本文關(guān)鍵詞：隧道裂隙巖體滲透系數(shù)試驗(yàn)研究　出處：《石家莊鐵道大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 裂隙巖體 單裂隙 垂直交叉裂隙 滲流與應(yīng)力耦合 滲透系數(shù) 三軸滲透試驗(yàn)

【摘要】：采用巴西劈裂生成單裂隙、垂直交叉裂隙,模擬隧道內(nèi)灰?guī)r的單一、交叉張性裂隙,在巖石多功能試驗(yàn)機(jī)上開(kāi)展單裂隙、垂直交叉裂隙圍巖滲流與應(yīng)力耦合、裂隙巖樣滲透系數(shù)與裂隙寬度、面積、粗糙度系數(shù)關(guān)系規(guī)律三軸試驗(yàn)研究,主要研究了試件軸壓、圍壓和水壓對(duì)裂隙滲透系數(shù)的影響;采用數(shù)值擬合方法給出了不同應(yīng)力條件下單裂隙、垂直交叉裂隙滲透系數(shù)計(jì)算公式及裂隙滲透系數(shù)與裂隙特征的關(guān)系曲線,為裂隙圍巖隧道滲流場(chǎng)特征分析奠定基礎(chǔ),試驗(yàn)主要成果:(1)試驗(yàn)中采用了裂隙面圖像處理的方法(Matlab圖像分析-AutoCAD圖像處理)對(duì)裂隙寬度測(cè)量方法進(jìn)行了改進(jìn),取得了較為精確的裂隙寬度試驗(yàn)數(shù)據(jù)。(2)試驗(yàn)中采用了自制縱剖儀裂隙圖像描繪,并與標(biāo)準(zhǔn)粗糙度區(qū)相對(duì)比的方法對(duì)裂隙粗糙度系數(shù)的測(cè)量方法進(jìn)行了改進(jìn)。(3)在軸向應(yīng)力、水壓力恒定的情況下圍壓增大,單裂隙的滲透系數(shù)與圍壓滿足乘冪關(guān)系,而垂直交叉裂隙的滲透系數(shù)與圍壓滿足對(duì)數(shù)關(guān)系。(4)單裂隙和垂直交叉裂隙,在圍壓、水壓力恒定時(shí),增大軸向應(yīng)力,滲透系數(shù)均與軸向應(yīng)力呈正比線性關(guān)系;軸向應(yīng)力增加導(dǎo)致的巖樣徑向鼓效應(yīng)是影響裂隙滲透系數(shù)的主導(dǎo)因素;在圍壓、軸向應(yīng)力恒定時(shí),裂隙滲透系數(shù)與水壓力呈正比線性關(guān)系。裂隙開(kāi)度隨著圍壓的增加而減小,但圍壓增加到一定程度后,會(huì)逐漸趨于穩(wěn)定,這是因?yàn)閲鷫翰荒苁沽严锻耆]合,裂隙滲流依然存在,且滲透系數(shù)遠(yuǎn)大于無(wú)裂隙巖體的滲透系數(shù)。(5)單裂隙或垂直交叉裂隙的滲透系數(shù)與裂隙面積成n次方關(guān)系。(6)在單裂隙粗糙度系數(shù)9,垂直交叉粗糙度系數(shù)數(shù)10時(shí),滲透系數(shù)與裂隙面積的關(guān)系由二次函數(shù)過(guò)渡到三次函數(shù)。(7)數(shù)值擬合出了滲透系數(shù)與單裂隙粗糙度系數(shù)(≤9)及端面面積之間的函數(shù)關(guān)系式。
[Abstract]:The single fracture and vertical cross fissure in Brazil are adopted to simulate the single and cross tensile fracture of limestone in tunnel. The single fracture is developed on the multifunctional rock testing machine and the seepage and stress coupling of the surrounding rock with vertical cross fracture is carried out. The relationship between fracture permeability coefficient and fracture width, area and roughness coefficient is studied by triaxial test. The influence of axial pressure, confining pressure and water pressure on fracture permeability coefficient is studied. The numerical fitting method is used to give the formula for calculating the permeability coefficient of vertical cross fractures and the relationship between fracture permeability coefficient and fracture characteristics under different stress conditions. It lays a foundation for the analysis of seepage field characteristics of fractured surrounding rock tunnel. In the experiment, the image processing method of fracture surface is used to improve the measuring method of crack width by using Matlab image analysis and AutoCAD image processing. A more accurate fracture width test data is obtained. The self-made longitudinal profile instrument is used to depict the fracture image in the test. The measurement method of fracture roughness coefficient is improved by comparing with the method of standard roughness zone. The confining pressure increases under the condition of constant axial stress and constant water pressure. The permeability coefficient and confining pressure of single fracture satisfy the power relation, while the permeability coefficient and confining pressure of vertical cross fracture satisfy logarithmic relation. 4) when the confining pressure and water pressure are constant, the permeability coefficient of single fracture and vertical cross fissure satisfies logarithmic relation. When the axial stress is increased, the permeability coefficient is proportional to the axial stress. The radial bulging effect of rock samples caused by the increase of axial stress is the dominant factor affecting the permeability coefficient of fractures. When the confining pressure and axial stress are constant, the fracture permeability coefficient is proportional to the water pressure. The crack opening decreases with the increase of confining pressure, but when the confining pressure increases to a certain extent, it tends to stabilize gradually. This is because the confining pressure can not make the fracture complete closure, fracture seepage still exists. And the permeability coefficient is much larger than the permeability coefficient of rock mass without fracture. 5) the relation between permeability coefficient of single crack or vertical cross crack and fracture area is n ~ (th). (6) the roughness coefficient of single fracture is 9. The vertical cross roughness coefficient is 10:00. The relationship between permeability coefficient and fracture area is transformed from quadratic function to cubic function. The functional relationship between permeability coefficient and roughness coefficient of single fracture (鈮，

本文編號(hào)：1432936