DN630供水管道定向钻穿越淮河工程的设计和施工     

朱旋  屈学平 《岩土钻凿工程》2011,(2):11-14

作为非开挖施工的一个分支,定向钻穿越技术得到了越来越广泛的应用。本文以DN630供水管道定向钻穿越淮河工程为例,介绍了定向钻穿越的技术特点,指出了设计基本原则及设计要素如管道钻进的入土角、出土角、曲率半径和穿越深度等确定方法,并阐述了定向钻穿越施工工艺流程及泥浆配制、钻导向孔、扩孔及管道回拖等主要施工工艺。  相似文献   

注浆技术在砂卵石地层水平（定）导向钻进工程中的应用研究     

梁小强  张可能  赵自亮 《岩土钻凿工程》2011,(2):24-29

本人在借鉴前人成果并结合施工经验的基础上,系统总结了砂卵石地层与非开挖钻进施工的适应性,对非开挖钻进施工中出现的问题进行了归纳和分类,并对其原因进行了分析和探讨。同时,为了解决非开挖导向钻进在复杂地层特别是砂卵石层中的施工难题,考虑采用注浆预加固技术对砂卵石层进行预先加固,以提高其强度,保证非开挖导向钻进的顺利进行。更进一步地,对水平孔中注浆预加固的三种方法（垂直注浆法、导管注浆法、随钻注浆法）在导向钻进工程中的概念、适用范围、优缺点以及实施控制要点等进行了对比和研究。  相似文献   

Seismic random noise attenuation and signal-preserving by multiple directional time-frequency peak filtering     

《Comptes Rendus Geoscience》2015,347(1):2-12

Time-frequency peak filtering (TFPF) is an effective method for seismic random noise attenuation. The linearity of the signal has a significant influence on the accuracy of the TFPF method. The higher the linearity of the signal to be filtered is, the better the denoising result is. With this in mind, and taking the lateral coherence of reflected events into account, we do TFPF along the reflected events to improve the degree of linearity and enhance the continuity of these events. The key factor to realize this idea is to find the traces of the reflected events. However, the traces of the events are too hard to obtain in the complicated field seismic data. In this paper, we propose a Multiple Directional TFPF (MD–TFPF), in which the filtering is performed in certain direction components of the seismic data. These components are obtained by a directional filter bank. In each direction component, we do TFPF along these decomposed reflected events (the local direction of the events) instead of the channel direction. The final result is achieved by adding up the filtering results of all decomposition directions of seismic data. In this way, filtering along the reflected events is implemented without accurately finding the directions. The effectiveness of the proposed method is tested on synthetic and field seismic data. The experimental results demonstrate that MD–TFPF can more effectively eliminate random noise and enhance the continuity of the reflected events with better preservation than the conventional TFPF, curvelet denoising method and F–X deconvolution method.  相似文献   

Variations in wave direction estimated using first and second order Fourier coefficients     

V. Sanil Kumar  N. M. Anand 《Ocean Engineering》2004,31(17-18):2105-2119

In most design applications such as alignment of the berthing structure and breakwater alignment, it becomes necessary to determine the direction of design wave. There are two different approaches to determine wave direction. One involves the use of first order Fourier coefficients (mean wave direction) while the other uses second order Fourier coefficients (principal wave direction). Both the average wave direction over the entire frequency range (0.03–0.58 Hz) and the direction corresponding to the peak frequency are used in practice. In the present study, comparison is made on wave directions estimated based on first and second order Fourier coefficients using data collected at four locations in the west and east coasts of India. Study shows that at all locations, the mean and principal wave directions for frequencies ranging from 0.07 to 0.25 Hz (±0.5 times peak frequency) co-vary with a correlation coefficient of 0.99 but at lower and higher frequencies, difference between the parameters is large. Average difference between the mean wave direction at peak frequency and the average over the frequency related to spectral energy more than 20% of maximum value is less, around 13°. Study shows that average difference in the sea and swell directions is around 39°.  相似文献   

HDD铺管引起地表工后变形的数值模拟分析     

刘耀东  石朋飞  乌效鸣 《岩土钻凿工程》2012,(4):1-5

水平定向钻进（HDD）是一种重要的非开挖铺管技术,在非开挖领域应用非常广泛。由于其会扰动周围地层以及造成地层损失,进而造成一定程度的地表变形,如地表沉降、地表水平变形等。本文采用有限差分数值模拟方法,运用FLAC3D软件分析了HDD铺管的引起的地表工后变形问题;综合考虑了不同地层内聚力、地表荷载及扩孔级数情况下的地表工后变形。  相似文献   

