变温度区间冻融作用下岩石物理力学性质研究及工程应用  

STUDY OF PHYSICO-MECHANICAL CHARACTERISTICS OF ROCK UNDER DIFFERENT FROZEN-THAWED CIRCLE TEMPERATURE RANGE AND ITS ENGINEERING APPLICATION

作　　者：闻磊[1,2] 李夕兵[2] 唐海燕[3] 翁磊[2] 

机构地区：[1]石家庄铁道大学工程力学系,河北石家庄050043 [2]中南大学资源与安全工程学院,湖南长沙410083 [3]长沙矿山研究院有限责任公司,湖南长沙410012

出　　处：《工程力学》2017年第5期247-256,共10页Engineering Mechanics

基　　金：河北省高等学校科学技术研究项目(QN2017131);国家自然科学基金项目(41272304;11472311)

摘　　要：利用取自西藏玉龙铜矿的花岗岩试样进行变温度区间的冻融循环实验,分析饱水状态花岗岩在四种温度区间(-10℃~20℃、-20℃~20℃、-30℃~20℃、-40℃~20℃)冻融循环作用下的质量损失率、饱和吸水率、单轴抗压强度、弹性模量、峰值应变、泊松比、冻融系数。将实验结果应用于具体工程实例中,采用强度折减法计算冻融循环对花岗岩边坡稳定性的影响程度,分析边坡破坏模式,并提出相应的防护措施。研究结果表明:随着冻融温度下限的降低,花岗岩试样质量损失率、饱和吸水率、峰值应变略有增大,单轴抗压强度、弹性模量有所减小,温度下限降低至-30℃以下时,花岗岩抗冻性由较好变为较差。温度区间是岩石冻融过程中影响其物理力学性质的重要原因,该研究可为岩石冻融循环室内实验与寒区岩质边坡工程的有效结合提供参考。The physico-mechanical behavior of granite （sampling from Tibet Yulong copper mine） has been investigated under different frozen-thawed temperatures in laboratory. The temperature range was classified into 4 groups： -10℃-20℃, -20℃-20℃, -30℃-20℃ and -40℃-20℃. Mass loss rate, saturated water absorptivity, uniaxial compressive strength, elastic modulus, peak strain, poisson ratio and coefficient of freezing and thawing were measured. The lab results were used to evaluate the stability of the slope of the Yulong copper mine. And corresponding safety factors of the slope before and after frozen-thawed cycles were calculated and compared. The results show that the decrease of the temperature lower limit leads to larger mass loss rate, larger saturated water absorptivity of granite, and larger peak strain, but lower uniaxial compressive strength and lower elastic modulus. When the lower limit of temperature is below -30℃, the frost-resistance of granite becomes worse. The temperature range is an important factor for the physico-mechanical characteristics of the rock under freezing-thawing cyclic effect. This study is useful for analyzing slope stability under the influence of freeze-thaw.

关 键 词：冻融循环 温度区间 岩石 物理力学特性 强度折减法 

分 类 号：TU452[建筑科学—岩土工程]