非开挖导向钻进浅层水平井施工实践          下载免费PDF全文

张建 《探矿工程》2010,37(2):64-66

用非开挖导向钻进管线铺设技术,在河北省廊坊市广阳区陈桑园村完成了一浅层水平水井的施工,详尽介绍了该水平井施工方法及施工工艺。  相似文献   

基于WAVEWATCH-Ⅲ模式的近10年南海波候统计分析   总被引：1，自引：1，他引：0  

郑崇伟  张霞 《气象与减灾研究》2011,34(1):48-55

基于国际上较为先进的第三代海浪数值模式WAVEWATCH-Ⅲ,以QuikSCAT/NCEP混合风场为驱动场,得到南海1999年8月-2009年7月的海浪场,并据此对近10 a南海的波候特征进行分析.结果表明:(1)南海受季风影响显著,风场和浪场的对应关系在季风盛行季节明显好于季风过渡季节.(2)南海南部海域的浪场对海表...  相似文献   

Extended imaging conditions for wave‐equation migration     

Paul Sava  Ivan Vasconcelos 《Geophysical Prospecting》2011,59(1):35-55

Wavefield‐based migration velocity analysis using the semblance principle requires computation of images in an extended space in which we can evaluate the imaging consistency as a function of overlapping experiments. Usual industry practice is to assemble those seismic images in common‐image gathers that represent reflectivity as a function of depth and extensions, e.g., reflection angles. We introduce extended common‐image point (CIP) gathers constructed only as a function of the space‐ and time‐lag extensions at sparse and irregularly distributed points in the image. Semblance analysis using CIP's constructed by this procedure is advantageous because we do not need to compute gathers at regular surface locations and we do not need to compute extensions at all depth levels. The CIP's also give us the flexibility to distribute them in the image at irregular locations aligned with the geologic structure. Furthermore, the CIP's remove the depth bias of common‐image gathers constructed as a function of the depth axis. An interpretation of the CIP's using the scattering theory shows that they are scattered wavefields associated with sources and receivers inside the subsurface. Thus, when the surface wavefields are correctly reconstructed, the extended CIP's are characterized by focused energy at the origin of the space‐ and time‐lag axes. Otherwise, the energy defocuses from the origin of the lag axes proportionally with the cumulative velocity error in the overburden. This information can be used for wavefield‐based tomographic updates of the velocity model, and if the velocity used for imaging is correct, the coordinate‐independent CIP's can be a decomposed as a function of the angles of incidence.  相似文献   

Wave transformation on a sub-horizontal shore platform, Tatapouri, North Island, New Zealand   总被引：1，自引：0，他引：1  

H. Ogawa  M.E. DicksonP.S. Kench 《Continental Shelf Research》2011,31(14):1409-1419

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Future evolution of a tidal inlet due to changes in wave climate, Sea level and lagoon morphology (Óbidos lagoon, Portugal)     

Nicolas Bruneau  André B. FortunatoGuillaume Dodet  Paula FreireAnabela Oliveira  Xavier Bertin 《Continental Shelf Research》2011,31(18):1915-1930

Tidal inlets are extremely dynamic, as a result of an often delicate balance between the effects of tides, waves and other forcings. Since the morphology of these inlets can affect navigation, water quality and ecosystem dynamics, there is a clear need to anticipate their evolution in order to promote adequate management decisions. Over decadal time scales, the position and size of tidal inlets are expected to evolve with the conditions that affect them, for instance as a result of climate change. A process-based morphodynamic modeling system is validated and used to analyze the effects of sea level rise, an expected shift in the wave direction and the reduction of the upper lagoon surface area by sedimentation on a small tidal inlet (Óbidos lagoon, Portugal). A new approach to define yearly wave regimes is first developed, which includes a seasonal behavior, random inter-annual variability and the possibility to extrapolate trends. Once validated, this approach is used to produce yearly time series of wave spectra for the present and for the end of the 21st century, considering the local rotation trends computed using hindcast results for the past 57 years. Predictions of the mean sea level for 2100 are based on previous studies, while the bathymetry of the upper lagoon for the same year is obtained by extrapolation of past trends. Results show, and data confirm, that the Óbidos lagoon inlet has three stable configurations, largely determined by the inter-annual variations in the wave characteristics. Both sea level rise and the reduction of the lagoon surface area will promote the accretion of the inlet. In contrast, the predicted rotation of the wave regime, within foreseeable limits, will have a negligible impact on the inlet morphology.  相似文献   

