Standard Test Methods for
One-Dimensional Consolidation Properties of Soils Using Incremental Loading 1
This standard is issued under the ﬁxed designation D 2435; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope* 1.1 These test methods covers procedures for determining the magnitude and rate of consolidation of soil when it is restrained laterally and drained axially while subjected to incrementally applied controlled-stress loading. Two alternative procedures are provided as follows: 1.1.1 TestMethod A—This test method is performed with constant load increment duration of 24 h, or multiples thereof. Time-deformation readings are required on a minimum of two load increments. 1.1.2 Test Method B—Time-deformation readings are required on all load increments. Successive load increments are applied after 100 % primary consolidation is reached, or at constant time increments as described inTest Method A.
NOTE 1—The determination of the rate and magnitude of consolidation of soil when it is subjected to controlled-strain loading is covered by Test Method D 4186.
requesting agency may specify Test Method B wherein the timedeformation readings are taken on all load increments.
1.2 This test method is most commonly performed on undisturbed samples of ﬁne grained soils naturallysedimented in water, however, the basic test procedure is applicable, as well, to specimens of compacted soils and undisturbed samples of soils formed by other processes such as weathering or chemical alteration. Evaluation techniques speciﬁed in this test method are generally applicable to soils naturally sedimented in water. Tests performed on other soils such as compacted and residual (weatheredor chemically altered) soils may require special evaluation techniques. 1.3 It shall be the responsibility of the agency requesting this test to specify the magnitude and sequence of each load increment, including the location of a rebound cycle, if required, and, for Test Method A, the load increments for which time-deformation readings are desired.
NOTE 2—Time-deformation readings are requiredto determine the time for completion of primary consolidation and for evaluating the coefficient of consolidation, cv. Since cv varies with stress level and load increment (loading or unloading), the load increments with timed readings must be selected with speciﬁc reference to the individual project. Alternatively, the
1.4 The values stated in SI units are to be regarded as the standard. Thevalues stated in inch-pound units are approximate and given for guidance only. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method. 1.4.1 In the engineering profession it is customary practice to use, interchangeably, units representing both mass and force, unless dynamic calculations (F = Ma) are involved. This implicitly combines twoseparate systems of units, that is, the absolute system and the gravimetric system. It is scientiﬁcally undesirable to combine two separate systems within a single standard. This test method has been written using SI units; however, inch-pound conversions are given in the gravimetric system, where the pound (lbf) represents a unit of force (weight). The use of balances or scales recording pounds ofmass (lbm), or the recording of density in lb/ft3 should not be regarded as nonconformance with this test method. 1.5 Observed and calculated values shall conform to the guidelines for signiﬁcant digits and rounding established in Practice D 6026, unless superceded by this test method, unless superceded by this test method. 1.5.1 The method used to specify how data are collected, calculated, or...