1.1 电子锥贯入仪测试通常用于确定地下地层，用于岩土工程和环境现场表征 ( 1. ) . 2. 在试验方法中详细讨论了电子锥贯入仪试验的岩土工程应用 D5778 然而，在环境现场表征应用中使用电子锥贯入仪测试涉及更多未讨论的考虑因素。对于环境现场表征，强烈建议在试验方法中使用压电锥（PCPT或CPTu）选项 D5778 因此，可以评估导水率和含水层静水压力的信息。 1.2 本规程的目的是讨论在进行环境现场表征试验时需要考虑的电子锥贯入仪试验方面。 1.3 用于环境现场表征项目的电子锥贯入仪测试通常需要蒸汽清洁推杆和灌浆孔。 根据项目范围、当地法规和公司偏好，有多种清洁和灌浆方法。详细讨论所有这些方法超出了本实践的范围。指南中详细解释了灌浆程序 D6001 . 1.4 锥贯入仪测试通常用于确定含水层的位置，以便安装井（实践 D5092/D5092M 指导 D6274 ). 锥体试验可与直接推土取样相结合，以确认土壤类型（指南 D6282/D6282M ). 直接推动液压注射成型（实践 D8037/D8037M )是另一种用于估算导水率和直接推塞试验的补充试验( D7242/D7242M )用于确认估计。圆锥贯入仪可以配备额外的传感器，用于地下水质量评估（实践 D6187 ). 其他传感器的位置必须符合试验方法的要求 D5778 . 1.5 本规程仅适用于涉及化学（有机和无机）废物的场所，并且由于钻井设备的特殊监测要求，不拟用于放射性或混合（化学和放射性）废物场所。 1.6 单位- 以国际单位制或磅单位（括号内）表示的数值应单独视为标准值。每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。电导率单位为米/秒或厘米/秒，具体取决于引用的来源。 1.7 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 ，除非被本标准取代。 1.8 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。 1.9 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。并非本惯例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。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。 1.10 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 环境现场表征项目几乎总是需要有关地下土壤地层和与地下水流速和方向相关的水力参数的信息。土壤地层学通常由各种钻井程序和解释钻孔日志中收集的数据来确定。电子压锥贯入仪测试是确定土壤地层的另一种方法，与传统的钻探和采样方法相比，它可能更快、更便宜，并提供更高的土壤单元分辨率。对于环境现场表征应用，电子压电锥还具有其他优点，即不会产生可能带来其他处置问题的污染岩屑 ( 2. , 3. , 4. , 5. , 6. , 7. , 8. , 9 , 10 ) . 调查人员可以从相邻钻孔中获取土壤样本，以进行对比，但在同一区域的先验信息或经验可能会排除进行钻孔的必要性 ( 11 ) . 大多数圆锥贯入仪钻机配备有直接推动式土壤采样器（指南 D6282/D6282M )可用于确认土壤类型。 4.2 电子压电锥贯入试验是一种现场调查方法，涉及: 4.2.1 将电子仪器探头推入地面（参见 图1 典型圆锥贯入仪的示意图）。孔隙压力元件的位置可能不同，但通常位于u形 2. 位置，如所示 图1 （试验方法 D5778 ). 4.2.3.3 Robertson提出了以下方程估计 k 从…起 我 c 并显示在 图4 ( 11 ) . 这些方程用于一些锥入度测试商业软件，以估计 k 基于标准化土壤行为类型。但是，如所示 表1和 2. ，估计值来自 我 c 不是很准确，例如，估计 k 该值的范围可能超过两个数量级。 图4 拟议关系 我 c 归一化土壤行为类型和估计的土壤渗透性， k （罗伯逊） ( 1. ) ) 4.3 当试图取回土壤气体或水样时，最好知道承载区（渗透区）的位置。虽然可以从低导水率的沉积物中回收土壤气体和水，但所需的时间通常使其不切实际。土壤气体和水样可以更快地从渗透带（如沙子）中提取。圆锥贯入仪尖端和摩擦数据通常可以非常准确地区分小于0.3 m[1 ft]的低渗透层和高渗透层。 4.4 电子锥贯入仪测试用于各种土壤类型。反应重量小于10吨的轻型设备通常仅限于粒径相对较小的土壤。获得的典型深度为20至40米[60至120英尺]，但重量为20吨或以上的较重设备达到70米[200英尺]以上的深度并不罕见。 由于贯入度是垂直力的直接结果，不包括旋转或钻孔，因此不能用于岩石或重胶结土壤。深度能力是许多因素的函数( D5778 ). 4.5 孔隙压力数据: 4.5.1 超孔隙水压力数据通常用于环境现场表征项目，以确定薄土层，该土层将是含水层或含水层。孔隙压力通道通常可以检测到这些薄层，即使它们小于20 mm[1 in]厚的 4.5.2 推压过程中获得的超孔隙水压力数据用于指示相对导水率。在电子锥贯入仪测试过程中会产生过量孔隙水压力。通常，高超孔隙水压力表示存在含水层（粘土），低超孔隙水压力表示存在含水层（砂）。然而，情况并非总是如此。 例如，如果在锥体尖端路肩上方进行监测，一些粉砂和过度固结土壤会产生负孔隙压力。看见 图1 . 因此，还必须评估数据的平衡。已经提出了通过动态超孔隙水压力测量来估计导水率的方法 ( 12 , 13 , 14 ) . 4.5.3 耗散试验: 4.5.3.1 一般来说，由于地下水主要流经砂而非粘土，因此对流经砂的水流进行建模是最关键的。在暂停测深的情况下，也可以监测孔隙压力数据。这称为孔隙压力耗散试验。快速消散的孔隙压力表明存在含水层，而非常缓慢的消散表明存在隔水层。 图5 显示了一个典型的耗散测试，显示了t 50 等待50确定 % 消散的最高压力。 在一些土壤中，在峰值孔隙压力出现之前，首先可能存在滞后。该示例还表明，达到了足够的时间，使孔隙压力达到完全均衡。 图5 示例耗散测试显示t 50 孔隙压力的测定和均衡（Robertson ( 2. ) ) 4.5.3.2 图6 显示了t之间的一个拟议关系 50 Robertson报告的耗散时间和水平导水率 ( 2. , 11 ) . 该图表使用了针对地面上覆岩应力归一化的尖端阻力。这需要估计土壤的湿密度和饱和密度以及估计的地下水位位置 ( 2. ) . 图表上的数据点是来自相关样本的实验室测试数据。 图6为10 cm 2. 直径为15 cm的圆锥体和校正系数是必需的 2. 圆锥体（乘法 k 按系数1.5计算的值） ( 2. ) . 图6 CPTu t之间的关系 50 （分钟）和土壤导水率( k )和归一化锥阻力Qtn（Robertson之后 ( 2. , 11 , 15 ) ) 4.5.3.3 包含在 图6 是Parez和Fauriel提出的耗散时间、土壤类型和导水率之间的关系 ( 15 ) . 此关系用于 4.5.3.4 通过高分辨率压电锥（HRP） ( 16 ) 用于砂土中的耗散试验。 4.5.3.4 干净砂中的孔隙压力衰减几乎是瞬时的。因此，很难用圆锥贯入仪测量砂土中的导水率。因此，直到最近，圆锥贯入仪还不经常用于测量环境应用中沙子的导水率。HRP锥使用特殊的高分辨率硬件和软件，即使在快速消散的砂层中也可以进行高分辨率数据采集 ( 16 , 17 ) 尽管最近的经验表明，这可能仅限于小于10的导水率值 -3 厘米/秒 ( 18 , 19 ) . 部分排水也可能成为土壤中锥体贯入试验的一个问题，其中t 50 <50秒，不排水锥入度的近似极限如所示 图6 ( 20 ) . 4.5.3.5 对地下水流动的彻底研究还包括确定水不能流动的地方。锥贯入仪孔压消散试验可以非常有效地用于研究围压单元的导水率。然而，在生产CPT时，长时间的过度耗散可能不经济。伯恩斯和梅恩 ( 21 ) 考虑到粘土的应力历史，开发了粘土孔隙压力耗散试验模型的方法，并可以预测 k 和固结特性。他们的方法使用地震压锥通过井下剪切波速测量来测量土壤刚度。 4.5.3.6 孔隙压力数据也可用于估计地下水位的深度或识别滞水带。 这是通过使多余的孔隙水压力达到平衡，然后减去适当的水头压力来实现的。由于产生了较高的超孔隙压力，典型的孔隙压力传感器配置为测量高达3.5 MPa[500 lb]的压力 f /在中。 2. ]或更多。由于传感器精度是最大范围的函数，因此相对深度与水位精度约为±100 mm[0.5 ft]。如果操作员允许传感器有足够的时间来散发穿透地下水位以上干燥土壤时产生的热量，则可以实现更好的精度。有时使用低压传感器只是为了更准确地确定地下水位的深度。例如，175 kPa[25 lb f /在中。 2. ]传感器将提供优于10毫米[0.5英寸]的精度。