FORMAT
BOOKS
PACKAGES
EDITION
PUBLISHER
CONTENT TYPE
Act
Admin Code
Announcements
Bill
Book
CADD File
CAN
CEU
Charter
Checklist
City Code
Code
Commentary
Comprehensive Plan
Conference Paper
County Code
Course
DHS Documents
Document
Errata
Executive Regulation
Federal Guideline
Firm Content
Guideline
Handbook
Interpretation
Journal
Land Use and Development
Law
Legislative Rule
Local Amendment
Local Code
Local Document
Local Regulation
Local Standards
Manual
Model Code
Model Standard
Notice
Ordinance
Other
Paperback
PASS
Periodicals
PIN
Plan
Policy
Product
Program
Provisions
Requirements
Revisions
Rules & Regulations
Standards
State Amendment
State Code
State Manual
State Plan
State Standards
Statute
Study Guide
Supplement
Technical Bulletin
All
|
Description of ASTM-D2435 2011ASTM D2435 / D2435M - 11Standard Test Methods for One-Dimensional Consolidation Properties of Soils Using Incremental LoadingActive Standard ASTM D2435 / D2435M | Developed by Subcommittee: D18.05 Book of Standards Volume: 04.08 ASTM D2435 / D2435MSignificance and Use
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. Estimates of this type are of key importance in the design of engineered structures and the evaluation of their performance. The test results can be greatly affected by sample disturbance. Careful selection and preparation of test specimens is required to reduce the potential of disturbance effects. Note 3Notwithstanding the statement 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. Agencies that meet the criteria of Practice D3740 generally are considered capable of competent and objective testing. Users of this test method are cautioned that compliance with Practice D3740 does not assure reliable testing. Reliable testing depends on many factors, and Practice D3740 provides a means of evaluation some of these factors. Consolidation test results are dependent on the magnitude of the load increments. Traditionally, the axial stress is doubled for each increment resulting in a load increment ratio of 1. For intact samples, this loading procedure has provided data from which estimates of the preconsolidation stress, using established interpretation techniques, compare favorably with field observations. Other loading schedules may be used to model particular field conditions or meet special requirements. 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. 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. 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. Several other evaluation techniques exist and may yield different estimates of the preconsolidation stress. 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. Consolidation test results are dependent upon the duration of each load increment. Traditionally, the load duration is the same for each increment and equal to 24 h. 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. It is necessary to use an interpretation technique which indirectly determines that consolidation is essentially complete. These test methods specify procedures for two techniques (Method A and Method B), however alternative techniques may be used when agreed to by the requesting agency and still be in conformance with these test methods. The apparatus in general use for these test methods do not have provisions for verification of saturation. Most intact samples taken from below the water table will be saturated. 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. 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. 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. Alternatively, the test may be performed using an apparatus equipped to saturate the specimen. 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: The soil is saturated and has homogeneous properties; The flow of pore water is in the vertical direction; The compressibility of soil particles and pore water is negligible compared to the compressibility of the soil skeleton; The stress-strain relationship is linear over the load increment; The ratio of soil permeability to soil compressibility is constant over the load increment; and Darcy's law for flow through porous media applies. 1. Scope p id='s00002'>1.1 These test methods cover 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 Test Method 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. This test method provides only the compression curve of the specimen and the results combine both primary consolidation and secondary compression deformations. 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 in Test Method A. 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. Note 1The determination of the rate and magnitude of consolidation of soil when it is subjected to controlled-strain loading is covered by Test Method D4186 . 1.2 These test methods are most commonly performed on saturated intact samples of fine grained soils naturally sedimented in water, however, the basic test procedure is applicable, as well, to specimens of compacted soils and intact samples of soils formed by other processes such as weathering or chemical alteration. Evaluation techniques specified in these test methods 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. In particular, the rate of consolidation (interpretation of the time curves) is only applicable to fully saturated specimens. 