高径比对板岩单轴抗压强度尺寸效应的试验研究

Experimental study on size effect to the uniaxial compressive strength of slate specimen as to the height diameter ratio

对不同高径比的板岩试件进行了大量单轴抗压强度试验,获得了3种风化程度的板岩强度随试件高径比增大而非线性减小的关系曲线及二者间的经验关系式。依据板岩标准试件与非标准试件的强度比值,提出了岩石强度尺寸效应系数的概念,绘制了不同风化程度的板岩强度尺寸效应系数随高径比增大而非线性增大的关系曲线,给出了3种不同风化程度板岩强度尺寸效应系数的经验计算式。试验结果分析表明,岩石风化程度不同(强度不同),其强度尺寸效应不同,即岩石强度越大,其尺寸效应越显著。本文经验公式的提出为非标准试件板岩单轴抗压强度的修正提供了新的便利途径,也可为其它各类岩石强度尺寸效应的修正提供参考。

According to lots of uniaxial compressive strength test(UCS) results on the slate specimen of different height diameter ratio,three relation curves and empirical formulas between the strengthen and the height diameter ratio are obtained.Based on the strength ratio between standard specimens and test specimens,the concept of rock strength size effect coefficient is put forward,the relation curves between the slate strength size effect coefficient and the height diameter ratio are drawn,and the empirical formulas of rock strength size effect coefficient are given for three different weathering degrees of slate.The results show that the size effect is more obvious with increase of the rock strength.The empirical formulas in this paper could provide a convenient method to correct the slate uniaxial compressive strength of non standard specimen,and also could provide reference for other types of rock.