ASTM粘性土不固结不排水三轴压缩试验标准试验方法

ASTM D 2850-03a 粘性土不固结不排水三轴压缩试验标准试验 1.Scope 1.范围 1.1 This test method covers determination of the strength and stress-strain relationships of a cylindrical specimen of either undisturbed or remolded cohesive soil. Specimens are subjected to a confining fluid pressure in a triaxial chamber. No drainage of the specimen is permitted during the test. The specimen is sheared in compression without drainage at a constant rate of axial deformation (strain controlled). 1.1 这个试验方法适用于确定圆柱形试样的强度与应力-应变关系,该样品可以是原状的或者是扰动的粘性土样。试样受到来自于压力室的一个限制变化压力的影响。在试验期间不允许试样排水。这个试样在不排水压缩的情况下被剪切的,轴向压力应控制在一个恒定速率下进行。 1.2 This test method provides data for determining undrained strength properties and stress-strain relations for soils. This test method provides for the measurement of the total stresses applied to the specimen, that is, the stresses are not corrected for pore-water pressure. 1.2 这个试验方法为确定土在不排水强度条件下与应力-应变的关系提供数据。这个试验提供给测定施加在试样上的总压力,当然,这个压力不是修正的孔隙水压力。 1.3 All observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D 6026. 1.3 所有的观测和计算值应遵从在D6026中确定的重要数位和舍入方法的指导方针。 1.3.1 The method used to specify how data are collected, calculated, or recorded in this standard is not directly related to the accuracy to which the data can be applied in design or other uses, or both. How one applies the results obtained using this standard is beyond its scope. 1.3.1 这个方法用于详细说明怎样收集数据,计算数据,或者记录数据。在这个标准下记录的数据与应用于或其他用途的数据精度没有直接关系。 1.4 The values stated in SI units are to be regarded as the standard. The values stated in inch-pound units and given in parenthesis are approximate. 1.4 在国际单位制中规定的数据被认为是标准的。在英制单位中和在圆括号里的数据是近似数据。 1.5 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 and health practices and determine the applicability of regulatory limitations prior to use. 1.5 这个标准不能用于声称是向一切关于安全方面的致辞,或者任何有关于它的使用。制定适当的安全和健康实践活动与调整其局限性的适用范围是这个标准使用者的。 2. Referenced Documents 2.相关的文件 2.1 ASTM Standards: 2.1 ASTM 标准 D 422 Method for Particle-Size Analysis of Soils D 653 Terminologry Relating to Soil, Rock, and Contained Fluids D 854 Test Method for Specific Gravit)r of Soils D 1587 Method for Thin-Walled Tube Sampling of Soils D 2166 Test Methods for Unconfined Compressive Stt}ength of Cohesive Soil D 2216 Test Method for Laboratory Determination of Water (Moisture) Content of Soil and Rock D 2487 Classification of Soils for Engineering Purposes D 2488 Practice for Description and Identification of Soils (Visual-Manual Procedure) D 3740 Practice for Evaluation of Agencies Engaged in the Testing and/or Tnspection of Soil and Rock as Used in Engineering Design and Construction D 4220 Practices for Preserving and Transporting Soil Samples D 4318 Test Method for Liquid Limit, Plastic Limit, and Plasticity Index of Soils D 4753 Specification for Evaluating, Selecting, and Specifying Balances and Scales for Use in Testing Soil and Rock, and Related Construction Materials D 4767 Test Method for Consolidated-Undrained Triaxial Compression Test on Cohesive Soils D 6026 Practice for Using Significant Digits in Geotechnical Data 3. Terminology 3.专业术语 3.1 Definitions-The definitions of terms used in this test method shall be in accordance with Terminology D 653. 3.1 定义-用于这个试验方法术语的定义应该于D 653术语学相一致。 3.2 Definitions of Terms Specific to This Standard: 3.2 针对此标准的术语定义: 3.2.1 failure--the stress condition at failure for a test specimen. Failure is often taken to correspond to the maximum principal stress difference (deviator stress) attained or the principal stress difference (deviator stress) at 15% axial strain, whichever is obtained first during the performance of a test. 3.2.1 破坏----一个试样在一个压力条件下的破坏。破坏经常与达到最大主应力差,或者在15%轴向压力下达到主应力差相一致,任何一个值都是在开始试验后最先获得的值。 