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. The required maximum stress level depends on the purpose of the test and must be agreed on with the requesting agency. In the absence of specific instructions, Section 11 provides the default load increment and load duration schedule for a standard test. Note 2Time-deformation readings are required to determine the time for completion of primary consolidation and for evaluating the coefficient of consolidation, c v . Since c v varies with stress level and loading type (loading or unloading), the load increments with timed readings must be selected with specific reference to the individual project. Alternatively, the requesting agency may specify Test Method B wherein the time-deformation readings are taken on all load increments. 1.4 These test methods do not address the use of a back pressure to saturate the specimen. Equipment is available to perform consolidation tests using back pressure saturation. The addition of back pressure saturation does not constitute non-conformance to these test methods. 1.5 Units The values stated in either SI units or inch-pound units [given in brackets] are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 1.5.1 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 two separate 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 of mass (lbm), or the recording of density in lb/ft 3 should not be regarded as nonconformance with this test method. 1.6 Observed and calculated values shall conform to the guidelines for significant digits and rounding established in Practice D6026 , unless superseded by this test method. 1.6.1 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. 1.7 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 and health practices and determine the applicability of regulatory limitations prior to use. ASTM Standards D422 Test Method for Particle-Size Analysis of Soils D653 Terminology Relating to Soil, Rock, and Contained Fluids D854 Test Methods for Specific Gravity of Soil Solids by Water Pycnometer D1587 Practice for Thin-Walled Tube Sampling of Soils for Geotechnical Purposes D2216 Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass D2487 Practice for Classification of Soils for Engineering Purposes (Unified Soil Classification System) D2488 Practice for Description and Identification of Soils (Visual-Manual Procedure) D3550 Practice for Thick Wall, Ring-Lined, Split Barrel, Drive Sampling of Soils D3740 Practice for Minimum Requirements for Agencies Engaged in Testing and/or Inspection of Soil and Rock as Used in Engineering Design and Construction D4186 Test Method for One-Dimensional Consolidation Properties of Saturated Cohesive Soils Using Controlled-Strain Loading D4220 Practices for Preserving and Transporting Soil Samples D4318 Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soils D4452 Practice for X-Ray Radiography of Soil Samples D4546 Test Methods for One-Dimensional Swell or Collapse of Cohesive Soils D4753 Guide for Evaluating, Selecting, and Specifying Balances and Standard Masses for Use in Soil, Rock, and Construction Materials Testing D6026 Practice for Using Significant Digits in Geotechnical Data D6027 Practice for Calibrating Linear Displacement Transducers for Geotechnical Purposes Keywords compressibility; compression curves; consolidation; consolidation coefficient; consolidation test; consolidometer; preconsolidation pressure; preconsolidation stress; primary consolidation; rebound; secondary compression; settlement; swelling: Compression testing--soil; Consolidation; Preconsolidation pressure; Primary consolidation; Rebound; Secondary compression; Settlement; Soil; Swelling; ICS Code ICS Number Code 93.020 (Earth works. Excavations. Foundation construction. Underground works) DOI: 10.1520/D2435_D2435M-11 ASTM International is a member of CrossRef. ASTM D2435 / D2435MThis book also exists in the following packages...Subscription InformationMADCAD.com ASTM Standards subscriptions are annual and access is unlimited concurrency based (number of people that can access the subscription at any given time) from single office location. For pricing on multiple office location ASTM Standards Subscriptions, please contact us at info@madcad.com or +1 800.798.9296.
Some features of MADCAD.com ASTM Standards Subscriptions are: - Immediate Access: As soon as the transaction is completed, your ASTM Standards Subscription will be ready for access.
For any further information on MADCAD.com ASTM Standards Subscriptions, please contact us at info@madcad.com or +1 800.798.9296.
About ASTMASTM International, formerly known as the American Society for Testing and Materials (ASTM), is a globally recognized leader in the development and delivery of international voluntary consensus standards. Today, some 12,000 ASTM standards are used around the world to improve product quality, enhance safety, facilitate market access and trade, and build consumer confidence. ASTM’s leadership in international standards development is driven by the contributions of its members: more than 30,000 of the world’s top technical experts and business professionals representing 150 countries. Working in an open and transparent process and using ASTM’s advanced electronic infrastructure, ASTM members deliver the test methods, specifications, guides, and practices that support industries and governments worldwide. |
GROUPS
|