天堂国产午夜亚洲专区-少妇人妻综合久久蜜臀-国产成人户外露出视频在线-国产91传媒一区二区三区

當(dāng)前位置:主頁 > 科技論文 > 交通工程論文 >

黃土溝谷地區(qū)橋梁樁基加固技術(shù)的應(yīng)用研究

發(fā)布時間:2018-08-05 11:33
【摘要】:黃土溝谷地區(qū)雨水和橋梁上部結(jié)構(gòu)排水長期沖刷作用下,橋梁樁周護(hù)坡產(chǎn)生不同程度的沖刷破壞,使單排雙柱式樁基產(chǎn)生承載能力不足、沉降與不均勻沉降等諸多問題。直接影響樁基結(jié)構(gòu)的正常使用和安全性,,對橋梁上部結(jié)構(gòu)的正常工作也產(chǎn)生極大隱患。 首先,在對樁基不同沖刷病害進(jìn)行識別的基礎(chǔ)上,結(jié)合對典型病害進(jìn)行的原因分析,建立了樁基水流沖刷破壞過程模型,并在此基礎(chǔ)上提出針對沖刷破壞的樁基混凝土結(jié)構(gòu)承載能力和耐久性評估方法。其次,在分析沖刷破壞對樁基豎向和橫向承載能力影響時,結(jié)合沖刷破壞后樁背側(cè)向土壓力對樁身的作用機理,通過建立在豎向力、橫向力和彎矩共同作用下的樁基復(fù)雜受力模型,得出了基于“m”法的樁身撓曲方程,分析了樁身水平位移、轉(zhuǎn)角、彎矩、剪力和樁側(cè)土抗力的變化規(guī)律,分析結(jié)果有助于對復(fù)雜受力狀態(tài)下的樁基承載能力及安全狀態(tài)作出評定。最后,在樁基加固方案初步設(shè)計的基礎(chǔ)上,通過有限差分軟件FLAC3D,使用NULL單元進(jìn)行沖刷過程模擬、ELASTIC、SHELL和CABLE單元進(jìn)行加固過程的模擬,建立了樁基典型沖刷病害全程數(shù)值模擬樁-土模型,分析了樁-土模型矢量變形、位移、樁身應(yīng)力、摩阻力、錨桿力在沖刷-加固全程中的變化,對結(jié)構(gòu)體系最大不平衡力和關(guān)鍵點進(jìn)行了全程跟蹤。通過數(shù)值計算結(jié)果可知,樁周土體沖刷破壞使樁身產(chǎn)生橫向撓曲、樁身出現(xiàn)拉應(yīng)力、產(chǎn)生反彎點、沉降值過大、承載能力不足等諸多問題,使樁基處于極不安全的狀態(tài),通過樁底高壓噴射注漿形成固結(jié)體、土體中打入錨桿和混凝土護(hù)面,能夠有效改善樁基不利受力,使整個樁-土體系處于較為安全的狀態(tài)。 本文針對不同沖刷破壞程度提出的加固關(guān)鍵技術(shù)和坡面防護(hù)技術(shù)相結(jié)合的加固方案初步設(shè)計可操作性強、加固效果明顯,能夠有效的解決實際工程中的問題,為今后同類問題的解決有借鑒意義。
[Abstract]:Under the long-term scour action of Rain Water and superstructure drainage in loess gully area, the slope protection around the bridge pile produces different degree of scour damage, resulting in many problems such as insufficient bearing capacity of single row double-column pile foundation, settlement and uneven settlement and so on. It directly affects the normal use and safety of pile foundation structure, and also has great hidden danger to the normal work of bridge superstructure. Firstly, on the basis of identifying the different erosion diseases of pile foundation, combined with the analysis of the causes of the typical diseases, the model of pile foundation erosion failure process is established. On this basis, a method for evaluating the bearing capacity and durability of pile foundation concrete structures with scour failure is proposed. Secondly, when analyzing the influence of erosion failure on the vertical and lateral bearing capacity of pile foundation, combined with the action mechanism of lateral earth pressure on pile body after erosion failure, through the establishment of vertical force, The complex force model of pile foundation under the action of transverse force and bending moment is obtained. The deflection equation of pile body based on "m" method is obtained, and the variation law of horizontal displacement, rotation angle, bending moment, shear force and soil resistance of pile side is analyzed. The analysis results are helpful to evaluate the bearing capacity and safety state of pile foundation under complex loading condition. Finally, on the basis of the preliminary design of the reinforcement scheme of pile foundation, through the finite difference software FLAC3D, the NULL element is used to simulate the scouring process and the CABLE element is used to simulate the strengthening process. The pile-soil model for the whole process of typical erosion disease of pile foundation is established, and the variation of vector deformation, displacement, stress of pile body, friction resistance and anchor force in the whole course of scouring and strengthening are analyzed. The maximum unbalanced force and key points of the structure system are tracked in the whole process. The results of numerical calculation show that the soil scour failure around the pile causes the pile body to produce transverse deflection, the pile body appears tensile stress, produces the reverse bending point, the settlement value is too large, the bearing capacity is insufficient and so on, so the pile foundation is in an extremely unsafe state. The consolidation body is formed by high pressure jet grouting at the bottom of the pile, and the anchor rod and the concrete surface are pushed into the soil, which can effectively improve the unfavorable force of the pile foundation and make the whole pile-soil system in a relatively safe state. In this paper, according to different scour failure degree, the key technology of reinforcement and slope protection technology are put forward. The preliminary design of reinforcement scheme is feasible, and the effect of reinforcement is obvious, which can effectively solve the problems in practical engineering. It can be used for reference for solving similar problems in the future.
【學(xué)位授予單位】:長安大學(xué)
【學(xué)位級別】:碩士
【學(xué)位授予年份】:2014
【分類號】:U443.15;U445.72

