1.1 该试验方法用于通过在圆形横截面岩石中的试验室承受均匀分布的径向载荷来确定岩体的原位变形模量；在不同位置测量后续岩石径向位移，由此计算变形模量。岩石的径向各向异性变形能力是在足够的位置进行的，也可以通过在试验箱沿线和周围不同位置采集的伸长计读数之间的差异以及每个加载顺序的深度来确定。 通过在选定的时间间隔内保持荷载恒定，也可以获得与时间相关的变形信息。 注1: 即使构成千斤顶的每个钢环均承受均匀载荷，由圆柱形试验室引起的变形也不可能均匀。理论上，变形将沿圆柱体变化，使其看起来像高斯概率曲线。 1.2 该测试方法基于美国填海局开发的程序，其特点是使用长引伸计，提供距离测试区足够远的底锚，用作零参考点( 图1 ) ( 1. ) . 2. 也可以使用另一种程序，即新奥地利方法，该方法基于一根参考杆，该参考杆由于试验荷载而从中间向下延伸至挠度区外的支柱，如所示 图2 ( 2. ) . 除了获取变形读数的不同方法外，这两种现场测试是相同的。参考文献中提供了有关径向顶升和数据分析的其他信息 ( 3- 8. ) . 图1 美国填海局使用的径向顶升试验装置的总图和方案( 1. , 9 ) 图2 径向顶升试验装置的纵向、横截面和特写视图( 2. ) 带圆圈数字: 1、测量剖面。2、距离等于有效载荷的长度。3、控制伸长计。4、压力表。5、参考光束。6、液压泵。7.平千斤顶。8、用于反作用框架曲率补偿的木质垫片。9、混凝土。10、开挖直径。11、测量直径。伸长计钻孔。百分表伸长计。14、钢筋。膨胀楔。16 开挖半径。17、测量半径。18、平面千斤顶的内接圆。锚杆或伸长计锚。反作用框架环。 这里显示的示例是奥地利方法，虽然已经过时，但显示了更常见设置的大多数基本组件。 1.3 测试结果的应用超出了本测试方法的范围，但可能是某些测试程序的组成部分。（参见 注释2 .) 注2: 例如，测试隧道周围的地应力将影响测试结果，这取决于测试结果的使用方式，并且可能需要在任何分析或建议中加以考虑。 1.4 原位岩石变形行为的测试受反应架和扁千斤顶的最大应力范围的限制。 1.5 单位- 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的合理数学转换，仅供参考，不被视为标准。以英寸磅以外的单位报告试验结果不应视为不符合本试验方法。 1.5.1 仪器的国际单位制是英寸的替代品- 磅单位和其他类似的国际单位都是可以接受的，前提是它们满足英寸磅仪器制定的技术要求。 1.5.2 在处理英寸磅单位时，使用英寸磅单位的重力系统。在这个系统中，磅（lbf）表示力（重量）的单位，而质量的单位是段塞。除非涉及动态（F=ma）计算，否则不会给出缓动单元。 1.5.3 缓动质量单位通常不用于商业实践；即密度、平衡等。 因此，本标准中质量的标准单位为千克（kg）或克（g）或两者兼有。此外，括号中未给出/显示等效英寸-磅单位（slug）。 1.5.4 工程/建筑行业的常见做法是同时使用磅来表示质量单位（lbm）和力（lbf）。这种做法隐含地结合了两个独立的单位制；绝对系统和引力系统。科学上不希望同时使用两套独立的英寸- 单一标准内的磅单位。如前所述，本标准包括英寸-磅单位的重力系统，不使用/呈现质量的段塞单位。然而，使用天平或天平记录磅质量（lbm）或记录密度（lbm/ft） 3. 不应视为不符合本标准。 1.5.5 仅使用一组单元进行计算；SI或重力英寸磅。允许使用其他单位，前提是在整个计算过程中使用适当的转换因子来保持单位的一致性，并保持类似的有效数字或分辨率，或两者都保持。 1.6 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。 1.6.1 为了将测量值或计算值与规定限值进行比较，测量值或计算值应四舍五入至规定限值中最接近的小数或有效数字。 1.6.2 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。 注3: 关于有效数字和舍入的讨论 1.6 关于有效数字、舍入、精度和读数数量的标准章节更倾向于手动读数。然而，即使使用任何电子数据采集系统，读数仍应等于或优于任何手动数据采集要求。 1.7 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。 1.8 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》中确立的国际公认标准化原则制定的。 ====意义和用途====== 5.1 岩体对现场荷载的响应数据为岩石力学科学、大坝、隧道、桥梁、高层结构和其他对基础材料或周围岩体施加压力的设施的施工提供了许多重要信息。 5.2 该试验方法类似于岩石钻孔中的旁压计或膨胀计试验。最显著的区别是，它涉及更大体积的岩体。 通过测试更大的岩石体积，可以更准确地确定不连续性和其他地质因素对岩体荷载响应的影响。( 图3 ) 图3 岩体模量 径向顶升试验比其他试验方法选项（如实验室（E））涉及更大体积的岩体 实验室 )和钻孔测试，而不是一些地球物理钻孔和跨孔测试。 5.3 当需要比通过较便宜的单轴顶进试验、实验室或其他试验方法或程序更准确地表示岩体特性的值时，应使用该试验方法。 此外，在计算机建模之前或之后获取此类数据，以验证和微调任何计算机模型输出，也可能很有价值。 5.4 该试验方法适用于设计有压无衬砌或衬砌隧道和竖井的示例。 注4: 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。

1.1 This test method is used to determine the in situ modulus of deformation of rock mass by subjecting a test chamber in rock of a circular cross-section to uniformly distributed radial loading; the consequent rock radial displacements are measured at various locations, from which the deformation modulus may be calculated. The radial anisotropic deformability of the rock is taken at enough locations that it can also be determined from the differences between the extensometer readings taken at various locations along and around the test chamber as well with depth from each loading sequence. Information on time-dependent deformation may be obtained as well by holding the loads constant for selected time intervals. Note 1: Deformations caused by a cylindrical test chamber are not likely uniform even if each steel ring forming the jack is uniformly loaded. Theoretically, the deformations will vary along the cylinder such that it looks like a gaussian probability curve. 1.2 This test method is based upon the procedures developed by the US Bureau of Reclamation, featuring long extensometers that provide a bottom anchor far enough away from the test zone to be used as a zero reference point ( Fig. 1 ) ( 1 ) . 2 An alternative procedure, the New Austrian method, is also available and is based on a reference bar going down the middle to support posts outside the deflection zone due to the testing loads and shown in Fig. 2 ( 2 ) . Other than a different method of taking deformation readings, the two field tests are the same. Additional information on radial jacking and data analysis is presented in References ( 3- 8 ) . FIG. 1 General Diagram and Scheme of a Radial Jacking Test Setup used by the US Bureau of Reclamation ( 1 , 9 ) FIG. 2 Longitudinal, Cross-section, and Close-up View of the Radial Jacking Test Setup ( 2 ) Circled numbers: 1. Measuring profile. 2. Distance equal to the length of active loading. 3. Control extensometer. 4. Pressure gauge. 5. Reference beam. 6. Hydraulic pump. 7. Flat jack. 8. Wood spacer for reaction frame curvature compensation. 9. Concrete. 10. Excavation diameter. 11. Measuring diameter. 12. Extensometer drillholes. 13. Dial gauge extensometer. 14. Steel rod. 15. Expansion wedges. 16. Excavation radius. 17. Measuring radius. 18. Inscribed circle for flat jacks. 19. Rockbolt or extensometer anchor. 20. Reaction frame ring. The example shown here is the Austrian method and, while outdated, shows most of the essential components of the more common setups. 