共查询到19条相似文献，搜索用时 328 毫秒
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YRY-4型钻孔应变观测抽水影响分析 总被引：1，自引：1，他引：0
分析泰安基准地震台YRY-4型钻孔应变仪仪器受不同位置抽水的影响,就地下岩石含水变化所产生的地形变干扰,简要分析地下水与地下岩石间的相互作用。这对地震前兆的研究有重要实用意义。 相似文献
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抽水对蓟县台形变观测的干扰机理研究 总被引：2，自引：4，他引：2
裴晓峰 《地震地磁观测与研究》1995,16(4):75-80
就蓟县台小辛庄山洞形变的抽水干扰，在抽水实验的基础上，研究了抽水干扰的机理及其规律，为形变台站减小抽水干扰的影响提出了可行性建议。 相似文献
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水可以存在于地壳中很深的部位。由于水的可压缩性很小,再加上毛细作用,水就在含水孔隙中造成流体压力,从而改变了岩体中的应力状态。而岩石的形变性质和流体的形变性质有明显的差别,所以流体压力所造成的应力场的改变以及流动的地下水的动态性质所造成的流体压力的连续变化,都对地质体系的形变特点起着不可忽视的影响。从油、气、水及地热资源的开发,地震的成因及控制,用土壤及岩石来支撑工程建筑,地壳对电波及机械波的响应,热液矿床的形成等许多方面来说,了解流体渗透的地质体系的形变特点显然都是重要的。各行业中的科学家和工程师都力求对支配 相似文献
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地震预报的实践发现,重力变化地区有时并没有地震发生或地震震级与重力变化量不符.其主要原因是与地形变、地下水有关.用弹性理论和动力学理论研究了测点高程变化、密度变化和质量迁移伴随的重力效应及其与地壳活动的关系,探讨了地壳垂直形变、地下水、降水量与重力变化关系,研究其影响量级、时间和方式、以获得与地震直接有关的重力前兆.理论与实践证明,抽取地下水或开采油田引起地壳形变与重力变化呈线性关系.提出了不同含水层对重力的作用和影响也不同.潜水是引起重力变化的主要因素,其次是降水量导致土壤湿度对重力的影响,承压水在无抽水情况下,它的升降对重力几乎没有什么影响.从华北及西南地区的重力观测资料入手,验证了理论与实践的一致性. 相似文献
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《地震研究》2020,(4)
分析计算安宁河断裂带上冕宁跨断层水准场地原始观测数据及年均速率结果,结合1-1C测段加密观测数据的差异性特征,重点对滑坡、抽水2个主要影响因素,利用有限元方法构建该场地三维Mohr-Coulomb弹塑性滑坡体模型及二维抽水影响的单向流固耦合模型,模拟获得2种主要因素的影响模式。结果显示:冕宁水准1-1C测线中距离1C点约300 m范围为古滑坡体所处边坡的坡脚区域,古滑坡体对坡脚区域长期的累积作用使得该区域存在隆升变形特征,进而使1-1C测段在抽水造成的大幅下降过程中出现沉降量逐渐减小后再次增大的特征;地下水抽取造成沿水井形成了较为明显的抽水漏斗沉降变形特征,在含水系统平衡被打破后,1号点所处土体边坡更易受到抽水带来的沉降变形影响,出现与井口处相当甚至比井口附近更大的沉降变形。 相似文献
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采用抽水、放水实验方法,研究地倾斜的变化量与地下水抽取量之间的关系、蓄水池池水变化量与地倾斜变化量之间的关系。通过对抽水实验数据分析研究可知:在放水速率(V放水9 m3/h)、总放水量(T82 m3)有限的前提下,弥渡地震台观测山洞正上方30 m处的蓄水池水量变化不会引起地倾斜观测资料的明显变化;而地下水抽取是造成地倾斜异常变化的主要原因,且地倾斜异常变化在时间上与抽水作业(起止时间)保持高度同步性;抽水活动持续时间与地倾斜变化量是成非线性关系:随抽水时间延长,地倾斜变化速率开始较快,随后减小。但在开始抽水2小时时段内表现为近似线性关系,即NS测向VNS=-0.045 53 ms/min,EW测向VEW=-0.079 71 ms/min。通过频域分析可知:弥渡地倾斜观测受抽水干扰的异常信号的频率在0.001 8~0.003 Hz之间。由此,笔者设计了带阻滤波处理软件对抽水干扰信号频段进行处理,降低了抽水作业对弥渡地倾斜观测的影响。 相似文献
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地下水在大地震前发生剧烈的水位升降、翻花冒泡,变色变味和某些化学元素的增减等异常现象已为许多地震所证实。因而地下水成为地震预报的有效手段之一。关于大地震前地下水的各种异常现象产生的物理机制问题,一般传统的看法认为,地震前由于应力的不断加强,使地面发生形变或者是含水层受压以及含水层的隔水层破裂而引起各种异常现象。但这 相似文献
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A confined aquifer may become unconfined near the pumping wells when the water level falls below the confining unit in the case where the pumping rate is great and the excess hydraulic head over the top of the aquifer is small. Girinskii's potential function is applied to analyze the steady ground water flow induced by pumping wells with a constant-head boundary in a mixed confined-unconfined aquifer. The solution of the single-well problem is derived, and the critical radial distance at which the flow changes from confined to unconfined condition is obtained. Using image wells and the superposition method, an analytic solution is presented to study steady ground water flow induced by a group of pumping wells in an aquifer bounded by a river with constant head. A dimensionless function is introduced to determine whether a water table condition exists or not near the pumping wells. An example with three pumping wells is used to demonstrate the patterns of potentiometric surface and development of water table around the wells. 相似文献
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Modeling effects of multinode wells on solute transport 总被引：1，自引：0，他引：1
Long-screen wells or long open boreholes with intraborehole flow potentially provide pathways for contaminants to move from one location to another in a ground water flow system. Such wells also can perturb a flow field so that the well will not provide water samples that are representative of ground water quality a short distance away from the well. A methodology is presented to accurately and efficiently simulate solute transport in ground water systems that include wells longer than the grid spacing used in a simulation model of the system and hence are connected to multiple nodes of the grid. The methods are implemented in a MODFLOW-compatible solute-transport model and use MODFLOW's Multi-Node Well Package but are generic and can be readily implemented in other solute-transport models. For nonpumping multinode wells (used to simulate open boreholes or observation wells, for example) and for low-rate pumping wells (in which the flow between the well and the ground water system is not unidirectional), a simple routing and local mixing model was developed to calculate nodal concentrations within the borehole. For high-rate pumping multinode wells (either withdrawal or injection, in which flow between the well and the ground water system is in the same direction at all well nodes), complete and instantaneous mixing in the wellbore of all inflows is assumed. 相似文献