3.2.2 unconsolidated-undrained compressive strength--the value of the principal stress difference (deviator stress) at failure. 3.2.2 不固结不排水压缩强度――主应力差在破坏时的值。 4. Significance and Use 4. 意义和应用 4.1 In this test method, the compressive strength of a soil is determined in terms of the total stress, therefore, the resulting strength depends on the pressure developed in the pore fluid during loading. In this test method, fluid flow is not permitted from or into the soil specimen as the load is applied, therefore the resulting pore pressure, and hence strength, differs from that developed in the case where drainage can occur. 4.1 在这个试验中,土的压缩强度以总的应力来达,因此,压力产生的作为结果的强度在孔隙水的加载中发展。在这个试验里,随着土样荷载的应用,是不允许液体的流出与流入的,因此,做为结果的孔隙压力与因此产生的强度,是不同于在排水发生的情况下产生的结果的。 4.2 If the test specimens are 100% saturated, consolidation cannot occur when the confining pressure is applied nor during the shear portion of the test since drainage is not permitted. Therefore, if several specimens of the same material are tested, and if they are all at approximately the same water content and void ratio when they are tested, they will have approximately the same undrained shear strength. The Mohr failure envelope will usually be a horizontal straight line over the entire range of confining stresses applied to the specimens if the specimens are fully saturated. 4.2 如果试样是100%饱和的,在限制压力的作用下固结不可能产生,当然,从不排水开始,试样的剪切部分也不可能产生。因此,假如做试验的几个试样采用相同的材料,相接近的含水量与孔隙比,它们将有近似一样的不排水剪强度。如果试样完全浸泡在水中,则在应用到试样上的整个限制压力的范围中,莫尔破坏包络线通常将是一个水平直线。 4.3 If the test specimens are partially saturated or compacted specimens, where the degree of saturation is less than 100%,consolidation may occur when the confining pressure is applied and during shear, even though drainage is not permitted. Therefore, if several partially saturated specimens of the same material are tested at different confining stresses, they will not have the same undrained shear strength. Thus, the Mohr failure envelope for unconsolidated undrained triaxial tests on partially saturated soils is usually curved. 4.3如果试样是部分的饱和或者是饱和度不小于100%的紧密试样,当应用上限制压力和在剪切过程中,即使在不排水的情况下,固结也可能发生。因此,如果一些部分饱和的试样,相同材料在不同的限制压力下做试验,它们将不会有相同的不排水剪强度。因此,部分饱和试样的不固结不排水三轴试验莫尔破坏包 络线通常都是弯的。 4.4 The unconsolidated undrained triaxial strength is applicable to situations where the loads are assumed to take place so rapidly that there is insufficient time for the induced pore-water pressure to dissipate and for consolidation to occur during the loading period (that is, drainage does not occur). 4.4不排水不固结三轴试验强度适用于下述情况:荷载假定发生的很快,以致于没有足够的时间引起孔隙水压力的驱散;和固结发生在加荷的过程中(当然,排水没有发生)。 4.5 Compressive strengths determined using this procedure may not apply in cases where the loading conditions in the field differ significantly from those used in this test method. 4.5压缩强度取决于利用这个程序不能应用于以下情况:原位加荷条件不同于它们用于这个试验中的条件。 5. Apparatus 5.仪器装置 5.1 Axial Loading Device-The axial loading device shall be screw jack driven by an electric motor through a geared transmission, a hydraulic loading device, or any other compression device with sufficient capacity and control to provide the rate of loading prescribed in 7.5. The rate of advance of the loading device shall not deviate by ±5% from the selected value. Vibrations due to the operation of the loading device shall be sufficiently small to not Cause dimensional changes in the specimen. 5.1 轴向加压装置——轴向加压装置应该是被机械马达驱动的螺丝千斤顶,它通过一个连接传动装置,一个水力加压设备,或者其他任何有足够能力的压缩设备,而且,它能控制加载的速率,并且按7.5节描述的。加压装置的加荷速率偏离所选值不应多于±5%。由加压设备引起的震动应该足够的小,这样才不能引起试样在空间的变化。 5.2 Axial Load-Measuring Device-The axial measuring device shall be a load ring, electronic load cell, hydraulic load cell, or any other load-measuring device capable of measuring the axial load to an accuracy of 1% of the axial load at failure and may be a part of the axial loading device.