本文關(guān)鍵詞：高溫后花崗巖物理力學(xué)性質(zhì)試驗研究　出處：《中國地質(zhì)大學(xué)(北京)》2017年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 高溫花崗巖 裂紋 物理力學(xué)性質(zhì) 溫度 圍壓

【摘要】：高溫巖體地?zé)衢_發(fā)利用、高放核廢料地下深層處置等高溫巖石力學(xué)問題涉及到高溫對巖石的作用。在高溫作用下,巖石的物理性質(zhì)、力學(xué)性質(zhì)、化學(xué)成分都會發(fā)生劇烈變化,因此高溫對巖石物理力學(xué)性質(zhì)的影響規(guī)律近年來成為專家學(xué)者們的研究熱點。花崗巖作為高溫巖石力學(xué)中廣泛遇到的巖石類型,其在高溫作用下物理力學(xué)性質(zhì)的變化規(guī)律受到研究人員的關(guān)注。本文以經(jīng)過不同高溫處理后的花崗巖巖樣為研究對象,觀察了高溫前后花崗巖巖樣外觀變化以及礦物形態(tài)變化,量測了高溫前后花崗巖巖樣物理性質(zhì)(質(zhì)量、體積、密度、縱波波速)變化,得到了高溫對花崗巖物理性質(zhì)的影響規(guī)律。除此之外,我們對不同高溫處理后的花崗巖巖樣進行了單軸與三軸實驗,得到了高溫對花崗巖力學(xué)性質(zhì)(抗壓強度、峰值應(yīng)變、彈性模量、粘聚力、內(nèi)摩擦角)的影響規(guī)律。主要結(jié)論如下:(1)500℃及以下溫度對花崗巖物理力學(xué)性質(zhì)影響較小,600℃開始,溫度對花崗巖影響較大,因此600℃為高溫影響花崗巖物理力學(xué)性質(zhì)的閾值;(2)花崗巖物理性質(zhì)指標(biāo)變化規(guī)律主要是:隨著溫度的升高,花崗巖暗色礦物氧化程度越來越高,巖樣紅棕色逐漸加深、質(zhì)量降低、體積增大,密度減小,縱波波速降低;(3)600℃時光鏡下觀察到礦物表面產(chǎn)生裂紋,并出現(xiàn)蝕變重結(jié)晶現(xiàn)象,800℃時裂紋變寬并發(fā)生貫通,1000℃時礦物發(fā)生熔融重結(jié)晶,裂紋減少,礦物表面變模糊;800℃時花崗巖巖樣表面出現(xiàn)可見裂紋,1000℃時可見裂紋增多;(4)隨著溫度的升高,花崗巖應(yīng)力應(yīng)變曲線壓密階段變長,彈性變形階段變短,屈服階段逐漸變長,花崗巖表現(xiàn)出軟化特性;(5)單軸條件下,隨著溫度上升,花崗巖強度降低,彈性模量降低、峰值應(yīng)變增長;三軸條件下,隨著溫度上升,花崗巖強度變化較小,彈性模量降低,峰值應(yīng)變增長;(6)隨著溫度升高,花崗巖粘聚力降低,內(nèi)摩擦角有稍微上升的趨勢;(7)500℃以下溫度處理后的花崗巖巖樣破壞形式均為剪切破壞,600℃以上溫度處理過的巖樣在圍壓低于15MPa時表現(xiàn)為拉伸破壞,高于15MPa時,轉(zhuǎn)變?yōu)榧羟衅茐?因此15MPa為花崗巖破壞形式轉(zhuǎn)變圍壓。
[Abstract]:The problems of high temperature rock mechanics, such as geothermal exploitation and utilization of high temperature rock mass and deep underground disposal of high radioactive nuclear waste, are related to the effect of high temperature on rock. Under the action of high temperature, the physical properties and mechanical properties of rock are concerned. Chemical composition will change dramatically, so the influence of high temperature on the physical and mechanical properties of rock has become a hot spot of experts and scholars in recent years. Granite is a widely encountered rock type in high temperature rock mechanics. The change of physical and mechanical properties under high temperature has attracted the attention of researchers. In this paper, granite samples after different high temperature treatment are taken as the research object. The physical properties (mass, volume, density, longitudinal wave velocity) of granite samples before and after high temperature were observed. In addition, we have done uniaxial and triaxial experiments on granite samples after different high temperature treatment, and obtained the mechanical properties (compressive strength) of granite treated by high temperature. The effects of peak strain, elastic modulus, cohesion force and angle of internal friction). The main conclusions are as follows: the temperature below 1 鈩，

本文編號：1440475