【摘要】：在自然界中,滑坡與大氣降雨有著密切的關(guān)系,降雨入滲成為了非飽和土體斜坡失穩(wěn)主要的誘發(fā)因素。據(jù)統(tǒng)計(jì)數(shù)據(jù)顯示,上世紀(jì)中期以來(lái),在強(qiáng)降雨作用下植被發(fā)育斜坡區(qū)發(fā)生失穩(wěn)事件的頻率越來(lái)越高,不僅極大的破壞當(dāng)?shù)氐纳鷳B(tài)平衡、打亂了人們正常的生活規(guī)律,而且對(duì)人們的生命財(cái)產(chǎn)安全構(gòu)成了嚴(yán)重威脅。隨著國(guó)民經(jīng)濟(jì)和地區(qū)基礎(chǔ)設(shè)施建設(shè)的不斷發(fā)展,涉及斜坡穩(wěn)定性方面的問(wèn)題越來(lái)越引起工程界的重視。然而,僅僅考慮在降雨條件下植被邊坡及淺層穩(wěn)定性的研究是不完善的,本文以云南省昭通頭寨、呈貢段家營(yíng)以及個(gè)舊象沖三個(gè)植被發(fā)育自然斜坡為研究對(duì)象,采用現(xiàn)場(chǎng)和室內(nèi)試驗(yàn)、統(tǒng)計(jì)分析以及數(shù)學(xué)模型等手段研究植被發(fā)育斜坡土體中根-土間隙的導(dǎo)流特性及其對(duì)降雨入滲的貢獻(xiàn),同時(shí)分析由根-土間隙引起的植被抑制淺層邊坡穩(wěn)定性的變化。本文研究取得的主要成果如下：(1)土體中根系密度隨著土層深度增加而急劇減少這一規(guī)律普遍存在,其空間分布受植被類(lèi)型、地質(zhì)條件、生長(zhǎng)時(shí)間和氣候條件等因素的影響。根-土間隙是植物根系伸展的一種普遍現(xiàn)象,其導(dǎo)流現(xiàn)象具有普遍存在性,不受地域、植被類(lèi)型、氣候條件以及地質(zhì)條件的限制而廣泛存在于斜坡土體中,且隨著土體深度的不斷增加根-土間隙的導(dǎo)流特性隨根系的衰減而減弱。(2)頭寨試驗(yàn)區(qū)和呈貢段家營(yíng)試驗(yàn)區(qū)土體的物理特征差異明顯,且季節(jié)的變化對(duì)土體的物理特性影響不大。頭寨試驗(yàn)區(qū)非飽和帶土體孔隙度、質(zhì)量含水率、有機(jī)質(zhì)含量及根系生物量集度均比段家營(yíng)試驗(yàn)區(qū)高,頭寨試驗(yàn)區(qū)土體具有高孔隙度-低容重-高含水率的物理性質(zhì)和高有機(jī)質(zhì)含量有關(guān)。相同土層深度處,頭寨試驗(yàn)區(qū)土體的滲透速度始終高于段家營(yíng)試驗(yàn)區(qū)土體的滲透速度,頭寨試驗(yàn)區(qū)土體的飽和滲透速度與初始滲透速度差異較大,而段家營(yíng)試驗(yàn)區(qū)土體的飽和滲透速度與初始滲透速度波動(dòng)幅度不大。(3)根-土間隙尺寸的大小對(duì)水分下滲的阻力特性的影響與Re有關(guān),間隙尺寸大小對(duì)摩擦阻力系數(shù)的影響與Re呈正相關(guān)性。相比傳統(tǒng)的阻力計(jì)算經(jīng)驗(yàn)公式和模型一,改進(jìn)的KAYS阻力模型對(duì)研究根-土間隙流道的阻力特性更貼近實(shí)際情況,具有一定的實(shí)用性；另外,基于納維埃-斯托克司方程式二次積分化解得到不同根-土間隙流道內(nèi)水分下滲速度分布,其結(jié)果基于水分動(dòng)態(tài)測(cè)量過(guò)程,從一定程度上反映了土體水分與根-土間隙的關(guān)系。(4)在降雨過(guò)程中,植被發(fā)育斜坡土體中根-土間隙具有很強(qiáng)的導(dǎo)流特性。頭寨試驗(yàn)區(qū)和呈貢段家營(yíng)試驗(yàn)區(qū)土體中根-土間隙的導(dǎo)流量分別占總?cè)霛B量的72%～82%和54%-70%,由于根-土間隙的存在促進(jìn)了土體水分的下滲,從而消弱或抑制了地表徑流的產(chǎn)生。
[Abstract]:In nature, landslides are closely related to atmospheric rainfall, and rainfall infiltration has become the main inducing factor of slope instability in unsaturated soil. According to statistical data, since the middle of the last century, the frequency of unstable events in slope areas developed by vegetation under the action of heavy rainfall has increased, not only greatly damaging the local ecological balance, but also disrupting people's normal life laws. Moreover, it poses a serious threat to the safety of people's life and property. With the development of national economy and regional infrastructure construction, more and more attention has been paid to slope stability. However, it is not perfect to study the slope and shallow stability of vegetation only under rainfall conditions. This paper takes three natural slopes of vegetation development in Zhaotong Village, Chenggong Duan Ying and Gejiuangchong as research objects. Field and laboratory tests, statistical analysis and mathematical models were used to study the conductivity of root soil gap in slope soil and its contribution to rainfall infiltration. At the same time, the change of stability of shallow slope caused by vegetation caused by root-soil gap is analyzed. The main results obtained in this paper are as follows: (1) the root density in soil decreases sharply with the increase of soil depth, and its spatial distribution is affected by vegetation types and geological conditions. Factors such as growth time and climatic conditions. Root-soil gap is a common phenomenon of plant root extension, and its diversion exists widely in slope soil mass without the restriction of region, vegetation type, climate condition and geological condition. With the increasing of soil depth, the conductivity of root soil gap decreases with the decay of root system. (2) the physical characteristics of soil in Touzhai experimental area and Chenggong Duan Jiaying experimental area are obviously different. The seasonal variation has little effect on the physical properties of soil. The soil porosity, mass moisture content, organic matter content and root biomass concentration of unsaturated zone in Touzhai experimental area were higher than those in Duan Jiaying experimental area. The physical properties of soil in Touzhai experimental area are related to the content of high organic matter, such as high porosity, low bulk density and high water content. At the same soil depth, the infiltration velocity of soil in Touzhai experimental area is always higher than that in Duan Jiaying experimental area, and the saturation permeability velocity of soil in Tou Zhai experimental area is different from that of initial seepage velocity. However, the saturation permeability velocity and initial permeability velocity of soil in Duan Jiaying experimental area fluctuated little. (3) the influence of the size of root soil gap on the resistance characteristics of water infiltration is related to Re. The effect of clearance size on friction resistance coefficient is positively correlated with Re. Compared with the traditional empirical formula and model of resistance calculation, the improved KAYS resistance model is more practical to study the resistance characteristics of root-soil gap passage. In addition, based on the quadratic integral solution of Navier-Stokes equation, the velocity distribution of water infiltration in different root-soil gap channels is obtained, and the results are based on the process of water dynamic measurement. To some extent, it reflects the relationship between soil moisture and root-soil gap. (4) during rainfall, the root soil gap in slope soil developed by vegetation has strong conductivity. In Touzhai Experimental area and Chenggong Duan Jiaying Experimental area, the conductivity of the root soil gap accounts for 72% of the total infiltration volume and 54% to 70% respectively. Because of the existence of the root soil gap, the infiltration of soil water is promoted. This weakens or suppresses the generation of surface runoff.
【學(xué)位授予單位】：昆明理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類(lèi)號(hào)】：P642.2

