本文關(guān)鍵詞：基于位移變化率和強(qiáng)度折減有限元的邊坡失穩(wěn)判定方法　出處：《農(nóng)業(yè)工程學(xué)報(bào)》2017年15期 　論文類型：期刊論文

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

【摘要】：采用強(qiáng)度折減有限元法計(jì)算邊坡穩(wěn)定時(shí),以變形為基礎(chǔ)的失穩(wěn)判據(jù)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(qiáng)度折減系數(shù)曲線的轉(zhuǎn)折突變作為失穩(wěn)判據(jù),并研究特征點(diǎn)的敏感性及選取范圍。計(jì)算結(jié)果表明,當(dāng)折減系數(shù)為1.42時(shí),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(zhuǎn)折。與位移相比,位移變化率-強(qiáng)度折減系數(shù)的曲線存在明顯的轉(zhuǎn)折突變,可更準(zhǔn)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(nèi)的特征點(diǎn),如位于非塑性區(qū)域且非滑動(dòng)土體時(shí),其位移變化率-強(qiáng)度折減系數(shù)的曲線發(fā)生轉(zhuǎn)折突變,但曲線在轉(zhuǎn)折點(diǎn)附近存在振蕩現(xiàn)象。通過位移變化率計(jì)算得到的54個(gè)安全系數(shù),平均值為1.420,變異系數(shù)為0.005 3,不同特征點(diǎn)根據(jù)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(shù)基本一致。當(dāng)特征點(diǎn)至坡頂?shù)木嚯x≤1倍坡高時(shí),特征點(diǎn)的位移12 mm,且位移變化率均較大,此時(shí)特征點(diǎn)對(duì)位移變化率較敏感;當(dāng)特征點(diǎn)至坡頂?shù)木嚯x1倍坡高時(shí),特征點(diǎn)位移在5~18 mm之間,但位移變化率大幅度降低,此時(shí)特征點(diǎn)對(duì)位移變化率的敏感性大幅度降低。考慮邊界約束的影響及特征點(diǎn)的敏感性,建議特征點(diǎn)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(hào)：1431733