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1981年8月13日11时01分内蒙丰镇发生Ms5.8级地震。震前河北省张家口地区的万全井、山西省大同市的217井和田村D_4井水位均出现明显的异常变化(图1)一、万全井水位异常变化万全井位于万全县黄家堡城西河西侧高河漫滩上,构造上处于万全盆地西缘断层带上,距震中113公里,井深217.3米。35米以上为第四系冲洪积砂砾石层。35米以下为上侏罗系南天门组。其上部为泥页岩、页岩夹砂岩及煤层。下部为石英斑岩夹断层角砾岩。观测段深度为171.37米-217.2米,含水层岩性为石英斑岩破碎带,属裂隙承压水。由于水头高不能观测静水位,采用泄流的方式进行动水位观测,使用SW-40型自 相似文献
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新疆04井水位突降异常的机理分析 总被引：3，自引：3，他引：0
通过04井地下不动力学条件和地球化学环境的综合分析，探讨了井水位突降异常变化的基本特征和相邻两并含水层孔隙压力动态的关系及相互作用过程。4b井喷（溢）水卸压是04井水位突降的直接原因。当04井的水位升高，水头高度达到并超过4b井井口的高度时，4b井开始喷水卸压，水头损失造成孔隙压力的降低而形成降落漏斗，造成04井水位突然下降，一旦4b井喷水停止，04井水位又开始上升并逐步恢复到正常水位高度。在04井水位持续突降变化阶段，可通过统计突降过程参数（如突降发生的频度、两次突降异常之间的时长等）判别地震前兆异常。 相似文献
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通过对福建永安井自数字化观测以来的水位、水温资料分析,认为该井水位的主要影响因素为降雨和上游水库泄洪的影响;水温的影响因素较为复杂,主要为水位变化、降雨及上游水库泄洪的影响,但影响水温变化的机理不同.水位的趋势变化对水温的影响是由于随着水位的上升或下降,会引起含水层中孔隙压力发生变化,从而引起水温梯度的变化;降雨对水温的影响变化是由于冷水的渗入,在含水层水头不变的情况下,低温水比例增大,高温水比例减小,从而使得水温下降;上游泄洪对水温造成的影响,是由于处于下游的井孔孔内的渗透率增大,导致水位升高引起水温梯度发生变化,从而使得水温升高. 相似文献
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以湖北万山井水温观测资料为研究对象,探究井内深度215 m和241.58 m处的水温动态特征及其主要干扰因素和映震能力。通过水温梯度分析和水温正常动态对比研究,认为：在井深215 m处,水温动态为稳定型;在井深241.58 m处,水温长期动态为升温漂移型,月动态为上升-阶变型,日动态为随机起伏型,升温漂移是仪器自身的零漂现象,随机起伏反映了仪器自身噪音或者对应井水温的随机变化。对水温主要干扰因素的分析表明,井深241.58 m处的水温异常主要来自人为干扰引起的井水震荡和探头线扰动,异常形态均表现为单个台阶或突跳。在2018年9月8日湖北襄阳襄城ML 3.2地震前后,该深度处水温均呈高频V型阶变异常,此为地震发生前后区域应力积累与释放对井水温的作用所致。 相似文献
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西影深井处在西安凹陷东南坡大雁塔热异常带上,位于西安电影制片厂后院。井深2000.41米。给水层有两层,分别是:1520—1527米和1560—1617米。1417米以上的环形空间用水泥封死,因之工农业取水层和地表水与该井给水层无水力学联系。从水位观测资料分析中发现,水位的升降变化与气压的升降变化同步性很强,反映了气压是水位变化的主要因素之一。 相似文献
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陶庄矿山诱发塌陷地震对承压井水位的影响 总被引：2，自引：0，他引：2
试用弹性理论和地下流体动力学分析了陶庄矿山诱发塌陷地震对承压井水位的影响,分析了井水位变化与陷地震震级及塌陷点距水地蝇距离之间的关系,通过对塌陷地震序列的分析,给出了较大塌陷地震前小塌陷地震增多的可能“前兆”。 相似文献
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The hydraulic conductivity of submerged sediments influences the interaction between ground water and surface water, but few techniques for measuring K have been described with the conditions of the submerged setting in mind. Two simple, physical methods for measuring the hydraulic conductivity of submerged sediments have been developed, and one of them uses a well and piezometers similar to well tests performed in terrestrial aquifers. This test is based on a theoretical analysis that uses a constant-head boundary condition for the upper surface of the aquifer to represent the effects of the overlying water body. Existing analyses of tests used to measure the hydraulic conductivity of submerged sediments may contain errors from using the same upper boundary conditions applied to simulate terrestrial aquifers. Field implementation of the technique requires detecting minute drawdowns in the vicinity of the pumping well. Low-density oil was used in an inverted U-tube manometer to amplify the head differential so that it could be resolved in the field. Another technique was developed to measure the vertical hydraulic conductivity of sediments at the interface with overlying surface water. This technique uses the pan from a seepage meter with a piezometer fixed along its axis (a piezo-seep meter). Water is pumped from the pan and the head gradient is measured using the axial piezometer. Results from a sandy streambed indicate that both methods provide consistent and reasonable estimates of K. The pumping test allows skin effects to be considered, and the field data show that omitting the skin effect (e.g., by using a single well test) can produce results that underestimate the hydraulic conductivity of streambeds. 相似文献
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孕震过程中孔隙压及地下水位变化的数值模拟 总被引：2，自引：2，他引：2
地震孕育过程中孕震区内各点的应力应变都将发生变化，介质的物性参数也将改变，因此孔隙压和地下水位随之改变。本文在研究孕震过程中包括扩容和断层蠕变效应在内的应力应变场的基础上，根据应力场与孔隙压场的耦合方程，把孔隙压场随应力场的应力变化定量地计算出来。计算结果表明，孕震过程中孔隙压的变化与应力场变的化的强弱及南的渗透性能等因素相关。孕震过程后期，震源区表现为扩容区并且孔隙压强以负压为主，此结果显示着震 相似文献
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Volatile organic compounds delected in ground water from wells at Test Area North (TAN) at the Idaho National Engineering Laboratory (INEL) prompted RCRA facility investigations in 1989 and 1990 and a CERCLA-driven RI/FS in 1992. In order to address ground water treatment feasibility, one of the main objectives, of the 1992 remedial investigation was to determine the vertical extent of ground water contamination, where the principle contaminant, of concern is trichloroethylene (TCE). It was hypothesized that a sedimentary interbed at depth in the fractured basalt aquifer could be inhibiting vertical migration of contaminants to lower aquifers. Due to the high cost of drilling and installation of ground water monitoring wells at this facility (greater than $100,000 per well), a real time method was proposed for obtaining and analyzing ground water samples during drilling to allow accurate placement of well screens in zones of predicted VOC contamination. This method utilized an inflatable pump packer pressure transducer system interfaced with a datalogger and PC at land surface. This arrangement allowed for real lime monitoring of hydraulic head above and below the packer to detect leakage around the packer during pumping and enabled collection of head data during pumping for estimating hydrologic properties. Analytical results were obtained in about an hour from an on-site mobile laboratory equipped with a gas chromalograplvmass spectrometer (GC/MS). With the hydrologic and analytical results in hand, a decision was made to either complete the well or continue drilling to the next test zone. In almost every case, analytical results of ground water samples taken from the newly installed wells closely replicated the water quality of ground water samples obtained through the pump packer system. 相似文献
