|摘要: ||順向坡的特性是具順層的結構，且因受到層間之錯動(bedding shear)常存在層間摩擦剪動的「泥縫(seam)」，其被蹍碎後的顆粒常比上下母岩更細微化或成黏土等級，因此其摩擦角常又比原來母岩更低、且更易吸水。因此，本文主要以兩片粗糙花崗岩面對夾層砂顆粒材料進行磨碎試驗，目的是在探討砂土顆粒材料受剪後顆粒大小、形狀、級配與顆粒間距離分佈特性之改變與產生細粒料(小於#200)的量變化。|
結果得致下列主要結論：(1) 本文自製的簡易型梳尺儀可用以量測岩面粗糙度，以利計算JRC。係採用108根直徑0.88 mm測釘排列於兩片鐵片中，再置放於花崗岩粗糙面上量測高程，量測後拍照各測釘高度投影剖面匯入繪圖軟體，標定基準線，可連接108個高程點即可繪出岩面剖面，並計算其JRC值。文中亦使用手機結合新式顯微鏡，可將手機顯微鏡應用於觀察砂顆粒細粒化後之形狀。 (2) 施加正向應力階段，顆粒就會破碎使粒徑變小，但粒徑尚皆大於#200尺寸；粒徑小於#200的細粒料則是在受剪後隨著剪動位移才變多。因在層間受剪破碎愈來愈小，故其整體抗剪摩擦角將漸低。 (3) 夾層顆粒於低正應力(
Consequent slope is a smooth layer structure and because by the bedding shear between the layers, there is often present interlayer friction shear move called "seam", which the particle broken after often than upper and lower rock more or a level of fine clay, so often surpasses the original rock friction angle lower and more absorbent.Therefore, this paper mainly two rough granite face sandwich sand particulate material grinding test, the purpose is to explore the distribution characteristics of sand particulate material change of distance between the after shear particle size, shape, gradation and fine particles produced by the amount of material (less than #200) change.
The results obtained to the following main conclusions:(1) Simple homemade comb foot instrument used to measure the surface roughness of the rock, in order to facilitate the calculation JRC. 108 diameter 0.88 mm using soil nails arranged in two iron sheet, and then placed in a granite surface roughness measuring height, measured after each soil nail pictures sectional height of the projector into graphics software, calibration baseline, 108 soil nails can be connected elevation points to draw a cross-section of rock face, and calculate the value of JRC. The paper also use the new handsets combined with the microscope, the microscope can phone the shape of fine sand particles are applied after the observation.(2) Stress is applied to the positive phase, the particles will be broken so that the particle size becomes smaller, but still larger than in particle size # 200; fine aggregate size of less than #200 is in the shear with only dynamic displacement increases. Because the interlayer shear crushing smaller and smaller, so the overall shear angle of friction will gradually lower.(3) Interlayer particles under low normal stress (