本文選題：水泥土　切入點(diǎn)：二次纖維　出處：《中國礦業(yè)大學(xué)》2015年碩士論文

【摘要】：近年來,隨著我國經(jīng)濟(jì)建設(shè)迅速發(fā)展,基礎(chǔ)設(shè)施建設(shè)的規(guī)模越來越大。很多工程不得不在軟土地基上進(jìn)行建設(shè),由于軟土物理力學(xué)性質(zhì)較差,因此需對(duì)軟土地基進(jìn)行人工加固。水泥土用于處理軟土地基取得了良好的效果,且由于其經(jīng)濟(jì)、環(huán)保和易于施工,現(xiàn)已廣泛應(yīng)用于房建、水利和交通等各類工程領(lǐng)域。然而也因早期強(qiáng)度低、后期變形大和韌性差等缺點(diǎn)而受到限制。本文本著發(fā)展“綠色”建材的宗旨,結(jié)合水泥土及其他水泥基材料的改性措施,利用二次纖維和微生物對(duì)水泥土的力學(xué)性能進(jìn)行改善。首先通過兩種改性水泥土的無側(cè)限抗壓強(qiáng)度試驗(yàn),對(duì)應(yīng)力-應(yīng)變曲線、強(qiáng)度、模量及韌性進(jìn)行了研究,分析了二次纖維或微生物和齡期對(duì)水泥土力學(xué)性能的影響。其次,通過微觀結(jié)構(gòu)試驗(yàn),如掃描電子顯微鏡試驗(yàn)和壓汞實(shí)驗(yàn),分析二次纖維或微生物改善水泥土力學(xué)性能的機(jī)理。再次,利用分離式霍普金森壓桿試驗(yàn)裝置進(jìn)行兩種改性水泥土的沖擊壓縮試驗(yàn),并對(duì)比分析兩種改性水泥土的靜態(tài)、動(dòng)態(tài)力學(xué)性能。然后,在損傷力學(xué)理論基礎(chǔ)上,為兩種改性水泥土選擇合適的損傷變量,并通過循環(huán)加-卸載試驗(yàn)揭示了兩種改性水泥土的損傷演化規(guī)律。最后,根據(jù)微生物增強(qiáng)水泥土的室內(nèi)試驗(yàn)結(jié)果,分別對(duì)復(fù)合地基的承載力特征值和加固區(qū)沉降量進(jìn)行計(jì)算。室內(nèi)試驗(yàn)結(jié)果表明:二次纖維可以有效增大水泥土的韌性;水泥土的強(qiáng)度、彈性模量和韌性隨著菌液濃度的增大而增大。與無側(cè)限抗壓強(qiáng)度試驗(yàn)結(jié)果相比,在沖擊荷載下,兩種改性水泥土的強(qiáng)度和彈性模量增大,韌性減小。微生物增強(qiáng)水泥土在復(fù)合地基中的應(yīng)用設(shè)計(jì)表明:隨著菌液濃度的增大,復(fù)合地基承載力特征值增大、加固區(qū)沉降量減小。
[Abstract]:In recent years, with the rapid development of economic construction in China, the scale of infrastructure construction is becoming larger and larger. Many projects have to be built on soft soil foundation, because of the poor physical and mechanical properties of soft soil. Therefore, it is necessary to strengthen the soft ground manually. The cement soil is used to treat the soft foundation with good results, and because of its economy, environmental protection and easy construction, it has been widely used in housing construction. Water conservancy and transportation are all kinds of engineering fields. However, they are also limited by the shortcomings of low early strength, large deformation and poor toughness in the later stage. This paper, in line with the purpose of developing "green" building materials, combines the modification measures of cement, soil and other cement-based materials. The mechanical properties of cement-soil were improved by secondary fiber and microorganism. Firstly, the stress-strain curve, strength, modulus and toughness of two kinds of modified cement-soil were studied by unconfined compressive strength test. The influence of secondary fiber or microorganism and age on the mechanical properties of cement soil was analyzed. Secondly, the microstructure test, such as scanning electron microscope (SEM) and mercury injection test, was used to analyze the effect of secondary fiber or microorganism and age on the mechanical properties of cement soil. The mechanism of improving the mechanical properties of cement soil by secondary fiber or microorganism is analyzed. Thirdly, the impact compression test of two kinds of modified cement soil is carried out by using separate Hopkinson pressure bar test device, and the static state of two kinds of modified cement soil is compared and analyzed. Dynamic mechanical properties. Then, on the basis of damage mechanics theory, the appropriate damage variables are selected for two kinds of modified cement-soil, and the damage evolution laws of two kinds of modified cement-soil are revealed by cyclic load-unloading test. According to the laboratory test results of microorganism reinforced cement soil, the bearing capacity characteristic value of composite foundation and the settlement of strengthened area are calculated respectively. The results of laboratory test show that the secondary fiber can effectively increase the toughness of cement soil, the strength of cement soil, the strength of cement soil, the strength of cement soil, the strength of cement soil and the strength of cement soil. The elastic modulus and toughness increase with the increase of the bacterial solution concentration. Compared with the unconfined compressive strength test results, the strength and elastic modulus of the two modified cement soils increase under impact load. The application design of microorganism reinforced cement soil in composite foundation shows that with the increase of bacterial concentration, the characteristic value of bearing capacity of composite foundation increases and the settlement of strengthened area decreases.
【學(xué)位授予單位】：中國礦業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TU43

【引證文獻(xiàn)】

相關(guān)會(huì)議論文 前1條

1 李閩飛;;天然纖維復(fù)合材料在建筑領(lǐng)域的應(yīng)用[A];第十七屆玻璃鋼/復(fù)合材料學(xué)術(shù)年會(huì)論文集[C];2008年

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本文編號(hào)：1675952