本文選題：加筋土 + 穩(wěn)定性��； 參考：《成都理工大學(xué)》2015年碩士論文

【摘要】：在西南紅層地帶等地形復(fù)雜地區(qū)開展基礎(chǔ)設(shè)施建設(shè)通常相當困難,具有可用地資源極為緊缺與缺少適合大規(guī)模工程建設(shè)的自然“開闊平地”的突出矛盾,這意味著在這類山地中進行開山填溝造地的人工高填方工程將成為解決建設(shè)用地的重要途徑之一,高填方體的穩(wěn)定性便成了影響工程安全穩(wěn)定運營的關(guān)鍵。本文以某機場南邊界加筋土邊坡為研究對象,通過對國內(nèi)外加筋土邊坡的研究現(xiàn)狀及目前仍存在的問題等方面進行歸納總結(jié),結(jié)合現(xiàn)場勘察、室內(nèi)分析,掌握了研究區(qū)的地質(zhì)背景及加筋土邊坡失穩(wěn)的影響因素,揭示了其變形破壞機制。在進行地質(zhì)分析基礎(chǔ)上,采用數(shù)值分析的方法,對影響加筋土邊坡穩(wěn)定性的因素進行分析,研究了降雨入滲條件下邊坡滲流場特征及穩(wěn)定性變化特征,然后以極限平衡法計算為研究手段,通過改變影響其穩(wěn)定性的放坡坡比,對穩(wěn)定性系數(shù)的變化進行優(yōu)化分析,得到既保證安全又兼顧經(jīng)濟的加固方案。主要研究成果如下:(1)加筋邊坡的破壞發(fā)展過程可以歸納為:由于降雨導(dǎo)致邊坡重度增大,填土抗剪強度降低,在坡內(nèi)形成貫通的圓弧形滑面,滑動面繞過加筋土擋土墻的加筋帶,從軟化的坡腳剪出。初步判斷加筋土邊坡失穩(wěn)模式為基底軟弱層的剪切滑移破壞,而降雨入滲是邊坡失穩(wěn)的誘發(fā)因素。結(jié)合邊坡變形破壞特征及穩(wěn)定性影響因素的研究,該邊坡發(fā)生了整體滑移破壞。(2)經(jīng)過反壓等加固措施處理的邊坡,結(jié)合變形跡象發(fā)展趨勢及位移監(jiān)測分析,判斷現(xiàn)階段邊坡處于緩慢蠕滑階段。導(dǎo)致邊坡經(jīng)過前期治理但仍然發(fā)生變形的主要誘因是強降雨。(3)隨著降雨持時的增加,雨水滲入到邊坡內(nèi)部,導(dǎo)致加筋土坡內(nèi)地下水位線的抬高,地下水位線的上升引起滲流場的變化,滲流場特征又決定著坡體內(nèi)基質(zhì)吸力的分布,基質(zhì)吸力的變化將會導(dǎo)致非飽和土抗剪強度的變化,從而影響著坡體的整體穩(wěn)定性。(4)隨著降雨持續(xù)時間延續(xù),出現(xiàn)邊坡穩(wěn)定性系數(shù)緩慢下降到最小值,降雨停止后開始逐漸回升的現(xiàn)象。(5)天然工況坡比為1:0.25條件下,邊坡處于基本穩(wěn)定狀態(tài),但安全儲備較低。從安全和經(jīng)濟角度考慮,坡比1:0.5較為合適。鑒于工程的復(fù)雜性,暴雨工況下需加強邊坡排水,尤其是坡體內(nèi)部積水應(yīng)當及時排走,從而保障邊坡的穩(wěn)定。
[Abstract]:It is usually very difficult to carry out infrastructure construction in areas with complex topography such as the southwest red beds, and there is a prominent contradiction between the extremely short supply of available land resources and the lack of natural "open flat land" suitable for large-scale engineering construction. This means that the artificial high fill project in this kind of mountainous area will become one of the important ways to solve the problem of construction land, and the stability of the high fill body will become the key to the safe and stable operation of the project. In this paper, the reinforced soil slope at the south boundary of an airport is taken as the research object. Through the summary of the current research situation and the existing problems of the reinforced soil slope at home and abroad, combined with the field investigation, the indoor analysis is carried out. The geological background of the study area and the influencing factors of the instability of reinforced soil slope are grasped, and the mechanism of deformation and failure is revealed. On the basis of geological analysis, the factors influencing the stability of reinforced soil slope are analyzed by numerical analysis method, and the characteristics of seepage field and stability of slope under rainfall infiltration are studied. Then, the limit equilibrium method is used as the research method. By changing the slope ratio which affects the stability of the slope, the stability coefficient is optimized and analyzed, and a reinforcement scheme is obtained, which can guarantee the safety as well as give consideration to the economy. The main research results are as follows: (1) the process of failure and development of reinforced slope can be summarized as follows: due to heavy increase of slope caused by rainfall, shear strength of fill soil decreases, and a circular arc slip surface is formed in the slope. The sliding surface bypasses the stiffened belt of the reinforced earth retaining wall and is cut out from the softened foot of the slope. It is preliminarily judged that the failure mode of reinforced soil slope is shear slip failure of the weak layer of the base, and rainfall infiltration is the inducing factor of slope instability. Combined with the study of the deformation and failure characteristics of the slope and the influencing factors of the stability of the slope, the slope with integral slippage failure occurred in the slope, which has been treated with backpressure and other reinforcement measures, combined with the development trend of the deformation signs and the monitoring and analysis of the displacement. It is judged that the slope is slowly creeping at the present stage. With the increase of rainfall duration, Rain Water seeps into the slope, which leads to the elevation of underground water level in reinforced soil slope. The rise of underground water level leads to the change of seepage field, and the characteristics of seepage field determine the distribution of matrix suction in slope, and the change of matrix suction will lead to the change of shear strength of unsaturated soil. Thus affecting the overall stability of the slope. 4) with the duration of the rainfall, the slope stability coefficient slowly decreased to the minimum value, and the slope ratio began to rise gradually after the rainfall stopped. The slope ratio of natural conditions was 1: 0.25. The slope is basically stable, but the safety reserve is low. From a security and economic point of view, the slope ratio of 1: 0.5 is more appropriate. In view of the complexity of the project, it is necessary to strengthen the drainage of the slope under heavy rain conditions, especially the water in the body of the slope should be discharged in time to ensure the stability of the slope.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TU43

