本文選題：加筋土邊坡　切入點：變形特征　出處：《蘭州交通大學》2015年碩士論文

【摘要】：加筋土是在土體內加入較強抗拉性能土工合成材料組成的復合土。隨著我國經濟與交通運輸業(yè)的快速發(fā)展,加筋土技術將越來越多的應用在路堤的修建中,用來提高路堤的承載力與穩(wěn)定性,并控制路堤變形。研究加筋路堤變形特性與承載力特性對加筋加筋土的工程應用及相關研究有重要意義。本文以某公路路堤為原型,首先通過理論分析計算了加筋路堤邊坡穩(wěn)定性系數(shù),得出不同因素對路堤邊坡穩(wěn)定性的影響。而后采用室內模型試驗以及三維數(shù)值模擬的方法,研究路堤邊坡在不同工況時的變形與承載力特性以及土體內附加應力分布、筋材受力分布及路堤破裂面形態(tài)的規(guī)律特征。通過分析得出以下結論:(1)運用所提出的理論公式,得出未加筋、二層水平加筋、二層立體加筋路堤邊坡的穩(wěn)定性系數(shù)呈增長態(tài)勢,另外立體加筋路堤中豎筋高度的增加也能夠使邊坡穩(wěn)定性系數(shù)明顯提高。(2)通過室內試驗發(fā)現(xiàn)筋材層數(shù)的增加會使邊坡極限承載力增大、坡頂沉降減小,而相同情況下立體加筋路堤相對于水平加筋路堤有著更大的極限承載力與更小的坡頂沉降量,同時發(fā)現(xiàn)立體加筋的豎筋高度會對路堤承載力與沉降方面有著較明顯的影響。(3)隨著路堤筋材層數(shù)增加或立體筋材豎筋高度增大都會使路堤邊坡的側向變形減小。觀測實驗中路堤破裂面形態(tài)之后發(fā)現(xiàn)到不論是水平加筋還是立體加筋路堤,其破裂面形態(tài)都不同于未加筋路堤,破裂面被筋條隔斷為多個圓弧面。(4)極限荷載作用下加筋路堤隨內附加應力隨著筋材層數(shù)的增加而增大,但相同層數(shù)布筋條件下立體加筋路堤附加應力大于傳統(tǒng)水平加筋路堤。(5)相同荷載作用下隨著加筋層數(shù)增多筋條上所受的會隨之減小,同時靠近路堤頂面筋材的變化率較大,遠離路堤頂面的筋材,拉力的變化率逐漸減小,曲線逐漸平緩。(6)通過數(shù)值模擬在坡頂沉降與筋材受力方面與模型試驗結果相互驗證,得出與模型試驗相同結論。以上結論可為加筋路堤邊坡的設計和施工提供參考和技術支持
[Abstract]:Reinforced soil is a composite soil with strong tensile properties. With the rapid development of economy and transportation in China, reinforced soil technology will be used more and more in the construction of embankment. To improve the bearing capacity and stability of embankment and to control the deformation of embankment. The study of deformation and bearing capacity characteristics of reinforced embankment is of great significance to the engineering application of reinforced soil and related research. In this paper, a highway embankment is used as prototype. Firstly, the stability coefficient of reinforced embankment slope is calculated by theoretical analysis, and the influence of different factors on the stability of embankment slope is obtained. The characteristics of deformation and bearing capacity of embankment slope under different working conditions, the distribution of additional stress in soil, the stress distribution of steel bar and the shape of breakage surface of embankment are studied. It is concluded that the stability coefficient of the embankment slope with no reinforcement, two layers of horizontal reinforcement and two layers of three-dimensional reinforced embankment shows an increasing trend. In addition, the increase of vertical reinforcement height in stereoscopic reinforced embankment can also increase the slope stability coefficient obviously.) through laboratory tests, it is found that the increase of reinforcement layer will increase the ultimate bearing capacity of the slope and decrease the settlement of the slope top. Under the same condition, the three-dimensional reinforced embankment has greater ultimate bearing capacity and smaller slope top settlement than the horizontal reinforced embankment. At the same time, it is found that the vertical reinforcement height of the embankment has obvious influence on the bearing capacity and settlement of the embankment. 3) the lateral deformation of the embankment slope will be reduced with the increase of the number of reinforcement layers or the height of the vertical reinforcement of the embankment. After observing the breakage surface morphology of the embankment in the experiment, it is found that the embankment is reinforced horizontally or stereoscopically. The fracture surface of the embankment is different from that of unreinforced embankment. Under the action of limit load, the reinforced embankment increases with the increase of the number of reinforced layers. However, the additional stress of three-dimensional reinforced embankment is greater than that of the traditional horizontal reinforced embankment under the condition of the same layer number of reinforcement.) under the same load, with the increase of reinforced layer, the stress on the reinforced bar will decrease, and the change rate of gluten material near the top of the road embankment will be larger than that of the traditional horizontal reinforced embankment. Far from the top surface of the embankment, the change rate of tensile force decreases gradually, and the curve is gradually flat. 6) through numerical simulation, the settlement of the slope top and the stress of the steel bar are verified with the model test results. These conclusions can provide reference and technical support for the design and construction of reinforced embankment slope.
【學位授予單位】：蘭州交通大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：U416.12

【參考文獻】

相關期刊論文 前3條

1 楊錫武,鐘以明;筋材結構對其加筋土強度特性的影響研究[J];重慶交通學院學報;2002年01期

2 楊錫武,歐陽仲春;加筋高路堤陡邊坡離心模型的研究[J];土木工程學報;2000年05期

3 朱湘,黃曉明;加筋路堤的室內模擬試驗和現(xiàn)場沉降觀測[J];巖土工程學報;2002年03期

，

本文編號：1676515