节理对砂岩变形及破坏特征影响研究

发布时间：2018-06-22 00:15

本文选题：节理岩体 + 试验　；参考：《地下空间与工程学报》2017年01期

【摘要】：工程岩体一般都含有各种不同级别的地质构造节理和软弱面,使得岩体的强度弱化。含有节理的岩体和完整岩石具有完全不同的力学性质。本文在三轴压缩试验的基础上,对不同节理倾角的三峡库区砂岩开展研究,探讨其变形及破坏特征。试验结果表明:(1)在同种围压下,节理岩样峰值强度的大小关系为:σ60°σ30°σ90°σ完整。(2)相同围压下,完整岩样弹性模量及变形模量均高于节理岩样,随着围压升高,岩样弹性模量和变形模量逐渐增大,其增长速度随围压增大而逐渐降低。(3)在低围压下(5 MPa),节理倾角对岩样弹性模量和变形模量影响较大,相比完整岩样有较大幅度地降低,其中30°倾角和60°倾角岩样降低程度较高,弹性模量最高达31%,变形模量最高达40%;随着围压增大(大于10 MPa),节理倾角对岩样变形参数影响逐渐减小,相比完整岩样,节理岩样弹性模量降低幅度小于15%,变形模量降低幅度小于10%。(4)节理倾角和围压对岩石的破坏机制均有较大的影响,节理倾角及围压不同,岩样破坏形式不同。
[Abstract]:Engineering rock mass generally contains various kinds of geological structural joints and weak planes, which weaken the strength of rock mass. Rock masses with joints have completely different mechanical properties from intact rocks. On the basis of triaxial compression test, the sandstone in three Gorges reservoir area with different joint inclination angles is studied, and its deformation and failure characteristics are discussed. The results show that: (1) under the same confining pressure, the relationship of peak strength of jointed rock samples is as follows: 蟽 60 掳蟽 30 掳蟽 90 掳蟽 integrity. (2) under the same confining pressure, the elastic modulus and deformation modulus of intact rock samples are higher than that of jointed rock samples, and with the increase of confining pressure, the elastic modulus and deformation modulus of intact rock samples are higher than those of jointed rock samples. The elastic modulus and deformation modulus of rock samples increase gradually, and the growth rate decreases gradually with the increase of confining pressure. (3) at low confining pressure (5 MPA), the dip angle of joint affects the elastic modulus and deformation modulus of rock samples greatly, and decreases greatly compared with the intact rock samples. Among them, the dip angle of 30 掳and 60 掳angle of rock samples are lower, the modulus of elasticity is up to 31 and the modulus of deformation is up to 40. With the increase of confining pressure (> 10 MPA), the effect of joint inclination angle on the deformation parameters of rock samples decreases gradually, compared with the intact rock samples. The decrease of elastic modulus of jointed rock samples is less than 15 and the decrease of deformation modulus is less than 10. (4) the fracture mechanism of rock is greatly affected by joint dip angle and confining pressure, and the failure forms of rock sample are different with different joint dip angle and confining pressure.
【作者单位】：三峡大学三峡库区地质灾害教育部重点实验室;长江科学院水利部岩土力学与工程重点实验室;贵阳勘测设计研究院工程科研分院;
【基金】：国家自然科学基金(51479102,51579017,51579138);国家自然科学基金重点项目(No.51439003) 中国水利水电科学研究院开放基金(IWHR-SKL-201218) 防灾减灾湖北省重点实验室(三峡大学)开放基金(2016KJZ01)
【分类号】：TU45

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