Standard Test Method for One-Dimension Consolidation Properties of Soil Using Incremental Loading. GeoTesting Express is a provider of Soil Testing Services – ASTM D, Standard Test Method for One-Dimensional Consolidation Properties of Soils. Buy ASTM D TEST METHODS FOR ONE-DIMENSIONAL CONSOLIDATION PROPERTIES OF SOILS USING INCREMENTAL.
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It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine astn applicability of regulatory limitations prior to use.
Agencies that meet the criteria of Practice D generally are considered capable of competent and objective testing. Traditionally, the load d243 is the same for each increment and equal to 24 h.
Evaluation techniques specified in this test method are generally applicable to soils naturally sedimented in water.
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The apparatus in general use does not have provisions for formal verification of pore pressure dissipation. It is necessary to use an interpretation technique which indirectly determines that consolidation is essentially complete. It is scientifically undesirable to combine two separate systems within a single standard. Two alternative procedures are provided as follows: Active view current version of standard. This test method provides only the compression curve of the specimen and the results combine both primary consolidation and secondary qstm deformations.
Tests performed on other d2453 materials such as compacted and residual weathered or chemically altered soils may require special evaluation techniques.
ASTM D Standard
Estimates of this type are of key importance in the design of engineered structures and the evaluation of their performance. The addition of d435 pressure saturation does not constitute non-conformance to these test methods. Several other evaluation techniques exist and may yield different estimates of the preconsolidation stress. Careful selection and preparation of test specimens is required to reduce the potential of disturbance effects.
This implicitly combines two separate systems of units, that is, the astj system and the gravimetric system. Referenced Documents purchase separately The documents listed below are referenced within the subject standard but are not provided as part of the standard. Alternatively, the test may be performed using an apparatus equipped to saturate the specimen. However, the time rate of deformation is very sensitive to degree of saturation and caution must be exercised regarding estimates for duration of settlements when partially saturated conditions prevail.
Users of this test method are d2453 that compliance with Practice D does not assure reliable testing.
Since c varies with stress level and load increment loading or unloadingthe load increments with timed readings must be selected with specific reference to the individual project. Tests performed on other soils such as compacted and residual weathered or chemically altered soils may require special evaluation techniques.
Time-deformation readings are required on a minimum of two load increments. 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 Note 2—Time-deformation readings are required to determine the time for completion of primary consolidation and for evaluating the coefficient of consolidation, c v.
Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method. Alternatively, the requesting agency may specify Test Method B wherein the time-deformation readings are taken on all load increments. These test methods specify procedures for two techniques Method A and Method Bhowever alternative techniques may be used when agreed to by the requesting agency and still be in conformance with these test methods.
The extent to which partial saturation influences the test results may be a part of the test evaluation and may include application of theoretical models other than conventional consolidation theory. For some soils, the rate of consolidation is such that complete consolidation dissipation of excess pore pressure will require more than 24 h. Alternative techniques to estimate the preconsolidation stress may be used when agreed to by the requesting agency and still be in conformance with these test methods.
How one applies the results obtained using this standard is beyond its scope. The required maximum stress level depends on the purpose of the test and must be agreed on with the requesting agency.
Evaluation techniques specified in these test methods assume the pore space is fully saturated and are generally applicable to soils naturally sedimented in water. Alternatively, the requesting agency may specify Test Method B wherein the time-deformation readings are taken on all load increments.
The test results can be greatly affected by sample disturbance. In particular, the rate of consolidation interpretation of the time curves is only applicable to fully saturated specimens. The values stated in inch-pound units are approximate and given for guidance only. Work Item s – proposed revisions of this standard. Load increment ratios of less than 1 may be desirable for soils that are highly sensitive or whose response is highly dependent on strain rate.
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Other loading schedules may be used to model particular field conditions or meet special requirements. These test methods use conventional consolidation theory based on Terzaghi’s consolidation equation to compute the coefficient of consolidation, c v. The analysis is based upon the following assumptions:. 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.
Inundation of the test specimen does not significantly change the degree of saturation of the test specimen but rather provides boundary water to eliminate negative pore pressure associated with sampling and prevents evaporation during the test.
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. This test method provides the compression curve with explicit data to account for secondary compression, the coefficient of consolidation for saturated materials, and the rate of secondary compression.
The interpretation method specified by these test methods to estimate the preconsolidation stress provides a simple technique to verify that one set of time readings are taken after the preconsolidation stress and that the specimen is loaded to a sufficiently high stress level.
For example, it may be desirable to inundate and load the specimen in accordance with the wetting or loading pattern expected in the field in order to best evaluate the response. 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.
Work Item s – proposed revisions of this standard.