1.1 这些测试方法仅限于低应变（<10 –4 %)两类水平传播地震波在土壤材料中的速度；初级压缩（ P波 ）和二次剪切（ S波 ）波浪。该标准假设用于分析获得的数据的方法基于测量距离上的首次到达时间或间隔到达时间。 1.2 讨论了数据的各种应用，并讨论了解释程序和设备，如震源、接收器和记录系统。涉及的其他项目包括钻孔间距、钻井、套管、灌浆、偏差测量和实际测试程序。 1.3 这些测试方法主要涉及实际的测试程序、数据解释和将产生统一测试结果的设备规格。数据缩减和解释仅限于各种地震波类型的识别、示例计算、斯内尔折射定律的使用和假设。 1.4 有几种设备可用于产生高质量的P波或垂直偏振的S波（ SV-波 ）或两者和水平极化S波（ SH波 ).几种类型的市售接收器和记录系统也可用于进行井间勘测。 1.5 所有记录和计算值应符合实践中建立的有效数字和四舍五入指南 D6026 . 1.5.1 这些测试方法中用于规定如何收集/记录和计算数据的程序被视为行业标准。所使用的程序不考虑材料变化、特殊目的研究或对用户目标的任何考虑。对比这些试验方法中规定的更多的有效数字或更好的灵敏度进行的测量不应被视为不符合本标准。 1.6 单位- 以SI单位或英寸-磅单位[括号中给出]表示的值应单独视为标准值。每个系统中陈述的值可能不完全等同；因此，每个系统应独立使用。合并两个系统的值可能导致不符合标准。以SI以外的单位报告试验结果不应视为不符合本试验方法。 1.7 本标准并不旨在解决与其使用相关的所有安全性问题（如果有）。本标准的使用者有责任在使用前建立适当的安全、健康和环境实践并确定法规限制的适用性。1.8 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》中确立的国际公认的标准化原则制定的。 ======意义和用途====== 5.1 井间地震测试提供了关于钻孔之间地下地层材料的地震波速度作为现场深度的函数的数据 ( 1 ) . 3 地震波速与重要的岩土弹性常数直接相关，岩土弹性常数是岩土基础设计中必不可少的输入参数。这些参数用于静态和动态荷载下的土壤行为分析，其中弹性常数是定义不同变形状态的模型的输入变量，例如弹性、弹性-塑料，和失败。导出的剪切波速在岩土工程设计中的另一个重要用途是土壤的液化评估。使用导出的P波和S波速度的示例总结如下: 5.1.1 用于静态/动态分析的输入； 5.1.2 用于计算剪切模量、杨氏模量和泊松比（假设密度已知或假设）； 5.1.3 用于使用适当的建筑规范确定地震场地类别；和 5.1.4 用于评估液化潜力。 5.2 试验方法中固有的基本假设如下: 5.2.1 假设水平分层。 5.2.2 斯内尔折射定律适用于纵波和横波以及从井间测试中得出的速度。如果在井间地震测试数据分析中不考虑Snell折射定律，报告应如此说明。在这种情况下，只要高速层与低速层相邻，就应特别注意，因为波可以折射穿过高速层并比直达波更快到达 ( 2 ) . 5.2.3 在与所研究的层相邻的较高速度材料处，将存在强振幅全内反射（见 图1 ).当入射角超过临界角时，它们就会出现；其结果是反射系数变得复杂，这又导致反射源波（4）中的失真。TIR会显著扭曲所需的直接传播路径源波，如果检测到，应在测试报告中记录。 附注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。符合执业准则的机构 D3740 通常被认为能够胜任和客观的测试/取样/检查。可靠的结果取决于许多因素；实践 D3740 提供了一种评估部分（但不是全部）这些因素的方法。

1.1 These test methods are limited to the determination of the low strain (<10 –4 %) velocity of two types of horizontally travelling seismic waves in soil materials; primary compression ( P-wave ) and secondary shear ( S-wave ) waves. The standard assumes that the method used to analyze the data obtained is based on first arrival times or interval arrival times over a measured distance. 1.2 Various applications of the data are addressed and interpretation procedures and equipment, such as seismic sources, receivers, and recording systems are discussed. Other items addressed include borehole spacing, drilling, casing, grouting, deviation surveys, and actual test procedures. 1.3 These test methods are primarily concerned with the actual test procedure, data interpretation, and specifications for equipment which will yield uniform test results. Data reduction and interpretation are limited to the identification of various seismic wave types, example computations, use of Snell's law of refraction, and assumptions. 1.4 There are several devices that can be used to generate high-quality P-waves or vertically polarized S-waves ( SV-waves ) or both and horizontally polarized S-waves ( SH-waves ). Several types of commercially available receivers and recording systems can also be used to conduct a crosshole survey. 1.5 All recorded and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026 . 1.5.1 The procedures used to specify how data are collected/recorded and calculated in these test methods are regarded as the industry standard. The procedures used do not consider material variation, special purpose studies, or any considerations for the user’s objectives. Measurements made to more significant digits or better sensitivity than specified in these test methods shall not be regarded a nonconformance with this standard. 1.6 Units— The values stated in either SI units or inch-pound units [given 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. Combining values from the two systems may result in non-conformance with the standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method. 1.7 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. 1.8 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 Crosshole seismic tests provide data about the seismic wave velocities of subsurface stratigraphic materials between boreholes as a function of depth at a site ( 1 ) . 3 Seismic wave velocities are directly related to the important geotechnical elastic constants, which are essential input parameters in geotechnical foundation designs. Such parameters are used in both analyses of soil behavior under both static and dynamic loads where the elastic constants are input variables into the models defining the different states of deformations such as elastic, elasto-plastic, and failure. Another important use of derived shear wave velocities in geotechnical design is in the liquefaction assessment of soils. Examples of the use of the derived P-wave and S-wave velocities are summarized as follows: 5.1.1 For input into static/dynamic analyses; 5.1.2 For computing shear modulus, Young's modulus, and Poisson's ratio (provided density is known or assumed); 5.1.3 For determining Seismic Site Class using the appropriate Building Code; and 5.1.4 For assessing liquefaction potential. 5.2 Fundamental assumptions inherent in the test methods are as follows: 5.2.1 Horizontal layering is assumed. 5.2.2 Snell’s law of refraction applies to P-waves and S-waves and to the velocities derived from crosshole tests. If Snell’s law of refraction is not considered in the analysis of Crosshole Seismic Testing data, the report shall so state. In that case special attention shall be given whenever high velocity layers are adjacent to low velocity layers, since waves can refract through the high velocity layers and arrive sooner than the direct waves ( 2 ) . 5.2.3 Strong amplitude Total Internal Reflections (TIRs) will be present where higher velocity materials are adjacent to the layer under investigation (see Fig. 1 ). They arise when the incident angle exceeds the critical angle; as a result of which reflection coefficients become complex, which in turn leads to distortions in the reflected source wave (4). TIRs can significantly distort the desired direct travel path source wave and, if detected, should be documented in the test report. 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 facility used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some, but not all, of those factors.