层状岩体单轴抗压强度的速率效应力学特性研究

Study on the Rate Effect Mechanical Properties of Uniaxial Compressive Strength of Layered Rock Mass

以地下工程建设中普遍存在的层状岩体为研究对象,针对不同层理角度岩样开展了大跨度单轴加载速率试验,系统研究了加载速率对千枚岩力学特性的影响,试验结果表明:千枚岩由于微裂隙的存在,加载速率对裂隙的发育存在一个临界值,随着加载速率的增加,峰值强度未单调增加,而是呈现先升后降再升的S型曲线;层理软弱物质的承载力有限,在高速率条件下,出现了弹性模量下降现象;总能量、弹性应变能、耗散能具有与强度类似的S型曲线变化规律,层理倾角为0°时能量最高、90°时能量最低。

In this paper,layered rock mass existing in underground engineering construction was taken as a research object.Aimed at rock samples with different bedding angles,the large-span uniaxial loading rate test was carried out to systematically study the influence of loading rate on the mechanical properties of phyllite.The results showed that due to the existence of micro-cracks,the loading rate of phyllite had a critical value for the development of cracks.With the increase of loading rate,the peak intensity did not increase monotonously,but presented an S-shaped curve that raised first,then fell and then raised.The bearing capacity of the layered weak material was limited.Under the high rate condition,the phenomenon that the elastic modulus decreased appeared.The total energy,elastic strain energy and dissipative energy had the S-curve variation law similar to the intensity.The energy was the highest as the bedding angle was 0°and was the lowest as the bedding angle was 90°.