岩土的一种强度准则及其变换应力法

发布时间：2018-04-27 16:16

本文选题：岩土材料 + 破坏　；参考：《力学学报》2017年03期

【摘要】：基于岩土摩擦性,假设岩土破坏是由其物理空间内特征面上的应力比决定,提出了等效应力比的概念,即物理空间特征面上的剪应力合力与正应力合力的比值.在二维条件下,等效应力比可表示为σ-τ坐标系下与摩尔圆相切的直线扣除截距正切值;在三维条件下,假设在XYZ空间内存在一三维物理空间平面,此三维空间特征平面的等效应力比为影响材料强度特性的决定性因素,基于上述三维空间特征面建立了强度准则并称之为a准则.SMP准则以及广义Mises准则都是a准则的特例,当二维坐标中的截距为零时,则强度准则退化为SMP(spatially mobilized plane)强度准则,而当正切角为零时,则强度准则退化为广义Mises准则.而当截距与外切角均不为零时,则强度准则为介于上述两者之间的一种强度准则,在偏平面上为介于SMP曲边三角形与广义Mises圆形之间的曲边三角形.在子午面上,采用考虑岩土压剪耦合的屈服准则,破坏准则采用幂函数表达式.在偏平面上提出了基于a准则的形状函数,并采用真三维应力状态表示的破坏强度准则表示在三轴压缩路径下以p,q二维应力变量表达的准则公式,推导得到了基于a准则的变换应力公式,可简单地将一般以p,q为基本变量的二维模型转变为三维应力模型.通过强度以及多种应力路径的测试对比,验证了a准则及基于该准则的变换应力公式的合理性.
[Abstract]:Based on the friction of rock and soil, it is assumed that the failure of rock and soil is determined by the stress ratio on the characteristic surface in the physical space. The concept of equivalent stress ratio is put forward, that is, the ratio of shear stress force to normal stress force on the characteristic plane of physical space. Under two dimensional conditions, the equivalent stress ratio can be expressed as the tangent of truncation of a straight line tangent to a molar circle in 蟽-蟿 coordinate system, and in three dimensional conditions, the existence of a three dimensional physical space plane in XYZ space is assumed. The equivalent stress ratio of the three-dimensional characteristic plane is the decisive factor affecting the strength characteristics of the material. Based on the above three-dimensional spatial characteristic surface, the strength criterion is established and called the SMP criterion and the generalized Mises criterion, which are all special cases of the a-criterion. When the intercept in the two-dimensional coordinate is 00:00, the strength criterion degenerates to the SMP(spatially mobilized plane strength criterion, and when the tangent angle is 00:00, the strength criterion degenerates to the generalized Mises criterion. When the intercept and the tangent angle are not 00:00, the strength criterion is a kind of strength criterion between the above two, and the curved triangle between the SMP curved triangle and the generalized Mises circle on the skew plane. On the meridian surface, the yield criterion considering the compression-shear coupling of rock and soil is adopted, and the failure criterion is expressed by power function. In this paper, the shape function based on a criterion is put forward on the partial plane, and the criterion formula of failure strength expressed by the true three dimensional stress state criterion under the triaxial compression path is presented by using the two dimensional stress variables of p / Q. A transformation stress formula based on a criterion is derived, which can simply transform a two-dimensional model with pnq as a basic variable into a three-dimensional stress model. The rationality of a criterion and the transformation stress formula based on the criterion are verified by comparing the strength and various stress paths.
【作者单位】：中国建筑科学研究院地基基础研究所;
【基金】：国家自然科学青年基金(11402260) 中国建筑科学研究院应用技术研究基金(20141602330730038) 住建部科技计划研究基金(20161602420730011)资助项目
【分类号】：TU43

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