UID:
kobvindex_GFZ20190717104545
Format:
v, 52 Seiten
,
Illustrationen
Series Statement:
CRREL Report 86-18
Content:
Findings from a six-year yield and laboratory program of frost action research in four principal areas are summarized. Research on the first topic, frost susceptibility index tests, led to selection of the Corps of Engineers frost design soil classification system as a useful method at the simplest level of testing. At a much more complex level, a new freezing test combined with a CBR test after thawing is recommended as an index of susceptibility to both frost heave and thaw weakening. Under the second topic, a soil column and dual gamma system were developed and applied to obtain soil data used in improving and validating a mathematical model of frost heave, the objective of the third research topic. The model was effectively improved, a probabilistic component was added, and it was successfully tested against field and laboratory measurements of frost heave. A thaw consolidation algorithm was added, which was shown to be useful in predicting the seasonal variation in resilient modulus of granular soils, the objective of the fourth topic. A laboratory testing procedure was developed for assessing the resilient modulus of thawed soil at various stages of the recovery process, as a function of the applied stress and the soil moisture tension, which increases as the soil gradually desaturates during recovery. The procedure was validated by means of appropriate analyses of deflections measured on pavements by a falling-weight deflectometer. Frameworks for implementing findings from the principal research topics are outlined. Keywords: Airfields, Freezing thawing, Frost heave, Frozen soil, Resilient modulus, Roads.
Note:
Contents
Abstract
Preface
Introduction
Field test sites
Frost-susceptibility index testing
Index tests selected
Laboratory test results
Conclusions
Soil column and dual gamma system
Design features
Test results
Mathematical model of frost heave and thaw settlement
Model development
Numerical approach
Probabilistic concepts
Model verification
Discussion
Seasonal variation in the resilient modulus of granular soils
Characterization by laboratory testing
Field verification
Summary of predictive approach
Simulating frost heave and pavement deflection
Method of evaluation
Results and discussion
Summary of findings
Frost-susceptibility index tests
Soil column and dual gamma system
Mathematical model of frost heave and thaw settlement
Seasonal variation in resilient modulus of granular soils
Implementation of research findings
Corps of engineers frost design soil classification system
New laboratory freeze-thaw test
Frost-heave model
Repeated-load triaxial test on frozen and thawed soil
Evaluation of seasonal variation of resilient modulus
Literature cited
In:
CRREL Report, 86-18
Language:
English
Keywords:
Forschungsbericht
URL:
https://apps.dtic.mil/docs/citations/ADA178243
URL:
https://hdl.handle.net/11681/9457
