软弱泥岩夹层对层状盐岩体力学特性影响研究

Influence of Weak Mudstone Intercalated Layer on Mechanical Properties of Laminated Salt Rock

我国岩盐矿床具有夹层多的特点,夹层对岩盐矿床开采和油气储库建造及稳定性均有极为不利的影响。泥岩是软弱夹层的主要组成部分,含软弱夹层的层状岩盐试件很难完整取得,在实验室进行了模拟软弱夹层对层状岩盐体力学特性影响的研究,实验发现泥岩试件随强度的提高,相应弹性模量也逐步增强,但体现横向变形能力的泊松比变化不大;含泥岩夹层岩盐试件的强度接近于泥岩,而泥岩的强度仅为纯岩盐的20-47%,说明软弱夹层对层状岩盐体的强度起决定作用。通过对层状岩盐进行应力-应变分析,得出泥岩夹层和岩盐的不同破坏方式是由于夹层附近的岩体拉压应力的相互转换造成的,同时分析了造成反复应力的原因。实验结果与层状岩体变形破坏的理论解释相一致,验证了理论的科学性,同时也获得了层状盐岩体的力学特性与软弱夹层特性的相关关系。对我国层状盐岩体油气储库建造具有指导意义和参考价值。

The salt deposit in China is characterized by more interlayers,these interlayers have negative effect to the salt mining,building and the stability of cavern.The mudstone is the main component in the interlayer,it is difficult to make a complete specimen with weak interlayer,we have done the test to simulate the influence of weak interlayer on mechanical properties of laminated salt rock,the results show that with the increase of strength the elastic modulus are escalated,but the Poissons ratio as an index of the deformability, changes a little ;the strength of salt rock with interlayer of mudstone is near to mudstone,but the stress of mudstone is only 20 -47% of salt rock strength, it shows that the weak interlayer has mainly effect to the strength of laminated salt rock. Through the analysis of strain-stress of laminated salt rock, it is clear that the different failure styles of mudstone interlayer and rock salt is due to that near the interlayer the tensile and compressive stress change into each otber,at the same timejwe have analyzed the reason of repeated stress, the result and theory explanation of interlayer rock mass deformation failure are consistent, to verify the theory is a scientific one, at the same time ,we have got the ralation between the mechanical properties of weak interlayer and laminated salt rock, this is important to oil-gas storage cavern built in laminated salt rock.