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 徐則民;;植被與斜坡非飽和帶大空隙[J];地學(xué)前緣;2007年06期

2 張治國(guó),趙紅茹;黃丘區(qū)不同地類(lèi)的降雨入滲試驗(yàn)[J];山西水土保持科技;1999年02期

3 陳喜,陳洵洪;美國(guó)Sand Hills地區(qū)地下水?dāng)?shù)值模擬及水量平衡分析[J];水科學(xué)進(jìn)展;2004年01期

4 吳發(fā)啟,范文波;土壤結(jié)皮對(duì)降雨入滲和產(chǎn)流產(chǎn)沙的影響[J];中國(guó)水土保持科學(xué);2005年02期

5 牛健植;余新曉;張志強(qiáng);;優(yōu)先流研究現(xiàn)狀及發(fā)展趨勢(shì)[J];生態(tài)學(xué)報(bào);2006年01期

6 吳華山;陳效民;邱琳;沃飛;;染色法測(cè)定、計(jì)算機(jī)解譯農(nóng)田土壤中大孔隙數(shù)量的研究[J];水土保持學(xué)報(bào);2006年03期

7 王文科，李俊亭;地下水流數(shù)值模擬的發(fā)展與展望[J];西北地質(zhì);1995年04期

8 張開(kāi)平,呂態(tài)能;新平縣曼蚌河滑坡型泥石流特征及治理[J];云南地理環(huán)境研究;2003年04期

9 朱文彬,劉寶琛;降雨條件下土體滑坡的有限元數(shù)值分析[J];巖石力學(xué)與工程學(xué)報(bào);2002年04期

10 徐則民,黃潤(rùn)秋,唐正光,王蘇達(dá);植被護(hù)坡的局限性及其對(duì)深層滑坡孕育的貢獻(xiàn)[J];巖石力學(xué)與工程學(xué)報(bào);2005年03期

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