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自然与饱水状态下深部斜长角闪岩蠕变特性 被引量:20
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作者 张春阳 曹平 +1 位作者 汪亦显 宁果果 《中南大学学报(自然科学版)》 EI CAS CSCD 北大核心 2013年第4期1587-1595,共9页
通过金川深部斜长角闪岩单轴压缩蠕变实验,选取典型蠕变曲线,发现该岩石黏弹性、黏塑性变形较瞬时变形偏小,卸载后弹性后效不显著。在5.1 MPa轴向应力下,自然状态的岩样近似纯弹性特征。饱水状态下岩样瞬时强度σ′b和长期强度σ′∞总... 通过金川深部斜长角闪岩单轴压缩蠕变实验,选取典型蠕变曲线,发现该岩石黏弹性、黏塑性变形较瞬时变形偏小,卸载后弹性后效不显著。在5.1 MPa轴向应力下,自然状态的岩样近似纯弹性特征。饱水状态下岩样瞬时强度σ′b和长期强度σ′∞总体低于自然状态,且σ′∞已接近深部高地应力,因此,对于深部节理、裂隙很发育的岩体,应特别注意巷道排水,防止围岩因长期强度降低而导致巷道变形和破坏。自然与饱水状态下岩样瞬时弹性应变εme、瞬时塑性应变εmp随应力增大而增加,但增速逐渐放缓,饱水状态下塑性变形更显著;相同应力下,饱水状态岩样蠕变量大于自然状态,应变速率也总体快于自然状态,2种状态的蠕变速率在20~30 h时都逐渐稳定,且速率曲线随应力增大,微裂隙压密,彼此逐渐靠近,岩样处于相对硬化阶段;当轴向应力达到66.3 MPa后,饱水状态蠕变速率有相对加速趋势,速率曲线随应力增大先往左下移动,再朝右上移动,而自然状态蠕变速率曲线总体向右上移动。最后,通过蠕变数据分析,推导γ=ασk型经验方程,对蠕变试验数据进行回归拟合,拟合结果证明该蠕变经验模型的正确性。金川矿区斜长角闪岩蠕变实验研究为分析深部巷道该类围岩流变稳定性及支护方案优化等提供有效帮助。 展开更多
关键词 斜长角闪岩 单轴压缩蠕变实验 长期强度 应变速率 蠕变经验模型 回归拟合
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Visco-elastoplastic damage constitutive model for compressed asphalt mastic 被引量:1
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作者 曾国伟 杨新华 +1 位作者 白凡 高虎 《Journal of Central South University》 SCIE EI CAS 2014年第10期4007-4013,共7页
In order to describe the three-stage creep behavior of compressed asphalt mastic, a visco-elastoplastic damage constitutive model is proposed in this work. The model parameters are treated as quadratic polynomial func... In order to describe the three-stage creep behavior of compressed asphalt mastic, a visco-elastoplastic damage constitutive model is proposed in this work. The model parameters are treated as quadratic polynomial functions with respect to stress and temperature. A series of uniaxial compressive creep experiments are performed at various stress and temperature conditions in order to determine these parameter functions, and then the proposed model is validated by comparison between the predictions and experiments at the other loading conditions. It is shown that very small permanent deformation at low stress and temperature increases rapidly with elevated stress or temperature and the damage may initiate in the stationary stage but mainly develops in the accelerated stage. Compared with the visco-elastoplastic models without damage, the predictions from the proposed model is in better agreement with the experiments, and can better capture the rate-dependency in creep responses of asphalt mastic especially below its softening point of 47 ℃ 展开更多
关键词 asphalt mastic visco-elastoplastic damage model compressive creep
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