冻融循环作用下板岩弹性参数及单轴抗压强度研究

发布时间：2018-01-04 22:00

本文关键词：冻融循环作用下板岩弹性参数及单轴抗压强度研究　出处：《岩土力学》2017年08期 　论文类型：期刊论文

【摘要】：为揭示冻融循环作用对板岩弹性参数及单轴抗压强度的影响,采用DX-40型低温数控箱、DNS100微型控制电子万能试验机进行7种层理倾角(?)、6种冻融循环次数的单轴压缩试验,对其5个弹性参数、单轴抗压强度及破坏类型的变化规律进行分析。试验结果表明:板岩弹性模量、剪切模量和单轴抗压强度随冻融循环次数增加呈指数下降趋势,泊松比随冻融循环次数增加呈线性增加趋势;板岩单轴抗压强度随层理倾角增加呈先减后增的变化趋势;冻融循环作用下板岩破坏类型有3种:当0°≤?≤26.6°时,沿与竖直轴线呈一定角度方向发生剪切破坏;当26.6°≤?≤83.0°时,沿层理面发生剪切破坏;当83.0°≤?≤90°时,沿垂直方向发生劈裂破坏。在Jaeger单弱面理论的基础上,建立了以冻融循环次数和层理倾角为控制变量的板岩单轴抗压强度预测模型,并通过试验数据验证了模型的合理性,表明该模型能较好地描述冻融循环次数和层理倾角对冻融板岩单轴抗压强度的影响。
[Abstract]:In order to reveal the effect of freeze-thaw cycle on rock elastic parameters and uniaxial compressive strength, using DX-40 type low temperature numerical control box, DNS100 electronic universal testing machine for 7 types of bedding dip (?), 6 kinds of frozen thawing cycles of uniaxial compression test, the 5 elastic parameters, variation of single axis the compressive strength and failure types were analyzed. The experimental results show that the rock elastic modulus, shear modulus and uniaxial compressive strength increases with the number of freeze-thaw cycles declines exponentially, Poisson's ratio increases with the number of freeze-thaw cycles increases linearly; the uniaxial compressive strength of rock plate showed a trend of first decrease and then increase with the bedding there are 3 kinds of angle increase; the effect of freeze-thaw damage of slate type: when 0 DEG? = 26.6 degrees, along the shear direction and the vertical axis is in a certain angle; when 26.6 DEG? = 83 degrees, shear failure along the bedding plane; when 83 DEG? = 90 degrees, along the vertical direction of splitting failure occurred. Based on Jaeger single plane theory, prediction model was established by frozen slate uniaxial compressive strength of thawing cycles and bedding angle as control variables, and through the test data to verify the rationality of the model, show that the model can effectively describe the freeze-thaw cycle and bedding angle on the effect of freeze-thaw on uniaxial compressive strength of slate.

【作者单位】：中南大学土木工程学院;中南大学高速铁路建造技术国家工程试验室;同济大学岩土及地下工程教育部重点实验室;同济大学地下建筑与工程系;
【基金】：国家自然科学基金项目(No.51578550,No.51538009) 中南大学研究生自主探索创新项目(No.2017zzts153)~~
【分类号】：TU45
【正文快照】： 冻融循环引发的温度场和力场耦合是高寒区工程不可回避的岩土工程问题,受冻融循环作用影响,岩石物理力学特性将发生显著变化,这种变化往往会造成严重的灾害事故。因此,研究冻融循环作用下岩石弹性参数及单轴抗压强度具有重要的理论意义与工程应用价值。板岩常表现为成层性,其

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