Expendable Doppler Penetrometer: A Performance Evaluation
Abstract
An expendable penetrometer using the Doppler principle has been developed expediently test seafloor soils to a depth of 9m (30 ft) at water depths to 6,000m (20,000 ft). The velocity of the penetrometer is measured as it penetrates seafloor soils. From the velocity record, soil penetrability and an estimate of the undrained shear strength profile can be calculated. The penetrometer has a mass of 173 kg (12 slugs), is 2.9m (9.5 ft) long, is 90mm (3. 5 in.) in diameter, and is easily deployed from a ship. This report presents data from 11 tests at four locations off the southern California coast. Undrained shear strength profiles determined from penetrometer data are compared to other types of in-situ data and core data. It is concluded that the expendable Doppler penetrometer is reliable and simple to use and that reasonable estimates (+ or - 30% of actual values) of undrained shear strength profiles can be obtained even though the analyzed phenomenon is complex. This tool will be of particular value in surveying potential embedment anchor or foundation locations and can, for some cases, provide information sufficient for design purposes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1977
- Accession Number
- ADA043912
Entities
People
- R. M. Beard
Organizations
- Naval Facilities Engineering Service Center