%0 Journal Article %T 岩质斜坡中缓倾裂隙分布与成因工程地质分析<br>Genesis Mechanism and Distribution of Gently-Dipping Brittle Discontinuities in Rock Slope %A 朱雷 %A 严明 %A 黄润秋 %A 高峰< %A br> %A ZHU Lei %A YAN Ming %A Huang Runqiu %A Gao Feng %J 西南交通大学学报 %D 2017 %R 10.3969/j.issn.0258-2724.2017.03.016 %X 针对岩质斜坡中缓倾角结构面不均匀分布这一地质现象，以云南怒江马吉水电站斜坡为例，在现场调查的基础上，运用地质过程机制分析和数值计算等方法，对岩质斜坡中缓倾角结构面的发育密度和河谷的演化史进行了分析研究，揭示了岩质斜坡中缓倾角结构面发育规律和成因.结果表明：在斜坡的表生改造段，中缓倾角结构面的发育表现出明显间隔性分布特征，即中缓倾角结构面密集段、稀疏段相间出现，存在 3~4 个相对密集的结构面发育带，密集段结构面的面密度为10~18条/10 m2，稀疏段结构面的面密度为5~8条/10 m2；中缓倾角裂隙的形成具有明显的阶段性，根据其几何及滑移特征，中缓倾角裂隙的形成是从雁列式微裂隙开始，随着裂隙的扩展、搭接，最终形成成具有工程地质意义的结构面；斜坡中缓倾角裂隙间隔性分布是由于挽近地质时期河谷演化过程中河谷的间歇性下切而导致的.<br>： A rock slope in Nujiang River (China) was taken as an example to better understand the distribution of the gently-dipping discontinuities subjected to river incision. Based on field surveys, geological analysis and numerical simulation, a study on the density and evolution of the gently-dipping discontinuities was carried out to reveal the distribution and genesis mechanism. The results indicate that the gently-dipping discontinuities in the epigenetic reworking stage have evolved to distribute at irregular intervals the discontinuities concentrate in certain zones (i.e., high-density zones), separated by some low-density zones. Totally, there are three to four high-density evolution zones of gently-dipping discontinuities. The density of discontinuities in these high-density zones ranges from 10 to 18 per 10 square meters, while the value in the low-density zones is 5 to 8 per 10 square meters. Moreover, the geometry and kinematic analyses of the system of discontinuities suggest that the genesis of the discontinuities can be synthesized into a progressive evolution model. The model suggests that the joint starts with the formation of an array of en-echelon cracks, with continued crack elongation and shearing; then they approach one another and interact, forming a complex joint system finally. According to the history of river valley evolution, a view is proposed that the river intermittent incision was the main factor resulting in the intermittently concentrated distribution of the gently-dipping discontinuities %K 岩质斜坡 %K 中缓倾角裂隙 %K 间隔性分布 %K 河谷下切 %K 形成机制 %K < %K br> %K rock slope %K gentle dipping discontinuities %K concentrated distribution %K river incision %K genesis mechanism %U http://manu19.magtech.com.cn/Jweb_xnjd/CN/abstract/abstract12438.shtml