experimental trends. For a multiple-layer fence system, the transmission coefficients become maximal as the layer spacing to wavelength ratio moves to 1/2. Conversely, the coefficients become minimal, as the ratio moves to 0.3. To estimate the maximum tension of the mooring line, both numerical calculations and laboratory experiments were executed. The numerical calculation results were similar to the experimental results.  相似文献   

含环向表面裂纹管道功率流特性与裂纹识别     

李天匀  朱翔  赵耀  严谨 《海洋工程》2007,25(1):57-63

研究在外力激励下含有环向表面裂纹损伤的壳式管道的波传播与功率流特性,并给出裂纹识别方法。管道的振动用Flügge方程来描述,通过将裂纹模拟为分布的线性弹簧,运用断裂力学理论,得到裂纹区域的局部柔度矩阵,从而建立外力作用处以及裂纹两侧区域的位移和内力的连续性条件对裂纹管道的功率流进行求解。讨论功率流特性与裂纹位置和管道特性等参数的关系,最后给出了裂纹识别的方法。  相似文献   

Regular wave pressures and forces on submerged pipelines near a sloping boundary     

K. A. Roopsekhar  V. Sundar 《Ocean Engineering》2004,31(17-18):2295-2317

The hydrodynamic pressures induced by regular waves around the circumference of a pipeline normal to the wave direction and near a rigid bed of slope 1:10 have been investigated in a wave flume. The pressures were integrated to obtain the force time history, from which the peak horizontal and vertical forces are evaluated. The maximum and root mean square horizontal and transverse force coefficients are correlated with the Keulegan–Carpenter (KC) number. The effect of the distance between the sloping bed and the pipeline on the force coefficients is discussed. The force coefficients are found to decrease with an increase in KC number and with the decrease in the relative clearance of the pipeline from the boundary. In addition, the reflection characteristics of the sloping bed in the presence of the pipeline as a function of surf similarity parameter and their comparison with the results from existing literature are also reported. The details of the model setup, experimental procedure, results and discussion are presented in this paper.  相似文献   

城市应急管理GIS模型与算法应用——以广州大学城为例     

陈颖彪  陈健飞  苏琪信 《地球信息科学学报》2009,11(1):62-69

随着城市建设的快速发展,各类危及国家和人民群众生命财产安全的突发性事故灾害时有发生.因此,为应对城市各种重大突发事件,城市必须建立一种应急机制或综合的应急管理信息系统.管道分析是GIS技术在城市应急管理模型中的具体应用,利用城市应急管理系统对地下网管进行综合管理,可以将管线信息有序的存入计算机管理系统,实现数据的更新和资源共享.本文以广州大学城管道数据为数据研究基础,结合国内外管网数据模型,在先前开发完成的广州大学城可视化平台基础上加入横断面分析、垂距分析和爆管分析三个分析模块,对管网模型进行了算法改进并编程进行了技术实现,这三个功能模块可以直观地让管理员清晰地了解地下管线的走向和它们之间的空间关系,方便管理各种事务,防止和控制突发事件的发生,尽可能地减少灾害的影响范围.这三个功能可以应用于管道设计、铺设、维修等工作,对社会的经济发展和建设起着保障的作用.  相似文献