复合式商业建筑的实践与思考     

黄炎冰 《中国勘察设计》2012,(6):76-79

本文通过对于上海浦江沃尔玛广场设计过程的概念探讨,试图廓清在特定城市区域,通过关键建筑的建设,达到丰富城市空间类型,改善城市空间品质的目的,也在设计整体实践中,思考当下特殊时期,新商业建筑的设计方法。  相似文献   

相控震源定向地震波信号分析   总被引：8，自引：6，他引：2       下载免费PDF全文

姜弢  林君  杨冬  陈祖斌 《地球物理学报》2008,51(5):1551-1556

应用可控震源地震勘探，当环境噪声很强，采用组合震源工作仍不能满足信噪比要求时，引入能形成定向地震波的相控震源.由相控震源定向照明地震理论分析，主波束方向上3单元相控震源产生的反射地震波信号信噪比比单震源高6.53~9.54 dB，比组合震源高1.76~4.77dB.为研究相控地震实际效果，在同一测区进行了三种震源地震对比实验.由单炮地震记录和水平叠加时间剖面可知，相控震源反射波信号信噪比明显高于单震源情况，略高于组合震源情况.进一步对反射波信号功率谱特性做定量分析，得到如下结果：与单震源情况相比，相控震源使各道反射波信号信噪比提高了0.75~8.15 dB，平均提高3.65 dB；与组合震源情况相比，各道信噪比提高了0.93~3.17 dB，平均提高2.02 dB，实验结果与理论分析吻合.综上所述可知，基于相控震源的定向照明地震技术是可行的，可以有效提高地震信号的信噪比.  相似文献   

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张四新  张希  王双绪  薛富平  刘立炜 《大地测量与地球动力学》2008,28(6):43-46

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Determination of the crop row orientations from Formosat-2 multi-temporal and panchromatic images     

《ISPRS Journal of Photogrammetry and Remote Sensing》2014

This paper presents a technique developed for the retrieval of the orientation of crop rows, over anthropic lands dedicated to agriculture in order to further improve estimate of crop production and soil erosion management. Five crop types are considered: wheat, barley, rapeseed, sunflower, corn and hemp. The study is part of the multi-sensor crop-monitoring experiment, conducted in 2010 throughout the agricultural season (MCM’10) over an area located in southwestern France, near Toulouse. The proposed methodology is based on the use of satellite images acquired by Formosat-2, at high spatial resolution in panchromatic and multispectral modes (with spatial resolution of 2 and 8 m, respectively). Orientations are derived and evaluated for each image and for each plot, using directional spatial filters (45° and 135°) and mathematical morphology algorithms. “Single-date” and “multi-temporal” approaches are considered. The single-date analyses confirm the good performances of the proposed method, but emphasize the limitation of the approach for estimating the crop row orientation over the whole landscape with only one date. The multi-date analyses allow (1) determining the most suitable agricultural period for the detection of the row orientations, and (2) extending the estimation to the entire footprint of the study area. For the winter crops (wheat, barley and rapeseed), best results are obtained with images acquired just after harvest, when surfaces are covered by stubbles or during the period of deep tillage (0.27 > R² > 0.99 and 7.15° > RMSE > 43.02°). For the summer crops (sunflower, corn and hemp), results are strongly crop and date dependents (0 > R² > 0.96, 10.22° > RMSE > 80°), with a well-marked impact of flowering, irrigation equipment and/or maximum crop development. Last, the extent of the method to the whole studied zone allows mapping 90% of the crop row orientations (more than 45,000 ha) with an error inferior to 40°, associated to a confidence index ranging from 1 to 5 for each agricultural plot.  相似文献   

浅论水平定向钻进敷设管材     

陈黎明  石靖 《岩土钻凿工程》2014,(2):23-28

水平定向钻进铺设技术在国内应用日益广泛,但是现行相关管材标准严重滞后,难以满足实际需要。本文对现行水平定向钻进铺设所涉及到的管材进行简要论述,建议相关部门尽快制定相关的水平定向钻进铺设管材标准,并与现行水平定向钻进技术规范协调一致,以促进水平定向钻进工程在国内的健康发展。  相似文献