本文選題：單點(diǎn)沖擊荷載 + 紅砂巖土��； 參考：《江西理工大學(xué)》2013年碩士論文

【摘要】：紅砂巖在我國分布廣泛,紅砂巖土被大量用于回填地基,強(qiáng)夯等沖擊荷載加固地基效果顯著,但關(guān)于強(qiáng)夯等沖擊荷載加固紅砂巖填土地基方面的研究相對滯后。本文針對紅砂巖土,利用改裝的擊實(shí)儀進(jìn)行室內(nèi)沖擊試驗(yàn),研究單點(diǎn)沖擊荷載在紅砂巖土中的作用效應(yīng)；通過現(xiàn)場強(qiáng)夯試驗(yàn)研究地基加固效果,得到如下主要結(jié)論： (1)強(qiáng)夯對紅砂巖填土地基的加固作用效應(yīng)是壓縮波的推拉作用、剪切波的剪脹或剪縮作用和瑞利波的翻滾作用的綜合結(jié)果。 (2)在沖擊荷載作用下,紅砂巖土粘聚力的增長幅度遠(yuǎn)大于內(nèi)摩擦角的增長幅度；紅砂·巖土的空間擊實(shí)效果,坑底土體好于坑周土體,輕錘高落好于重錘低落。 (3)在沖擊荷載作用下,夯坑的累計(jì)夯沉量隨夯擊數(shù)增加的變化規(guī)律可分為增速較快和增速較慢兩個(gè)階段；坑底土體以豎向位移為主,坑周土體以水平位移為主；隨著單擊夯擊能的增加(15、20、25、30N·m),使土體產(chǎn)生顯著位移的作用范圍,在水平方向從3.0～3.5cm變化至6.0～6.5cm,在豎直方向從9.0～10.0cm變化至18.0～19.0cm；隨著系統(tǒng)平衡狀態(tài)程度的不斷提高,夯擊能用于提高系統(tǒng)平衡狀態(tài)程度的能量減少,能量利用率降低,系統(tǒng)趨于某個(gè)與夯擊能對應(yīng)的相對穩(wěn)定的平衡狀態(tài),不同的夯擊能對應(yīng)著不同的穩(wěn)定平衡狀態(tài)。 (4)以本文的強(qiáng)夯施工參數(shù)加固紅砂巖填土地基效果良好,達(dá)到了工程的設(shè)計(jì)要求。 本文的研究成果對豐富強(qiáng)夯等沖擊荷載加固地基理論,指導(dǎo)沖擊荷載加固地基實(shí)踐,提高受沖擊荷載作用的地基基礎(chǔ)設(shè)計(jì)水平等有較大意義。
[Abstract]:Red sandstone is widely distributed in China, red sandstone soil is widely used in backfill foundation, dynamic compaction and other impact loads to strengthen the foundation effect is remarkable, but the research on strengthening red sandstone fill foundation with impact load such as dynamic compaction is relatively lagging behind. In this paper, the effect of single point impact load on red sandstone soil is studied by indoor impact test with modified compaction instrument, and the effect of foundation reinforcement is studied by field dynamic compaction test. The main conclusions are as follows: (1) the reinforcement effect of dynamic compaction on the red sandstone fill foundation is the push-pull effect of compression wave. The comprehensive result of shear expansion or shearing shrinkage of shear wave and rolling action of Rayleigh wave. Under impact load, the increase of cohesive force of red sandstone soil is much larger than that of internal friction angle. The space compaction effect of red sand rock is that the bottom soil is better than the surrounding soil, and the light hammer falls better than the heavy hammer. The variation law of the cumulative compaction volume with the increase of the number of compaction can be divided into two stages: the vertical displacement in the bottom of the pit and the horizontal displacement in the surrounding soil. With the increase of click-ramming energy, the range of significant displacement of soil changes from 3.0~3.5cm to 6.0cm in horizontal direction and from 9.0~10.0cm to 19.0cmin vertical direction. Tamping can be used to improve the energy reduction of the system equilibrium state, the energy utilization ratio is reduced, and the system tends to a relatively stable equilibrium state corresponding to the tamping energy. Different tamping energy corresponds to different stable equilibrium state. The research results of this paper have great significance for enriching the theory of dynamic compaction and other impact load strengthening foundation, guiding the practice of impact load strengthening foundation and improving the design level of foundation subjected to impact load.
【學(xué)位授予單位】：江西理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2013
【分類號】：TU472.31

【共引文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 呂爽;利用夯擊地面變形估算夯后地基沉降及夯后地基性狀的研究[D];江西理工大學(xué);2013年

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本文編號：2031120