Effects of Subgrade Moisture Content on Permanent Deformation of Pavements
碩士 === 國立中央大學 === 土木工程研究所 === 91 === The resilient modulus and cumulative permanent strain of subgrade soils under various traffic and environmental conditions are important considerations for the design of a pavement against fatigue and rutting failures. A simple model was developed to evaluate the...
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| Format: | Others |
| Language: | zh-TW |
| Published: |
2003
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| Online Access: | http://ndltd.ncl.edu.tw/handle/20376274750541214884 |
| Summary: | 碩士 === 國立中央大學 === 土木工程研究所 === 91 === The resilient modulus and cumulative permanent strain of subgrade soils under various traffic and environmental conditions 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 at different moisture contents under repeated loads. The empirical model was derived from the observed behavior of an A-7-5 cohesive soil. Then the response of the pavement and the corresponding resilient modulus of subgrade were calculated under various traffic and environmental conditions using the three-dimensional finite element program ABAQUS. The study also compares pavement response using elastic and elasto-plastic subgrade material models.
The results reveal that subgrade at higher moisture content has a larger influence on the pavement response. As axle load and tire pressure increase, changes in subgrade moisture content on pavement response become more pronounced. Pavement failure is controlled by the permanent deformation when the subgrade is at high water content; while it is controlled by the fatigue cracking when the subgrade is at optimum moisture content. In addition, strains in the pavement system obtained using elasto-plastic subgrade material model are higher than those obtained using elastic model.
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