Fractional flow dimensions and hydraulic properties of a fracture-zone aquifer, Leppävirta, Finland     

J. Leveinen  E. Rönkä  J. Tikkanen  E. Karro 《Hydrogeology Journal》1998,6(3):327-340

 In order to characterize the hydraulic properties of an aquifer in Finland comprising two subvertical fracture zones, observation-well responses were matched with generalized radial flow (GRF) type curves. The responses in six wells out of seven are consistent with the GRF model. The fractional flow dimensions (1–1.2 and 1.5) were determined by regression analysis of straight-line slopes and type-curve matching. In each test, the flow dimensions in the neighboring fracture zone range from 2–2.25. Comparisons of the late-time responses with the asymptotic GRF solution and the flow dimensions obtained by reversing the pumping and observation points suggest homogeneous hydraulic properties. Deviations in responses can be explained by flow-path tortuosity. After assessments of the extent of the flow and radial distances along the fracture system, hydraulic conductivities and storativities were determined from the results of the type-curve matching procedure. The obtained hydraulic conductivities are 1.3×10^–5 to 7.9×10^–5 m/s and 5.0×10^–6 to 2.5×10^–5 m/s for the western and the eastern fracture zones, respectively. The results were verified by applying them to analytical solutions for pumping wells. The calculated pumping-well responses are consistent with the observations. The analysis of flow dimension also enhances qualitative interpretations on the hydrogeology of fracture zones. Received, April 1997 · Revised, September 1997 · Accepted, May 1998  相似文献   

用PLD器件设计任意地址范围译码器的简便方法     

周立 《地球科学与环境学报》1998,(Z1)

本文提供一种用ＰＬＤ器件设计任意地址范围译码器的简便方法。该方法给出了利用地址区间边界值直接写出地址译码逻辑式的三个设计规则和为进一步简化设计过程的两个补充设计规则。本设计方法对于用ＦＭ软件进行ＰＬＤ器件开发非常方便和实用。  相似文献   

探针法测定冻土的导水率   总被引：1，自引：0，他引：1  

张津生  福田正己 《冰川冻土》1991,13(4):349-357

  相似文献   

电阻率层析成像法在辽阳活断层探测中的应用     

孟琪  王亚会  吴明大 《东北地震研究》2010,26(2):15-19

电阻率层析成像法是近年来迅速发展起来的地球物理新技术,目前逐渐成为工程物探中的主要方法。在辽阳市地震活断层与地震危险性评价研究中运用该方法取得了良好的效果。通过在目标区布设探测剖面,辅以浅层地震,地质钻探,可以准确地探测断层的几何结构和物理特征,为辽阳市活断层探测与地震危险性评价研究提供准确可靠的物探依据。  相似文献   

海洋平台液压升降系统仿真研究     

孙永泰 《海洋工程》2008,26(1):93-97

对平台液压升降模拟仿真系统研究的必要性进行分析,针对自升式平台作业工况和机理,提出总体设计方案,进行各部分的研究设计。在软件方面,建立虚拟仪器测试系统,该系统的建立实现了平台升降系统的仿真及液压阀件的测试。  相似文献   

常用粮仓地坪沉降观测方法及精度分析          下载免费PDF全文

李本贤  缪德都  毛宁利  薄怀志 《山东国土资源》2008,24(7)

中央直属储备粮库是国家重要的基础设施，为确保新建粮库储粮安全，必须进行粮库新仓初始装粮压仓试验，利用仓内地坪沉降观测数据对云梯升降法、悬尺法、倒尺法的精度进行分析，得出倒尺法是仓内地坪沉降观测的最佳方法。  相似文献   

��ʮ�塱����ǰ�׹۲��豸����ͨѶ���Ӧ��̽��   总被引：6，自引：2，他引：4  

王秀英  周振安  刘爱春 《大地测量与地球动力学》2008,28(4):131-135

????????塱????豸??????????????е????????о???????????豸???????????????????????????????????????????IPv6???緢?????????????顣  相似文献   

