重金属污染物侵入对岩石力学性能影响的研究

通过抗剪强度试验、风化耐久性强度试验、耐崩解试验、点荷载试验,对受重金属污染的泥岩、页岩、砂岩的力学强度变化特性进行了研究,并根据试验结果绘制了3种岩石抗压强度与重金属含量的关系曲线,采用线性回归法分析了岩石抗压强度与重金属质量比的相关关系。研究结果表明:在岩性、含水量、试验条件等相同的条件下, 3种重金属污染岩石的力学强度都随着重金属污染物含量的增加而减小; 重金属污染的泥岩、砂岩和页岩的单轴抗压强度与重金属质量比关系分别呈幂函数(泥岩、砂岩)、对数函数(页岩)关系,关系分化度为较显著-显著负相关。根据Weibull分布定律与对流-扩散特性建立了重金属污染物侵入与延伸性能方程,并对泥岩试验结果进行了计算,绘制了侵入性能、延伸性能与时间的关系曲线。结果表明: 4种金属元素在泥岩中平均侵入性能与延伸性能的大小顺序为Cd2+ Pb2+ Cu2+ Zn2+,且元素活性越大,侵入能力与延伸能力越强,侵入性能随着时间变化而逐渐减小,延伸性能随时间变化而逐渐增加。

LABORATORY STUDY ON EFFECTS OF MECHANICAL BEHAVIOR OF ROCKS DUE TO INVASION OF HEAVY METAL POLLUTANTS

Mudstone, shale and sandstone contaminated with heavy metals are studied with shear strength test, endurance strength test, resistant to disintegration test and point loading test. According to the results, the relationship curves of compressive strength and heavy metal content are drawn. The relationship between compressive strength of the rock and mass ratio of heavy metals is analyzed with linear regression method. The results show that the mechanical strength of the three contaminated rocks decreases with the increasing of heavy metal content under the same conditions such as lithology, water content, and test condition. The relationship between uniaxial compressive strength and mass ratio of heavy metals is a logarithmic function for contaminated mudstone and sandstone and power function for contaminated shale. The differentiation of relationship is a more significant or significant negative correlation. The equations of intrusion and extension performances are established according Weibull distribution law and convection-diffusion characteristic. The test results of mudstone are calculated. The curves between intrusive performance, extended performance and time are drawn. The results show that the average order of intrusive performance and extended performance of four metal elements in shale is Cd2+ Pb2+ Cu2+ Zn2+. The element activity is greater, the invasive capacity and extended capacity are stronger. The intrusion performance gradually decreases and the extended performance gradually increases with changing time.