【摘要】：隨著城市軌道交通、地下空間的開發(fā)以及超高層建筑等項目的日益增多,深基坑工程也越趨頻繁,其中,地下連續(xù)墻加鋼筋混凝土內支撐的支護體系是一種較新的用于深基坑支護的方法。本文以南寧市某采用地下連續(xù)墻加鋼筋混凝土內支撐支護結構的工程為例,利用有限元軟件Midas GTS對該工程進行數值分析。在從最大支撐軸力、地下連續(xù)墻最大變形及最大地表沉降值等三個方面驗證了支護方案可行的基礎上,分別對橫撐、縱撐和角撐的軸力隨著施工階段(荷載)的動態(tài)變化進行了分析,總結了支撐軸力隨施工階段的動態(tài)變化規(guī)律。針對目前基坑的規(guī)模大、施工工期長的特點,研究了溫度作用對支撐性能的影響,工況包括升溫和降溫兩個過程,從不同溫差、支撐溫度變化路徑及支撐問的溫度差異這三個方面研究了支撐軸力的動態(tài)變化規(guī)律及地下連續(xù)墻的變形規(guī)律。結果表明,溫度作用不論是對于支撐軸力還是連續(xù)墻的變形,其影響都是非常大的。文章還探究了支撐的穩(wěn)定性,推導了當支撐在自重、軸向壓力與立柱抬升等多種因素共同影響下支撐中部總彎矩的計算式及支撐的撓曲線方程。通過計算得出當立柱抬升的位移達到0.030m時,由立柱抬升引起的彎矩可占到支撐中部總彎矩的82.91%,可知立柱抬升對于支撐中部總彎矩的影響亦是十分顯著的。另外,從所推導的計算式可知基坑的寬度與支撐中部總彎矩有著密切的關系,因此還分析了基坑寬度和立柱抬升引起的支撐中部彎矩與支撐中部總彎矩的比值、支撐自重引起的支撐中部彎矩與支撐中部總彎矩的比值三者之間的關系。
[Abstract]:With the increasing number of projects such as urban rail transit, development of underground space and super-high-rise buildings, deep foundation pit projects are becoming more frequent, among which, The retaining system of underground continuous wall with reinforced concrete internal brace is a new method for deep foundation pit support. Taking a project with underground continuous wall and reinforced concrete internal bracing structure in Nanning as an example, the numerical analysis of this project is carried out by using the finite element software Midas GTS. On the basis of verifying the feasibility of the supporting scheme from three aspects: the maximum supporting axial force, the maximum deformation of the diaphragm wall and the maximum settlement value of the ground surface, the lateral brace is carried out separately. The dynamic variation of the axial force of the brace and the angle brace with the construction stage (load) is analyzed, and the rule of the dynamic variation of the axial force of the brace with the construction stage is summarized. In view of the characteristics of large scale and long construction period of foundation pit at present, the influence of temperature action on support performance is studied. The working conditions include heating up and cooling down, from different temperature difference. The dynamic variation law of supporting axial force and the deformation law of underground continuous wall are studied in three aspects: the path of supporting temperature change and the difference of supporting temperature. The results show that the effect of temperature on the axial force of bracing and the deformation of continuous wall is very great. The stability of the brace is also investigated, and the calculation formula of the total bending moment and the deflection curve equation of the brace under the influence of various factors, such as self-weight, axial pressure and column lift, are derived. The results show that the moment caused by column uplift can account for 82.91% of the total bending moment of the middle part of the bracing when the displacement of the column is 0.030m. It can be seen that the effect of the column lifting on the total bending moment of the middle part of the bracing is also very significant. In addition, the formula derived shows that the width of the foundation pit is closely related to the total bending moment in the middle of the bracing, so the ratio of the width of the foundation pit and the ratio of the central bending moment of the bracing to the total bending moment of the central bracing caused by the lifting of the column is also analyzed. The relationship between the ratio of the moment in the middle and the total moment in the middle of the brace caused by the weight of the brace.
【學位授予單位】：廣西大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TU753

【參考文獻】

相關期刊論文 前1條

1 馮虎;高丹盈;徐春蕾;;立柱隆起對深基坑鋼支撐受力特性的影響分析[J];地下空間與工程學報;2014年04期

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本文編號：2439384