Effect of Sampling Disturbance on Laboratory-Measured Soil Properties
Abstract
Soil properties must be accurately determined for reliable and economical design of geotechnical structures. Typically, undisturbed soil samples are taken from a prospective foundation and brought to the laboratory where the in situ properties of interest are measured. However, laboratory- determined properties are impacted by the amount and kind of disturbance which occurs during sampling. Design of foundations and soil structures based on properties different from true in situ properties could result in structures with performance and maintenance problems, or unnecessarily expensive structures if designs are made very conservative to compensate for sampling disturbance. This report discusses some of the causes of sampling disturbance, how various investigators have analyzed mechanisms causing disturbance, and how equipment design and sampling techniques have been modified to minimize disturbance. The effect of sampling disturbance on various soil properties (strength, Young's modulus, compressibility, permeability) is discussed along with laboratory techniques for minimizing the effects of sampling disturbance. Severity of sampling disturbance as the result of (a) release of hydraulic and earth pressure, (b) compression, shear, and tension during sampling, (c) mechanical shock and temperature change during storage, and (d) compression and shear during extraction and specimen preparation in the laboratory are discussed. Area ratio, Laboratory testing, Sampling disturbance, Compressibility, Perfect sampling, Shear strength, Inside clearance ratio, Permeability, Thin walled sampling tube.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1992
- Accession Number
- ADA257268
Entities
People
- Paul A. Gilbert