Details:

Creators:
Khoury, Charbel N. ; Miller, Gerald A. ; Abousleiman, Youane N.
Khoury, Charbel N. ; Miller, Gerald A. ; Abousleiman, Youane N. Less -
Corporate Creators:
University of Oklahoma. School of Civil Engineering and Environmental Science
Corporate Contributors:
Oklahoma Transportation Center
Subject/TRT Terms:
[+]
Granular Soils Hysteresis Modulus Of Resilience Resilient Modulus, Suction, Hysteresis Soil Suction Subgrade (Pavements)
Publication/ Report Number:
OTCREOS7.1-27-F
Resource Type:
Tech Report
Geographical Coverage:
Oklahoma
Corporate Publisher:
Oklahoma Transportation Center
Abstract:
The mechanical behavior of subgrade soil is influenced by the seasonal variations in moisture content. To better understand this behavior, it is crucial to study the relationship between soil moisture content and matric suction known as the Soil Water Characteristic Curve (SWCC). This relationship is hysteretic, i.e., at a given suction the moisture content differs depending on the drying and wetting paths. Research described in this report represents the beginning effort to understand the relationship of the SWCC to resilient modulus of subgrades. The behavior of the SWCC has been widely studied and various models have been developed to capture this hysteretic behavior, but limited experimental data are available under different applied stresses. The lack of SWCC experimental data is due to the long testing time required for unsaturated soils. A new procedure was developed to shorten equilibrium time and obtain SWCC data as fast as possible. This new approach was used and SWCC tests under different stress states on silty soil specimens under drying, wetting, secondary drying, and along scanning curves were performed. Results from this study helped improve and validate existing models briefly described in this report. The primary focus of this study was the effect of hydraulic hysteresis on the resilient modulus (Mr) of a cohesionless silty soil. Suction-controlled Mr tests were performed on compacted samples along the primary drying and wetting, secondary drying and wetting paths. A relationship between resilient modulus (Mr) and matric suction identified as the resilient modulus characteristic curve (MRCC) was developed. MRCC results indicated that Mr increased with suction along the drying curve. On the other hand, results of tests along the primary wetting curve indicated higher Mr than along the primary drying and the secondary drying curves. A new model to predict the MRCC results during drying and wetting (i.e., hydraulic hysteresis) is proposed based on the SWCC hysteresis. The model predicted favorably the drying and then the wetting results using the SWCC at all stress levels.
Format:
PDF
Funding:
DTRT-06-G-0016
Collection(s):
US Transportation Collection University Transportation Centers
Main Document Checksum:
[+]
urn:sha256:e7a325a8bbd11503252a94bfadbf13cf735ecc40a1956eb76779c31b871e8075
Download URL:
https://rosap.ntl.bts.gov/view/dot/20481/dot_20481_DS1.pdf
File Type:

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