初始应力各向异性结构性土的侧限压缩特性及数学模拟  

Confined compression features and mathematical modeling of artificially structured soils with initial stress-induced anisotropy

作　　者：聂青[1] 魏巍[1] 罗开泰[1] 刘恩龙[1] 

机构地区：[1]四川大学水利水电学院,四川成都610065

出　　处：《岩土工程学报》2013年第S2期774-778,共5页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51009103)

摘　　要：为了探讨结构性土的力学特性和变形机理,对人工制备的4组不同胶结特性的初始各向同性、初始应力各向异性结构性土,以及重塑土进行侧限压缩试验。比较压缩曲线可以看出,结构性土压缩曲线存在明显的结构屈服应力;随着结构的逐渐破损,结构性土与重塑土的孔隙比趋于相近。水泥含量越高,土骨架强度越高,土的结构屈服应力越大。由于先期固结压力的影响,初始应力各向异性结构性土的结构屈服应力大于初始各向同性结构性土的结构屈服应力。对基于岩土破损力学理论的结构性土压缩曲线数学表达式中的参数进行确定,并将模拟结果与试验数据进行对比,结果表明模拟结果能较好地反映各向异性结构性土的压缩特性。To investigate the deformation mechanism and mechanical features of structured soils, the confined consolidation tests are performed on 4 groups of artificially initial isotropic and anisotropic structured soils with different bonding properties and remoulded soils. It can be seen from the compression curves that the structural yield stress of the structured soils exists obviously. As the bonding between soil particles break up gradually, the void ratios of the structured soils and remoulded soils tend to be similar. The higher the cement content, the higher the strength of the soil skeleton and the greater the structural yield stress. Because of the influence of the pre-consolidation pressure, the structural yield stress of the structured soils with initial stress-induced anisotropy is higher than that of the initial isotropic structured soils. The parameters in the expression of compression curve of the structured soils based on the theory of breakage mechanics for geological materials are determined, and the simulated results are compared with the test ones, which demonstrates that the numerical results can well reflect the compression properties of anisotropic structured soils.

关 键 词：人工制备结构性土 胶结特性 侧限压缩 初始应力各向异性 

分 类 号：TU43[建筑科学—岩土工程]