本文關(guān)鍵詞： 塔木素 粘土巖 力學(xué)特性研究 高放廢物 地質(zhì)處置　出處：《東華理工大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：粘土巖是高放廢物地質(zhì)處置庫的重要候選圍巖之一,內(nèi)蒙古巴音戈壁盆地塔木素地區(qū)是我國高放廢物地質(zhì)處置粘土巖場址的重點篩選區(qū)域,粘土巖的物理性能及力學(xué)特性是評價候選圍巖場址中重要的參數(shù)之一。本文通過試驗研究了巴音戈壁盆地塔木素地區(qū)粘土巖的物理化學(xué)性能及力學(xué)性能,根據(jù)實驗數(shù)據(jù)探討了該粘土巖的力學(xué)特性的產(chǎn)生機(jī)理,分析其產(chǎn)生的原因。主要獲得以下幾點認(rèn)識:(1)塔木素粘土巖宏觀特征上表現(xiàn)為結(jié)構(gòu)致密,巖石固結(jié)程度非常高。巖石主要由粘土礦物、鈉長石、白云石以及方沸石組成,礦物顆粒細(xì)小,分布均勻。(2)通過試驗研究得到塔木素地區(qū)粘土巖的天然含水率為1.11~2.52%、天然塊體密度為2.25~2.65 g/cm3、顆粒密度為2.41~2.72 g/cm3、孔隙率為2.58~6.64%。該粘土巖的吸附性能優(yōu)異,巖土材料的比表面積為10.24~39.78 m2/g之間。該粘土巖的滲透系數(shù)為10-8~10-9 cm/s,滲透率為10-13~10-14 cm2,屬于極微透水的巖土材料。該粘土巖各方面特性滿足高放廢物處置庫的基本要求。(3)塔木素地區(qū)粘土巖具有較高的聲波速度、點荷載強(qiáng)度、抗拉強(qiáng)度和單軸抗壓強(qiáng)度,并且其聲波速度、抗拉強(qiáng)度、單軸抗壓強(qiáng)度均與塊體密度表現(xiàn)出良好的正相關(guān)性。由于粘土巖本身的結(jié)構(gòu)非常致密,其力學(xué)強(qiáng)度的變化趨勢與埋深沒有顯著的相關(guān)性。通過熱—力耦合條件下的三軸試驗,發(fā)現(xiàn)該粘土巖的力學(xué)強(qiáng)度和變形會隨著圍壓的增加而增加,破壞后峰值應(yīng)力迅速下降,并伴有體積的迅速膨脹現(xiàn)象,呈現(xiàn)應(yīng)變軟化特征,巖石中的裂隙屬于非穩(wěn)定破裂傳播,變形屬于脆性破壞的特征;此外由于粘土礦物受到溫度條件的影響,導(dǎo)致該巖石的力學(xué)強(qiáng)度會隨著溫度的升高而下降,并在90℃、30MPa圍壓條件下呈現(xiàn)出明顯的塑性變形特征。(4)通過FLAC 3D模擬塔木素粘土巖在受力后的變性特征,并記錄在加載過程中巖石材料所發(fā)生的位移變化。再與實際試驗中的所記錄的結(jié)果進(jìn)行對比,發(fā)現(xiàn)兩者有類似的變化趨勢,說明摩爾-庫倫本構(gòu)模型及相關(guān)的材料參數(shù)在一定程度上能夠反映該粘土巖的受力后的狀況。(5)綜合對比瑞士Mont Terri高放廢物地質(zhì)處置地下實驗室Opalinus粘土巖和法國高放廢物地質(zhì)處置庫Meuse/Haunt Marn場址Callovo-Oxfordian粘土巖的力學(xué)特性,塔木素地區(qū)粘土巖具有更高的力學(xué)強(qiáng)度、彈性模量和內(nèi)摩擦角。為我國高放廢物地質(zhì)處置庫圍巖的篩選提供了重要的依據(jù)。
[Abstract]:Clay rock is one of the important candidate rock rocks for geological disposal of high-level radioactive waste, and the Tashu area of Bayingobi Basin in Inner Mongolia is the key screening area for the geological disposal of clay rock of high-level radioactive waste in China. The physical and mechanical properties of clay rocks are one of the important parameters in evaluating candidate surrounding rock sites. The physical and chemical properties and mechanical properties of clay rocks in Tashu area of Bayingobi Basin have been studied by experiments in this paper. Based on the experimental data, the mechanism of the mechanical properties of the clay rock is discussed, and the causes are analyzed. The main results are as follows: 1) the macroscopical characteristics of the lignin clay rock of the tower are densified. The rock is mainly composed of clay minerals, albite, dolomite and donites, and the mineral particles are fine. The natural moisture content of clay rock is 1.112.52 and the density of natural block is 2.25 ~ 2.65 g / cm ~ 3. The particle density is 2.41 ~ 2.72 g / cm ~ 3 and the porosity is 2.58 ~ 6.64. The clay rock has excellent adsorption performance. The specific surface area of the rock and soil materials is between 10.24 ~ 39.78 m2 / g and the permeability coefficient of the clay rock is 10-8 ~ (-9) cm/s. The permeability is 10-13 ~ 10 ~ (-14) cm2. The characteristics of the clay rock meet the basic requirements of the high-level radioactive waste repository. The clay rock in the area of the tower lignin has high acoustic velocity and point load strength. The tensile strength and uniaxial compressive strength, and the sound velocity, tensile strength and uniaxial compressive strength all show a good positive correlation with the bulk density. Through triaxial tests under thermal-mechanical coupling conditions, it is found that the mechanical strength and deformation of the clay rock will increase with the increase of confining pressure. After failure, the peak stress decreases rapidly, accompanied by rapid expansion of volume, showing strain-softening characteristics, cracks in the rock belong to the propagation of non-stable fracture, deformation belongs to the characteristics of brittle failure; In addition, due to the influence of temperature on the clay minerals, the mechanical strength of the rock will decrease with the increase of temperature, and the mechanical strength of the rock will decrease at 90 鈩，

本文編號：1448556