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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Link to Active This link will always route to the current Active version of the standard. The values stated in inch-pound units are approximate and given for guidance only. Referenced Documents 2d435 separately The documents listed below are referenced within the subject standard but are not provided as part of the standard.
Note 3—Notwithstanding the d24335 on precision and bias contained in this standard, the precision of this test method is dependent on the competence of the personnel performing the test and suitability of the equipment and facilities used. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method. Alternatively, the test may be performed using an apparatus equipped to saturate the specimen.
Evaluation techniques specified in this test method are generally applicable to soils naturally sedimented in water. In the absence of specific instructions, Section 11 provides the default load increment and load duration schedule for a standard test. For intact samples, this loading procedure has provided data from which estimates of d4235 preconsolidation stress, using established interpretation techniques, compare favorably with field observations.
The compressibility of soil particles and pore water is negligible compared to the compressibility of the soil skeleton. This astn method provides d245 the compression curve of the specimen and the results combine satm primary consolidation and secondary compression deformations. How one applies the results obtained using this standard is beyond its scope.
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.
It is scientifically undesirable to combine two separate systems within a single standard.
Other loading schedules may be used asym model particular field conditions or meet special requirements. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other.
Alternative techniques to estimate the preconsolidation stress may be used when agreed to by ast, requesting agency and still be in conformance with these test methods.
Agencies that meet the criteria of Practice D generally are considered capable of competent and objective testing. 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.
It is scientifically undesirable to combine two separate systems within a single standard. These test methods use conventional consolidation theory based on Terzaghi’s consolidation equation to compute the coefficient of consolidation, c v. Combining values from the two systems may result in non-conformance with the standard.
The data from the consolidation test are used to estimate the magnitude and rate of both differential and total settlement of a structure or earthfill. The test results can be greatly affected by sample disturbance. Evaluation techniques specified in these test asttm assume the pore space is fully saturated and are generally applicable to soils naturally sedimented in water. Tests performed on other unsaturated materials such as compacted and residual weathered or chemically altered soils may require special evaluation techniques.
Load increment ashm of less than 1 d2345 be desirable for soils that are highly sensitive or whose response is highly dependent on strain rate. 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.
Equipment is available to perform consolidation tests using back pressure saturation. astn
Careful selection and preparation of test specimens is required to reduce the potential of disturbance effects. Reliable testing depends on many factors, and Practice D provides a means of evaluation some of these factors.
Estimates of this type are of key importance in the design of engineered structures and the evaluation of their performance. 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. Alternatively, the requesting agency may specify Test Method B wherein the time-deformation readings are taken on all load increments.
How one applies the results obtained using this standard is beyond its scope. 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. Traditionally, the axial stress is doubled for each increment resulting in a load increment ratio of 1. 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.
Consolidation test results are dependent on the magnitude of the load increments. The apparatus in general use for these test methods do not have provisions for verification of saturation. 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.
ASTM D Standard
Two alternative procedures are provided as follows:. Inundation astmm 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.
Historical Version s – view previous versions of standard.
The addition of back pressure saturation does not constitute non-conformance to these test methods. The required maximum stress level depends on the purpose of the test and must be agreed on with the requesting agency. Work Item s – proposed revisions of this standard.
Two alternative procedures are provided as follows:. For some soils, the rate of consolidation is such that complete consolidation dissipation of excess pore pressure will require more than 24 h. The apparatus in general use does not have provisions for formal verification of pore pressure dissipation. Work Item s – proposed revisions of this 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.
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 Several other evaluation techniques exist and may yield different estimates of the preconsolidation stress. It is necessary to use an interpretation technique which indirectly determines that consolidation is essentially complete.