Nonlinear Elastic Constitutive Model of Soil-Structure Interfaces Under Relatively High Normal Stress

The shear characteristics of soil-structure interfaces with different roughness are studied systematically by us-ing the DRS-1 high normal stress and residual shear apparatus. The experimental results indicate that,under a relatively high normal stress,normal stress and the coefficient of structural roughness are the most important factors affecting the mechanical interface characteristics. The relationship between shear stress and shear displacement of the soil-structure interface is a hyperbolic curve with high regression accuracy. Based on our experimental results,a nonlinear elastic con-stitutive model of the soil-structure interface under relatively high normal stress is established with a definite physical meaning for its parameters. The model can predict the strain hardening behavior of the soil during the shearing process. The results show an encouraging agreement with experimental data from direct shear tests.

温度压力对皮膜表计量误差及经济效益的影响

针对四川省南充市低压天然气居民用户使用皮膜表产生天然气计量误差的问题,基于膜式表的计量原理及膜式表用户分布情况,从温度和压力两方面研究分析了膜式表计量误差的成因,并进一步阐述了其计量误差对经济效益产生的影响,提出了应采用智能式膜式燃气表和可对新用户或到期需更换燃气表的用户安装具有温压补偿装置的燃气表以减小计量误差的建议。