摘要
为揭示盐岩水溶造腔过程中难溶夹层力学特性与卤水浸泡时间的关系,更好地了解夹层的软化规律和范围,为预测和控制夹层的破坏垮塌提供理论支持,以云应盐矿中的泥质硬石膏夹层为研究对象,进行不同浸泡时间下的单轴压缩和巴西劈裂软化试验研究,发现其力学强度随卤水浸泡时间劣化明显,其中,单轴抗压强度、弹性模量、泊松比与卤水浸泡时间呈显著的DoseResp函数关系,抗拉强度与浸泡时间呈显著的Slogistic1函数关系,且试件的单轴压缩及巴西劈裂试验的破坏形式随浸泡时间的增加有从张拉破坏向剪切破坏的渐变趋势。通过分析试验结果发现,卤水对夹层力学强度的软化作用与夹层可溶物含量、夹层成分遇水膨胀的不均性、卤水的润滑作用和矿物晶键的软化作用均存在密切相关。推导了基于浸泡时间的夹层损伤演化方程,建立夹层轴向和径向的软化深度模型,并将其应用于水溶造腔过程中难溶夹层软化范围的划定。此外,基于夹层抗拉强度与卤水浸泡时间的关系,给出判定和预测夹层局部软化破坏的最大拉应力强度准则。
The uniaxial compression and Brazilian splitting tests on the argillaceous anhydrite from the interlayers of the mine at Yunying were conducted with the different time lengths of immersion in order to reveal the mechanical characteristics （such as the softening） of the insoluble interlayer upon brine immersion and to provide the theoretical guide for the prediction and control of the interlayer destruction during the process of the cavity building inside the rock salt. It was found that the mechanical strengths of interlayer deteriorated significantly with the increasing of the time length of brine immersion. The relationships of the uniaxial compressive strength,the elastic modulus and Poisson′s ratio with the time lengths of brine immersion were fit well with DoseResp function. While the relationship between the tensile strength and the time length of brine immersion was fit with Slogistic1 function. The failure modes of the specimens in the uniaxial compression and Brazilian split tests were gradually changed from the tension failure to the shear failure as the time length of immersion was increased. It was found from the results of the test that the softening effect of brine was closely related with the soluble content of interlayer,the heterogeneity of hydraulic swelling of the interlayer ingredients,the lubrication of brine and the softening effect on the crystal bonding of minerals. An equation of the damage evolution with the time of immersion for interlayers was derived according to the experimental data and a model for softened depth of＆amp;nbsp;interlayer in the axial and radial directions was established. The model was applied to determine the softened range of the insoluble interlayer during the process of cavity building in rock salt. In addition,a criterion of maximum tensile stress was presented for the determination and prediction of the local softening damage of interlayers based on the relationship between the tensile strengths and the time lengths of brine immersion.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2014年第5期865-873,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(51304256)
中国博士后科学基金资助项目(2013M540620)
博士点基金–优先发展领域资助项目(20130191130003)
关键词
岩石力学
浸泡时间
夹层
损伤演化方程
软化深度模型
强度准则
rock mechanics
immersion length of time
interlayer
evolution equation of damage
softening depth model
strength criteria