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In this study, we use borehole temperature data and stable isotopes to delineate the flow system and estimate the effect of urbanization in the Nagaoka area of Japan. Temperature profiles were measured four times in observation wells during the period 2000-2001 and compared with those measured in the same wells during the period 1977-1983 (Taniguchi 1986). Water was sampled in both observation and pumping wells during the same period. The temporal and spatial variability in temperature indicate clearly the effect of urban warming and heavy pumping on the ground water system. Urban warming caused higher temperatures recently as compared to the older values, and pumping caused induced recharge from the river to the ground water. The stable isotope data show the ground water flow system is divided into shallow, intermediate, and deep systems, and that land use and infiltration rate are affecting the shallow flow system. 相似文献
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Abstract. Ground water rising to within 6 m (20 feet) of average ground surface elevations in Louisville, Kentucky caused concern to municipal officials and building owners in the central urban area. An average rise of more than 11 m (35 feet) occurred between 1969 and 1980.
An evaluation of foundation conditions and structural configurations in central Louisville indicated rising ground water could create:
1. slight but significant possibilities of structural settlement problems;
2. high possibilities of damage to basement floors and walls; and
3. very high possibilities for disruption of utility conduits.
Efforts to determine the cause of this rise in ground-water level have focused on the historical relationships between ground-water levels, pumpage rates and precipitation values.
Historical data indicated that ground-water levels in a system undisturbed by man could reach ground surface elevations in central Louisville. Preliminary studies indicated a strong relation between average ground-water levels and changes in pumping rates and incident precipitation. A further detailed study showed extremely high correlation (R = 0.995) between average ground-water levels in 1966–1980 and cumulative departures in precipitation and pumping rates from 1950–1965 average precipitation and pumping rates.
A study of the feasibility of lowering ground-water levels while simultaneously storing energy in the aquifer system was begun but was interrupted by devastating explosions of hexane in the sewers beneath south-central Louisville on February 13, 1981. Although a dry year in 1980 and no change in pumping rate have slowed the rise in ground-water level temporarily, long-term solutions to this problem need to be developed. 相似文献
An evaluation of foundation conditions and structural configurations in central Louisville indicated rising ground water could create:
1. slight but significant possibilities of structural settlement problems;
2. high possibilities of damage to basement floors and walls; and
3. very high possibilities for disruption of utility conduits.
Efforts to determine the cause of this rise in ground-water level have focused on the historical relationships between ground-water levels, pumpage rates and precipitation values.
Historical data indicated that ground-water levels in a system undisturbed by man could reach ground surface elevations in central Louisville. Preliminary studies indicated a strong relation between average ground-water levels and changes in pumping rates and incident precipitation. A further detailed study showed extremely high correlation (R = 0.995) between average ground-water levels in 1966–1980 and cumulative departures in precipitation and pumping rates from 1950–1965 average precipitation and pumping rates.
