摘要
鉴于有无填充物条件下岩体裂隙渗流规律巨大差异,以及工程岩体中大量渗流裂隙为原岩破碎物填充的剪切滑移裂隙,研究加载路径、轴压、围压、裂隙深度、原岩充填物粒径等因素对渗流量的影响对岩质边坡渗流参数的选取及稳定性判别。针对带人工切割裂纹的宜昌地区砂岩裂隙渗流开展试验研究,得到如下结论:(1)填充砂粒在没有冲紧密实之前,不但受到轴压的加载路径影响,还受到围压的加载路径影响,其渗流量测量数据是没有可重复性的。经过4次以上围压轴压加卸循环后,渗流数据趋于稳定,具有可重复性。(2)裂隙深度小于2.5cm时,含密实充填物的裂隙渗流量与轴压的关系大致呈线性;裂隙深度达到2.5cm后,两者为非线性关系,这主要是裂隙深度增大导致砂粒位置和结构的改变可能性增大造成。(3)对有充填裂隙岩体,围压影响显著,而对开度较大的无充填的裂隙,围压对渗流量的影响极小,这是因为围压造成的岩体形变量对于开度较大的裂隙过水断面而言量级过小造成。(4)轴压小于0.03MPa或围压小于1MPa时,填充物粒度对渗流量影响呈无序性;轴压大于0.03MPa且围压大于1MPa时,砂粒度越大,对应的渗流量就越大,此时,轴压越大,填充物粒度对渗流量的影响越显著,随着围压的增长,3种不同粒度对应的流量保持的大小关系和相互比例趋于稳定。
In view of the great differences of the seepage law of the fractured rock with or without filling materials, and that most of the seepage fractures in the engineering rock mass are the shear sliding fractures filled with the original rock broken materials, the research of the influence on seepage discharge caused by the factors such as loading paths, axial compression, confining pressure, fracture depth, particle size of original rock fillings etc., has important reference value to the selection of the seepage parameters and the stability discrimination of the rock slope. With the experimental study of the fracture seepage aiming at the sandstone with artificial cutting fractures in Yichang area, some conclusions are drawn as follows： （1） The metrical data of seepage discharge do not have the repeatability before filling sand grains are tightly. It is not only under the influence of the axial pressure loading path, but also under the influence of the confining pressure way. The seepage velocity tends to be stable with repeatability after more than four times of loading and unloading cycles under axial pressure and confining pressure. （2） There is a linear relationship between the axial pressure and the seepage discharge of large opening fracture with solid fillings when the fracture depth is less than 2.5 cm, then after the fracture depth reaches 2.5 cm, the relationship becomes nonlinear. And it is mainly because that the increasing fracture depth induces the increment of the change possibility of the sand position and structure. （3） To the fractured rock mass with fillings, the influence of the confining pressure is significant, but to the big opening fracture without fillings, the influence of the confining pressure on the seepage discharge is little, it is because the order of the shape variable of rock mass caused by the confining pressure is too small compared to the wetted cross-section of the fracture with big opening. （4） When axial pressure is less than 0.03 MPa or confining pressure i
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2010年第2期366-374,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(90610029)
三峡大学科学基金资助项目(KJ2009B061
KJ2009A033)
关键词
岩石力学
原岩充填物
剪切滑移裂隙
砂岩
裂隙渗流
加载路径
粒径
rock mechanics
original rock fillings
shear sliding fractures
sandstone
fracture seepage
loading path
particle size
