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Research On Properties Of Flexible Foundation Composite Ground

Posted on:2004-11-01Degree:DoctorType:Dissertation
Country:ChinaCandidate:R L FengFull Text:PDF
GTID:1102360125466742Subject:Road and Railway Engineering
Abstract/Summary:PDF Full Text Request
Directed against the composite formed by the powder deep mixing piles under the embankment, the paper puts forward the flexible foundation composite ground. At present, the theory of rigid foundation composite ground is used to design the flexible foundation composite ground, and there are some unsuitable aspects. Directed against this, through FEM, model test and in-situ test, the paper studies the stress, deformation and strength properties of the flexible foundation composite ground, modifies the formula of the rigid foundation composite ground.Based on the program of MARC, the paper uses FEM of plane to research the properties of composite ground under flexible uniform load and embankment load. The paper selects the elastic-plastic constitutive model, which is based on the Mohr-Coulomb yield criterion, analyzes the effect of composite ground. In the use of MARC, simulates the relative slip between the pile and the soil by the definition of contact body, realizes the stepping load of the embankment which make the simulation more close to the engineering practice.Based on the program of MARC, the paper studies the factors which affect the stress, deformation and strength properties of the flexible foundation composite ground, confirms the failure mode of the flexible foundation composite ground, argues the affection of the pile and the foundation stiffness to the bearing capacity of the soil in the composite foundation.Though model test, the paper studies the pile-soil interaction mechanics under the flexible uniform load, finds out the factors affect the skin friction of piles.Based on the above results, knowledge of soil mechanics and elastic mechanics, the paper establishes the P- 8 calculating formula of the flexible foundation composite ground. On the basis of this, the paper modifies the bearing capacity formula of the deep mixing pile in the criterion.On the basis of the modified formula, the paper analyzes and evaluates the bearing capacity of two solid engineering, and compares it with the original design and the in-situ test results.
Keywords/Search Tags:composite ground, flexible foundation, MARC software, model test, in-situ test, stress and deformation properties, strength properties, bearing capacity properties .
PDF Full Text Request
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