温度传感器和适当校准的结合允许高精度和快速的数据收集。 然而，必须小心，以防止这些传感器因超压快速上升而损坏。一些较新的系统允许无滞后的大爆破压力保护，使用户能够在高度分层的环境中收集数据，而不必担心传感器损坏。 4.5.3.7 当与适当的模型相结合时，可以从多个CPT位置收集的最终压力值得出三维梯度。一旦推导出梯度分布，并生成导水率和有效孔隙度分布，就可以推导并可视化渗流速度分布。这类信息对环境调查和修复设计至关重要。如果污染物浓度分布已知，可以使用相同的软件推导污染物质量通量的三维分布。 4.6 有关典型岩土电子锥贯入仪测试的完整描述，请参阅测试方法 D5778 . 4.7 本实践对土壤进行现场测试。未获得土壤样本。对该实践结果的解释提供了渗透土壤类型的估计。车载CPT单杆土壤采样器( D6282/D6282M )可用于短离散间隔土壤采样。使用连续直推双管取样器，可以在单独位置快速获得连续土芯( D6282/D6282M ). 调查人员可以从相邻位置获取土壤样本，以进行对比，但在同一区域的先验信息或经验可能会排除对土壤样本进行钻孔的必要性。 4.8 某些地下条件可能会阻止锥体贯入。在坚硬岩石中不可能穿透，在较软的岩石（如粘土岩和页岩）中通常不可能穿透。 粗颗粒，如砾石、鹅卵石和巨砾，可能难以穿透或损坏锥体或推杆。根据土层的强度和厚度，水泥土区可能难以渗透。如果存在阻止表面直接推动的地层，则可以采用旋转或冲击钻井方法通过阻碍层推进钻孔，以达到测试区。 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 本身并不能保证可靠的结果。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。 实践 D3740 是为从事土壤和岩石或两者的实验室测试或检查的机构开发的。因此，它并不完全适用于执行该现场实践的机构。然而，这种做法的用户应该认识到，实践框架 D3740 适用于评估执行此实践的机构的质量。目前，还没有已知的合格国家机构来检查执行这种做法的机构。

1.1 The electronic cone penetrometer test often is used to determine subsurface stratigraphy for geotechnical and environmental site characterization purposes ( 1 ) . 2 The geotechnical application of the electronic cone penetrometer test is discussed in detail in Test Method D5778 , however, the use of the electronic cone penetrometer test in environmental site characterization applications involves further considerations that are not discussed. For environmental site characterization, it is highly recommended to use the Piezocone (PCPT or CPTu) option in Test Method D5778 so information on hydraulic conductivity and aquifer hydrostatic pressures can be evaluated. 1.2 The purpose of this practice is to discuss aspects of the electronic cone penetrometer test that need to be considered when performing tests for environmental site characterization purposes. 1.3 The electronic cone penetrometer test for environmental site characterization projects often requires steam cleaning the push rods and grouting the hole. There are numerous ways of cleaning and grouting depending on the scope of the project, local regulations, and corporate preferences. It is beyond the scope of this practice to discuss all of these methods in detail. A detailed explanation of grouting procedures is discussed in Guide D6001 . 1.4 Cone penetrometer tests are often used to locate aquifer zones for installation of wells (Practice D5092/D5092M , Guide D6274 ). The cone test may be combined with direct push soil sampling for confirming soil types (Guide D6282/D6282M ). Direct push hydraulic injection profiling (Practice D8037/D8037M ) is another complementary test for estimating hydraulic conductivity and direct push slug tests ( D7242/D7242M ) and used for confirming estimates. Cone penetrometers can be equipped with additional sensors for groundwater quality evaluations (Practice D6187 ). Location of other sensors must conform to requirements of Test Method D5778 . 1.5 This practice is applicable only at sites where chemical (organic and inorganic) wastes are a concern and is not intended for use at radioactive or mixed (chemical and radioactive) waste sites due to specialized monitoring requirements of drilling equipment. 1.6 Units— The values stated in either SI units or in-lb units (presented in brackets) are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Units for conductivity are either m/s or cm/s depending on the sources cited. 1.7 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 , unless superseded by this standard. 1.8 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. 1.9 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 this 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 consideration of a project's many unique aspects. The word "Standard" in the title means only that the document has been approved through the ASTM consensus process. 