层状岩体水平受荷桩嵌固深度研究

发布时间：2019-03-22 19:24

【摘要】：嵌固深度是决定水平受荷桩稳定性及承载能力的关键因素之一。因此,在对水平受荷桩进行设计时,确定合理的嵌固深度尤为重要。论文采用单桩水平静载荷室内模型试验和数值模拟计算等手段,以西南地区某输电工程输电杆塔的嵌岩灌注桩基础为原型。通过改变嵌固段岩体的层面倾角、桩基嵌固深度、桩径、桩身强度等因素,分析嵌岩桩的桩顶位移、桩身弯矩、桩侧土压力、桩侧土体变形等变化规律,进而对各因素影响下的层状岩体水平受荷桩的承载性能、嵌固效果进行研究,并获得各层面倾角下的桩基最大嵌固深度,对指导嵌岩桩设计具有一定的意义。论文得到以下主要结论:(1)当嵌固段岩体存在层面时,水平受荷桩的承载性能明显降低,并且随着层面倾角的改变,桩基承载性能的变化也存在一定的规律:完整基岩场地层面倾角0°场地层面倾角30°场地层面倾角-30°场地。(2)当嵌固段岩体的层面倾角不同,其嵌固效果也将发生改变,由好到坏依次为,完整基岩场地层面倾角0°场地层面倾角90°场地层面倾角30°场地层面倾角-30°场地层面倾角-60°场地层面倾角60°场地;(3)通过增大嵌固深度、桩身直径,可以改善嵌岩桩的嵌固效果。而增加桩身强度对桩基的嵌固效果的改善无明显作用;(4)通过对比不同嵌固深度的嵌岩桩水平承载力特征值变化规律,确定完整基岩、基岩层面倾角为0°、30°、-30°、60°、-60°、90°场地所对应的最大嵌固深度,为嵌岩桩设计进行指导。
[Abstract]:Embedded depth is one of the key factors to determine the stability and bearing capacity of horizontally loaded piles. Therefore, it is very important to determine the reasonable embedded depth in the design of horizontal pile. By means of single pile horizontal static load indoor model test and numerical simulation, this paper takes the rock-socketed cast-in-situ pile foundation of transmission tower in a transmission project in southwest China as the prototype. By changing the dipping angle of rock mass, the depth of pile foundation, the diameter of pile, the strength of pile and so on, the change rule of pile top displacement, pile bending moment, soil pressure on pile side and deformation of soil on pile side is analyzed, and the variation rules of pile top displacement, pile bending moment, pile side earth pressure and soil deformation are analyzed. Furthermore, the bearing capacity and embedding effect of horizontally loaded piles in layered rock mass affected by various factors are studied, and the maximum embedded depth of pile foundation under various dip angles is obtained, which has certain significance for guiding the design of rock-socketed piles. The main conclusions of this paper are as follows: (1) when there is a layer in the rock mass, the bearing capacity of the horizontal loaded pile decreases obviously, and with the change of the dip angle of the plane, the bearing capacity of the horizontal loading pile decreases obviously. The change of bearing capacity of pile foundation also has certain regularity: the plane inclination of complete bedrock site is 0 掳, the dip angle of site plane is 30 掳- 30 掳site. (2) when the dipping angle of rock mass is different, the embedding effect will also change. From good to bad, the inclination of site plane is 0 掳, the inclination of site plane is 90 掳, the angle of site plane is 30 掳, the dip angle of site plane is 60 掳, the inclination angle of site plane is 60 掳. (3) the embedding effect of rock-socketed pile can be improved by increasing the embedded depth and the diameter of pile. However, increasing the strength of pile has no obvious effect on the improvement of the embedding effect of pile foundation. (4) by comparing the variation law of the horizontal bearing capacity of rock-socketed piles with different embedded depth, the maximum embedding depth corresponding to 0 掳, 30 掳,-30 掳, 60 掳,-60 掳, 90 掳sites of complete bedrock is determined, and the slope angle of bedrock layer is 0 掳, 30 掳,-30 掳,-60 掳,-60 掳and 90 掳, respectively. To guide the design of rock-socketed piles.
【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

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