本文關鍵詞： 重力式擋土墻 主動土壓力 統(tǒng)一強度理論 有限填土 遺傳算法 優(yōu)化設計　出處：《湖南大學》2015年碩士論文　論文類型：學位論文

【摘要】：隨著城市的不斷發(fā)展,土地資源愈發(fā)緊張,經(jīng)常發(fā)生擬建建筑基坑擋墻與既有建筑地下室外墻相隔很近的情況。對于山區(qū)擋土墻,常因靠近巖石邊坡,從而形成有限填土空間。若運用庫倫和朗金理論來計算土壓力,則需要墻后填土有足夠的寬度,以使滑裂面充分發(fā)展。因此,有限填土情況下的擋土墻土壓力計算和擋土墻截面優(yōu)化設計均亟待解決,且具有廣闊的前景。本文對擋土墻后有限填土土壓力以及擋土墻截面優(yōu)化設計進行了較為深入的探討,主要內容如下:首先,假定擋土墻后填土滑動面為通過墻踵的多楔體平面,基于極限平衡理論,推導得到了墻后填土區(qū)狹窄,墻面傾斜、粗糙,填土面向上傾斜,并考慮地面超載和地震影響的無黏性土主動土壓力解。隨著墻后填土寬度的改變,破壞模式實現(xiàn)從單楔體到雙楔體甚至三楔體的轉換,使得計算更加靈活。計算結果表明:隨著填土寬度的減小,土壓力隨之減少,且恒小于庫倫值。而當墻面傾角較大時,該方法與庫倫法差別較小。這是由于隨著墻面傾角的增加,填土頂面的寬度也隨之增加,使得其破壞模式傾向于與庫倫法相近的情況。然后,假定擋土墻后填土滑動面為通過墻踵的平面雙滑塊模式,基于MorhCoulomb強度理論和極限分析原理,推導出適用于無黏性土的主動土壓力解。結果表明:本方法得到的土壓力呈非線性分布,且土壓力強度隨深度增大而增大,在靠近墻底處其增幅逐漸減小。其次,假定擋土墻后填土滑動面為通過墻踵的對數(shù)螺旋面和平面組合模式,基于統(tǒng)一強度理論和極限分析原理,推導出適用于黏性土的主動土壓力解。當材料切應力系數(shù)B=2,統(tǒng)一強度理論回歸為Morh-Coulomb強度理論。結果表明:該方法所得土壓力系數(shù)大于本文以極限平衡理論為基礎提出的方法所得的解。這是由于基于極限分析方法所得解為土壓力的上限解,且土壓力合力作用點一直在變化,不總在距離墻踵1/3墻高處。最后,以擋土墻截面面積為目標函數(shù),以截面幾何參數(shù)為設計標量,將抗滑抗傾覆穩(wěn)定性、基底應力和結構構造要求作為約束條件,建立了有限填土重力式擋土墻優(yōu)化模型,提出了基于遺傳算法有限填土重力式擋土墻智能優(yōu)化計算方法,并基于MATLAB編制了優(yōu)化計算程序。將本方法應用于貴州某電廠擋墻設計,分析發(fā)現(xiàn):在滿足抗滑和抗傾覆的條件下,優(yōu)化后節(jié)約面積38%,符合經(jīng)濟效益。
[Abstract]:With the continuous development of the city, the land resources become more and more tight. It often happens that the retaining wall of foundation pit of the proposed building is very close to the exterior wall of the basement of the existing building. For the retaining wall of the mountain area, it is often due to being close to the rock slope. If Coulomb and Rankine theory are used to calculate the earth pressure, it is necessary to have enough width of the backfill to make the slip surface develop fully. The calculation of the earth pressure of the retaining wall and the optimum design of the section of the retaining wall under the condition of limited fill are urgent to be solved. In this paper, the finite fill pressure behind the retaining wall and the optimization design of the retaining wall section are discussed in depth. The main contents are as follows: first. Assuming that the sliding surface of the backfill of retaining wall is a multi-wedge plane passing through the heel of the wall, based on the limit equilibrium theory, the narrow backfill area, the slope of the wall surface, the roughness of the backfill surface and the upward inclination of the fill are derived. The active earth pressure solution of non-clay soil affected by ground overload and earthquake is taken into account. With the change of backfill width, the failure mode can be transformed from single wedge to double wedge or even three-wedge. The calculation results show that the earth pressure decreases with the decrease of the fill width and is always less than the Coulomb value. The difference between the method and the Coulomb method is small. This is because the width of the top surface increases with the increase of the inclination of the wall, which makes the failure mode tend to be similar to that of the Coulomb method. Then. It is assumed that the sliding surface of the backfill of retaining wall is a plane double-slide model passing through the heel of the wall, based on the MorhCoulomb strength theory and the limit analysis principle. The results show that the soil pressure obtained by this method is nonlinear, and the soil pressure intensity increases with the increase of depth. The increment decreases gradually near the bottom of the wall. Secondly, it is assumed that the sliding surface behind the retaining wall is a logarithmic spiral plane and a plane combination model passing through the heel of the wall, based on the unified strength theory and the limit analysis principle. The active earth pressure solution suitable for clay is derived. The unified strength theory is regressed to the Morh-Coulomb strength theory. The results show that:. The soil pressure coefficient obtained by this method is larger than that obtained by the method based on the limit equilibrium theory, which is due to the fact that the solution based on the limit analysis method is the upper limit solution of the earth pressure. And the earth pressure acting point has been changing, not always at the height of 1/3 wall from the heel of the wall. Finally, taking the cross-section area of retaining wall as the objective function and the geometric parameters of the section as the design scalar, the stability of anti-slide and anti-capsizing will be achieved. The optimization model of gravity retaining wall with finite fill is established and the intelligent optimization method of gravity retaining wall with limited fill based on genetic algorithm is proposed. This method is applied to the design of retaining wall of a power plant in Guizhou province. It is found that under the conditions of anti-skid and anti-overturning, the optimized area is saved by 38%. Accord with economic benefit.
【學位授予單位】：湖南大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TU476.4;TU432

