接触面积对波传播规律及节理力学特性影响  

EFFECTS OF CONTACT AREA ON STRESS WAVE PROPAGATION AND JOINT MECHANICAL PROPERTIES

作　　者：刘婷婷[1] 李建春[1] 李海波[1] 李娜娜[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071

出　　处：《岩石力学与工程学报》2014年第9期1749-1755,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(41272348;11072257);国家自然科学基金杰出青年基金项目(51025935)

摘　　要：自然界中节理的接触往往不是完全接触,而是部分接触。为考虑节理表面的接触面积对应力波传播规律的影响,采用分离式霍普金森压杆试验装置对不同接触面积的试样进行冲击试验。由于接触面积模拟的难操作性,试验中,采用不同数量的小试样定义小试样的横截面积和与入射杆(透射杆)横截面积的比为接触面积率。通过试验研究接触面积对应力波透射率的影响。基于应力波一维传播理论分析作用在试样上的应力,以及试样在应力波的作用下产生的应变与位移。试验结果表明:随着接触面积的增加,应力波的透射系数增加,且两者呈现非线性关系。当接触面积相同时,随着试样长度的增加,应力波的透射系数会出现小幅度减小,即当节理具有相同的接触面积时,节理的厚度将会影响应力波的传播。此外,随着节理的闭合量的增加,透射系数呈现出近似线性形式的减小。这个试验并不能模拟真实的节理,但是主要是从另一个角度来说明节理的接触面积对波传播以及对节理力学特性的影响。Joints always contact partly in nature. To study the effect of the contact area,the Hopkinson pressure bar test system was used to carry out the impact experiments on different specimens. In the experiment,the small samples were considered to represent the joints and the different contact areas were created by the different numbers of samples used in each experiment. The transmitting coefficient of wave propagation through joints was obtained. The experimental results showed a positive correlation between the contact area and the transmitting coefficient,and a negative correlation between the contact length and the transmitting coefficient. A formula of transmitting coefficient was obtained by fitting the experimental data considering the effect of the contact area. And the correlation of the closure of joints and the transmitting coefficient showed that the transmitting coefficient increased approximately linearly with the increase of the closure. The experiment did not simulate the real joints, but it revealed the influences of contact area on the transmission efficient and the mechanical properties of joint from another perspective.

关 键 词：岩石力学 应力波 节理 接触面积 透射系数 

分 类 号：TU45[建筑科学—岩土工程]