1.10 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 Environmental site characterization projects almost always require information regarding subsurface soil stratigraphy and hydraulic parameters related to groundwater flow rate and direction. Soil stratigraphy often is determined by various drilling procedures and interpreting the data collected on borehole logs. The electronic piezocone penetrometer test is another means of determining soil stratigraphy that may be faster, less expensive, and provide greater resolution of the soil units than conventional drilling and sampling methods. For environmental site characterization applications, the electronic piezocone also has the additional advantage of not generating contaminated cuttings that may present other disposal problems ( 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ) . Investigators may obtain soil samples from adjacent borings for correlation purposes, but prior information or experience in the same area may preclude the need for borings ( 11 ) . Most cone penetrometer rigs are equipped with direct push soil samplers (Guide D6282/D6282M ) that can be used to confirm soil types. 4.2 The electronic piezocone penetration test is an in situ investigation method involving: 4.2.1 Pushing an electronically instrumented probe into the ground (see Fig. 1 for a diagram of a typical cone penetrometer). The position of the pore pressure element may vary but is typically located in the u 2 position, as shown in Fig. 1 (Test Method D5778 ). 4.2.3.3 Robertson proposed the following equations estimating k from I c and shown on Fig. 4 ( 11 ) . These equations are used for some cone penetration testing commercial software for estimates of k based on normalized soil behavior type. However, as shown on Tables 1 and 2 , the values estimated from I c are not very accurate for example, the estimated k value may range over two orders of magnitude. FIG. 4 Proposed Relationship Between I c and Normalized Soil Behavior Type and Estimated Soil Permeability, k (Robertson ( 1 ) ) 4.3 When attempting to retrieve a soil gas or water sample, it is advantageous to know where the bearing zones (permeable zones) are located. Although soil gas and water can be retrieved from sediments with low hydraulic conductivity, the length of time required usually makes it impractical. Soil gas and water samples can be retrieved much faster from permeable zones, such as sands. The cone penetrometer tip and friction data generally can distinguish between lower and higher permeability zones less than 0.3 m [1 ft] very accurately. 4.4 The electronic cone penetrometer test is used in a variety of soil types. Lightweight equipment with reaction weights of less than 10 tons generally are limited to soils with relatively small grain sizes. Typical depths obtained are 20 to 40 m [60 to 120 ft], but depths to over 70 m [200 ft] with heavier equipment weighing 20 tons or more are not uncommon. Since penetration is a direct result of vertical forces and does not include rotation or drilling, it cannot be utilized in rock or heavily cemented soils. Depth capabilities are a function of many factors ( D5778 ). 4.5 Pore Pressure Data: 4.5.1 Excess pore water pressure data often are used in environmental site characterization projects to identify thin soil layers that will either be aquifers or aquitards. The pore pressure channel often can detect these thin layers even if they are less than 20 mm [1 in.] thick. 