在含单裂隙岩体的试验中,对裂纹类型和试样破坏模式的研究可以帮助预测裂纹的萌生、扩展等现象,然而在工程结构设计中,应该更加关注岩体的承载力,即破坏强度。为了研究裂隙与岩体强度的关系,采用FLAC3D建立相应试样的数值计算模型,同时改变其中单裂隙的倾角、长度等参数,通过对多组试样的加载试验,研究了单裂隙的几何参数(裂隙倾角、长度和张开度)对岩样破坏强度的影响。结果表明:随着裂隙长度的增大,试样峰值应力不断降低;随着裂隙倾角的增大,试样峰值应力整体呈增大趋势,但是当倾角<60°时,增长较缓慢,当倾角>60°时,峰值应力迅速增大;在试验范围内,随着裂隙张开度的增大,试样峰值应力基本保持不变。研究成果可为预测含单裂隙岩体的裂纹扩展和强度提供参考依据。
Abstract
In tests of rock specimens containing single flaw, researching the crack types and failure modes are conducive to predicting the initiation and propagation of cracks; yet in engineering design, the bearing capacity, namely damage strength, should receive more attention. In order to investigate into the relation between crack and rock strength, we built numerical models for corresponding test specimens in FLAC3D, and furthermore researched theinfluence of single crack’s geometric parameters (inclusive of inclination angle, length, and thickness) on the damage strength of rock specimens by adjusting the parameters in numerical model. Results revealed that the peak strength of specimen declined continuously as crack length increased; while when inclination angle increased, peak strength displayed a trend of increasing in general, increasing slowly when inclination angle was smaller than 60°and rapidly when inclination angle was larger than 60°. Within the test range, peak strength remained unchanged as flaw thickness increased.
关键词
单裂隙 /
FLAC3D /
单轴压缩 /
几何参数 /
峰值应力 /
破坏模式
Key words
single flaw /
FLAC3D /
uniaxial compression /
geometric parameters /
peak strength /
failure mode
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基金
国家自然科学基金项目(51474249,51774322);中南大学“创新驱动计划”项目(2016CX019);河南省瓦斯地质与瓦斯治理重点实验室开放基金项目(WS2013A01)
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