本文關(guān)鍵詞： 高填方 壓實(shí)土 加載速率 固結(jié)蠕變 工后沉降　出處：《湘潭大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：西部大開發(fā)戰(zhàn)略已經(jīng)進(jìn)入了加速發(fā)展階段，交通系統(tǒng)日益完善，在這些地區(qū)建設(shè)高速公路，無法避免地遇到越來越多的高填方路堤。高填方路堤的路基質(zhì)量與壓實(shí)填土的工程性質(zhì)密切相關(guān)，其工后沉降問題也已成為公路交通工程領(lǐng)域的重要研究課題之一，但現(xiàn)階段對(duì)高填方路堤工后沉降預(yù)測(cè)方法的研究還需要進(jìn)一步補(bǔ)充和完善。 本文以人工制備的路堤壓實(shí)土為主要對(duì)象，開展了壓實(shí)土的率敏性和一維固結(jié)蠕變?cè)囼?yàn)，旨在分析壓實(shí)土的流變力學(xué)特性；由此流變特性結(jié)合有限元軟件ABAQUS對(duì)高填方路堤進(jìn)行數(shù)值模擬，力求為高填方路堤工后沉降預(yù)測(cè)的研究提供參考，主要內(nèi)容包括： （1）基于室內(nèi)常規(guī)土工試驗(yàn)的規(guī)程，進(jìn)行了壓實(shí)土在不同圍壓下的三軸CD率敏性試驗(yàn)，結(jié)果表明，壓實(shí)土的加載速率力學(xué)效應(yīng)很顯著，其CD峰值強(qiáng)度隨加載速率的增大，呈現(xiàn)先減小后增大的趨勢(shì)，具有臨界速率現(xiàn)象；壓實(shí)土在低圍壓下的應(yīng)力應(yīng)變曲線呈明顯的應(yīng)變軟化，表明土體壓實(shí)過程中積累了一定的應(yīng)力歷史，，為重塑超固結(jié)土，并隨著壓實(shí)度的提高，應(yīng)變軟化現(xiàn)象增強(qiáng)。 （2）對(duì)不同加載下的壓實(shí)土進(jìn)行了一維固結(jié)蠕變?cè)囼?yàn)，分析了壓實(shí)土的應(yīng)變與時(shí)間、孔隙比與時(shí)間對(duì)數(shù)等關(guān)系曲線，發(fā)現(xiàn)壓實(shí)土具有明顯的非線性蠕變變形，應(yīng)力水平越高，蠕變現(xiàn)象越顯著。相同條件下，壓實(shí)度越大，土體的結(jié)構(gòu)性強(qiáng)度表現(xiàn)得越明顯，土體的最終累積變形量越小。此外，擬合了壓實(shí)土的對(duì)數(shù)形式蠕變方程和含應(yīng)力影響的冪函數(shù)蠕變模型，表征了壓實(shí)土的應(yīng)力與應(yīng)變關(guān)系，并從微觀角度解釋了壓實(shí)土的蠕變變形機(jī)理。 （3）結(jié)合壓實(shí)土的流變性狀，通過大型有限元軟件ABAQUS對(duì)蘭臨高速公路K5+536處高填方路段建立數(shù)值模型，并進(jìn)行分層填筑模擬，分析高填方路堤沉降變形規(guī)律，計(jì)算結(jié)果與實(shí)測(cè)結(jié)果較吻合，由此可為同類型的高填方路堤沉降規(guī)律研究及工后沉降預(yù)測(cè)提供參考。
[Abstract]:The western development strategy has entered the stage of accelerated development, the traffic system becomes more and more perfect, the highway construction in these areas, the high embankment inevitably encounter more and more closely related. The engineering properties of subgrade compaction quality and high embankment fill, the settlement after construction has become one of the important research topics in the field of traffic engineering but the research on prediction method for the settlement of high fill embankment stage also need to further supplement and improve.
In this paper, the compaction of embankment soil artificially prepared as the main object, the rate sensitivity and one-dimensional consolidation creep tests of compacted soil, to analyze the rheological mechanical properties of compacted soil; the rheological properties of the finite element software ABAQUS to simulate high embankment, and strive for the high embankment settlement prediction research the main contents include reference:
(1) for laboratory routine soil test based on the compacted soil under different confining pressure three axis CD rate sensitivity test, the results show that the loading rate of compacted soil mechanics effect is significant, the CD peak intensity increases with increasing loading rate, decreased first and then increased, with critical rate the phenomenon of soil compaction; under low confining pressure stress strain curve showed that strain softening, soil compaction process and accumulated stress history for remolded overconsolidated soil, and with the increased degree of compaction, strain softening phenomenon is enhanced.
(2) the one-dimensional consolidation creep tests on compacted soil under different loading were analyzed, the strain and the compacted soil, the relationship between pore ratio and time logarithm curve, found that the compacted soil has obvious nonlinear creep deformation, the stress level is higher, the creep phenomenon is more significant. Under the same conditions, the degree of compaction large, the structural strength of soil was more obvious, the final cumulative soil deformation amount is small. In addition, the logarithmic form fitting creep equation of compacted soil and water stress on the power function creep model, characterization of compacted soil stress and strain, and explained the mechanism of creep deformation of compacted soil from the microcosmic point of view.
(3) combined with the rheological properties of compacted soil, the finite element software of ABAQUS on LAN Lin highway at K5+536 high embankment numerical model is established, and layered simulation, analysis of high embankment settlement deformation law. The calculated results agree well with experimental results, which can provide reference for prediction of settlement of high embankment of the same type the study on the settlement of and after work.

【學(xué)位授予單位】：湘潭大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類號(hào)】：U416.1

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本文編號(hào)：1501560