本文關鍵詞：基于位移變化率和強度折減有限元的邊坡失穩(wěn)判定方法　出處：《農業(yè)工程學報》2017年15期 　論文類型：期刊論文

  更多相關文章： 邊坡穩(wěn)定性 模型 邊界條件 強度折減法 有限元法 位移變化率

【摘要】：采用強度折減有限元法計算邊坡穩(wěn)定時,以變形為基礎的失穩(wěn)判據具有顯著的物理意義和工程意義。該文采用變步長的折減方法,基于位移變化率-強度折減系數曲線的轉折突變作為失穩(wěn)判據,并研究特征點的敏感性及選取范圍。計算結果表明,當折減系數為1.42時,坡頂水平位移變化率、豎向位移變化率和總位移變化率均發(fā)生急劇性的轉折。與位移相比,位移變化率-強度折減系數的曲線存在明顯的轉折突變,可更準確、明顯地判斷邊坡穩(wěn)定的安全度。至坡頂一定距離范圍內的特征點,如位于非塑性區(qū)域且非滑動土體時,其位移變化率-強度折減系數的曲線發(fā)生轉折突變,但曲線在轉折點附近存在振蕩現(xiàn)象。通過位移變化率計算得到的54個安全系數,平均值為1.420,變異系數為0.005 3,不同特征點根據水平位移變化率、豎向位移變化率和總位移變化率得到的安全系數基本一致。當特征點至坡頂的距離≤1倍坡高時,特征點的位移12 mm,且位移變化率均較大,此時特征點對位移變化率較敏感;當特征點至坡頂的距離1倍坡高時,特征點位移在5~18 mm之間,但位移變化率大幅度降低,此時特征點對位移變化率的敏感性大幅度降低�？紤]邊界約束的影響及特征點的敏感性,建議特征點的選取范圍為:與坡頂距離為1倍坡高的范圍。
[Abstract]:When the strength reduction finite element method is used to calculate the slope stability, the deformation-based instability criterion is of great physical and engineering significance. In this paper, the variable step reduction method is adopted. Based on the abrupt change of displacement rate-strength reduction coefficient curve as the criterion of instability, the sensitivity and selection range of characteristic points are studied. The calculation results show that when the reduction coefficient is 1.42. The change rate of horizontal displacement, vertical displacement and total displacement of the top of the slope have a sharp turning point. Compared with the displacement, the curve of displacement change rate and strength reduction coefficient has obvious abrupt change and can be more accurate. The characteristic points within a certain distance from the top of the slope, such as in the non-plastic region and non-sliding soil, the curve of displacement change rate and strength reduction coefficient has a turning and abrupt change. But there is oscillation near the turning point, 54 safety factors calculated by displacement change rate, the average value is 1.420, and the coefficient of variation is 0.0053. According to horizontal displacement rate, vertical displacement change rate and total displacement change rate, the safety coefficient of different characteristic points is basically the same. When the distance from the feature point to the top of the slope is 鈮，

本文編號：1431733