Simulating short‐circuiting flow in a constructed wetland: the implications of bathymetry and vegetation effects     

Joong‐Hyuk Min  William R. Wise 《水文研究》2009,23(6):830-841

Short‐circuiting flow, commonly experienced in many constructed wetlands, reduces hydraulic retention times in unit wetland cells and decreases the treatment efficiency. A two‐dimensional (2‐D), physically based, distributed modelling approach was used to systematically address the effects of bathymetry and vegetation on short‐circuiting flow, which previously have been neglected or lumped in one‐dimensional wetland flow models. In this study, a 2‐D transient hydrodynamics with advection‐dispersion model was developed using MIKE 21 and calibrated with bromide tracer data collected at the Orlando Easterly Wetland Cell 7. The estimated topographic difference between short‐circuiting flow zone and adjacent area ranged from 0·3 to 0·8 m. A range of the Manning roughness coefficient at the short‐circuiting flow zone was estimated (0·022–0·045 s m^?1/3). Sensitivity analysis of topographical and vegetative heterogeneity deduced during model calibration shows that relic ditches or other ditch‐shaped landforms and the associated sparse vegetation along the main flow direction intensify the short‐circuiting pattern, considerably affecting 2‐D solute transport simulation. In terms of hydraulic efficiency, this study indicates that the bathymetry effect on short‐circuiting flow is more important than the vegetation effect. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Dynamics of deformation and water flow in heterogeneous porous media and its impact on soil properties     

Shih‐Jung Wang  Kuo‐Chin Hsu 《水文研究》2009,23(25):3569-3582

The interaction of geomechanics and flow within a soil body induces deformation and pore pressure change. Deformation may change hydrogeological and elastic properties, which alters the mechanical behaviour and results in non‐linearity. To investigate this interaction effect in a heterogeneous porous medium, a stochastic poroelastic model is proposed. Monte Carlo simulations are performed to determine the mean and uncertainty of the parameter changes, displacement, and change in pore water pressure. Hydraulic conductivity is treated as the only random variable in the coupled geomechanics‐flow system due to its large variation compared to other mechanical and hydrogeological properties in natural environments. The three considered non‐linear models for the interaction between parameters and deformation are those that consider (1) porosity and hydraulic conductivity; (2) porosity and Young's modulus; and (3) a combined effect that includes porosity, hydraulic conductivity, and Young's modulus. Boundary effects on the coupled system are also explored. The relationships between changes of porosity, hydraulic conductivity, and Young's modulus are analytically shown to be non‐linear. Among the considered parameters, the deformation effect induces the largest reduction in hydraulic conductivity. The deformation‐induced change in hydraulic conductivity shows the most significant effect on the mean and variance of the change in pore water pressure and displacement, while changes in Young's modulus have the least effect. When the deformation effect is considered, the superposition relationship does not exist in the mean displacement and mean change in pore water pressure for the three scenarios considered; it exists for the case without deformation effects. Deformation also causes a reduction in the effective hydraulic conductivity for the whole domain. The scenario that considers both loading and discharge boundaries has larger changes in hydrogeological and geo‐mechanical parameters than those in scenarios that consider loading and discharge boundaries separately. The results indicate that the interaction between deformation and changes in parameters has a profound effect on the poroelastic system. The effect of deformation should thus be considered in modelling and practice. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

固体粉末稳态法发射光谱分析新型进样器的研制及应用          下载免费PDF全文

吴静  张齐维  潘淑春  邢智  戈学渝  陈芝琰 《岩矿测试》2008,27(3):223-226

介绍了一种新型固体粉末进样装置,它由样品气溶胶喷射系统、高频火花雾化控制电路等部分构成,并阐述了装置的工作原理和结构设计。通过对化探样品中痕量B、Pb、Sn和Ag等元素的对比测定试验表明,利用新研制的进样装置代替原来的双高频火花雾化进样器,可使单样平均残留率由原先的26.7%降到0.79%;对比试验表明,方法的精密度(RSD,n=12)由原先的4.31%～6.81%提高到2.37%～3.43%。  相似文献