摘要
Finite element method was performed to investigate the influences of beam stiffness, foundation width and cushion thickness on the beating capacity of beam foundation on underlying weak laminated clay. The comparison between numerical results and results from field test including plate-bearing test and foundation settlement observation shows reasonable agreement. According to the numerical results, the beam width, length, cross section and cushion thickness were optimized. The results show that the stresses in subgrade soil decrease greatly with increasing the cushion thickness and width of foundation. However, the foundation settlement and influencing depth of displacement also increase correspondingly under conditions of relatively thinner cushion thickness. For the foundations on underlying weak layer, increasing foundation width merely might be inadequate for improving the bearing capacity, and the appropriate width and cushion thickness depend on the response of subgrade. A comparison between rigid and flexible beams was also discussed. The influence of a flexible beam foundation on subgrade is relatively smaller under the same loading conditions, and the flexible beam foundation appears more adaptable to various subgrades. The proposed flexible beam foundation was adopted in engineering. According to the calculation results, beam width of 2.4 m and cushion thickness of 0.8 m are proposed, and a flexible beam foundation is applied in the optimized design, which is confirmed reasonable by the actual engineering.
Finite element method was performed to investigate the influences of beam stiffness,foundation width and cushion thickness on the bearing capacity of beam foundation on underlying weak laminated clay.The comparison between numerical results and results from field test including plate-bearing test and foundation settlement observation shows reasonable agreement.According to the numerical results,the beam width,length,cross section and cushion thickness were optimized.The results show that the stresses in subgrade soil decrease greatly with increasing the cushion thickness and width of foundation.However,the foundation settlement and influencing depth of displacement also increase correspondingly under conditions of relatively thinner cushion thickness.For the foundations on underlying weak layer,increasing foundation width merely might be inadequate for improving the bearing capacity,and the appropriate width and cushion thickness depend on the response of subgrade.A comparison between rigid and flexible beams was also discussed.The influence of a flexible beam foundation on subgrade is relatively smaller under the same loading conditions,and the flexible beam foundation appears more adaptable to various subgrades.The proposed flexible beam foundation was adopted in engineering.According to the calculation results,beam width of 2.4 m and cushion thickness of 0.8 m are proposed,and a flexible beam foundation is applied in the optimized design,which is confirmed reasonable by the actual engineering.
基金
Projects(50778181, 51178472) supported by the National Natural Science Foundation of China
Project(2007045) supported by the Transportation Department of Hunan Province,China
