1.1 本指南涵盖了如何使用直接（直接）空气旋转钻井程序进行地质环境勘探和安装地下水质监测设备。 注1: 本指南中有关空气旋转钻井方法的直接术语表示压缩空气通过钻杆柱注入旋转钻头。空气冷却钻头，并将钻屑输送到钻杆柱和井壁之间环形空间的表面。 注2: 本指南不包括在单独指南中讨论的岩土现场特征的考虑因素。 1.2 用于地质环境勘探的直接空气旋转钻井通常涉及安全规划、管理和文件编制。本指南无意专门论述勘探和现场安全。 1.3 以国际单位制表示的数值应视为标准值。括号中给出的值仅供参考。 1.4 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。 1.5 所有观察值和计算值均应符合实践中确定的有效数字和舍入准则 D6026 . 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。所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； 通常情况下，增加或减少报告数据的有效位数以与这些考虑因素相称。考虑分析方法或工程设计中使用的有效数字超出了本标准的范围。 1.6 本指南提供了有组织的信息收集或一系列选项，并不推荐具体的行动方案。本文件不能取代教育或经验，应与专业判断一起使用。并非本指南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。 1.7 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====== 4.1 直接空气旋转钻井在地质环境勘探中的应用可能涉及采样、取芯、现场或孔隙流体测试、在未固结或固结材料中为后续钻井活动安装套管，以及在未固结和固结材料中安装地下水质量监测装置。 与其他方法相比，使用直接空气旋转钻井方法的几个优点可能包括能够相当快速地钻穿固结材料，并且在许多情况下，不需要向钻孔中引入钻井液。当水敏材料（即易碎砂岩或湿陷性土壤）可能妨碍使用水基旋转钻井方法时，通常采用空气旋转钻井技术来推进钻孔。空气旋转钻井的一些缺点可能包括未使用套管的松散材料中的钻孔完整性较差，以及污染物和空气中粉尘的潜在挥发。 注3: 直接空气旋转钻井使用加压空气循环钻屑。在某些情况下，可以向气流中注入水或泡沫添加剂或两者，以改善岩屑- 提升能力和岩屑返回。如果没有仔细维护和监测钻井压力和技术，在高压下使用空气可能会导致地层材料破裂或钻孔受到严重侵蚀。如果钻孔损坏变得明显，则应考虑其他钻井方法。 注4: 用户可以在进行采样、现场或孔隙流体测试或取芯的同一钻孔内安装监测装置。 4.2 本指南中涉及的地下水质监测装置通常包括筛网或多孔进水管和立管，通常安装有过滤器组，以延长进水装置的使用寿命，并配有隔离密封件和低渗透性回填，以阻止流体在钻孔渗透的水文单元之间的移动或地表水的渗透（见实践） D5092 ). 由于压力计主要是用于测量地下水头的装置，因此只有在考虑装置的整体质量，包括接触采样水或气体的材料质量后，才应将压力计转换为水质监测装置。 注5: 水质监测装置和压力计应具有足够的套管密封、环形隔离密封和回填土，以阻止污染物在水文单元之间的移动。

1.1 This guide covers how direct (straight) air-rotary drilling procedures may be used for geoenvironmental exploration and installation of subsurface water-quality monitoring devices. Note 1: The term direct with respect to the air-rotary drilling method of this guide indicates that compressed air is injected through a drill-rod column to a rotating bit. The air cools the bit and transports cuttings to the surface in the annulus between the drill-rod column and the borehole wall. Note 2: This guide does not include considerations for geotechnical site characterizations that are addressed in a separate guide. 1.2 Direct air-rotary drilling for geoenvironmental exploration will often involve safety planning, administration, and documentation. This guide does not purport to specifically address exploration and site safety. 1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only. 1.4 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. 1.5 All observed and calculated values are to conform to the guidelines for significant digits and rounding established in Practice D6026 . 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 objective; and it is common practice to increase or reduce the 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 analysis method or engineering design. 1.6 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide 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 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. 1.7 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 ====== 4.1 The application of direct air-rotary drilling to geoenvironmental exploration may involve sampling, coring, in situ or pore-fluid testing, installation of casing for subsequent drilling activities in unconsolidated or consolidated materials, and for installation of subsurface water-quality monitoring devices in unconsolidated and consolidated materials. Several advantages of using the direct air-rotary drilling method over other methods may include the ability to drill rather rapidly through consolidated materials and, in many instances, not require the introduction of drilling fluids to the borehole. Air-rotary drilling techniques are usually employed to advance drill hole when water-sensitive materials (that is, friable sandstones or collapsible soils) may preclude use of water-based rotary-drilling methods. Some disadvantages to air-rotary drilling may include poor borehole integrity in unconsolidated materials without using casing, and the potential for volitization of contaminants and air-borne dust. Note 3: Direct-air rotary drilling uses pressured air for circulation of drill cuttings. In some instances, water or foam additives, or both, may be injected into the air stream to improve cuttings-lifting capacity and cuttings return. The use of air under high pressures may cause fracturing of the formation materials or extreme erosion of the borehole if drilling pressures and techniques are not carefully maintained and monitored. If borehole damage becomes apparent, consideration to other drilling method(s) should be given. Note 4: The user may install a monitoring device within the same borehole in which sampling, in situ or pore-fluid testing, or coring was performed. 4.2 The subsurface water-quality monitoring devices that are addressed in this guide consist generally of a screened or porous intake and riser pipe(s) that are usually installed with a filter pack to enhance the longevity of the intake unit, and with isolation seals and a low-permeability backfill to deter the movement of fluids or infiltration of surface water between hydrologic units penetrated by the borehole (see Practice D5092 ). Inasmuch as a piezometer is primarily a device used for measuring subsurface hydraulic heads, the conversion of a piezometer to a water-quality monitoring device should be made only after consideration of the overall quality of the installation to include the quality of materials that will contact sampled water or gas. Note 5: Both water-quality monitoring devices and piezometers should have adequate casing seals, annular isolation seals, and backfills to deter movement of contaminants between hydrologic units.