冲击荷载作用下花岗岩损伤与渗流特征演化规律  

DAMAGE AND PERMEABILITY EVOLUTION OF GRANITE UNDER IMPACT LOADS

作　　者：徐帅陵[1] 刘晓忠[1] 李志华[1] 王强 韩程 XU Shuailing;LIU Xiaozhong;LI Zhihua;WANG Qiang;HAN Cheng(Sinopec Petroleum Engineering Design Co.,Ltd.,Dongying 257026,China;China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中石化石油工程设计有限公司,东营257026 [2]中国地质大学(北京),北京100083

出　　处：《工程地质学报》2024年第6期2166-2174,共9页Journal of Engineering Geology

摘　　要：爆破振动是影响岩石构筑物稳定性和渗流特性的主要因素之一。本文针对爆破振动对地下水封油库围岩渗透性影响机制科学问题,结合霍普金森杆试验和岩石三轴渗流试验,开展了系统研究,分析了冲击荷载作用下花岗岩渗透性演化规律。通过现场获取典型花岗岩试样,并开展霍普金森压杆试验,研究了不同冲击速度和冲击循环次数下的花岗岩损伤演化规律;对于冲击损伤后的试样开展三轴渗流试验,研究了不同损伤量和水头差下花岗岩渗透性的演化规律。研究表明:花岗岩损伤量随冲击速度和冲击次数增大而增大。花岗岩破坏形态随损伤量增长依次经历无明显破坏(00.16)3个阶段。当损伤量小于0.16时,花岗岩破坏程度较低,花岗岩等效渗透系数小于1.4×10^(-9)cm·s^(-1)并随损伤量增长呈指数型缓慢增长。随着损伤量不断增长,花岗岩破碎明显,甚至出现贯通裂隙,此时花岗岩等效渗透系数以数量级为单位急剧增长。论文研究成果明确了冲击荷载作用下花岗岩损伤程度与地下水位对花岗岩渗透性的影响规律,可为研究爆破施工扰动对地下水封油库水封可靠性分析提供理论依据,并为类似工程提供参考。Blasting vibration is one of the major factors affecting the stability and permeability characteristics of rock structures.Combined with SHPB tests and rock triaxial seepage tests,this paper systematically studies the permeability evolution of granite under impact loads.Through typical granite samples obtained in the research area,SHPB tests were conducted to study the damage evolution of granite under various impact velocities and times.Then,triaxial seepage tests were conducted to study the permeability evolution of damaged granite under different damage variables and water head differences.Research showed that the damage variable increased with an increase in impact velocity or times.As the damage variable increased,the destruction form of granite underwent three stages in turn:no obvious failure(0<D≤0.1),edge collapse(0.1<D≤0.16),and crack penetration failure(D>0.16).When the water head difference was 0.8 MPa or 1 MPa and the damage variable was less than 0.16,the equivalent permeability coefficient of granite was less than 1.4×10^(-9) cm·s^(-1) and increased exponentially and slowly with the increase of the damage variable.When the damage variable was greater than 0.16,the granite was significantly broken and even presented penetrating cracks.The equivalent permeability coefficient increased sharply by orders of magnitude with the increase of the damage variable.This research illustrates the influence of damage and groundwater level on the permeability of granite under blasting vibration and develops the theory of water sealing reliability of underground water-sealed oil storage.

关 键 词：地下水封油库 花岗岩 冲击荷载 花岗岩动力损伤 花岗岩渗透性 

分 类 号：TE822[石油与天然气工程—油气储运工程]