本文選題：碎石土邊坡 + 穩(wěn)定性��； 參考：《蘭州交通大學(xué)》2013年碩士論文

【摘要】：邊坡穩(wěn)定性研究至今仍是巖土工程界一個熱點研究方向，也是一項復(fù)雜而未能很好解決的技術(shù)難題。邊坡的穩(wěn)定受很多因素的影響，如降雨、地震、人工開挖、各種荷載作用、巖土體工程性質(zhì)等，而降雨和地震則是最主要也是較為常見的兩個因素，至今仍是邊坡穩(wěn)定性研究的重點。所以，對邊坡與降雨或地震之間的關(guān)系進行分析研究對于邊坡失穩(wěn)的預(yù)防與整治將起到非常重要的作用。 根據(jù)降雨和地震影響下邊坡穩(wěn)定性的研究現(xiàn)狀以及尚未解決的問題，本文以樓房山碎石土滑坡為工程背景，建立FLAC3D三維數(shù)值模型，通過計算結(jié)果來分析降雨和地震對碎石土邊坡穩(wěn)定性的影響及其破壞機理。本文主要研究內(nèi)容包括以下幾方面： （1）以均質(zhì)邊坡為例，用FLAC3D強度折減法分別計算了單因素變化條件下邊坡的穩(wěn)定系數(shù)值，采用敏感性分析法分析各影響因素對邊坡穩(wěn)定性的影響程度，得到各因素對碎石土邊坡穩(wěn)定性影響程度的大小關(guān)系為：內(nèi)摩擦角邊坡坡角粘聚力土體密度。 （2）建立樓房山碎石土滑坡FLAC3D數(shù)值計算模型，，分析了降雨影響下邊坡的應(yīng)力場、位移場、塑性區(qū)及剪應(yīng)變增量分布規(guī)律，研究了邊坡在降雨影響下的失穩(wěn)破壞機理。結(jié)果表明，在降雨條件下，碎石土邊坡的穩(wěn)定性隨著含水率的增加呈先緩慢減小后急劇減小的特征，并存在明顯的臨界特性，含水率11.3%是邊坡穩(wěn)定性變化的臨界點。 （3）利用FLAC3D數(shù)值計算模型，分析了地震作用下邊坡的應(yīng)力場、位移場、塑性區(qū)及剪應(yīng)變增量分布規(guī)律，研究了邊坡在地震荷載作用下的失穩(wěn)破壞機理。結(jié)果表明，在很微小的地震荷載作用下，碎石土邊坡就會發(fā)生失穩(wěn)，且邊坡破壞程度隨地震水平加速度的增加而增大；碎石土邊坡在地震作用下主要發(fā)生受壓破壞，只在邊坡坡頂部位出現(xiàn)小面積的拉應(yīng)力區(qū)域，此部位發(fā)生張拉破壞；而在碎石土邊坡底部，由于其主應(yīng)力方向發(fā)生改變,土體處于雙向受壓狀態(tài),發(fā)生剪切破壞。 （4）利用FLAC3D數(shù)值計算模型，分析降雨和地震共同作用下邊坡的應(yīng)力場、位移場、塑性區(qū)及剪應(yīng)變增量分布規(guī)律，研究了邊坡在降雨和地震共同作用下的失穩(wěn)破壞機理，說明當(dāng)?shù)卣鹋c降雨共同作用時，邊坡的穩(wěn)定性較地震或降雨單獨作用時要低；在含水率保持不變的情況下，隨著地震荷載的增加，碎石土邊坡的穩(wěn)定性在逐漸降低；在地震水平加速度保持不變的情況下，隨著含水率的增加，碎石土邊坡的穩(wěn)定性在逐漸降低。 本文通過分析樓房山碎石土滑坡工程在降雨與地震及降雨和地震共同作用下邊坡的失穩(wěn)破壞機理，充分揭示降雨入滲和地震震動引起碎石土邊坡破壞的模式及其發(fā)展過程，給出在降雨與地震影響下碎石土邊坡穩(wěn)定性的變化特點，從而為預(yù)防和整治邊坡失穩(wěn)提供更為適用的經(jīng)驗。
[Abstract]:Slope stability research is still a hot research direction in geotechnical engineering field, and it is also a complicated and unsolved technical problem. The stability of slope is affected by many factors, such as rainfall, earthquake, artificial excavation, various loads, engineering properties of rock and soil, etc. Rainfall and earthquake are the two most common factors. Up to now, it is still the focus of slope stability research. Therefore, the analysis and study of the relationship between slope and rainfall or earthquake will play a very important role in slope instability prevention and remediation. According to the present situation of slope stability under the influence of rainfall and earthquake and the unsolved problems, this paper takes the debris landslide of building mountain as the engineering background, and establishes the FLAC3D three-dimensional numerical model. The influence of rainfall and earthquake on the stability of gravel slope and its failure mechanism are analyzed. The main contents of this paper include the following aspects: 1) taking homogeneous slope as an example, FLAC3D strength reduction method is used to calculate the slope stability coefficient under the condition of single factor change, and the sensitivity analysis method is used to analyze the influence degree of each influencing factor on slope stability. The influence of various factors on the stability of gravel slope is obtained as follows: internal friction angle slope angle cohesion soil density. (2) the FLAC3D numerical calculation model of rockfill landslide is established, and the stress field, displacement field, plastic zone and shear strain increment distribution law of slope under the influence of rainfall are analyzed, and the failure mechanism of slope under the influence of rainfall is studied. The results show that the stability of macadam slope decreases slowly and then decreases sharply with the increase of moisture content under rainfall condition, and has obvious critical characteristics. The critical point of slope stability change is water content of 11.3%. 3) the stress field, displacement field, plastic zone and shear strain increment distribution of slope under earthquake are analyzed by using FLAC3D numerical model, and the failure mechanism of slope under earthquake load is studied. The results show that, under the action of very small earthquake load, the gravel slope will lose stability, and the failure degree of the slope will increase with the increase of horizontal acceleration of the earthquake, and the crushed soil slope will mainly be destroyed under the earthquake, and the failure degree of the gravel slope will increase with the increase of the horizontal acceleration of the earthquake. Only a small area of tensile stress occurs at the top of the slope, but at the bottom of the gravel slope, the soil is subjected to biaxial compression and shear failure because of the change of the direction of the principal stress. (4) the stress field, displacement field, plastic zone and shear strain increment distribution of slope under the action of rainfall and earthquake are analyzed by using FLAC3D numerical calculation model, and the failure mechanism of slope instability under the joint action of rainfall and earthquake is studied. The results show that the slope stability is lower when the earthquake and rainfall work together than the earthquake or rainfall alone, and the stability of the gravel slope decreases gradually with the increase of the seismic load when the water content remains constant. With the increase of water content, the stability of gravel slope decreases gradually when the horizontal acceleration of earthquake remains unchanged. In this paper, the failure mechanism of slope instability caused by rainfall, earthquake, rainfall and earthquake is analyzed, and the failure mode and development process of gravel slope caused by rainfall infiltration and earthquake vibration are fully revealed. The variation characteristics of slope stability of gravel soil under the influence of rainfall and earthquake are given, thus providing more suitable experience for preventing and rectifying slope instability.
【學(xué)位授予單位】：蘭州交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2013
【分類號】：TU43

