發(fā)布時間：2018-03-23 14:35

  本文選題：復(fù)合土釘墻　切入點(diǎn)：變形　出處：《西南交通大學(xué)》2017年碩士論文

【摘要】：土釘+預(yù)應(yīng)力錨索+攪拌樁復(fù)合基坑支護(hù)結(jié)構(gòu)在工程中得到了廣泛應(yīng)用,但是現(xiàn)階段關(guān)于該結(jié)構(gòu)工作特性的研究成果還較少,導(dǎo)致理論明顯滯后于工程實(shí)踐。針對這一現(xiàn)狀,本文結(jié)合工程實(shí)例,采用 Midas/GTS(Geotechnical and Tunnel Analysis System)有限元分析程序?qū)υ擃愋蛷?fù)合土釘支護(hù)結(jié)構(gòu)的工作性狀進(jìn)行了詳細(xì)分析,得到的研究成果及結(jié)論如下:1.通過對基坑變形的監(jiān)測數(shù)據(jù)與Midas/GTS有限元程序計(jì)算結(jié)果比較分析,結(jié)果表明,該有限元程序能較好地模擬基坑的工作性狀。2.加入攪拌樁后,支護(hù)結(jié)構(gòu)的受力變形性狀發(fā)生了明顯變化,復(fù)合結(jié)構(gòu)的變形形態(tài)與樁錨式支護(hù)結(jié)構(gòu)相似,其側(cè)向變形呈中間大、上下兩端較小的變化規(guī)律,且最大值約在0.75倍開挖深度處,土釘?shù)妮S力呈沿長度方向遞減的變化趨勢。3.按照軸力的不同分布形態(tài),可以將土釘分為軸力遞增型、弓形及軸力遞減型三種。軸力遞增型土釘主要分布在基坑的上部,其軸力沿土釘長度方向遞增;軸力呈弓形的土釘主要分布在基坑的中部,其軸力為中間最大,兩端較小;軸力遞減型土釘主要分布在基坑的下部,其軸力在土釘與攪拌樁接觸的部位最大,往后逐漸減小。4.施加預(yù)應(yīng)力能有效控制基坑的側(cè)向變形,且預(yù)應(yīng)力施加在基坑的側(cè)向變形最大值對應(yīng)的部位時,對變形的限制效果最好。5.在基坑的穩(wěn)定性計(jì)算中,其穩(wěn)定性系數(shù)取基坑強(qiáng)度折減計(jì)算不收斂對應(yīng)的強(qiáng)度折減系數(shù)存在不合理之處,取基坑強(qiáng)度折減系數(shù)與側(cè)向變形關(guān)系曲線中拐點(diǎn)對應(yīng)的折減系數(shù)作為基坑的穩(wěn)定性系數(shù)更為合理。6.影響支護(hù)結(jié)構(gòu)穩(wěn)定性的因素包括土釘?shù)拈L度、坑底超挖深度、攪拌樁的直徑及嵌固深度等,其中,基坑下部土釘?shù)拈L度是影響基坑穩(wěn)定性的關(guān)鍵因素。
[Abstract]:Soil nailing prestressed anchor cable mixing pile composite foundation pit support structure has been widely used in engineering, but at present, there are few research results on the working characteristics of the structure, which leads to the theory obviously lagging behind the engineering practice. In this paper, the working behavior of this type of composite soil nailing support structure is analyzed in detail by using Midas/GTS(Geotechnical and Tunnel Analysis system finite element analysis program combined with an engineering example. The research results and conclusions are as follows: 1.Through comparing the monitoring data of foundation pit deformation with the results of Midas/GTS finite element program, the results show that the finite element program can simulate the working behavior of foundation pit. The deformation behavior of the supporting structure has changed obviously. The deformation pattern of the composite structure is similar to that of the pile-anchor support structure. The lateral deformation of the composite structure is large in the middle, the upper and lower ends are smaller, and the maximum value is about 0.75 times of the excavation depth. The axial force of soil nailing tends to decrease in the direction of length. According to the different distribution form of axial force, the soil nailing can be divided into three types: axial force increasing type, arch type and axial force decreasing type. The axial force increasing type soil nailing mainly distributes in the upper part of foundation pit. The axial force increases gradually along the length of the soil nailing, the axial force of the soil nailing with bow shape is mainly distributed in the middle of the foundation pit, the axial force is the largest in the middle and the two ends are small, and the decreasing axial force is mainly distributed in the lower part of the foundation pit. The axial force is the largest in the contact part between soil nailing and mixing pile, and then gradually decreases .4.When the application of prestress can effectively control the lateral deformation of foundation pit, and the prestress is applied to the position corresponding to the maximum lateral deformation of foundation pit, In the calculation of the stability of foundation pit, the stability coefficient is taken from the strength reduction calculation of foundation pit, and the strength reduction coefficient corresponding to the convergence of the strength reduction calculation of foundation pit is unreasonable. It is more reasonable to take the reduction coefficient corresponding to the inflexion point in the curve of strength reduction and lateral deformation of foundation pit as the stability coefficient of foundation pit. The factors affecting the stability of supporting structure include the length of soil nailing, the depth of overdigging at the bottom of the pit. Among them, the length of soil nailing at the bottom of the foundation pit is the key factor affecting the stability of the foundation pit.
【學(xué)位授予單位】：西南交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2017
【分類號】：TU753

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 黃銳;羅書學(xué);高勝君;陳良軍;;坑底局部超挖對復(fù)合土釘受力性狀的影響研究[J];路基工程;2016年06期

2 彭文祥;謝雨軍;徐松山;王苑;錢華;;預(yù)應(yīng)力錨桿復(fù)合土釘墻工作性狀試驗(yàn)研究[J];中南大學(xué)學(xué)報(bào)(自然科學(xué)版);2015年04期

3 王輝;程建華;趙洪波;;考慮預(yù)應(yīng)力的復(fù)合土釘支護(hù)結(jié)構(gòu)側(cè)移計(jì)算[J];廣西大學(xué)學(xué)報(bào)(自然科學(xué)版);2014年04期

4 陳云生;劉佑榮;;復(fù)合土釘支護(hù)結(jié)構(gòu)的FLAC~(3D)三維仿真分析[J];四川建筑科學(xué)研究;2014年02期

5 朱逢斌;繆林昌;顧歡達(dá);程月紅;;A case study on behaviors of composite soil nailed wall with bored piles in a deep excavation[J];Journal of Central South University;2013年07期

6 劉斌;楊敏;;攪拌樁對復(fù)合土釘墻整體穩(wěn)定系數(shù)的影響分析[J];建筑科學(xué)與工程學(xué)報(bào);2012年02期

7 周健;李飛;張姣;崔積弘;;復(fù)合土釘墻支護(hù)基坑顆粒流數(shù)值模擬研究[J];同濟(jì)大學(xué)學(xué)報(bào)(自然科學(xué)版);2011年07期

8 應(yīng)惠清;顧浩聲;;軟土地區(qū)土釘現(xiàn)場試驗(yàn)及土釘結(jié)構(gòu)的穩(wěn)定性分析[J];巖石力學(xué)與工程學(xué)報(bào);2011年05期

9 俞登華;尹驥;;復(fù)合土釘支護(hù)基坑位移和穩(wěn)定性的有限元分析[J];巖土工程學(xué)報(bào);2010年S1期

10 董誠;鄭穎人;陳新穎;唐曉松;;深基坑土釘和預(yù)應(yīng)力錨桿復(fù)合支護(hù)方式的探討[J];巖土力學(xué);2009年12期

，

本文編號：1653885