1.1 本规程涵盖了确定非渗漏承压含水层的透过率和蓄水系数的分析程序。它用于分析流入或流出恒定流量或注入井的径向流期间收集的水位响应数据。 1.2 该分析程序与其他程序一起，与试验方法中给出的现场程序一起使用 D4050 . 1.3 限制- 本规程在确定含水层水力特性方面的局限性主要与现场情况和本规程简化假设之间的对应关系有关（见 5.1 ). 1.4 所有观察值和计算值应符合实践中确定的有效数字和舍入准则 D6026 . 1.4.1 本标准中用于规定如何收集/记录或计算数据的程序被视为行业标准。此外，它们代表了通常应保留的有效数字。使用的程序不考虑材料变化、获取数据的目的、特殊目的研究或用户目标的任何考虑因素；通常的做法是增加或减少报告数据的有效位数，以与这些考虑因素相称。考虑工程设计分析方法中使用的有效数字超出了本标准的范围。 1.5 本实践提供了一组用于执行一个或多个特定操作的说明。 本文件不能取代教育或经验，应与专业判断一起使用。并非实践的所有方面都适用于所有情况。本ASTM标准不代表或取代必须根据其判断给定专业服务的充分性的谨慎标准，也不应在不考虑项目的许多独特方面的情况下应用本文件。本文件标题中的“标准”一词仅表示该文件已通过ASTM共识程序获得批准。 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 假设: 5.1.1 油井以恒定速率排放， Q . 5.1.2 油井直径无限小，完全穿透含水层。 5.1.3 非渗漏含水层是均质、各向同性和广泛的。非渗漏含水层从封闭层获得的水贡献很小。 5.1.4 油井排放仅来自含水层中的蓄水。 5.1.5 假设含水层和油井条件的几何形状如所示 图1 . 5.2.3 泰斯方法在非承压含水层中的应用: 5.2.3.1 虽然这些假设适用于承压或承压条件，但如果水位下降与含水层的饱和厚度相比较小，或者如果水位下降因含水层厚度的减少而得到纠正，并且延迟重力屈服的影响较小，则泰斯解可应用于无侧限含水层。 5.2.3.2 含水层厚度减少- 在非承压含水层中，当抽水井附近的水位下降时，就会发生脱水。如Jacob所示，当水位下降是含水层厚度的重要组成部分时，需要对水位下降进行修正 ( 5. ) . 提款， s ，需要替换为 s ′，等效承压含水层中的水位下降，其中: 5.2.3.3 重力屈服效应- 在非承压含水层中，延迟重力屈服效应可能会使应用THIS方法的测试早期的水位降测量无效。延迟重力产额的影响在远处和远处的部分穿透观测井中可以忽略不计， r ，来自控制井，其中: 之后， t ，如中所示 等式9 来自纽曼 ( 6. ) . 哪里: S y = 比产量。对于全穿透观测井，延迟产量的影响在远处可以忽略不计， r 在里面 等式8 在下列时间的十分之一之后: 等式9 . 注1: 本标准产生的结果的质量取决于执行该标准的人员的能力，以及所用设备和设施的适用性。符合实践标准的机构 D3740 通常认为能够胜任和客观的测试/采样/检查等。本标准的用户应注意遵守惯例 D3740 本身不能确保可靠的结果。可靠的结果取决于许多因素；实践 D3740 提供了一种评估其中一些因素的方法。

1.1 This practice covers an analytical procedure for determining the transmissivity and storage coefficient of a nonleaky confined aquifer. It is used to analyze data on water-level response collected during radial flow to or from a well of constant discharge or injection. 1.2 This analytical procedure, along with others, is used in conjunction with the field procedure given in Test Method D4050 . 1.3 Limitations— The limitations of this practice for determination of hydraulic properties of aquifers are primarily related to the correspondence between the field situation and the simplifying assumptions of this practice (see 5.1 ). 1.4 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 . 1.4.1 The procedures used to specify how data are collected/recorded or calculated, in this standard are regarded as the industry standard. In addition, they are representative of the significant digits that generally should be retained. The procedures used do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the user’s objectives; and it is common practice to increase or reduce significant digits of reported data to be commensurate with these considerations. It is beyond the scope of this standard to consider significant digits used in analytical methods for engineering design. 1.5 This practice offers a set of instructions for performing one or more specific operations. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of the practice may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without the consideration of a project’s many unique aspects. The word “Standard” in the title of this document means only that the document has been approved through the ASTM consensus process. 1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. ====== Significance And Use ====== 5.1 Assumptions: 5.1.1 Well discharges at a constant rate, Q . 5.1.2 Well is of infinitesimal diameter and fully penetrates the aquifer. 5.1.3 The nonleaky aquifer is homogeneous, isotropic, and aerially extensive. A nonleaky aquifer receives insignificant contribution of water from confining beds. 5.1.4 Discharge from the well is derived exclusively from storage in the aquifer. 5.1.5 The geometry of the assumed aquifer and well conditions are shown in Fig. 1 . 5.2.3 Application of Theis Method to Unconfined Aquifers: 5.2.3.1 Although the assumptions are applicable to artesian or confined conditions, the Theis solution may be applied to unconfined aquifers if drawdown is small compared with the saturated thickness of the aquifer or if the drawdown is corrected for reduction in thickness of the aquifer, and the effects of delayed gravity yield are small. 5.2.3.2 Reduction in Aquifer Thickness— In an unconfined aquifer dewatering occurs when the water levels decline in the vicinity of a pumping well. Corrections in drawdown need to be made when the drawdown is a significant fraction of the aquifer thickness as shown by Jacob ( 5 ) . The drawdown, s , needs to be replaced by s ′, the drawdown that would occur in an equivalent confined aquifer, where: 5.2.3.3 Gravity Yield Effects— In unconfined aquifers, delayed gravity yield effects may invalidate measurements of drawdown during the early part of the test for application to the Theis method. Effects of delayed gravity yield are negligible in partially penetrating observation wells at and beyond a distance, r , from the control well, where: After the time, t , as given in Eq 9 from Neuman ( 6 ) . where: S y = the specific yield. For fully penetrating observation wells, the effects of delayed yield are negligible at the distance, r , in Eq 8 after one tenth of the time given in the Eq 9 . Note 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself ensure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.