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 龍剛;宣以瓊;;高壓旋噴樁在橋梁樁基加固工程中的應(yīng)用[J];安徽建筑工業(yè)學(xué)院學(xué)報(自然科學(xué)版);2010年03期

2 楊明龍;高明贊;;樁底注漿技術(shù)在橋梁樁基加固中的應(yīng)用實例[J];湖南交通科技;2010年04期

3 楊勇;廖原;;高壓旋噴鋼管樁在橋梁樁基加固中的應(yīng)用[J];廣東建材;2010年06期

4 魏洪昌;;增補樁基加固法系統(tǒng)研究[J];公路交通科技;2006年S1期

5 王斌;;樁基礎(chǔ)在濕陷性黃土的應(yīng)用和發(fā)展[J];甘肅科技;2008年08期

6 丘偉,曾紅華;廣韶線流溪河大橋的橋梁樁基加固補強方法[J];廣西交通科技;2003年04期

7 何潤景;;淺談橋梁缺陷樁基成因及常見加固方法[J];黑龍江交通科技;2008年07期

8 萬友明;高壓噴射注漿技術(shù)及其在公路工程中的應(yīng)用[J];湖南城建高等?茖W(xué)校學(xué)報;2003年03期

9 馮忠居,馮瑞玲,趙占廠,謝永利;黃土濕陷性對橋梁樁基承載力的影響[J];交通運輸工程學(xué)報;2005年03期

10 何秋萍;楊天森;;淺析基樁的負(fù)摩阻力[J];巖土工程界;2005年12期



本文編號:2165669

資料下載
論文發(fā)表

本文鏈接:http://sikaile.net/kejilunwen/jiaotonggongchenglunwen/2165669.html


Copyright(c)文論論文網(wǎng)All Rights Reserved | 網(wǎng)站地圖 |

版權(quán)申明:資料由用戶0f1bc***提供,本站僅收錄摘要或目錄,作者需要刪除請E-mail郵箱bigeng88@qq.com