本文選題：垃圾填埋場(chǎng)覆蓋層 + 植物根系�。� 參考：《哈爾濱工業(yè)大學(xué)》2015年碩士論文

【摘要】：垃圾填埋場(chǎng)終場(chǎng)覆蓋層的長(zhǎng)期服役性能已經(jīng)引起了越來(lái)越多關(guān)注,覆蓋層在干濕循環(huán)的作用下會(huì)開裂,導(dǎo)致覆蓋層的滲水能力增強(qiáng)。終場(chǎng)覆蓋層通常種植植物,植物對(duì)裂隙的開展有一定的限制作用,但是至今沒有對(duì)植物根系與裂隙同時(shí)存在對(duì)覆蓋層水力特性的影響的研究。本文將研究含有植物根系與裂隙土體的水力特性。本文采用室內(nèi)土柱試驗(yàn)來(lái)研究含有植物根系與裂隙土體的水力特性。設(shè)計(jì)了一套可以直接獲取含植物根系現(xiàn)場(chǎng)土樣,并能夠直接進(jìn)行室內(nèi)土柱滲透試驗(yàn)的試驗(yàn)裝置。試驗(yàn)裝置包括降水裝置、土柱主體、排水收集裝置三部分。采用自主設(shè)計(jì)的試驗(yàn)裝置,從室外試驗(yàn)場(chǎng)地獲得了現(xiàn)場(chǎng)土樣,進(jìn)行了室內(nèi)土柱滲透試驗(yàn),并對(duì)試驗(yàn)結(jié)果進(jìn)行了對(duì)比分析。室內(nèi)土柱滲透試驗(yàn)分為四組,土樣分別為重塑土樣、不含根系含裂隙的室外現(xiàn)場(chǎng)土樣、含狗牙根草根系的室外現(xiàn)場(chǎng)土樣、含香根草根系的室外現(xiàn)場(chǎng)土樣。四種土樣在相同的降水條件下收集到底部滲水的時(shí)間不同,重塑土樣在降水持續(xù)57.5小時(shí)收集到底部滲水,不含根系含裂隙的室外現(xiàn)場(chǎng)土樣在降水持續(xù)12小時(shí)收集到底部滲水,含狗牙根草根系的室外現(xiàn)場(chǎng)土樣在降水開始20小時(shí)收集到底部滲水,含香根草根系的室外現(xiàn)場(chǎng)土樣在降水開始1.3小時(shí)收集到底部滲水。與室外不含根系的土樣相比,狗牙根草根系能夠提高覆蓋層的防滲能力,香根草根系使室外覆蓋層的防滲能力減弱。對(duì)比各組土樣不同深度在相同基質(zhì)吸力下的滲透系數(shù),可以發(fā)現(xiàn)香根草根系對(duì)覆蓋層滲透性的影響深度超出140 mm,狗牙根草與裂隙對(duì)覆蓋層的影響深度不超過(guò)140 mm厚度。根據(jù)試驗(yàn)結(jié)果,結(jié)合已有計(jì)算非飽和滲透系數(shù)的公式,建立了計(jì)算含有草根土體的非飽和滲透系數(shù)模型,模型參數(shù)與草根參數(shù)直接相關(guān)。
[Abstract]:More and more attention has been paid to the long-term service performance of the landfill terminal overlay. The overburden will crack under the action of dry and wet cycle, which leads to the enhancement of the water seepage ability of the overburden. Plants are usually planted in the final covering layer, which has a limited effect on the development of cracks, but there is no research on the influence of the root system and the crack on the hydraulic characteristics of the cover layer at the same time. In this paper, the hydraulic characteristics of the soil with plant roots and fissures are studied. In this paper, laboratory soil column test is used to study the hydraulic characteristics of soil with plant roots and fissures. A set of experimental equipment was designed, which can directly obtain soil samples containing plant roots and directly carry out soil column permeation test in laboratory. The test device consists of three parts: dewatering device, soil column body and drainage collection device. The field soil samples were obtained from the outdoor test site with a self-designed test device. The indoor soil column permeation test was carried out, and the test results were compared and analyzed. The soil column permeation test was divided into four groups. The soil samples were remolded soil samples, outdoor soil samples without root cracks, outdoor soil samples with root system, and field soil samples with vetiver root system. Four kinds of soil samples were collected under the same precipitation conditions and the time of water seepage at the bottom was different. The remolded soil samples were collected to the bottom seepage in 57.5 hours of precipitation, while outdoor soil samples without root cracks were collected to the bottom seepage in 12 hours of precipitation. At the beginning of 20 hours of precipitation, the soil samples collected from the outdoor field with the root system of Herba doggeana were collected into the bottom seepage, while the soil samples containing the root system of Vetiveria root were collected to the bottom at 1.3 hours of precipitation. Compared with the soil samples without root system outside, the root system can improve the anti-seepage ability of the cover layer, and the root system of vetiver grass can weaken the anti-seepage ability of the outdoor cover layer. By comparing the permeability coefficient of soil samples at different depths under the same matrix suction, it was found that the influence depth of root system on overburden permeability was more than 140mm, and the influence depth of root and fissure on the overburden was not more than 140mm. Based on the experimental results and the existing formulas for calculating the unsaturated permeability coefficient, a model for calculating the unsaturated permeability coefficient of the soil with grass roots is established. The model parameters are directly related to the grass root parameters.
【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TU411.4;TU993

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相關(guān)期刊論文 前1條

1 李雄威;孔令偉;郭愛國(guó);;氣候影響下膨脹土工程性質(zhì)的原位響應(yīng)特征試驗(yàn)研究[J];巖土力學(xué);2009年07期

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本文編號(hào)：2010253