抗滑桩嵌固段最小临坡距及无效嵌固深度研究

发布时间：2018-09-13 15:33

【摘要】：在现有的抗滑桩设计中,一般是把抗滑桩设置于滑面平缓的地段,将嵌固段视为半无限空间,并以此来进行抗滑桩嵌固深度的设计和稳定性计算。当斜坡场地的抗滑桩嵌固段土体由于地形或人工开挖造成嵌固段出现临坡或倾斜地形时,抗滑桩的稳定性会受到相应的影响。对于嵌固段临坡的地形,当抗滑桩嵌固段的临坡距过小,达不到半无限空间状态时,抗滑桩的侧向承载能力就会相应降低。对于嵌固段倾斜的地形,抗滑桩的稳定性会直接受到斜坡地形的影响。目前对于嵌固段临坡或倾斜条件下抗滑桩桩前土体稳定性的研究也不足。因此有必要对嵌固段临坡条件下的最小临坡距与倾斜条件下的无效嵌固深度进行研究,以便给实际工程中嵌固段临坡或倾斜条件下的抗滑桩设计、施工及其稳定性计算提供参考。本文提出了碎石土斜坡场地条件下的抗滑桩嵌固段最小临坡距的取值方法,结合数值模拟和物理模拟研究了各因素对最小临坡距的影响,提出了最小临坡距计算公式。并结合最小临坡距,提出了抗滑桩无效嵌固深度的计算公式。主要结论如下:(1)借鉴《建筑地基基础设计规范理解与应用》中边坡地基最小临坡距取值方法,提出了抗滑桩嵌固段的最小临坡距取值方法。并根据最小临坡距,提出了无效嵌固深度的计算方法。(2)用flac3d数值模拟定性、定量的研究了嵌固深度、坡度、滑坡推力、滑坡推力作用点对最小临坡距的影响,发现最小临坡距随滑坡推力、坡度的增加而增加,随嵌固深度的增加而减少,与滑坡推力作用点的关系不大。并验证了数值模拟中最小临坡距取值方法的适用性。(3)用物理模拟的实验方法定性、定量的分析了嵌固深度、坡度、推力对最小临坡距的影响,发现各因素对最小临坡距的影响与数值模拟中的一致。并验证了物理模拟中最小临坡距取值方法的适用性。(4)结合正交实验方法拟合出了最小临坡距和无效嵌固深度的计算公式。
[Abstract]:In the existing anti-slide pile design, the anti-slide pile is generally set in the smooth section of the slide surface, and the fixed segment is regarded as a semi-infinite space, and the design and stability calculation of the embedded depth of the anti-slide pile are carried out. The stability of the anti-slide pile will be affected when the slope or slope is caused by the landform or artificial excavation. The lateral bearing capacity of the anti-slide pile will be reduced when the distance between the adjacent slopes of the embedded section is too small to reach the semi-infinite space state for the landform near the slope of the embed section and the lateral bearing capacity of the anti-slide pile will be reduced accordingly. The stability of anti-slide pile is directly affected by the slope terrain for the slope. At present, the study on the stability of soil in front of anti-slide pile under the condition of embed slope or slope is also insufficient. Therefore, it is necessary to study the minimum distance between the adjacent slope of the embedded section and the invalid depth of the embedded section in order to design the anti-slide pile under the condition of the embed section or the slope in the actual engineering. Construction and stability calculation provide reference. In this paper, the method of selecting the minimum critical slope distance of the fixed section of anti-slide pile in the condition of gravel soil slope site is put forward. The influence of various factors on the minimum critical slope distance is studied by combining numerical simulation and physical simulation, and the formula for calculating the minimum critical slope distance is put forward. The formula for calculating the invalid embedded depth of anti-slide pile is put forward based on the minimum critical slope distance. The main conclusions are as follows: (1) based on the method of determining the minimum critical distance of slope foundation in the Code for Design and Application of Building Foundation, a method for determining the minimum critical slope distance of the embedded section of anti-slide pile is put forward. According to the minimum critical slope distance, the calculation method of invalid embedded depth is put forward. (2) the influence of embedded depth, slope and landslide thrust on the minimum critical slope distance is quantitatively studied by flac3d numerical simulation. It is found that the minimum slope distance increases with the increase of the thrust of the landslide and decreases with the increase of the embedded depth, which has little relationship with the action point of the thrust of the landslide. The applicability of the minimum critical slope distance method in numerical simulation is verified. (3) the influence of the embedded depth, slope and thrust on the minimum critical slope distance is analyzed qualitatively and quantitatively by the physical simulation method. It is found that the influence of various factors on the minimum critical slope distance is consistent with that in the numerical simulation. The applicability of the minimum critical slope distance method in physical simulation is verified. (4) the formulas for calculating the minimum critical slope distance and the invalid embedded depth are fitted with the orthogonal experimental method.
【学位授予单位】：成都理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU473.1;P642.22

【参考文献】