岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2014年
11期
2351-2359
,共9页
土力学%承载力%极限平衡%浅埋矩形基础%滑动面%正应力
土力學%承載力%極限平衡%淺埋矩形基礎%滑動麵%正應力
토역학%승재력%겁한평형%천매구형기출%활동면%정응력
soil mechanics%bearing capacity%limit equilibrium%rectangular shallow footing%slip surface%normal stress
提出一种能够计算浅埋矩形基础地基承载力的三维分析方法。首先,假设滑动面为一组由沿基础长轴方向的具有不同初始半径的螺旋线构成的三维椭球滑面;然后,对基于滑面正应力修正的三维边坡极限平衡方法进行改进,建立基于滑面正应力修正的计算固定三维滑面极限承载力方法;最后,通过改变螺旋线极点位置,构造所有可能破坏的滑动面,试算不同滑面所对应的极限承载力,搜索出的最小值即为基础极限承载力,其对应的滑面即为破坏滑动面。为使该方法能用传统的叠加法公式进行地基承载力计算,给出三维条件下的各地基承载力系数值,并研究基础长宽比和土的内摩擦角对各系数的影响。用该方法和给出的三维地基承载力系数分别对算例进行计算分析,并和其他方法进行比较,结果表明该方法合理可靠,能够方便、快速计算矩形基础地基承载力。
提齣一種能夠計算淺埋矩形基礎地基承載力的三維分析方法。首先,假設滑動麵為一組由沿基礎長軸方嚮的具有不同初始半徑的螺鏇線構成的三維橢毬滑麵;然後,對基于滑麵正應力脩正的三維邊坡極限平衡方法進行改進,建立基于滑麵正應力脩正的計算固定三維滑麵極限承載力方法;最後,通過改變螺鏇線極點位置,構造所有可能破壞的滑動麵,試算不同滑麵所對應的極限承載力,搜索齣的最小值即為基礎極限承載力,其對應的滑麵即為破壞滑動麵。為使該方法能用傳統的疊加法公式進行地基承載力計算,給齣三維條件下的各地基承載力繫數值,併研究基礎長寬比和土的內摩抆角對各繫數的影響。用該方法和給齣的三維地基承載力繫數分彆對算例進行計算分析,併和其他方法進行比較,結果錶明該方法閤理可靠,能夠方便、快速計算矩形基礎地基承載力。
제출일충능구계산천매구형기출지기승재력적삼유분석방법。수선,가설활동면위일조유연기출장축방향적구유불동초시반경적라선선구성적삼유타구활면;연후,대기우활면정응력수정적삼유변파겁한평형방법진행개진,건립기우활면정응력수정적계산고정삼유활면겁한승재력방법;최후,통과개변라선선겁점위치,구조소유가능파배적활동면,시산불동활면소대응적겁한승재력,수색출적최소치즉위기출겁한승재력,기대응적활면즉위파배활동면。위사해방법능용전통적첩가법공식진행지기승재력계산,급출삼유조건하적각지기승재력계수치,병연구기출장관비화토적내마찰각대각계수적영향。용해방법화급출적삼유지기승재력계수분별대산례진행계산분석,병화기타방법진행비교,결과표명해방법합리가고,능구방편、쾌속계산구형기출지기승재력。
A new method was proposed for three-dimensional analysis of the bearing capacity of shallow rectangular footing based on the modification of normal stresses over the slip surface. Firstly,the shape of the slip surface was assumed as an ellipsoid composed of a set of log-spirals with different initial radii in the direction of the longer axis of the footing base. Secondly , a method for calculating the bearing capacity of a fixed three-dimensional slip surface was established based on the modification of normal stresses over the slip surface to improve the limit equilibrium solution of 3D slope stability. Finally,the bearing capacities were obtained for the footing with selected fixed three-dimensional slip surfaces resulted from changing the positions of the pole of log-spirals so that the minimum bearing capacity was determined. The bearing capacity coefficients were then given for calculating the bearing capacity with the method of superposition in the conventional bearing capacity formula. The effects of the angle of internal friction and the length-width ratio of footing were investigated. An example was presented to calculate the bearing capacity and the calculated results were compared with those from other methods. The results demonstrate its accuracy,reasonability and high effectiveness in the three-dimensional bearing capacity analysis of rectangular shallow footing.