1.3 Application of the test results is beyond the scope of this test method, but may be an integral part of some testing programs. (See Note 2 .) Note 2: For example, in situ stresses around the test tunnel will affect the test results, depending on how the test results will be used and may need to be considered in any analyzes or recommendations. 1.4 Testing of the in situ rock deformation behavior is limited by the maximum stress range of the reaction frame and the flat jacks. 1.5 Units— The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are rationalized mathematical conversions to SI units that are provided for information only and are not considered standard. Reporting of test results in units other than inch-pound shall not be regarded as nonconformance with this test method. 1.5.1 The SI units presented for apparatus are substitutions of the inch-pound units, other similar SI units should be acceptable, providing they meet the technical requirements established by the inch-pound apparatus. 1.5.2 The gravitational system of inch-pound units is used when dealing with inch-pound units. In this system, the pound (lbf) represents a unit of force (weight), while the unit for mass is slugs. The slug unit is not given unless dynamic (F=ma) calculations are involved. 1.5.3 The slug unit of mass is typically not used in commercial practice; that is, density, balances, and so on. Therefore, the standard unit for mass in this standard is either kilogram (kg) or gram (g) or both. Also, the equivalent inch-pound unit (slug) is not given/presented in parenthesis. 1.5.4 It is common practice in the engineering/construction profession to concurrently use pounds to represent both a unit of mass (lbm) and of force (lbf). This practice implicitly combines two separate systems of units; the absolute and the gravitational systems. It is scientifically undesirable to combine the use of two separate sets of inch-pound units within a single standard. As stated, this standard includes the gravitational system of inch-pound units and does not use/present the slug unit for mass. However, the use of balances or scales recording pounds of mass (lbm) or recording density in lbm/ft 3 shall not be regarded as nonconformance with this standard. 1.5.5 Calculations are done using only one set of units; either SI or gravitational inch-pound. Other units are permissible, provided appropriate conversion factors are used to maintain consistency of units throughout the calculations, and similar significant digits or resolution, or both are maintained. 1.6 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 , unless superseded by this standard. 1.6.1 For purposes of comparing measured or calculated value(s) with specified limits, the measured or calculated value(s) shall be rounded to the nearest decimal or significant digits in the specified limits. 1.6.2 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, the 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. Note 3: The discussion about significant digits and rounding in 1.6 above and within the standard sections that follow about significant digits, rounding, accuracy, and the number of readings is geared more toward manual type readings. However, even with any electronic data acquisition system, the readings should still be taken equal to or better than with any manual data acquisition requirements. 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 Data on the response of a rock mass to in situ loading provides essential information for many purposes in the science of rock mechanics, in the construction of dams, tunnels, bridges, high-rise structures, and other facilities that exert pressure on the foundation material or surrounding rock mass. 5.2 This test method is similar to a pressuremeter or dilatometer test in rock boreholes. The most significant difference is it engages a much larger volume of the rock mass. By testing a larger rock volume, the influence of discontinuities and other geologic factors on rock mass response to loading is more accurately determined. ( Fig. 3 ) FIG. 3 Modulus of Rock Mass Radial jacking test engages a larger volume of the rock mass than with other test method options, such as laboratory (E lab ) and borehole tests other than some geophysical borehole and cross-hole tests. 5.3 This test method should be used when values are required which represent the rock mass properties more accurately than can be obtained through less expensive uniaxial jacking tests, laboratory, or other test methods or procedures. Also, it could be valuable for obtaining such data before or after computer modeling to verify and fine-tune any computer model output. 5.4 Examples of when this test method would be useful is to design pressurized unlined or lined tunnels and shafts. Note 4: 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.