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We designed and evaluated a “tube seepage meter” for point measurements of vertical seepage rates (q), collecting groundwater samples, and estimating vertical hydraulic conductivity (K) in streambeds. Laboratory testing in artificial streambeds show that seepage rates from the tube seepage meter agreed well with expected values. Results of field testing of the tube seepage meter in a sandy‐bottom stream with a mean seepage rate of about 0.5 m/day agreed well with Darcian estimates (vertical hydraulic conductivity times head gradient) when averaged over multiple measurements. The uncertainties in q and K were evaluated with a Monte Carlo method and are typically 20% and 60%, respectively, for field data, and depend on the magnitude of the hydraulic gradient and the uncertainty in head measurements. The primary advantages of the tube seepage meter are its small footprint, concurrent and colocated assessments of q and K, and that it can also be configured as a self‐purging groundwater‐sampling device. 相似文献
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Chia‐Shyun Chen 《水文研究》2008,22(8):1119-1124
When a slug test is conducted in a highly permeable aquifer, a shallow pressure transducer in the well casing produces an oscillatory pressure head that is representative of the water level fluctuation, whereas a deep pressure transducer in the well casing yields an oscillatory pressure head that is different from the water level change. Although the solutions for shallow and deep pressure head are different, it is found that the ratios of the subsequent extremity displacements are in an identical relationship (an extremity can be a maximum or a minimum in the oscillatory pressure head). Based on this relationship, an analytical data analysis method for the determination of the hydraulic conductivity is developed for both shallow and deep pressure transducer data. This analytical method is applied to the pressure head measured at different depths in the well casing of a well partially penetrating an unconfined coarse sand aquifer. Satisfactory results are obtained, validating the applicability of this analytical method for pressure transducer data at any depth in a well casing. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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A New System for Ground Water Monitoring 总被引：4，自引：0，他引：4
Bengt-Arne Torstensson 《Ground Water Monitoring & Remediation》1984,4(4):131-138
This paper describes a new system for ground water monitoring, "the BAT System," which includes the following functions: (a) sampling of ground water in most types of soils, (b) measurement of pore water pressure, and (c) in situ measurement of hydraulic conductivity. The system can also be used for tracer tests. The system utilizes a permanently installed filter tip attached to a steel or PVC pipe. Installation is normally performed by pushing the tip down to the desired depth. The filter tip can also be buried beneath a landfill. The primary feature of the new system is that the filter tip contains a self-sealing quick coupling unit, which makes it possible to temporarily connect the filter tip to adapters for various functions, e.g. water sampling and for measurement of pore pressure and hydraulic conductivity. The new technique makes sampling of both pressurized water and gas possible. Samples are obtained directly in hermetically sealed, pre-sterilized sample cylinders. Sampling of ground water and measurement of pore pressure can be repeated over a long period of time with undiminished accuracy. This technique is also well-adapted for taking water samples from different strata in a soil profile, in both the saturated and unsaturated zones. Actual installations range from 0.5 to 60m depth. 相似文献
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A curve-matching method is developed for the analysis of depth-dependent pressure head responding to a slug test in a highly permeable aquifer. The depth dependency is due to the fact that the pressure transducer is placed at depth relatively far from the initial water level. The Springer and Gelhar solution and a depth correction relation are used to generate theoretical curves of pressure head vs. time. A trial-and-error procedure is established to find the theoretical curve best fitting the field data by adjusting the two unknown parameters, the horizontal hydraulic conductivity, and the effective length of the water column. Analytic relations for some oscillation characteristics of the converted pressure head are derived. A field example indicates that the theoretical relations and the curve-matching method developed herein are suitable to deal with the oscillatory head data dependent on depth of measurement. Nevertheless, it is recognized that placing the pressure transducer close to the initial water level and using a small initial water displacement can effectively avoid complicating the data analysis, such that previous, simpler data analysis methods can be used. 相似文献