本文選題：全風(fēng)化花崗巖 + 三軸試驗(yàn)��； 參考：《華南理工大學(xué)》2015年碩士論文

【摘要】：花崗巖在我國(guó)東南部的分布范圍非常廣泛,由其風(fēng)化而來(lái)的全風(fēng)化花崗巖,有著特殊的性質(zhì),且在工程上經(jīng)常遇到,需要對(duì)全風(fēng)化花崗巖各項(xiàng)物理力學(xué)性質(zhì)有著充分的認(rèn)識(shí),才能避免工程事故的發(fā)生。本文針對(duì)深圳某基坑的全風(fēng)化花崗巖進(jìn)行了剪切特性方面的研究,對(duì)其原狀土和重塑土進(jìn)行不同圍壓下的固結(jié)排水和固結(jié)不排水試驗(yàn),討論其應(yīng)力-應(yīng)變關(guān)系、剪切破壞特征,基于“結(jié)構(gòu)貢獻(xiàn)率”分析受荷過(guò)程中結(jié)構(gòu)性的變化規(guī)律,并結(jié)合本課題組對(duì)花崗巖殘積土的研究成果,對(duì)比分析全風(fēng)化花崗巖和花崗巖殘積土物理力學(xué)性質(zhì)的差異。主要的研究成果如下:1.本文研究的全風(fēng)化巖孔隙比較大,天然含水率不高,粗顆粒含量較高,屬于含砂的中液限粘質(zhì)土(水電部SD128-84分類法)或粉粘土質(zhì)砂土(吳能森綜合分類法)。2.從固結(jié)排水和固結(jié)不排水三軸試驗(yàn)得到:(1)原狀全風(fēng)化花崗巖具有較強(qiáng)的結(jié)構(gòu)性,但隨著圍壓的增大,在固結(jié)壓縮階段結(jié)構(gòu)性的作用逐漸被削弱。(2)結(jié)構(gòu)性的存在使原狀土的粘聚力高于重塑土,對(duì)內(nèi)摩擦角影響不大。(3)原狀樣沒(méi)有出現(xiàn)單一明顯的剪切帶,而是呈現(xiàn)出復(fù)雜的破壞形態(tài),土樣表面凹凸不平;而重塑土樣均呈現(xiàn)出較明顯的光順鼓狀破壞。3.基于“結(jié)構(gòu)貢獻(xiàn)率”得到原狀土在固結(jié)作用和剪切過(guò)程中結(jié)構(gòu)性的變化規(guī)律:(1)原狀土的結(jié)構(gòu)性將隨固結(jié)壓力增大而降低直至完全消失。(2)原狀結(jié)構(gòu)性在剪切過(guò)程中經(jīng)歷了從逐漸發(fā)揮到逐漸損傷的過(guò)程。以峰值結(jié)構(gòu)貢獻(xiàn)率來(lái)衡量土體的結(jié)構(gòu)性大小。(3)以“結(jié)構(gòu)貢獻(xiàn)率”曲線下降起始點(diǎn)作為應(yīng)變局部化開(kāi)始產(chǎn)生的標(biāo)志,圍壓越大,應(yīng)變局部化越早發(fā)生。(4)不排水條件下土體結(jié)構(gòu)的剪切破壞速率相對(duì)于排水條件下有一定的減緩,同時(shí)有效應(yīng)力的減小也削弱了其結(jié)構(gòu)性的發(fā)揮。4.對(duì)比全風(fēng)化花崗巖和花崗巖殘積土得到:(1)全風(fēng)化巖的平均含水量、孔隙比及其細(xì)粒部分的液限和塑性指數(shù)都比殘積土小,粗顆粒含量明顯多于殘積土。(2)基于“結(jié)構(gòu)貢獻(xiàn)率”的對(duì)比,可知全風(fēng)化巖的結(jié)構(gòu)性強(qiáng)于殘積土。(3)同一圍壓下,原狀全風(fēng)化巖比殘積土表現(xiàn)出更高的強(qiáng)度和剪切模量。對(duì)于重塑土,全風(fēng)化巖排水強(qiáng)度高于殘積土,但在不排水強(qiáng)度低于重塑殘積土。(4)土體中粗細(xì)顆粒的含量、孔隙比、圍壓和排水條件對(duì)土體的破壞形態(tài)有較大影響。(5)摻砂對(duì)本身細(xì)顆粒含量較多的花崗巖殘積土的破壞形態(tài)影響較大,而對(duì)于本身粗顆粒含量較多的全風(fēng)化花崗巖,則影響較小。
[Abstract]:The granite is widely distributed in the southeast of China. The fully weathered granite from the weathered granite has special properties and is often encountered in engineering, so it is necessary to have a full understanding of the physical and mechanical properties of the weathered granite. In order to avoid the occurrence of engineering accidents. In this paper, the shear characteristics of fully weathered granite in a foundation pit in Shenzhen are studied. The consolidation and undrained tests of undisturbed soil and remolded soil under different confining pressures are carried out, and the stress-strain relationship and shear failure characteristics are discussed. Based on the "structural contribution rate" analysis of the structural changes in the process of loading, and combined with the research results of our group on granite residual soil, the physical and mechanical properties of fully weathered granite and granite residual soil are compared and analyzed. The main research results are as follows: 1: 1. The total weathered rock studied in this paper has relatively large porosity, low natural moisture content and high coarse particle