组合冷却后高温花岗岩物理力学及劈裂面粗糙度试验研究  

Experimental study on mechanical performances and cleavage surface roughness of high-temperature granite after combined cooling

作　　者：崔翰博[1] 唐巨鹏[1] 姜昕彤[1] CUI Hanbo;TANG Jupeng;JIANG Xintong(School of Mechanics and Engineering,Liaoning Technical University,Fuxin,Liaoning 123000,China)

机构地区：[1]辽宁工程技术大学力学与工程学院,辽宁阜新123000

出　　处：《岩石力学与工程学报》2021年第7期1444-1459,共16页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点研发计划项目(2016YFC0600901);国家自然科学基金面上项目(51874165);辽宁省“兴辽英才计划”项目(XLYC1902106)。

摘　　要：注流采热过程中干热岩(hot dry rock,HDR)浸水冷却降温与干燥自然降温区域间会形成新裂隙通道,裂隙的粗糙度直接对流体渗流传热过程产生影响。因此,以松辽盆地北部大庆地区花岗岩为研究对象,对组合冷却(单一岩体部分自然冷却,部分浸水冷却)不同初始温度(100℃~600℃)与不同冷却比例(完全自然冷却、1/4浸水冷却、1/2浸水冷却、3/4浸水冷却、完全浸水冷却)试件进行巴西劈裂试验,利用自行研制的粗糙度轮廓测试仪对劈裂面粗糙度进行测量,研究上述条件下花岗岩物理力学特性(表观温度、浸水面上移高度、外观形态、抗拉强度)与劈裂面粗糙度特性(高差参数:高差峰值谷值分布、高度均方差;纹理参数:粗糙度系数、粗糙角)变化规律,并考量高差参数与纹理参数间关系,同时建立抗拉强度与粗糙度特性间拟合曲线。研究表明:(1)初始温度越高,岩体表观温度降幅越大,浸水冷却一侧降温速率高于自然冷却。(2)浸水冷却过程中,浸水高度会产生上移,温度越高,上升程度越明显,出现了初始温度500℃,600℃表观温度低于400℃试件的异常现象。(3)温度升高,高差峰值分布区域逐渐向浸水区域扩展;初始温度600℃、浸水冷却高度比为3/4,抗拉强度损失最大(84.88%,14.84%),裂隙高差参数、纹理参数达到最值。(4)温度不同,试件抗拉强度与粗糙度特征间拟合系数较高;浸水比例不同,拟合系数虽有不同程度下降,但仍保持一定相关性,利用抗拉强度去判断岩体劈裂面粗糙度具备较高可行性。上述研究有望为HDR热破裂时裂隙扩展规律的判定提供一定参考。During injection heat mining,new crack passages are developed between water cooling parts and natural cooling parts of hot dry rock(HDR),and crack roughness has direct effects on seepage heat transfer of fluids.In this study,taking the granite in Daqing area of northern Songliao basin as the research object,Combined cooling of different initial temperatures(100℃-600℃)and different cooling ratios(0%immersion cooling,25%immersion cooling,50%immersion cooling,75%immersion cooling and 100%immersion cooling)were performed on the specimens(partly placed in water and partly kept in air),and Brazilian split tests on the heat-treated specimens were performed.The cleavage surface roughness of the samples was measured by the customized roughness profiler to clarify the variations of physical and mechanical properties(apparent temperature,upshift of immersion surface,morphology and tensile strength)and cleavage surface roughness features(height difference parameters:distributions of peak and trough of height difference and mean square error of height;texture parameters:roughness coefficient and rough angle)of granite under the specific conditions.Meanwhile,the correlation of height difference parameters and texture parameters was investigated and the tensile strength-roughness fitting curve was developed.The results demonstrate that the reduction of the apparent temperature of the rock is proportional to the initial temperature and the reduction rate of the immersion cooling part exceeds that of the natural cooling part.During immersion water cooling,the immersion surface shifts upward and the upshift is proportional to the temperature.In extreme cases,the apparent temperature may be below 400℃when the initial temperature is 500℃-600℃.The distribution of the height difference peak appears to the water cooling part as the temperature increases.With an initial temperature of 600℃and an immersion cooling height ratio of 3/4,the tensile strength loss is maximized(84.88%,14.84%)and crack height difference parameters a

关 键 词：岩石力学 组合冷却 热破裂 浸水冷却比例 劈裂面粗糙度 

分 类 号：TU45[建筑科学—岩土工程]