【參考文獻】

相關期刊論文 前10條

1 王曉亮;李光范;杜娟;吳小鋒;;降雨和蒸發(fā)對非飽和土土壓力的影響[J];應用力學學報;2014年03期

2 應宏偉;朱偉;黃東;謝新宇;李冰河;;狹窄黏性填土剛性擋墻主動土壓力研究[J];巖土工程學報;2012年S1期

3 應宏偉;黃東;謝新宇;;考慮鄰近地下室外墻側壓力影響的平動模式擋土墻主動土壓力研究[J];巖石力學與工程學報;2011年S1期

4 張健;胡瑞林;劉海斌;王珊珊;;基于統(tǒng)一強度理論朗肯土壓力的計算研究[J];巖石力學與工程學報;2010年S1期

5 馬平;秦四清;錢海濤;;有限土體主動土壓力計算[J];巖石力學與工程學報;2008年S1期

6 黃亞娟;趙均海;田文秀;;基于雙剪統(tǒng)一強度理論的剛性結構物豎直土壓力計算[J];建筑科學與工程學報;2008年01期

7 李峰;郭院成;;基坑工程有限土體主動土壓力計算分析研究[J];建筑科學;2008年01期

8 陳棟梁;黨進謙;;重力式擋土墻的截面優(yōu)化設計研究[J];巖土力學;2007年09期

9 高江平;劉元烈;俞茂宏;;統(tǒng)一強度理論在擋土墻土壓力計算中的應用[J];西安交通大學學報;2006年03期

10 高江平;俞茂宏;;雙剪統(tǒng)一強度理論在空間主動土壓力計算中的應用[J];西安建筑科技大學學報(自然科學版);2006年01期

相關會議論文 前1條

1 李小春;許東俊;劉世煜;安民;;真三軸應力狀態(tài)下拉西瓦花崗巖的強度、變形及破裂特性試驗研究[A];中國巖石力學與工程學會第三次大會論文集[C];1994年

，

本文編號：1464259