CAJ | 학술논문

柱状节理岩体是溢出型火成岩常见的结构性岩体，对其在三轴应力下变形和强度特性的正确认识，是水利水电及地下洞室等大型岩体工程论证和设计需要解决的关键问题之一。为此，采用石膏混合材料制作柱体与最大主应力σ1具有不同夹角β的模拟柱状节理岩体试件，通过对试件进行不同围压下的三轴压缩试验研究柱状节理岩体变形和强度特性，得到其在三轴压缩下弹性模量和峰值强度随β角的变化规律。由试验结果可知：在同一级围压下，弹性模量和峰值强度随夹角β增大呈递减趋势，即弹性模量和峰值强度随夹角增大先减小，在β=45°时最小，而后随夹角增大保持相对不变。此外，利用试验数据建立柱状节理岩体弹性模量和峰值强度与夹角β之间的经验关系式，通过比较发现经验关系式与实测数据吻合较好。最后对试件的破坏类型与特征进行了归纳，总结了柱状节理岩体在三轴压缩下的4种典型破坏类型，并对其破坏机制进行了分析。
주상절리암체시일출형화성암상견적결구성암체，대기재삼축응력하변형화강도특성적정학인식，시수이수전급지하동실등대형암체공정론증화설계수요해결적관건문제지일。위차，채용석고혼합재료제작주체여최대주응력σ1구유불동협각β적모의주상절리암체시건，통과대시건진행불동위압하적삼축압축시험연구주상절리암체변형화강도특성，득도기재삼축압축하탄성모량화봉치강도수β각적변화규률。유시험결과가지：재동일급위압하，탄성모량화봉치강도수협각β증대정체감추세，즉탄성모량화봉치강도수협각증대선감소，재β=45°시최소，이후수협각증대보지상대불변。차외，이용시험수거건립주상절리암체탄성모량화봉치강도여협각β지간적경험관계식，통과비교발현경험관계식여실측수거문합교호。최후대시건적파배류형여특정진행료귀납，총결료주상절리암체재삼축압축하적4충전형파배류형，병대기파배궤제진행료분석。
The columnar jointed rock mass is a common kind of structure rock mass in extrusive igneous rocks, and correct understanding the deformation and strength characteristics of columnar jointed rock mass under triaxial stress condition was one of the key problems that should be solved for the demonstration and design of large scale rock mass projects such as hydropower station and underground cavern excavations. Therefore,in this paper, plaster mixture was used to prepare simulated columnar jointed rock mass specimens with different dip anglesβ between the direction of maximum principal stress1σand column prisms. Conventional triaxial compression tests with different confining pressures are carried out on these specimens and the variations of Young′s modulus and peak compression strength with dip angleβare obtained. From the experimental results,it is found that for seven groups of specimens under the same confining pressure,the curves of Young′s modulus and peak strength vs. dip angleβresemble as decreasing order-shaped,that is,the Young's modulus and peak strength decrease with dip angleβ from 0°to 45°and the minimum values of Young's modulus and peak strength occur atβ= 45°,then the Young′s modulus and peak strength remain relatively constant with the increase of dip angle. Furthermore,based on the experimental results,an empirical expression is proposed to predict the Young's modulus and peak strength of columnar jointed rock mass specimens. It is found that the empirical expression can well predict the changes of Young′s modulus and peak strength with dip angleβby comparing the theoretical curve with experimental data. Additionally,four types of typical failure modes of columnar jointed rock mass under triaxial compression condition are summarized based on test results and the failure mechanisms are also discussed.