【參考文獻】

相關(guān)期刊論文 前10條

1 譚曉慧;平面滑動邊坡的可靠度計算及敏感性分析[J];安徽地質(zhì);2001年01期

2 時衛(wèi)民,鄭宏錄,劉文平,鄭穎人;三峽庫區(qū)碎石土抗剪強度指標(biāo)的試驗研究[J];重慶建筑;2005年02期

3 欒茂田,武亞軍,年廷凱;強度折減有限元法中邊坡失穩(wěn)的塑性區(qū)判據(jù)及其應(yīng)用[J];防災(zāi)減災(zāi)工程學(xué)報;2003年03期

4 吳兆營,薄景山,劉紅帥,丁仁杰,齊文浩,劉德東;巖體邊坡地震穩(wěn)定性動安全系數(shù)分析方法[J];防災(zāi)減災(zāi)工程學(xué)報;2004年03期

5 朱向東;尚岳全;;碎石土邊坡破壞機理的敏感性分析[J];防災(zāi)減災(zāi)工程學(xué)報;2007年01期

6 言志信;張森;張學(xué)東;段建;;地震邊坡失穩(wěn)機理及穩(wěn)定性分析[J];工程地質(zhì)學(xué)報;2010年06期

7 齊云龍;周勇;黃棟;;地震和降雨作用下的邊坡穩(wěn)定性分析[J];科學(xué)技術(shù)與工程;2010年26期

8 寧萬輝;寧健;俞美華;柯傳芳;;降雨對碎石土邊坡穩(wěn)定性的影響分析[J];水電能源科學(xué);2011年01期

9 吳兆營,景立平,薄景山;土石壩地震穩(wěn)定性分析評述[J];世界地震工程;2003年01期

10 陳天健;蔡和倫;黃彥榮;顏宏益;張佑舜;;人工降雨模型試驗研究降雨入滲對滑坡類型之影響[J];水土保持研究;2012年01期

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