The important parameters that influence the mechanical property of the pavinglayer on an orthotropic steel bridge deck are the paving layer thickness and modulus of the asphaltconcrete surfacing. Three important indic...The important parameters that influence the mechanical property of the pavinglayer on an orthotropic steel bridge deck are the paving layer thickness and modulus of the asphaltconcrete surfacing. Three important indices that control the typical failures of the paving layerare the maximum tensile stress of paving layer, the maximum shear stress between the steel deck andthe paving layer, and the maximum deflection on the paving surface. In this paper, the analyticalmodel of paving systems on orthotropic steel bridge deck is established, and the finite elementmethod is adopted to study the stress and strain of paving system. With the variation of asphaltconcrete modulus in high or low temperature season, the influences of paving layer thickness onthree control indices are researched. The results provide a theoretical basis for the determinationof thickness of the paving layer on the steel bridge deck.展开更多
Several groups of direct shear tests of Nanning expansive soil samples were carded out by improved direct shear apparatus. The results of the characteristics of the ultimate shear stress and residual shear stress at t...Several groups of direct shear tests of Nanning expansive soil samples were carded out by improved direct shear apparatus. The results of the characteristics of the ultimate shear stress and residual shear stress at the interface of expansive soil-structure are presented as follows： linear relation can approximately reflect changes between the both shear stress and the three factors： vertical load, water content and dry density, just different degrees from each other; increasing the vertical load from 25 kPa to 100 kPa （up by 300%） can cause the average increase of ultimate shear stress from 58% （for samples with 1.61 g/cm^3） to 80% （for samples with 1.76 g/cm^3）, and an close average increase of 180% for the residual shear stress; increasing the water content from 14.1% to 20.8% （up by 47.5%） can cause the average decrease of the ultimate shear stress from 40% （for samples with 25 kPa） to 80% （for samples with 100 kPa）, and the average decrease from 25% （for samples with 25 kPa） to 30% （for samples with 100 kPa） for the residual shear stress; increasing the dry density from 1.61 g/cm^3 to 1.76 g/cm^3 （up by 9.3%） can cause the average increase of ultimate shear stress from 92% （for samples with 25 kPa） to 138% （for samples with 100 kPa）, and an average increase of 4% for the residual shear stress. Sensitive analysis was further made to explain reasons causing the differences of the both shear stress induced by the three factors.展开更多
文摘The important parameters that influence the mechanical property of the pavinglayer on an orthotropic steel bridge deck are the paving layer thickness and modulus of the asphaltconcrete surfacing. Three important indices that control the typical failures of the paving layerare the maximum tensile stress of paving layer, the maximum shear stress between the steel deck andthe paving layer, and the maximum deflection on the paving surface. In this paper, the analyticalmodel of paving systems on orthotropic steel bridge deck is established, and the finite elementmethod is adopted to study the stress and strain of paving system. With the variation of asphaltconcrete modulus in high or low temperature season, the influences of paving layer thickness onthree control indices are researched. The results provide a theoretical basis for the determinationof thickness of the paving layer on the steel bridge deck.
基金Projects(50378097 50678177) supported by the National Natural Science Foundation of ChinaProject (01JJY3043) supported by the Natural Science Foundation of Hunan Province, China
文摘Several groups of direct shear tests of Nanning expansive soil samples were carded out by improved direct shear apparatus. The results of the characteristics of the ultimate shear stress and residual shear stress at the interface of expansive soil-structure are presented as follows： linear relation can approximately reflect changes between the both shear stress and the three factors： vertical load, water content and dry density, just different degrees from each other; increasing the vertical load from 25 kPa to 100 kPa （up by 300%） can cause the average increase of ultimate shear stress from 58% （for samples with 1.61 g/cm^3） to 80% （for samples with 1.76 g/cm^3）, and an close average increase of 180% for the residual shear stress; increasing the water content from 14.1% to 20.8% （up by 47.5%） can cause the average decrease of the ultimate shear stress from 40% （for samples with 25 kPa） to 80% （for samples with 100 kPa）, and the average decrease from 25% （for samples with 25 kPa） to 30% （for samples with 100 kPa） for the residual shear stress; increasing the dry density from 1.61 g/cm^3 to 1.76 g/cm^3 （up by 9.3%） can cause the average increase of ultimate shear stress from 92% （for samples with 25 kPa） to 138% （for samples with 100 kPa）, and an average increase of 4% for the residual shear stress. Sensitive analysis was further made to explain reasons causing the differences of the both shear stress induced by the three factors.
