To obtain the vertical earth pressure on a soft foundation box culvert and investigate the interaction of the soil-culvert-foundation system, both a centrifugal model test and a numerical simulation were conducted and...To obtain the vertical earth pressure on a soft foundation box culvert and investigate the interaction of the soil-culvert-foundation system, both a centrifugal model test and a numerical simulation were conducted and the comparisons with the current methods to determine the load on a culvert were completed. The results of the model test and numerical analysis are in satisfactory agreement, which shows that the direction of the shear stress between the culvert and the adjacent embankment depends on the differential settlement between them. A vertical earth pressure concentration appears on the culvert with a rigid piles foundation because of a downward shear stress. The ratio of the load on a soft foundation culvert and the overburden pressure above the culvert raises first and then decreases as the backfill height increases. In order to reduce the load on a culvert, it is suggested to limit the stiffness difference of the foundations under the culvert and embankment and to use a light backfill over the culvert.展开更多
Concrete box culverts are widely used in expressways in mountain areas.Many problems frequently take place due to improperly estimated vertical earth pressures on culverts.The prevailing Chinese General Code for Desig...Concrete box culverts are widely used in expressways in mountain areas.Many problems frequently take place due to improperly estimated vertical earth pressures on culverts.The prevailing Chinese General Code for Design of Highway Bridges and Culverts(CGCDHBC)stipulates the computation of the design load on culverts primarily based on the linear earth pressure theory,which cannot accurately describe the variation of the vertical load on culverts in trenches.In this paper,a full-scale experiment and numerical simulation were conducted to evaluate the variation of vertical earth pressures on culvert and soil arching in backfill.The variations of foundation pressure and settlement were also analyzed.The result revealed that the soil arch forms when the backfill on the culvert reaches a certain height.The soil arching effect reduces the stress concentration on the crown of the culvert but it is unstable.The vertical earth pressure on top of the culvert is significantly different from that recommended by the CGCDHBC.展开更多
基金Project(2012AA112504) supported by the National High Technology Research and Development Program of ChinaProjects(51108048,51478054) supported by the National Natural Science Foundation of China
文摘To obtain the vertical earth pressure on a soft foundation box culvert and investigate the interaction of the soil-culvert-foundation system, both a centrifugal model test and a numerical simulation were conducted and the comparisons with the current methods to determine the load on a culvert were completed. The results of the model test and numerical analysis are in satisfactory agreement, which shows that the direction of the shear stress between the culvert and the adjacent embankment depends on the differential settlement between them. A vertical earth pressure concentration appears on the culvert with a rigid piles foundation because of a downward shear stress. The ratio of the load on a soft foundation culvert and the overburden pressure above the culvert raises first and then decreases as the backfill height increases. In order to reduce the load on a culvert, it is suggested to limit the stiffness difference of the foundations under the culvert and embankment and to use a light backfill over the culvert.
基金supported by the Hubei Communications Department,P.R.China(Grant No.[2005]361).
文摘Concrete box culverts are widely used in expressways in mountain areas.Many problems frequently take place due to improperly estimated vertical earth pressures on culverts.The prevailing Chinese General Code for Design of Highway Bridges and Culverts(CGCDHBC)stipulates the computation of the design load on culverts primarily based on the linear earth pressure theory,which cannot accurately describe the variation of the vertical load on culverts in trenches.In this paper,a full-scale experiment and numerical simulation were conducted to evaluate the variation of vertical earth pressures on culvert and soil arching in backfill.The variations of foundation pressure and settlement were also analyzed.The result revealed that the soil arch forms when the backfill on the culvert reaches a certain height.The soil arching effect reduces the stress concentration on the crown of the culvert but it is unstable.The vertical earth pressure on top of the culvert is significantly different from that recommended by the CGCDHBC.