4.5.2 Excess pore water pressure data taken during push are used to provide an indication of relative hydraulic conductivity. Excess pore water pressure is generated during an electronic cone penetrometer test. Generally, high excess pore water pressure indicates the presence of aquitards (clays), and low excess pore water pressure indicates the presence of aquifers (sands). This is not always the case, however. For example, some silty sands and over-consolidated soils generate negative pore pressures if monitored above the shoulder of the cone tip. See Fig. 1 . The balance of the data, therefore, also must be evaluated. There have been methods proposed to estimate hydraulic conductivity from dynamic excess pore water pressure measurements ( 12 , 13 , 14 ) . 4.5.3 Dissipation Tests: 4.5.3.1 In general, since the groundwater flows primarily through sands and not clays, modeling the flow through the sands is most critical. The pore pressure data also can be monitored with the sounding halted. This is called a pore pressure dissipation test. A rapidly dissipating pore pressure indicates the presence of an aquifer while a very slow dissipation indicates the presence of an aquitard. Fig. 5 shows a typical dissipation test showing the t 50 determined by waiting for 50 % of the highest pressure registered to dissipate. In some soils there can first be a lag before the peak pore pressure occurs. This example also shows that sufficient time was reached to allow the pore pressure to reach full equalization. FIG. 5 Example Dissipation Test Showing t 50 Determination and Equalization of Pore Pressure (Robertson ( 2 ) ) 4.5.3.2 Fig. 6 shows one proposed relationship between t 50 dissipation time and horizontal, hydraulic conductivity reported by Robertson ( 2 , 11 ) . This chart uses a tip resistance normalized for overburden stresses in the ground. This requires the estimation of the wet and saturated density of the soil and estimated water table location ( 2 ) . The data points on the chart are laboratory test data from correlated samples. Figure 6 is developed for 10 cm 2 diameter cones and a correction factor is required for 15 cm 2 cones (multiply k values by factor of 1.5) ( 2 ) . FIG. 6 Relationship Between CPTu t 50 (in minutes) and Soil Hydraulic Conductivity ( k ) and Normalized Cone Resistance, Qtn (After Robertson ( 2 , 11 , 15 ) ) 4.5.3.3 Included in Fig. 6 is a proposed relationship between dissipation time, soil type, and hydraulic conductivity proposed by Parez and Fauriel ( 15 ) . This relationship is used in 4.5.3.4 by the high resolution piezocone (HRP) ( 16 ) for dissipation tests in sands. 4.5.3.4 A pore pressure decay in a clean sand is almost instantaneous. The hydraulic conductivity, therefore, is very difficult to measure in a sand with a cone penetrometer. As a result, until recently the cone penetrometer was not used very often for measuring the hydraulic conductivity of sands in environmental applications. The HRP cone uses special high resolution hardware and software to allow for high resolution data collection even in rapidly dissipating sand formations ( 16 , 17 ) , although recent experience indicates that this might be limited to hydraulic conductivity values less than 10 -3 cm/s ( 18 , 19 ) . Partial drainage can also become an issue for cone penetration testing in soils where t 50 < 50s and the approximate limits for undrained cone penetration are shown on Fig. 6 ( 20 ) . 4.5.3.5 A thorough study of groundwater flow also includes determining where the water cannot flow. Cone penetrometer pore pressure dissipation tests can be used very effectively to study the hydraulic conductivity of confining units. However, long excessive times for dissipation may not be economical in production CPT. Burns and Mayne ( 21 ) have developed methods to model the pore pressure dissipations tests in clays considering the stress history of the clays and can predict k and consolidation characteristics. Their method uses a seismic piezocone to measure the soil stiffness using down-hole shear wave velocity measurements. 