【參考文獻】

相關(guān)期刊論文 前9條

1 張明;胡瑞林;譚儒蛟;崔芳鵬;;降雨型滑坡研究的發(fā)展現(xiàn)狀與展望[J];工程勘察;2009年03期

2 李澄宙;地震作用下加筋土擋土墻的有限元分析[J];廣東土木與建筑;2001年09期

3 唐曉松;王永甫;鄭穎人;;土工格柵加筋土擋墻在復(fù)雜工程地質(zhì)條件下的應(yīng)用[J];防災(zāi)減災(zāi)工程學(xué)報;2013年S1期

4 董健;張明;羅玉珊;王進;楊帆;;山區(qū)復(fù)雜地形條件下超高土工格柵加筋土路堤的穩(wěn)定性分析[J];長江科學(xué)院院報;2014年03期

5 張盧明;何敏;鄭明新;楊放仁;楊鵬飛;;降雨入滲對滑坡滲流場和穩(wěn)定性的影響分析[J];鐵道工程學(xué)報;2009年07期

6 張孟喜,孫鈞;土工合成材料加筋土應(yīng)變軟化特性及彈塑性分析[J];土木工程學(xué)報;2000年03期

7 楊果林,王永和;加筋土擋墻在重復(fù)荷載作用下的模型試驗與動態(tài)響應(yīng)分析[J];巖石力學(xué)與工程學(xué)報;2002年10期

8 周世良;何光春;汪承志;楊成渝;;臺階式加筋土擋墻模型試驗研究[J];巖土工程學(xué)報;2007年01期

9 詹良通,吳宏偉,包承綱,龔壁衛(wèi);降雨入滲條件下非飽和膨脹土邊坡原位監(jiān)測[J];巖土力學(xué);2003年02期

，

本文編號：1953309