content. It belongs to medium liquid limit clay soil containing sand (SD128-84 classification of Ministry of Water and electricity) or silty clay sandy soil (Wu Nenson comprehensive classification method). From the triaxial tests of consolidated drainage and consolidation undrained, it is found that the intact fully weathered granite has a strong structure, but with the increase of confining pressure, During the consolidation and compression stage, the effect of structural structure was gradually weakened. 2) the cohesive force of undisturbed soil was higher than that of remolded soil, but had little effect on the internal friction angle. The surface of the soil samples is uneven, while the reconstructed soil samples show obvious smooth and drum damage. 3. Based on the "contribution rate of structure", the structural changes of undisturbed soil during consolidation and shear process are obtained. (1) the structure of undisturbed soil decreases with the increase of consolidation pressure, and then disappears completely. 2) during shear process, the structure of undisturbed soil decreases. Has experienced the process from gradually exertion to gradually injures. The structural size of soil is measured by the peak structural contribution rate. (3) the decreasing starting point of the "structural contribution rate" curve is taken as the symbol of the beginning of strain localization, and the larger the confining pressure, the greater the confining pressure is. The earlier strain localization occurs. (4) the shear failure rate of soil structure under undrained condition is slower than that under drainage condition, and the decrease of effective stress also weakens its structural exertion. Comparing fully weathered granite and granite residual soil, the average water content, porosity ratio and the liquid limit and plastic index of the fine grain part of the weathered rock are smaller than those of the residual soil. Based on the comparison of "structural contribution rate", it can be concluded that the structure of total weathered rock is stronger than that of residual soil. 3) under the same confining pressure, the strength and shear modulus of undisturbed weathered rock are higher than that of residual soil. For remolded soil, the drainage strength of total weathered rock is higher than that of residual soil, but the undrained strength is lower than that of remolded residual soil. Confining pressure and drainage condition have great influence on the failure form of soil mass. (5) Sand admixture has a great influence on the failure form of granite residual soil with more fine grain content, while it has less effect on the total weathered granite with more coarse grain content.
【學(xué)位授予單位】：華南理工大學(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 王清,唐大雄,張慶云,趙繼增;中國(guó)東部花崗巖殘積土物質(zhì)成分和結(jié)構(gòu)特征的研究[J];長(zhǎng)春地質(zhì)學(xué)院學(xué)報(bào);1991年01期

