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陸鳳池1，  葉海桃2

(1南京金宸建筑設(shè)計(jì)有限公司，南京210019; 2長江南京航道工程局，南京210011)

 

[摘要] 頂管工程中，由于頂力的作用具有間歇性和短暫性，且被動土壓力所需的位移量遠(yuǎn)大于主動土壓力所需的位移量，因此后背土體被壓實(shí)至剪切破壞時，前壁土體與井壁會產(chǎn)生短暫性脫空，從而在計(jì)算沉井水平承載力時可以不考慮前壁主動土壓力的作用，僅考慮井底、井側(cè)摩阻力和后背土壓力的作用。根據(jù)井壁后背土體剪切破壞條件，推導(dǎo)出了后背土壓力計(jì)算公式。從該公式可以看出，圓形沉井后背土體徑向土壓力增量按正弦函數(shù)形式分布。通過算例分析可知，本文計(jì)算方法是可行的。

[關(guān)鍵詞] 頂管；沉井；土反力；頂力；水平承載力

中圖分類號：TU753.4    文獻(xiàn)標(biāo)識碼：A  文章編號：1002-848X(2012) S2-0523-04

 

Lu Fengchi1, Ye Haitao2

(1 Nanjing Kingdom Architecture Design Co., Ltd., Nanjing 210019, China; 2 Nanjing Changjiang Waterway Engineering Bureau, Nanjing 210011, China)

 

Abstract: Jacking force is intermittent and transient in pipe jacking engineering, and the displacement of the maximum passive earth pressure is much greater than the active earth pressure'. Therefore, when the soil of the back wall of sinking well is shear failure,  the soil of front wall will be separated from the sinking well. The horizontal bearing capacity of sinking well is consist of bottom friction, lateral wall friction and passive earth pressure of back wall without active earth pressure of front wall. The formula of earth pressure was derived according to shear failure of the soil of the back wall. It shows that the radial earth pressure mcrement of back wall is distributed on circular sinking well by sinusoidal function form. The method of this paper is feasible by the analysis of a case.

Keywords: pipe jacking; sinking well; earth counterforce; jacking force; horizontal bearing capacity