两相介质波动问题显式有限元方法稳定性研究   总被引：2，自引：0，他引：2  

李亮  杜修力  李立云  翟威 《地震工程学报》2011,33(3):218-222,227

基于动力反应递推计算格式传递矩阵的性质,进行了饱和两相介质波动问题时域显式有限元方法稳定性问题的研究。定义了综合考虑各种影响因素的稳定性判别指标——传递因子;研究了稳定性影响因素,包括时间步长、空间步距和渗透系数取值的作用规律;给出了方法稳定性的实用判别准则。研究结果表明:时间步长、空间步距和渗透系数取值都对饱和两相介质波动问题的时域显式有限元方法的稳定性有较为显著的影响。随着时间步长的增大,方法的稳定性降低;随着空间步距的增大,方法的稳定性增加;当渗透系数取值增大时,方法的稳定性增加。  相似文献   

Validation study of the distinct lattice spring model (DLSM) on P-wave propagation across multiple parallel joints     

J.B. Zhu  G.F. Zhao  X.B. Zhao  J. Zhao 《Computers and Geotechnics》2011

A validation study of the distinct lattice spring model (DLSM) for wave propagation problems is performed. DLSM is a microstructure-based numerical model, which is meshless and has advantages in modelling dynamic problems where stress wave propagation is important. To verify the applicability of DLSM to modelling wave propagation through a discontinuous medium, the virtual wave source (VWS) method is used to obtain analytical solutions for wave propagation across a jointed rock mass. Numerical modelling results of the commercial code UDEC are selected as the reference. The effects of particle size and lattice rotation angle on wave propagation are first studied. Then, the results of wave transmission across a single joint with a different joint stiffness and across multiple parallel joints with different joint spacings are derived with DLSM, UDEC and VWS. These results are in good agreement with each other. Therefore, the capability of DLSM to model P-wave propagation across jointed rock mass is verified, which provides confidence for the further application of DLSM to modelling more complex problems.  相似文献   

重力式导向防斜钻具在钻孔灌注桩施工中的应用及探讨          下载免费PDF全文

廖光华 《探矿工程》2011,38(1):63-65

介绍了一种高垂直度要求钻孔灌注桩施工的防斜钻具——重力式导向防斜钻具的设计、加工,及其在福州至银川高速公路九江长江公路大桥桥基工程中的使用效果,从理论上分析了该钻具的防斜原理。  相似文献   

叠前深度偏移技术在城市活动断层探测中的优势     

王志辉  韩立国  贺文静  周积响 《城市地质》2011,6(1):52-55

本文介绍了Kirchhoff积分法叠前深度偏移和波动方程叠前深度偏移两种偏移方法,并通过对Marmousi数据模型和实际数据资料处理,对比叠前深度偏移成像与叠后时间偏移成像和常规叠加剖面的应用效果。实际结果表明：对于速度横向变化剧烈的复杂地质体,叠前深度偏移成像精度更高,适合于城市活动断层的高精度探测。  相似文献   

瑞雷波法在建筑高边坡勘察中的应用     

丁月双  李连营  刘运涛 《岩土工程技术》2011,25(3):142-145

结合一项边坡工程实例,将瑞雷波技术应用到人工填方建筑高边坡勘察工程中,探测出边坡区基岩面埋深、风化层厚度及坡面起伏形态等,并在“重点坡段”关键位置布置钻孔,对原始坡面埋深进行了校核。结果表明,探察结果与钻探结果具有很好一致性,充分展现了瑞雷波勘探技术在建筑高边坡勘察中的可行性和有效性。  相似文献