2 雷華陽(yáng),肖樹(shù)芳;軟土結(jié)構(gòu)性的試驗(yàn)研究及其對(duì)工程特性的影響[J];吉林大學(xué)學(xué)報(bào)(地球科學(xué)版);2004年01期

3 王清,王鳳艷,肖樹(shù)芳;土微觀結(jié)構(gòu)特征的定量研究及其在工程中的應(yīng)用[J];成都理工學(xué)院學(xué)報(bào);2001年02期

4 張啟輝,李蓓,趙錫宏,董建國(guó);上海粘性土剪切帶形成的平面應(yīng)變?cè)囼?yàn)研究[J];大壩觀測(cè)與土工測(cè)試;2000年05期

5 吳義祥;工程粘性土微觀結(jié)構(gòu)的定量評(píng)價(jià)[J];中國(guó)地質(zhì)科學(xué)院院報(bào);1991年02期

6 曲永新,吳宏偉,尚彥軍;華南花崗巖殘積土紅土化程度的地帶性與香港該類土不發(fā)育的原因[J];工程地質(zhì)學(xué)報(bào);2000年01期

7 趙建軍,王思敬,尚彥軍,岳中琦;香港全風(fēng)化花崗巖飽和直剪試驗(yàn)中的剪脹問(wèn)題[J];工程地質(zhì)學(xué)報(bào);2005年01期

8 吳宏偉,尚彥軍,曲永新,Ｐ．Ｍ．Ｂａｎｎａ;香港花崗巖風(fēng)化分級(jí)化學(xué)指標(biāo)體系與風(fēng)化殼分帶[J];工程地質(zhì)學(xué)報(bào);1999年02期

9 熊傳祥,周建安,龔曉南,簡(jiǎn)文彬;軟土結(jié)構(gòu)性試驗(yàn)研究[J];工業(yè)建筑;2002年03期

10 趙建軍,王思敬,尚彥軍,岳中琦;香港全風(fēng)化花崗巖的固結(jié)特性[J];河海大學(xué)學(xué)報(bào)(自然科學(xué)版);2005年01期

相關(guān)博士學(xué)位論文 前9條

1 龐小朝;深圳原狀全風(fēng)化花崗巖的試驗(yàn)和本構(gòu)模型研究[D];中國(guó)鐵道科學(xué)研究院;2011年

2 王助貧;三軸試驗(yàn)土樣變形的數(shù)字圖像測(cè)量方法及其應(yīng)用[D];大連理工大學(xué);2002年

3 夏旺民;黃土彈塑性損傷本構(gòu)模型及工程應(yīng)用研究[D];西安理工大學(xué);2005年

4 吳能森;結(jié)構(gòu)性花崗巖殘積土的特性及工程問(wèn)題研究[D];南京林業(yè)大學(xué);2005年

5 房后國(guó);深圳灣結(jié)構(gòu)性淤泥土固結(jié)機(jī)理及模型研究[D];吉林大學(xué);2005年

6 李志勇;公路路基動(dòng)強(qiáng)度設(shè)計(jì)方法及其在全風(fēng)化花崗巖路基中的應(yīng)用研究[D];西南交通大學(xué);2005年

7 葉朝漢;軟土剪切帶試驗(yàn)及其應(yīng)用的研究[D];同濟(jì)大學(xué);2007年

8 何群;客運(yùn)專線全風(fēng)化花崗巖改良土隧—隧過(guò)渡段動(dòng)力特性及穩(wěn)定性研究[D];中南大學(xué);2007年

9 馮志焱;非飽和黃土的結(jié)構(gòu)性定量化參數(shù)與結(jié)構(gòu)性本構(gòu)關(guān)系研究[D];西安理工大學(xué);2008年

相關(guān)碩士學(xué)位論文 前6條

1 蔣向陽(yáng);全風(fēng)化花崗巖道路邊坡工程設(shè)計(jì)研究[D];西南交通大學(xué);2005年

2 馬宏劍;湛江地區(qū)全風(fēng)化花崗巖路用特性與地理信息系統(tǒng)應(yīng)用研究[D];東南大學(xué);2006年

3 梁棟;全風(fēng)化花崗巖地基沉降變形特性試驗(yàn)研究[D];西南交通大學(xué);2010年

4 曾朋;花崗巖殘積土的壓實(shí)特性及崩解特性研究[D];華南理工大學(xué);2012年

5 肖晶晶;花崗巖殘積土的結(jié)構(gòu)性及應(yīng)力應(yīng)變關(guān)系試驗(yàn)研究[D];華南理工大學(xué);2012年

6 袁文熠;花崗巖殘積土三軸試驗(yàn)應(yīng)變局部化特征研究[D];華南理工大學(xué);2013年

，

本文編號(hào)：1908902