基于离心模型试验的地基附加应力修正

为提高对路基沉降的精度控制,对2种中等压缩性土地基在路基自重作用下的地基附加应力分布规律进行了离心模型试验,并通过PLAXIS2D有限元数值计算和现场测试参数反算地基附加应力进行了验证.基于试验结果,提出了考虑路基宽高比影响的路基中心处地基附加应力修正计算方法.研究结果表明:在路基荷载作用下,附加应力在浅层地基中衰减较快,随地基深度增大,衰减逐渐减慢,与Boussinesq解得到的地基附加应力衰减曲线存在显著差异;修正方法计算的地基附加应力与现场测试参数的反算结果基本吻合. 

Revision of Additional Stress in Soils Based on Centrifuge Model Tests

To improve the accuracy of embankment settlement control of high-speed railway, centrifuge model tests with different loading methods were conducted to investigate the distribution of additional stress in two medium-compression soils under subgrade load. In addition, numerical computations with PLAXIS2D finite element program and field tests were performed to verify the experimental distribution of additional stress. On the test results, a modified calculation method for additional stress considering the effect of width-to-height ratio was proposed. The research results show that additional stress decreases more quickly near the foundation surface, but its attenuation is gradually decelerated with depth increasing. There exist a significant difference between the distribution of additional stress based on the Boussinesq solution and that acquired from the centrifuge model tests. Furthermore, the additional stress calculated by the modified method approaches the calculation result based on the field test data.