AASHTO T236
Full Name
AASHTO T236 – Standard Method of Test for Direct Shear Test of Soils under Consolidated Drained Conditions
Scope
AASHTO T236 is a standard test method used to determine the consolidated drained shear strength of soil. Shear strength is a fundamental parameter in geotechnical engineering, essential for evaluating the stability of slopes, retaining walls, embankments, and foundations. This test is particularly suitable for situations where complete consolidation has occurred under the existing overburden and failure is reached slowly, allowing excess pore water pressure to dissipate.
Key aspects of AASHTO T236:
- Principle: the test involves placing a soil specimen in a shear box apparatus and applying a normal stress to consolidate the soil. After consolidation, the two halves of the shear box are moved relative to each other at a constant rate, shearing the specimen. The maximum shear stress that the soil can withstand before failure is recorded.
- Test procedure: AASHTO T236 outlines the steps for preparing the soil specimen, applying the normal stress, allowing for drainage, consolidating the specimen, and conducting the shear test. The test can be performed in either single shear or double shear mode.
- Data analysis: the test results, including shear stress and normal stress, are used to construct a Mohr-Coulomb failure envelope, which graphically represents the relationship between shear strength and normal stress for the soil. This information is then used in geotechnical design calculations.
Significance of AASHTO T236:
- Geotechnical design: the consolidated drained shear strength obtained from this test is a critical parameter in the design of earth retaining structures, slopes, embankments, and foundations.
- Soil characterization: the test provides valuable insights into the shear strength behavior of soils under drained conditions, which is essential for understanding their engineering properties and potential applications.
- Quality control: AASHTO T236 provides a standardized test method for determining the consolidated drained shear strength, ensuring consistency and reliability in the evaluation of soil properties across different laboratories and projects.
AASHTO T236 Accredited Laboratory
Applied Testing & Geosciences, LLC is accredited for performing tests using the AASHTO T236 standard.
Our laboratory offers comprehensive soil testing services, including the determination of consolidated drained shear strength using AASHTO T236. Our experienced technicians utilize modern equipment and adhere to strict quality control procedures to provide accurate and reliable test results for your geotechnical projects.
Contact us for more information.
Resources
Keywords
direct shear test; consolidated drained shear strength; soil; shear box; normal stress; shear stress; mohr-coulomb failure envelope; drainage; consolidation