循环荷载作用下斜长花岗岩弹性模量演化规律  

ELASTIC MODULUS'S EVOLUTION LAW OF PLAGIOGRANITE UNDER CYCLIC LOADING

作　　者：胡广[1] 赵其华[1] 何云松[1] 韩刚[1] 

机构地区：[1]地质灾害防治与地质环境保护国家重点实验室(成都理工大学),成都理工大学环境与土木工程学院,成都610059

出　　处：《工程地质学报》2016年第5期881-890,共10页Journal of Engineering Geology

基　　金：国家重点基础研究发展计划(973)项目(2011CB013501);国家自然科学基金项目(42272333)资助

摘　　要：通过MTS815岩石力学试验机开展斜长花岗岩循环荷载试验,揭示循环次数、围压、含水率对斜长花岗岩弹性模量变化规律的影响,分析饱和与天然试样应力功、弹性应变能、耗散能随循环次数的演化规律。根据能量演化规律将岩石压缩变形破坏过程划分为4个阶段,研究各阶段切线模量与耗散能之间的关系。试验结果表明:(1)同一个应力水平切线模量随循环次数呈先增大后降低的趋势,其降低幅度随循环次数与应力水平增加而增大。(2)围压抑制了裂纹扩展,随围压增加切线模量弱化幅度减小。(3)饱和试样比天然试样切线模量弱化幅度大,说明水的存在加剧饱和试样内部结构损伤。(4)耗散能增加是引起切线模量弱化的内在因素,两者的变化规律呈现出很好的相关性。This paper presents the increasing-amplitude cycle loading experiment of plagiogranite through the MTS815 rock mechanics testing machine. It examines the effects of number of cycle, confining pressure and moisture content on elastic modulus, and analyzes the variation of work stress,elastic strain energy and dissipated energy with increasing number of cycle. The process of rock compression deformation and failure is divided into four stages according to the energy change law. It researches the relationship between tangent modulus and dissipated energy. The experimental results show that：（1） The tangent modulus at the same stress level is increased and then decreased at the cycle times increases. Its decreasing amplitude increases as cycles and stress level increase. （2） The weakened amplitude of tangent modulus decreases with increase of confining pressure. （3） The weakened amplitude of tangent modulus of saturated samples is bigger than that of natural samples, which shows that water is aggravated damage on saturated samples. （4） The increase of dissipated energy is the cause of the tangent modulus weakening. The change rules of dissipated energy and tangent modulus are correlative.

关 键 词：循环荷载 斜长花岗岩 弹性模量 能量 

分 类 号：P642.3[天文地球—工程地质学]