【摘要】：砒砂巖為陸相碎屑巖系,由于其上覆巖層厚度小,壓力低,造成其成巖程度低,砂粒間膠結(jié)程度差,結(jié)構(gòu)強(qiáng)度低,最大特點(diǎn)是遇水如泥,遇風(fēng)成砂,造成嚴(yán)重的水土流失。近年來,內(nèi)蒙古鄂爾多斯砒砂巖區(qū)水利工程建設(shè)逐年遞增,深入研究砒砂巖的力學(xué)性能顯得刻不容緩；同時(shí),在進(jìn)行滑坡體穩(wěn)定性計(jì)算時(shí),許多滑坡在滑動(dòng)前一般要逐漸發(fā)展形成一個(gè)滑動(dòng)面,此滑動(dòng)面上抗剪強(qiáng)度已由峰值強(qiáng)度降到殘余強(qiáng)度,所以殘余強(qiáng)度也是必須要研究的問題；考慮到含水率對(duì)砒砂巖的影響極為重要且不同粒徑砒砂巖的抗侵蝕能力存在顯著差異。綜合上述,針對(duì)不同粒徑和不同含水率共同作用下砒砂巖重塑土進(jìn)行反復(fù)直剪試驗(yàn),探討了峰值強(qiáng)度和殘余強(qiáng)度的變化規(guī)律。在第一次剪切中,不同粒徑范圍試樣應(yīng)力-應(yīng)變曲線均出現(xiàn)明顯峰值,粒徑范圍為0.5-0.25mm試樣的抗剪強(qiáng)度最低,工程特性最差,較大粒徑范圍試樣的顆粒破碎明顯,在較高含水率作用下,相對(duì)較粗顆粒更易破碎,而細(xì)小顆粒含量隨著含水率降低而增高。不同粒徑范圍試樣的抗剪強(qiáng)度隨著含水率的增大而線性下降,在較低法向應(yīng)力作用下,含水率對(duì)抗剪強(qiáng)度的影響更劇烈；粘聚力和內(nèi)摩擦角均隨含水率的增大而減小,但粘聚力減小的幅度更明顯。三種粒徑范圍下試樣殘余粘聚力隨含水率的增大基本呈線性下降,其中粒徑范圍為0.5-0.25mm試樣突變較明顯。在剪切開始階段,試樣表現(xiàn)出減縮特性,隨著剪切位移的增大,表現(xiàn)出剪脹性。采用R. simon剪脹模型有一定的缺陷,不能描述初始剪縮現(xiàn)象。所以,本文用SAS軟件進(jìn)行回歸分析,得到一個(gè)新的剪脹回歸方程,試驗(yàn)值和擬合值有良好的擬合度。
[Abstract]:The soft sandstone is a continental clastic rock series. Because of its low overlying layer thickness and low pressure, it has low diagenetic degree, poor cementation degree between sand grains and low structural strength. The biggest characteristic is that it meets water such as mud and wind-formed sand, which results in serious soil erosion. In recent years, the construction of water conservancy projects in the Ordos soft rock area of Inner Mongolia has been increasing year by year, so it is urgent to study the mechanical properties of the soft rock in depth, and at the same time, when calculating the stability of the landslide body, Many landslides generally develop into a sliding surface before sliding, and the shear strength on the sliding surface has been reduced from peak strength to residual strength, so the residual strength is also a problem to be studied. Considering the influence of water content on the Pisha sandstone, there are significant differences in the corrosion resistance of different size Pisha sandstone. Based on the above, repeated direct shear tests were carried out for the remolded soil under the combined action of different particle size and different moisture content, and the variation law of peak strength and residual strength was discussed. In the first shear, the stress-strain curves of samples with different particle size range show obvious peak value. The range of particle size is the lowest shear strength of 0.5-0.25mm specimen, and the worst of engineering properties. Under the action of higher water content, relative coarse particles are more easily broken, while the content of fine particles increases with the decrease of water content. The shear strength of samples with different particle size ranges decreases linearly with the increase of moisture content. Under the action of lower normal stress, the effect of water content on shear strength is more intense, and the cohesion and internal friction angle decrease with the increase of moisture content. But the decrease of cohesion is more obvious. The residual cohesion of the samples decreases linearly with the increase of moisture content in the three particle size ranges, in which the 0.5-0.25mm sample mutation is obvious in the particle size range. At the beginning of shearing, the specimen showed the property of reducing shrinkage, and with the increase of the shear displacement, the specimen showed the dilatancy of shear. The R. simon shear expansion model has some defects and can not describe the initial shearing shrinkage. In this paper, a new regression equation of shear expansion is obtained by regression analysis with SAS software, and the test value and fitting value have good fitting degree.
【學(xué)位授予單位】：內(nèi)蒙古農(nóng)業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TU45

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 葉浩;石建省;侯宏冰;石迎春;程彥培;郭嬌;;內(nèi)蒙古南部砒砂巖巖性特征對(duì)重力侵蝕的影響[J];干旱區(qū)研究;2008年03期

2 劉艷;牛國(guó)權(quán);;砒砂巖地區(qū)水土流失影響因素淺析[J];內(nèi)蒙古水利;2012年03期

3 王愿昌;吳永紅;寇權(quán);閔德安;常玉忠;張絨君;;砒砂巖分布范圍界定與類型區(qū)劃分[J];中國(guó)水土保持科學(xué);2007年01期

4 趙國(guó)際;內(nèi)蒙古砒砂巖地區(qū)水土流失規(guī)律研究[J];水土保持研究;2001年04期

5 遲明杰;趙成剛;李小軍;;砂土剪脹機(jī)理的研究[J];土木工程學(xué)報(bào);2009年03期

6 唐政洪,蔡強(qiáng)國(guó),李忠武,趙懷玉;內(nèi)蒙古砒砂巖地區(qū)風(fēng)蝕、水蝕及重力侵蝕交互作用研究[J];水土保持學(xué)報(bào);2001年02期

7 魏汝龍;總應(yīng)力法計(jì)算土壓力的幾個(gè)問題[J];巖土工程學(xué)報(bào);1995年06期

8 陳守義;各向異性線彈性體的剪脹與壓斜[J];巖土力學(xué);1990年01期

9 繆林昌,仲曉晨,殷宗澤;膨脹土的強(qiáng)度與含水量的關(guān)系[J];巖土力學(xué);1999年02期

10 王光進(jìn);楊春和;張超;冒海軍;王偉;;粗粒含量對(duì)散體巖土顆粒破碎及強(qiáng)度特性試驗(yàn)研究[J];巖土力學(xué);2009年12期

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