土的静态空间滑动面及其强度准则适应性研究

天然黄土是一种具有结构性的特殊土,这使得天然黄土的强度规律比一般土体复杂。首先,利用自主专利研发的真三轴试验仪器对不同结构性天然黄土进行真三轴试验,分析了在岩土工程中常用的莫尔-库仑强度准则和SMP强度准则对不同结构性原状黄土的适应性。在此基础上提出多种静态空间滑动面并建立与之相关联的强度准则,分析其对不同结构性原状黄土的适应性。研究结果表明,对不同结构性的原状黄土,两个传统强度准则在描述其强度时都存在不小的误差,其所描述的强度都比结构性原状黄土的实际值小,其误差随着结构性的增强而逐渐增大。而新建立的轴对称压缩(σ₂>σ₁=σ₃)静态空间滑动面强度准则和轴对称挤伸(σ₁=σ₂>σ₃)静态空间滑动面强度准则能更好地适应不同结构性原状黄土的强度规律。

Stud on the Static Spatially Mobilized Plane and Its Strength Criterion Adaptability

Natural loess is a kind of special structural soil, which makes its strength law more complex than that of the general soil. Among many strength criterions commonly used in geotechnical engineering practice are mainly Mohr-Coulomb criterion and Matsuoka-Nakai criterion. The two criterions have been analyzed about the adaptability to different undisturbed structural loess in this paper. In the analysis of the traditional strength criterion spatially mobilized plane and its basic characteristics, this paper proposed a variety of static spatially mobilized planes with its unchanging normal directions, analyzed these static spatially mobilized planes and established the associated strength criterion. By use of the experimental results of several structural loess by self-developed true triaxial apparatus, the adaptability of these strength criterion has been analyzed. Comparative analysis showed that the two groups (six) static spatially mobilized plane and its strength criterion can be in a certain extent reflects the strength of the soil damage, and the axisymmetric compression (σ_{2>σ1=σ3) static spatially mobilized plane strength criterion and axisymmetric extrusion extension (σ1=σ2>σ3) static spatially mobilized plane strength criteria, can better reflect the undisturbed loess structural damage.}