Resilient Modulus and Plastic Strain of Unsaturated Cohesive Subgrade Soils

2006 ◽  
Author(s):  
Johnson H. S. Kung ◽  
H. D. Lin ◽  
Shu-Jung Yang ◽  
Wei-Hsing Huang
Keyword(s):  
Plastic Strain ◽  
Resilient Modulus ◽  
Subgrade Soils

Model for Resilient Modulus and Permanent Strain of Subgrade Soils

1998 ◽  
Vol 1619 (1) ◽  
pp. 85-93 ◽  
Author(s):  
A.S. Muhanna ◽  
M.S. Rahman ◽  
P.C. Lambe
Keyword(s):  
Simple Model ◽  
Plastic Strain ◽  
Confidence Intervals ◽  
Empirical Model ◽  
Resilient Modulus ◽  
Cohesive Soil ◽  
Repeated Loading ◽  
Subgrade Soils ◽  
Permanent Strain ◽  
Proposed Model

The resilient modulus and cumulative permanent strain of subgrade soils under anticipated repeated loading are important considerations for the design of a pavement against fatigue and rutting failures. A simple model was developed to evaluate the resilient modulus and accumulated permanent strain of cohesive subgrade soils under repeated loads. The empirical model was derived from the observed behavior of an A-6 cohesive soil. The model was tested against an A-5 soil. The proposed model was found to predict adequately the resilient modulus and the accumulated plastic strain for all A-6 and A-5 specimens with 90 percent confidence intervals of 0.61 and 1.4, and 0.66 and 1.39, respectively.

Evaluation of Seasonal Effects on Subgrade Soils

2003 ◽  
Vol 1821 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Andrew G. Heydinger
Keyword(s):  
Seasonal Variations ◽  
Resilient Modulus ◽  
Monitoring Program ◽  
Test Site ◽  
Pavement Design ◽  
Seasonal Effects ◽  
Pavement Performance ◽  
Climatic Effects ◽  
Subgrade Soils ◽  
Frost Penetration

One objective of the FHWA’s Long-Term Pavement Performance (LTPP) program is to determine climatic effects on pavement performance. The LTPP instrumentation program includes seasonal monitoring program (SMP) instrumentation to monitor the seasonal variations of moisture, temperature, and frost penetration. Findings from the SMP instrumentation are to be incorporated into future pavement design procedures. Data from SMP instrumentation at the Ohio Strategic Highway Research Program Test Road (US-23, Delaware County, Ohio) and other reported results were analyzed to develop empirical equations. General expressions for the seasonal variations of average daily air temperature and variations of temperature and moisture in the fine-grained subgrade soil at the test site are presented. An expression for the seasonal variation of resilient modulus was derived. Average monthly weighting factors that can be used for pavement design were computed. Other factors such as frost penetration, depth of water table, and drainage conditions are discussed.

scholarly journals Resilient modulus and cumulative plastic strain of frozen silty clay under dynamic aircraft loading

2021 ◽  
Vol 3 (10) ◽  
Author(s):  
Xiaolan Liu ◽  
Xianmin Zhang ◽  
Xiaojiang Wang
Keyword(s):  
Plastic Strain ◽  
Resilient Modulus ◽  
Confining Pressure ◽  
Frozen Soil ◽  
Triaxial Tests ◽  
Silty Clay ◽  
Research Findings ◽  
Cumulative Plastic Strain ◽  
Construction Operation ◽  
Compaction Degree

AbstractThis paper describes an investigation into the factors influencing the resilient modulus and cumulative plastic strain of frozen silty clay. A series of dynamic triaxial tests are conducted to analyze the influence of the temperature, confining pressure, frequency, and compaction degree on the resilient modulus and cumulative plastic strain of frozen silty clay samples. The results show that when the temperature is below − 5 °C, the resilient modulus decreases linearly, whereas when the temperature is above − 5 °C, the resilient modulus decreases according to a power function. The resilient modulus increases logarithmically when the frequency is less than 2 Hz and increases linearly once the frequency exceeds 2 Hz. The resilient modulus increases as the confining pressure and compaction degree increase. The cumulative plastic strain decreases as the temperature decreases and as the confining pressure, frequency, and compaction degree increase. The research findings provide valuable information for the design, construction, operation, maintenance, safety, and management of airport engineering in frozen soil regions.

Hybrid Formulation of Resilient Modulus for Cohesive Subgrade Soils Utilizing CPT Test Parameters

2020 ◽  
Vol 32 (9) ◽  
pp. 06020011
Author(s):  
Behnam Ghorbani ◽  
Arul Arulrajah ◽  
Guillermo Narsilio ◽  
Suksun Horpibulsuk ◽  
Myint Win Bo
Keyword(s):  
Resilient Modulus ◽  
Subgrade Soils ◽  
Hybrid Formulation ◽  
Test Parameters ◽  
Cpt Test

Testing Methodology for Resilient Modulus of Base Materials

1996 ◽  
Vol 1547 (1) ◽  
pp. 46-52 ◽  
Author(s):  
S. Nazarian ◽  
R. Pezo ◽  
S. Melarkode ◽  
M. Picornell
Keyword(s):  
Resilient Modulus ◽  
Design Method ◽  
Testing Procedure ◽  
State Agencies ◽  
Technical Literature ◽  
Subgrade Soils ◽  
Base Materials ◽  
Texas Department ◽  
Confining Pressures ◽  
End Restraint

Resilient moduli of base and subgrade materials are important parameters in the new pavement design method adopted by AASHTO and many state agencies. Several testing protocols for determining the resilient moduli of subgrade soils have been proposed and evaluated in the technical literature. Unfortunately, less effort has been focused on developing protocols appropriate for base materials. The main objective was to describe a resilient modulus testing procedure that has been developed for the Texas Department of Transportation. The proposed procedure contains the main steps of the AASHTO T294-92 procedure, with several exceptions. Namely, the loading sequence of the T294-92 procedure was modified to avoid subjecting the specimens to high devi-atoric stresses at low confining pressures. The conditioning cycles were replaced by a procedure in which the specimen was grouted to the platens to minimize disturbance to the specimen during stage testing. The effects of end restraint on the vertical strains were minimized by measuring the deformations of the middle one-third of the specimen. To avoid well-known problems with mounting linear variable differential transformers on the specimen, noncontact probes were used to measure deformations. To maximize the amount of information gained, the lateral deformations were also measured with noncontact probes to determine the Poisson's ratio. On the basis of tests on nine synthetic specimens with known properties and nine different base materials from different parts of Texas, it was concluded that the proposed methodology yields accurate and repeatable results.

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