不同倾斜角度单桩复合地基受力变形规律试验研究

发布时间：2018-01-03 22:37

本文关键词：不同倾斜角度单桩复合地基受力变形规律试验研究　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：在桩体复合地基侧向进行堆载或卸载开挖会对复合地基中桩体产生侧向作用力,从而促使桩体产生侧移,桩身会产生倾斜而成为倾斜桩。随着倾斜角度的增加,桩体复合地基的承载能力会有所降低,但国内外主要对倾斜基桩的承载能力进行了相关的研究,采用的方法包括理论分析、数值计算、室内模拟试验、现场测试等,获得了许多宝贵的研究成果。对于倾斜桩复合地基的承载能力则较少涉及。本文对竖向加载条件下不同倾斜角度单桩复合地基的受力变形性状以及破坏规律进行了试验研究。在试验过程中,在桩顶、桩周土顶以及复合地基顶部分别设置沉降标并连接百分表测试得到不同倾斜角度桩在竖向荷载作用下的沉降变化规律,在桩身两侧凹槽内粘贴电阻应变片测试不同倾斜角度单桩桩身弯矩以及轴力摩阻力变化规律,揭示了倾斜过程中复合地基受力变形规律以及单桩桩身的受力变化情况,结合理论分析取得了如下主要结论:(1)在相同的荷载作用下,随着倾斜角度的增大单桩复合地基的沉降也不断增加,证明倾斜角度增大对单桩复合地基的承载能力产生了不利的影响。(2)倾斜的单桩复合地基都产生了侧向的移动,且桩顶部的侧移要大于底部的侧移,倾斜角度越大的单桩产生的侧向位移也越大。(3)不同倾角单桩复合地基桩身弯矩情况不相同,桩身弯矩随着倾斜角度的增大出现了较为复杂的变化,并且随着倾斜角度的增大,桩身的最大弯矩也在不断增加。(4)桩侧摩阻力也随着桩身倾斜角度的增加出现了较为明显的变化,随着倾斜角度的增加在桩身的相同位置出现了不同方向的侧摩阻力,大小差别也较大,证明桩身倾斜对桩身侧向摩阻力的分布影响非常明显。(5)随着倾斜角度的增加桩身受到的最大土抗力也在增大,并且随着倾斜角度的增加在桩身的中下部产生了不同方向的侧向土抗力,使桩身产生了弯矩而且随着倾角的增大侧向受力情况更为复杂,使桩身产生了更为复杂的弯矩变化,证明桩身倾斜对桩体本身造成了不利影响。
[Abstract]:The lateral loading or unloading excavation in the pile composite foundation will produce lateral force on the pile body in the composite foundation, which will promote the pile body to move sideways, and the pile body will be inclined and become inclined pile. With the increase of the inclined angle, the pile body will be inclined. The bearing capacity of pile composite foundation will be reduced, but the research on bearing capacity of inclined pile is mainly carried out at home and abroad. The methods adopted include theoretical analysis, numerical calculation and indoor simulation test. Field tests, etc. Many valuable research results have been obtained. The bearing capacity of inclined pile composite foundation is less concerned. The deformation behavior and failure law of single pile composite foundation with different inclined angles under vertical loading are studied in this paper. In the course of the experiment. At the top of the pile, the top of the soil around the pile and the top of the composite foundation, the settlement of the pile with different inclined angles under vertical load is obtained by setting the settlement scale and connecting the percentile meter. The resistance strain gauges on both sides of the pile body are used to test the bending moment and axial force friction of single pile with different inclined angles. The stress and deformation law of composite foundation and the stress change of single pile body are revealed in the process of inclination. The main conclusions of this paper are as follows: 1) under the same load combined with theoretical analysis. With the increase of inclined angle, the settlement of single pile composite foundation is also increasing. It is proved that the increase of inclined angle has an adverse effect on the bearing capacity of single pile composite foundation. (2) the single pile composite foundation with inclined slope produces lateral movement, and the lateral displacement of the pile top is greater than that of the bottom. The lateral displacement of single pile with larger inclined angle is also larger. 3) the bending moment of single pile composite foundation with different inclination angle is different, and the bending moment of pile body appears more complex change with the increase of inclined angle. And with the increase of the inclined angle, the maximum bending moment of the pile body is also increasing. 4) the frictional resistance of the pile side also appears more obvious change with the increase of the inclined angle of the pile body. With the increase of the inclined angle, the side friction in different directions appears in the same position of the pile body, and the magnitude is also different. It is proved that the influence of inclined pile body on the distribution of lateral friction is very obvious. 5) the maximum soil resistance of pile body is also increasing with the increase of inclined angle. And with the increase of the inclined angle, the lateral soil resistance in different directions is produced in the middle and lower part of the pile body, which makes the bending moment of the pile body and the lateral force situation more complicated with the increase of the inclination angle. The bending moment change of pile body is more complicated, which proves that the inclined pile body has adverse effect on pile body itself.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU473.1

【相似文献】