本文關(guān)鍵詞：低溫下巖土體非整數(shù)階元件組合蠕變模型研究　出處：《安徽理工大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 凍結(jié)巖土 本構(gòu)關(guān)系 泥巖 蠕變 分?jǐn)?shù)階導(dǎo)數(shù) 西原蠕變

【摘要】：不同的巖土體在不同的環(huán)境下,其蠕變特性不盡相同,很多學(xué)者已經(jīng)在軟巖土和巖石領(lǐng)域做了大量的土工力學(xué)試驗(yàn)和總結(jié),例如黏土、黃土等,多集中在巖土的抗壓穩(wěn)定性和流變性方面,運(yùn)用的方法和理論也是千差萬(wàn)別,但受制于理論模型的選用及優(yōu)化處理的復(fù)雜性,在凍結(jié)泥巖、硅藻泥巖等的蠕變研究方面,特別是模型的構(gòu)造及參數(shù)的優(yōu)化處理上還存在著一定的研究余地,正因于此,為了得到一種能夠更加精確描述東北地區(qū)深層凍結(jié)巖土體的蠕變特性規(guī)律的西原蠕變模型,特選取了該地區(qū)具有代表性的巖土試樣——泥巖、硅藻泥巖作為分析對(duì)象,鑒于其在現(xiàn)場(chǎng)復(fù)雜的環(huán)境(主要考慮低溫)及地質(zhì)條件下將會(huì)產(chǎn)生預(yù)想不到的蠕變變形,分析其受溫度、荷載、土質(zhì)類別以及時(shí)間等因子的影響顯得尤為重要。合理的巖土本構(gòu)關(guān)系是應(yīng)該建立在大量的有針對(duì)性的蠕變?cè)囼?yàn)基礎(chǔ)之上,結(jié)合必要的元件模型理論以及引入新的算法和分?jǐn)?shù)階導(dǎo)數(shù)理論,建立特定元件模型來(lái)研究和分析其力學(xué)性質(zhì)。利用自行研制的凍土試驗(yàn)機(jī)對(duì)試樣在三種溫度水平(-5℃、-10℃、-15℃)和三種加載系數(shù)(0.3、O.5、0.7)下展開(kāi)強(qiáng)度和蠕變?cè)囼?yàn),分析其與各種環(huán)境因子的影響并進(jìn)行相應(yīng)蠕變模型的擬合比較,進(jìn)而得到適用的模型參數(shù)。以整數(shù)階西原蠕變模型為基礎(chǔ),’選取改進(jìn)的模擬退火優(yōu)化算法進(jìn)行優(yōu)化處理,得到分?jǐn)?shù)階西原蠕變模型,該模型的參數(shù)具有易處理的特點(diǎn),形式相對(duì)簡(jiǎn)單,具有一定的統(tǒng)一性。通過(guò)對(duì)比整數(shù)階西原蠕變模型和優(yōu)化后的分?jǐn)?shù)階導(dǎo)數(shù)西原蠕變模型,可以發(fā)現(xiàn)后者在蠕變模擬的全階段都具有很高的相關(guān)性,特別是在模擬曲線的拐點(diǎn)附近。另外,在計(jì)算過(guò)程中需要調(diào)整的參數(shù)也比較少,充分說(shuō)明了分?jǐn)?shù)階導(dǎo)數(shù)西元蠕變模型的合理性,且在現(xiàn)場(chǎng)施工領(lǐng)域具有不可否認(rèn)的蠕變預(yù)測(cè)預(yù)判之工程意義。
[Abstract]:Different rock and soil in different environments, its creep characteristics are different, many scholars have done a large number of geotechnical tests and summary in the field of soft rock and rock, such as clay, loess and so on. Most of them focus on the stability and rheology of rock and soil, and the methods and theories used are different, but they are restricted by the complexity of the selection of theoretical model and the optimization of treatment, so they are frozen mudstone. There is still some room for study on the creep of diatom mudstone, especially on the structure of the model and the optimization of the parameters, which is the reason. In order to obtain a new creep model which can more accurately describe the creep characteristics of deep frozen rock and soil in Northeast China, the representative geotechnical sample-mudstone in this area is selected. In view of the complex environment (mainly considering low temperature) and geological conditions, diatom mudstone will produce unexpected creep deformation, so it is analyzed that it is subjected to temperature and load. The influence of soil type and time is particularly important. A reasonable constitutive relation of rock and soil should be established on the basis of a large number of targeted creep tests. Combined with the necessary component model theory and the introduction of a new algorithm and fractional derivative theory. A specific element model was established to study and analyze the mechanical properties of the samples. The test machine was used to test the samples at three temperatures (-5 鈩，

本文編號(hào)：1387168