原状与重塑冻结黏土单轴抗压对比试验
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摘要
以某矿区地下不同深度的黏土为研究对象,采用冻土的单轴压缩试验,在3种温度下对原状与重塑人工冻土进行压缩指标及破坏特征的测定,并分析了因不同温度及不同深度下压缩特征的变化规律。结果表明:原状冻黏土在-5℃时呈现腰鼓状的塑性破坏,-10℃与-15℃下则为脆性破坏,重塑冻黏土在-5℃与-10℃下呈现塑性破坏,-15℃下则为脆性破坏;冻土的抗压强度随温度降低而增强,抗压强度与温度的关系可用指数函数来进行拟合,3种温度中-10℃情况下的峰值应变最大;温度越低弹性模量越大,弹性模量与温度的关系呈线性关系,相比于重塑冻黏土,温度对原状冻黏土弹性模量的影响更大;温度越低,深度对抗压强度比值的影响越小,重塑冻黏土的抗压强度越接近原状冻黏土的抗压强度。
Taking the clay in different depths of a mining area as the research object, the uniaxial compression test of frozen soil was used to determine the compression index and failure characteristics of undisturbed and remolded artificial frozen soil at three temperatures, and the variation laws of compression characteristics under different temperatures and depths were analyzed. The results show that the undisturbed frozen clay exhibits waist-drum plastic failure at-5 ℃ and brittle failure at-10 ℃ and-15℃; the remolded frozen clay presents plastic failure at-5 ℃ and-10 ℃, and brittle failure at-15 ℃. The compressive strength of frozen soil increases with the decrease of temperature. The relationship between compressive strength and temperature can be fitted by exponential function. The peak strain of frozen soil is the highest at-10 ℃. The lower the temperature, the greater the elastic modulus, the relationship between modulus of elasticity and temperature is linear, and the influence of temperature on the original frozen clay elastic modulus is greater; the lower the temperature is, the less the influence of depth on compressive strength ratio is, and the compressive strength of undisturbed remolded frozen clay is closer to that of undisturbed frozen clay.
Taking the clay in different depths of a mining area as the research object, the uniaxial compression test of frozen soil was used to determine the compression index and failure characteristics of undisturbed and remolded artificial frozen soil at three temperatures, and the variation laws of compression characteristics under different temperatures and depths were analyzed. The results show that the undisturbed frozen clay exhibits waist-drum plastic failure at-5 ℃ and brittle failure at-10 ℃ and-15℃; the remolded frozen clay presents plastic failure at-5 ℃ and-10 ℃, and brittle failure at-15 ℃. The compressive strength of frozen soil increases with the decrease of temperature. The relationship between compressive strength and temperature can be fitted by exponential function. The peak strain of frozen soil is the highest at-10 ℃. The lower the temperature, the greater the elastic modulus, the relationship between modulus of elasticity and temperature is linear, and the influence of temperature on the original frozen clay elastic modulus is greater; the lower the temperature is, the less the influence of depth on compressive strength ratio is, and the compressive strength of undisturbed remolded frozen clay is closer to that of undisturbed frozen clay.
引文
[1]曹伟,盛煜.煤矿开采过程中的冻土环境问题与对策[J].水文地质与工程地质,2013,40(5):91-96.
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[3]陈湘生.人工冻土瞬时无侧限抗压强度特征的试验研究[J].建井技术,1991(6):32-35.
[4]李洪升,杨海天,常成,等.冻土抗压强度对应变速率敏感性分析[J].冰川冻土,1995,17(1):40-48.
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[6]刘增利,李洪升,朱元林,等.冻土单轴压缩动态试验研究[J].岩土力学,2002,23(1):12-16.
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[8]李海鹏,林传年,张俊兵,等.饱和冻结黏土在常应变率下的单轴抗压强度[J].岩土工程学报,2004,26(1):105-109.
[9]尹珍珍,陈有亮,王鹏.上海人工冻结黏土单轴无侧限抗压强度试验研究[J].岩土力学,2012,33(3):788.
[10]吉琳,马巍.冻土的力学性质及研究现状[J].岩土力学,2010,31(1):133-143.
[11] GB/T 50123—1999土工试验方法标准[S].
[12]李海鹏,林传年,张俊兵,等.原状与重塑人工冻结黏土抗压强度特征对比试验研究[J].岩石力学与工程学报,2003,22(增2):2861-2864.
[13]霍亮,林斌.重塑对人工冻结黏土力学参数影响试验研究[J].煤炭工程,2011(10):110-112.
[14]贺俊,杨平,何文龙.苏州地铁典型土层冻土力学特性研究[J].水文地质工程地质,2010,37(5):72-76.
[15]黄星,李东庆,明锋,等.冻土的单轴抗压、抗拉强度特性试验研究[J].冰川冻土,2016,38(5):1346.
[2]崔托维奇H A.冻土力学[M].张长庆,朱元林,译.北京:科学出版社,1985:160-170.
[3]陈湘生.人工冻土瞬时无侧限抗压强度特征的试验研究[J].建井技术,1991(6):32-35.
[4]李洪升,杨海天,常成,等.冻土抗压强度对应变速率敏感性分析[J].冰川冻土,1995,17(1):40-48.
[5]马芹永.人工冻土单轴抗拉、抗压强度的试验研究[J].岩土力学,1996,17(3):76-81.
[6]刘增利,李洪升,朱元林,等.冻土单轴压缩动态试验研究[J].岩土力学,2002,23(1):12-16.
[7]刘增利,张小鹏,李洪升.原位冻结黏土单轴压缩试验研究[J].岩土力学,2007,28(12):2657-2660.
[8]李海鹏,林传年,张俊兵,等.饱和冻结黏土在常应变率下的单轴抗压强度[J].岩土工程学报,2004,26(1):105-109.
[9]尹珍珍,陈有亮,王鹏.上海人工冻结黏土单轴无侧限抗压强度试验研究[J].岩土力学,2012,33(3):788.
[10]吉琳,马巍.冻土的力学性质及研究现状[J].岩土力学,2010,31(1):133-143.
[11] GB/T 50123—1999土工试验方法标准[S].
[12]李海鹏,林传年,张俊兵,等.原状与重塑人工冻结黏土抗压强度特征对比试验研究[J].岩石力学与工程学报,2003,22(增2):2861-2864.
[13]霍亮,林斌.重塑对人工冻结黏土力学参数影响试验研究[J].煤炭工程,2011(10):110-112.
[14]贺俊,杨平,何文龙.苏州地铁典型土层冻土力学特性研究[J].水文地质工程地质,2010,37(5):72-76.
[15]黄星,李东庆,明锋,等.冻土的单轴抗压、抗拉强度特性试验研究[J].冰川冻土,2016,38(5):1346.