【摘要】：懸掛式防滲墻主要功能是限制管涌發(fā)展和改變滲流場(chǎng)流態(tài)。由于繞滲作用，墻后的水流速度會(huì)大大降低，流線方向會(huì)改變，有效滲徑會(huì)增加；墻后水力坡降分布不均，有極大的，也有較小的，導(dǎo)致墻后土的滲透性發(fā)生改變，在流態(tài)的變化中形成新的平衡，直至最終破壞。 目前關(guān)于懸掛式防滲墻限制管涌發(fā)展方面研究較多，但墻后的流態(tài)是尚未研究透的內(nèi)容。本文針對(duì)懸掛式防滲墻后土體滲流場(chǎng)的研究，做了以下工作： （1）對(duì)懸掛式防滲墻模擬試驗(yàn)技術(shù)做了改進(jìn)。采用壓力水袋模擬覆蓋層，有效地防止了砂槽上部漏水和覆蓋層地面產(chǎn)生空隙；使用透明紗布消除排水液面“張力”對(duì)下游排水順暢性的影響。 （2）繪制試驗(yàn)流網(wǎng)圖，對(duì)比砂槽內(nèi)各區(qū)域等水頭線的疏密變化，并與有限元計(jì)算結(jié)果對(duì)比，證明了墻后土的滲透性有發(fā)生變化。 （3）引入當(dāng)量滲透系數(shù)K，相對(duì)水力坡降I 'x，測(cè)壓管相對(duì)位勢(shì)φi，結(jié)合試驗(yàn)總流量，從四個(gè)方面進(jìn)一步論證墻后土的滲流場(chǎng)的變化。先利用K和I 'x分析砂槽整體的變化，然后利用I 'x和φi分區(qū)域分析砂槽局部的變化，證明了在滲透力的作用下，懸掛式防滲墻周?chē)纳百|(zhì)土層會(huì)有細(xì)顆粒的移動(dòng)、淤積現(xiàn)象，達(dá)到從宏觀的試驗(yàn)現(xiàn)場(chǎng)驗(yàn)證微觀的砂顆粒移動(dòng)淤積現(xiàn)象的目的。 （4）最終通過(guò)分析，找出了砂槽最主要的細(xì)顆粒淤積區(qū)是下游靠近擋板端部的砂層區(qū)域，最主要的細(xì)顆粒流失區(qū)是擋板正下方最接近擋板的區(qū)域。并根據(jù)分析結(jié)果，調(diào)整各區(qū)域的滲透系數(shù)，，通過(guò)有限元計(jì)算，驗(yàn)證試驗(yàn)分析結(jié)果的合理性。
[Abstract]:The main function of hanging cutoff wall is to limit the development of pipe and change the flow state of seepage field. As a result of the seepage around the wall, the velocity of water behind the wall will be greatly reduced, the direction of the streamline will be changed, the effective seepage diameter will be increased, the hydraulic slope behind the wall will be distributed unevenly, and there will be great and smaller, which will result in the change of the permeability of the soil behind the wall. A new equilibrium is formed in the variation of the flow state until it is finally destroyed. At present, there are many researches on the development of suspended cutoff wall, but the flow pattern behind the wall is not fully studied. In this paper, the following work has been done to study the seepage field of soil behind the suspended impervious wall: (1) the simulation test technology of the suspended cutoff wall has been improved. The pressure water bag is used to simulate the overburden, which effectively prevents the leakage of the upper part of the sand trough and the void on the ground of the overburden. The influence of the "tension" of the drainage surface on the downstream drainage smoothness is eliminated by the use of transparent gauze. (2) drawing the test flow net diagram, The density variation of the isobaric head lines in each area of the sand trough is compared and compared with the results of the finite element calculation. It is proved that the permeability of the soil behind the wall has changed. (3) the change of seepage field of soil behind the wall is further demonstrated from four aspects by introducing the equivalent permeability coefficient K, the relative hydraulic gradient I x, the relative potential 蠁 I of the pressure measuring pipe and the total experimental discharge. Using K and I x to analyze the overall change of sand trough, and then using I X and 蠁 I to analyze the local change of sand trough, it is proved that under the action of permeability, the movement and deposition of fine particles will occur in the sandy soil around the suspended impervious wall. In order to verify the microscopic sand particle moving and silting phenomenon from the macroscopic test site. (4) finally, through the analysis, we find out that the most important fine grain silt area in the sand trough is the sand bed area near the end of the baffle. The main fine particle loss area is the area closest to the baffle directly below the baffle. According to the analysis results, the permeability coefficient of each region is adjusted, and the rationality of the experimental results is verified by finite element calculation.
【學(xué)位授予單位】：華南理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TV543.8

【參考文獻(xiàn)】

相關(guān)期刊論文 前9條

1 李思慎;長(zhǎng)江重要堤防隱蔽工程建設(shè)中的防滲處理[J];長(zhǎng)江科學(xué)院院報(bào);2000年S1期

2 張家發(fā),吳昌瑜,李勝常,王滿(mǎn)興;堤防加固工程中防滲墻的防滲效果及應(yīng)用條件研究[J];長(zhǎng)江科學(xué)院院報(bào);2001年05期

3 張家發(fā),朱國(guó)勝,曹敦侶;堤基滲透變形擴(kuò)展過(guò)程和懸掛式防滲墻控制作用的數(shù)值模擬研究[J];長(zhǎng)江科學(xué)院院報(bào);2004年06期

4 楊曉東,丁留謙;堤防地基防滲技術(shù)[J];防滲技術(shù);1999年03期

5 周紅星,曹洪,林潔梅;管涌破壞機(jī)理模型試驗(yàn)覆蓋層模擬方法的影響研究[J];廣東水利水電;2005年02期

6 鄭水清,陳榮波;懸掛式防滲帷幕的電模擬試驗(yàn)[J];廣東土木與建筑;2004年06期

7 劉心巖;堤防滲流狀態(tài)及防滲墻結(jié)構(gòu)型式分析[J];黑龍江水利科技;2004年03期

8 劉川順,劉祖德,王長(zhǎng)德;沖積地基堤防垂直防滲方案研究[J];巖石力學(xué)與工程學(xué)報(bào);2002年03期

9 楊秀竹,陳福全,雷金山,王星華;懸掛式帷幕防滲作用的有限元模擬[J];巖土力學(xué);2005年01期

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