ASTM D3689
Full Name
ASTM D3689 – Standard Test Methods for Deep Foundations Under Static Axial Tensile Load
Scope
ASTM D3689 outlines procedures for testing the axial deflection of deep foundation elements under static tensile loads. These tests help evaluating the performance and capacity of deep foundations subjected to uplift forces. The standard applies to various deep foundation types, including drilled shafts, driven piles, auger cast piles, and others, regardless of their installation method. While the standard focuses on individual elements, it acknowledges that test results might not fully represent the long-term behavior of an entire foundation system.
Key aspects of ASTM D3689:
- Scope: the standard covers static axial tensile load testing for both vertical and inclined deep foundation elements. It emphasizes that project-specific requirements may necessitate additional procedures beyond the minimum requirements outlined in the standard. Any deviations must be approved by the foundation engineer.
- Terminology: standard terminology is used to ensure clarity and consistency. Specific terms like “deep foundation element”, “reaction”, “telltale rod”, and “toe” are defined within the standard.
- Test methods: ASTM D3689 details several test methods, including the Quick Test, Maintained Load Test, Constant Rate of Uplift Test, and Cyclic Loading Test. The choice of method depends on project requirements and the information sought. Optional methods may yield different results and require approval from the foundation engineer.
- Reaction system: the standard highlights the importance of a robust reaction system to resist downward movement during the application of upward (tensile) loads to the test element.
- Measurements: displacement measurements are essential, along with load measurements, to characterize the load-displacement response of the foundation element.
- Data interpretation: the foundation engineer is responsible for interpreting the test results and determining the suitability of the foundation element for its intended purpose.
Test methods summary:
- Quick test: this method involves applying incremental loads to the foundation element and measuring the corresponding displacements. It’s a relatively quick test, suitable for preliminary assessments.
- Maintained load test: this optional test involves maintaining a constant load for a specific duration and monitoring the displacement over time. It helps assess creep behavior.
- Constant rate of uplift test: this optional test involves applying the load at a constant rate and measuring the displacement. It provides a different perspective on the load-displacement relationship compared to the quick test.
- Cyclic loading test: this optional test involves repeated cycles of loading and unloading to evaluate the foundation element’s response to fluctuating loads.
Testing according to ASTM D3689 provides critical information for:
- Verifying design assumptions: confirming that the foundation element can withstand the anticipated tensile loads.
- Assessing load-displacement behavior: understanding how the foundation element deforms under load.
- Evaluating side shear resistance: gaining insights into the contribution of side shear to the overall capacity.
- Determining ultimate capacity: identifying the maximum tensile load the foundation element can sustain.
- Assessing long-term performance: evaluating the potential for creep and other time-dependent effects.
ASTM D3689 Accredited Laboratory
Applied Testing & Geosciences, LLC is accredited for performing tests using the ASTM D3689 standard. Our team of can assist you in selecting the appropriate test method, designing the test setup, and interpreting the results.
Contact us today to discuss your testing needs and ensure the reliability and safety of your deep foundation projects.
Resources
Keywords
deep foundation; static axial tensile load; field testing; axial load test; deep foundation capacity; loading procedure; jack; load cell; reference beam; pile; ultimate capacity; side shear resistance; deflection; settlement; creep