本文選題：膨脹土　切入點(diǎn)：微觀結(jié)構(gòu)　出處：《長(zhǎng)安大學(xué)》2015年博士論文　論文類(lèi)型：學(xué)位論文

【摘要】：膨脹土是膨脹土地區(qū)公路路基塌陷、崩解、隆起等病害的主要原因。膨脹土遇水膨脹、失水收縮后使得膨脹土體產(chǎn)生裂縫,且反復(fù)性較強(qiáng),嚴(yán)重影響了工程建設(shè)的進(jìn)度,加大了膨脹土地區(qū)公路建設(shè)的難度,是公路建設(shè)質(zhì)量和公路運(yùn)行安全的隱患。當(dāng)膨脹土膨脹性較弱時(shí),可在工程建設(shè)中使用,但弱膨脹土分類(lèi)較為粗略,針對(duì)性不強(qiáng),因此,對(duì)弱膨脹土進(jìn)行試驗(yàn)研究,制定弱膨脹土分級(jí)標(biāo)準(zhǔn)、路基填料分級(jí)標(biāo)準(zhǔn)和邊坡坡度標(biāo)準(zhǔn)對(duì)于制定弱膨脹土地區(qū)路基邊坡處治控制標(biāo)準(zhǔn)具有重要意義。通過(guò)系統(tǒng)分析目前國(guó)內(nèi)外相關(guān)研究成果,采用理論研究和試驗(yàn)分析相結(jié)合的方法對(duì)隴南地區(qū)弱膨脹土的細(xì)化分級(jí)標(biāo)準(zhǔn)、采用弱膨脹土作為填料和路塹邊坡坡度控制技術(shù)標(biāo)準(zhǔn)進(jìn)行研究。利用掃描電鏡和XRD試驗(yàn)對(duì)甘肅省隴南地區(qū)弱膨脹土從微觀角度進(jìn)行膨脹性分析,通過(guò)對(duì)膨脹土的微觀形態(tài)和礦物成分的定性和定量的研究,揭示了弱膨脹土具有膨脹性的內(nèi)在機(jī)理,為分析弱膨脹土的工程特性提供依據(jù)。通過(guò)膨脹土土工試驗(yàn),分析了甘肅省隴南地區(qū)弱膨脹土的基本性質(zhì),并在無(wú)荷載和有荷載膨脹率試驗(yàn)的基礎(chǔ)上,研究了含水率、干密度等影響因素與膨脹土膨脹性的關(guān)系,并以此推導(dǎo)出弱膨脹土無(wú)荷載和有荷載膨脹率預(yù)估公式,為提出弱膨脹土細(xì)化分類(lèi)標(biāo)準(zhǔn)和弱膨脹土填料填筑分級(jí)標(biāo)準(zhǔn)和路塹邊坡坡度控制標(biāo)準(zhǔn)奠定基礎(chǔ)。對(duì)膨脹土膨脹性判別指標(biāo)進(jìn)行分析,并結(jié)合甘肅省隴南地區(qū)弱膨脹土的膨脹性能,將膨脹土膨脹性分類(lèi)指標(biāo)進(jìn)行細(xì)化,制定弱膨脹土膨脹性分級(jí)指標(biāo)。在膨脹土膨脹性試驗(yàn)的基礎(chǔ)上,對(duì)弱膨脹土膨脹性分級(jí)指標(biāo)進(jìn)行判別對(duì)比分析。在膨脹土膨脹力試驗(yàn)的基礎(chǔ)上,基于膨脹土上覆荷載壓力與膨脹力平衡的思想,制定弱膨脹土作為填料時(shí)的上覆路基厚度標(biāo)準(zhǔn)。并采用FLAC-3D軟件對(duì)弱膨脹土填料填筑標(biāo)準(zhǔn)進(jìn)行驗(yàn)證。根據(jù)弱膨脹土分級(jí)標(biāo)準(zhǔn)對(duì)弱膨脹土邊坡坡度進(jìn)行分級(jí)。并制定十天高速公路甘肅段膨脹土分布路段處治措施。
[Abstract]:Expansive soil is the main cause of road subgrade collapse, collapse, uplift and other diseases in expansive soil area. The difficulty of highway construction in expansive soil area is increased, which is the hidden danger of highway construction quality and highway running safety. When expansive soil is weak, it can be used in engineering construction, but the classification of weak expansive soil is rough and the pertinence is not strong. The weak expansive soil was tested and studied, and the classification standard of weak expansive soil was established. The classification standard of subgrade filler and slope gradient standard are of great significance to establish the control standard of subgrade slope treatment in weakly expansive soil area. The method of combining theoretical research with experimental analysis is used to classify the weak expansive soil in Longnan area. Using weakly expansive soil as filler and slope control standard of cutting slope, the swelling property of weakly expansive soil in Longnan area of Gansu Province was analyzed by scanning electron microscope (SEM) and XRD test. Through the qualitative and quantitative study on the microscopic morphology and mineral composition of expansive soil, the inherent mechanism of dilatancy of weakly expansive soil is revealed, which provides a basis for analyzing the engineering characteristics of weakly expansive soil. The basic properties of weakly expansive soil in Longnan area of Gansu Province are analyzed. On the basis of the test of no load and load expansion rate, the relationship between water content, dry density and swelling property of expansive soil is studied. Based on this, the formulas for predicting the expansion rate of weakly expansive soil without load and load are derived. It lays a foundation for the classification standard of weak expansive soil, the standard for filling and grading of weak expansive soil and the control standard for slope gradient of cutting slope. The discriminant indexes of expansive soil are analyzed. Combining with the expansive property of weak expansive soil in Longnan area of Gansu Province, the expansive property classification index of expansive soil is refined, and the classification index of expansive property of weak expansive soil is established. Based on the test of expansive force of expansive soil and the thought of equilibrium of overburden pressure and expansion force on expansive soil, the classification index of dilatancy of weakly expansive soil is analyzed. The overlying subgrade thickness standard when weak expansive soil is used as filler is formulated, and the filling standard of weak expansive soil is verified by FLAC-3D software. According to the classification standard of weak expansive soil, the slope of weak expansive soil slope is classified, and the slope of weak expansive soil slope is determined. Treatment measures of expansive soil distribution section in Gansu section of ten-day expressway.
【學(xué)位授予單位】：長(zhǎng)安大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：U416.1

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本文編號(hào)：1570892