4.5.3.6 The pore pressure data also can be used to estimate the depth to the water table or identify perched water zones. This is accomplished by allowing the excess pore water pressure to equilibrate and then subtract the appropriate head pressure. Due to high excess pore pressures being generated, typical pore pressure transducers are configured to measure pressures up to 3.5 MPa [500 lb f /in. 2 ] or more. Since transducer accuracy is a function of maximum range, this provides a relative depth to water level accuracy of about ±100 mm [0.5 ft]. Better accuracy can be achieved if the operator allows sufficient time for the transducer to dissipate the heat generated while penetrating dry soil above the water table. Lower pressure transducers are sometimes used just for the purpose of determining the depth to the water table more accurately. For example, a 175-kPa [25-lb f /in. 2 ] transducer would provide accuracy that is better than 10 mm [0.5 in.]. Incorporation of a temperature transducer and appropriate calibration allows for high precision and rapid data collection. Caution must be used, however, to prevent these transducers from being damaged due to a quick rise in excess pressure. Some newer systems allow for large burst pressure protection without hysteresis, which enables users to collect data in highly stratified environments without as much concern for transducer damage. 4.5.3.7 When coupled with appropriate models, three dimensional gradient can be derived from final pressure values collected from multiple CPT locations. Once gradient distributions have been derived, and hydraulic conductivity and effective porosity distributions have been generated, seepage velocity distributions can be derived and visualized. This type of information is critical to environmental investigations and remediation design. If contaminant concentration distributions are known, the same software can be used to derive three dimensional distributions of contaminant mass flux. 4.6 For a complete description of a typical geotechnical electronic cone penetrometer test, see Test Method D5778 . 4.7 This practice tests the soil in situ. Soil samples are not obtained. The interpretation of the results from this practice provides estimates of the types of soil penetrated. Onboard CPT single rod soil samplers ( D6282/D6282M ) are available for short discrete interval soil sampling. Continuous soil cores can be obtained rapidly in a separate location using continuous direct push dual tube samplers ( D6282/D6282M ). Investigators may obtain soil samples from adjacent locations for correlation purposes, but prior information or experience in the same area may preclude the need for borings for soil samples. 4.8 Certain subsurface conditions may prevent cone penetration. Penetration is not possible in hard rock and usually not possible in softer rocks, such as claystones and shales. Coarse particles, such as gravels, cobbles, and boulders may be difficult to penetrate or cause damage to the cone or push rods. Cemented soil zones may be difficult to penetrate depending on the strength and thickness of the layers. If layers are present which prevent direct push from the surface, rotary or percussion drilling methods can be employed to advance a boring through impeding layers to reach testing zones. 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 assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors. Practice D3740 was developed for agencies engaged in the laboratory testing or inspection of soils and rock or both. As such, it is not totally applicable to agencies performing this field practice. However, users of this practice should recognize that the framework of Practice D3740 is appropriate for evaluating the quality of an agency performing this practice. Currently there is no known qualifying national authority that inspects agencies that perform this practice.