抗滑桩嵌固段最小临坡距及无效嵌固深度研究
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。
关键词：抗滑桩最小临坡距无效嵌固深度数值模拟物理模拟
The rearch on the the minimum vertical distance and invalid embedded depth of embedded ction of anti-sliding
Abstract
In the design of the existing anti slide pile, the anti slide pile is generally arranged in the smooth part of the sliding surface, and the embedded ction is regarded as a mi infinite space. The stability of anti slide piles will be affected by the prence of slope or inclined terrain when the embedded ction of the anti slide pile is caud by topography or artificial excavation. For the slope of the emb
edded ction, the lateral bearing capacity of the anti slide pile will be reduced when the vertical distance of embedded ction of anti-sliding is too small to reach the state of mi infinite space. The stability of the anti slide pile is affected by the slope topography directly for the slope of the embedded ction. At prent, there are few rearches on the stability of anti slide piles in the slope or inclined terrain. It is necessary to rearch on the the minimum vertical distance in slope and Invalid embedment depth in inclined terrain, to provide reference for anti slide pile design and construction and stability calculation in slope or inclined terrain.
In this paper, the method of lecting the minimum vertical distance of the anti slide pile in gravel soil is put forward, and the influence of each factor on the minimum vertical distance has been analysis by numerical simulation and physical simulation. Bad on the minimum vertical distance, the calculation formula of the invalid embedded depth of anti slide pile is propod. The main conclusions are as follows:
(1) Bad on the method of minimum vertical distance of slope foundation in the code for design of building foundation, the paper puts forward the method of lecting the minimum vertical distance of anti slide piles. According to the minimum vertical distance of the slope, the calculation method of the invalid embedment depth is put forward.
(2) Using FLAC3D numerical simulation study of effect of buried depth, slope, landslide thrust ,action point of landslide thrust on minimum vertical distance, minimum vertical distance increas with increasing slope, landslide thrust, and decread with the increa of depth, with little relation to action point of landslide thrust. And the accuracy of the method for the determination of the minimum vertical distance in numerical simulation is verified.
(3) Using physical simulation experiment method to study of the effect of depth, slope, slope thrust on minimum vertical distance, and the effect on minimum vertical distance of the factors is the same with numerical simulation, and verify the accuracy of sampling method from physical simulation in the smallest Pro slope.
(4) The formula for calculating the minimum vertical distance and the invalid embedment depth is fitted with the orthogonal experimental method.
Key words: anti slide pile the minimum vertical distance invalid embedded depth numerical simulation physical simulation
目录
第1章引言 (1)
1.1 研究背景及意义 (1)
1.2 国内外研究现状及分析 (2)
1.2.1 侧向受荷桩研究现状 (2)
1.2.2 抗滑桩桩土相互作用研究现状 (4)
1.2.3 抗滑桩稳定性分析研究现状 (5)
1.2.4 主要存在的不足 (7)
1.3 研究内容和技术路线 (8)
1.3.1 研究内容 (8)
1.3.2 技术路线 (8)
第2章最小临坡距数值模拟研究 (10)
2.1 数值模拟模型 (10)
2.1.1 FLAC 3D简介 (10)
2.1.2 几何模型建立 (10)
2.2 模型计算参数 (12)
2.3 加载方式 (12)
2.4 最小临坡距取值方法 (12)
2.5 各因素对最小临坡距的影响 (14)
2.5.1 滑坡推力作用点 (14)
2.5.2 单位有效宽度上的滑坡推力 (15)
2.5.3 嵌固深度 (17)
2.5.4 坡度对最小临坡距的影响 (18)
2.6 数值模拟中的最小临坡距适用性验证 (20)
2.7 本章小结 (23)
第3章最小临坡距物理模拟研究 (25)
3.1 物理模拟试验 (25)
3.1.1 试验原型 (25)
3.1.2 相似比确定 (25)
3.1.3 模型设计 (26)
3.1.4 模型制作 (27)
3.1.5 土体材料 (28)
3.1.6 加载方案 (28)
3.1.7 量测系统 (30)
3.2 模型试验加载过程 (33)
3.2.1 一号模型 (33)
3.2.2 二号模型 (35)
3.2.3 三号模型 (37)
3.2.4 四号模型 (39)
3.3 物理模拟中各因素对最小临坡距的影响 (41)
3.3.1 推力 (41)
3.3.2 嵌固深度 (46)
3.3.3 坡度 (49)
3.4 物理模拟中的最小临坡距适用性验证 (51)
3.5 本章小结 (56)
第4章最小临坡距与无效嵌固深度计算方法 (57)
4.1 物理模拟和数值模拟对比分析 (57)
4.2 数值模拟三因素正交实验 (58)
4.3 最小临坡距公式拟合 (61)
4.4 无效嵌固深度及其计算公式 (62)
4.5计算公式适用验证 (63)
4.5.1 最小临坡距计算公式适应性验证 (63)
4.5.2 无效嵌固深度计算公式准确性验证 (66)
4.5.3 计算公式适用范围 (70)
4.6 本章小结 (72)
第5章结论与展望 (73)
5.1 结论 (73)
5.2 展望 (73)
致谢 (75)
参考文献 (76)