A study of the feasibility of lowering ground-water levels while simultaneously storing energy in the aquifer system was begun but was interrupted by devastating explosions of hexane in the sewers beneath south-central Louisville on February 13, 1981. Although a dry year in 1980 and no change in pumping rate have slowed the rise in ground-water level temporarily, long-term solutions to this problem need to be developed. 相似文献
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怀来地震台伸缩仪观测曲线年变形态每年出现2次较大幅度的阶跃型上升,且变化幅度大小不同。对该地震台观测山洞周边4 km范围内抽水井的分布、2016-2017年季节性抽水时间、抽水量、群井开抽数量等进行调查,并与伸缩仪观测曲线异常变化进行对比分析,发现在时间及变化幅度上,二者同步性较好,分析认为形变观测的周期性大幅度上升变化应与观测山洞周边群井抽水有关,非地震前兆异常变化;并对抽水引起的形变观测机理进行初步分析,提出干扰消除方法。 相似文献
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西安地裂缝近期活动与热水井水位关系研究 总被引：4，自引：0，他引：4
本文根据西安小寨地裂缝与西影井第三系深层热水水位的观测资料,分析了二者变化周期的准同步和相位的滞后性特征,并结合地面沉降速率和周围地震活动性,探讨了地裂缝与第三系深层承压水位之间存在内在联系的原因,以及抽水—地面沉降对地裂缝影响的构造动态调制作用. 相似文献
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Recirculating well pairs are a proven means of implementing bioremediation and may also be useful for applying other in situ ground water remediation technologies. A bromide tracer test was performed to characterize the hydraulic performance of a recirculating well pair installed at Moffett Field, California. In particular, we estimate two important properties of the recirculating well pair: (1) the fraction of captured water that is recycled between the wells, and (2) the travel-time distribution of ground water in the induced zone of recirculation. We also develop theoretical estimates of these two properties and demonstrate they depend upon a dimensionless pumping rate, denoted xi. The bromide breakthrough curve predicted from theory agrees well with that determined experimentally at Moffett Field. The minimum travel time between the wells is denoted t(min). In theory, t(min) depends inversely on Q, the pumping rate in the recirculating wells, and is proportional to a2, the square of the distance between the wells. Both the experimental and theoretical travel-time distributions indicate that at least half the recirculating water travels between the wells along fast flowpaths (travel time < 2*t(min)). Therefore, when designing recirculating well pairs, engineers should ensure that t(min) will be sufficiently high to allow biologically mediated reactions (or other in situ remediation processes) sufficient time to proceed. 相似文献
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Regional ground water flow is most usually estimated using Darcy's law, with hydraulic conductivities estimated from pumping tests, but can also be estimated using ground water residence times derived from radioactive tracers. The two methods agree reasonably well in relatively homogeneous aquifers but it is not clear which is likely to produce more reliable estimates of ground water flow rates in heterogeneous systems. The aim of this paper is to compare bias and uncertainty of tracer and hydraulic approaches to assess ground water flow in heterogeneous aquifers. Synthetic two-dimensional aquifers with different levels of heterogeneity (correlation lengths, variances) are used to simulate ground water flow, pumping tests, and transport of radioactive tracers. Results show that bias and uncertainty of flow rates increase with the variance of the hydraulic conductivity for both methods. The bias resulting from the nonlinearity of the concentration–time relationship can be reduced by choosing a tracer with a decay rate similar to the mean ground water residence time. The bias on flow rates estimated from pumping tests is reduced when performing long duration tests. The uncertainty on ground water flow is minimized when the sampling volume is large compared to the correlation length. For tracers, the uncertainty is related to the ratio of correlation length to the distance between sampling wells. For pumping tests, it is related to the ratio of correlation length to the pumping test's radius of influence. In regional systems, it may be easier to minimize this ratio for tracers than for pumping tests. 相似文献
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Predicting the future performance of horizontal wells under varying pumping conditions requires estimates of basic aquifer parameters, notably transmissivity and storativity. For vertical wells, there are well-established methods for estimating these parameters, typically based on either the recovery from induced head changes in a well or from the head response in observation wells to pumping in a test well. Comparable aquifer parameter estimation methods for horizontal wells have not been presented in the ground water literature. Formation parameter estimation methods based on measurements of pressure in horizontal wells have been presented in the petroleum industry literature, but these methods have limited applicability for ground water evaluation and are based on pressure measurements in only the horizontal well borehole, rather than in observation wells. This paper presents a simple and versatile method by which pumping test procedures developed for vertical wells can be applied to horizontal well pumping tests. The method presented here uses the principle of superposition to represent the horizontal well as a series of partially penetrating vertical wells. This concept is used to estimate a distance from an observation well at which a vertical well that has the same total pumping rate as the horizontal well will produce the same drawdown as the horizontal well. This equivalent distance may then be associated with an observation well for use in pumping test algorithms and type curves developed for vertical wells. The method is shown to produce good results for confined aquifers and unconfined aquifers in the absence of delayed yield response. For unconfined aquifers, the presence of delayed yield response increases the method error. 相似文献