微型CFG桩侧阻力提高系数试验研究

发布时间：2018-05-04 01:10

本文选题：微型CFG桩 + 桩侧阻力　；参考：《中南大学学报(自然科学版)》2017年01期

【摘要】：为分析微型CFG桩单桩承载力实测值比按现行CFG桩规范公式所得计算值大的原因,选择150 mm和250 mm这2种桩径、不同长径比的微型CFG桩进行现场足尺试验。试验桩采用先挤土成孔后分段填混合料振密法施工工艺,桩端阻力通过土压力盒测定,单桩承载力通过静载荷试验测定,并对试验桩进行实地开挖。提出微型CFG桩单桩承载力计算修正公式。研究结果表明:微型CFG桩单桩承载力实测值大于按规范公式所得计算值,单桩承载力提高主要是由于桩侧阻力提高,为此引入微型CFG桩侧阻力提高系数k;在相同桩径条件下,长径比增大,微型CFG桩侧阻力提高系数减小;当长径比相同时,桩径小的单桩侧阻力提高系数大;工程运用时k可取1.1~1.4。
[Abstract]:In order to analyze the reason why the measured value ratio of bearing capacity of miniature CFG pile is large according to the formula of current CFG pile code, two kinds of piles with 150mm and 250mm diameter and different ratio of length and diameter are selected to carry out field full-scale test. The test pile is constructed by the method of compacting the soil first and then filling the mixture by stages. The pile tip resistance is measured through the earth pressure box, the bearing capacity of the single pile is measured by static load test, and the test pile is excavated on the spot. A modified formula for calculating the bearing capacity of single CFG pile is presented. The results show that the measured value of bearing capacity of micro CFG pile is larger than the calculated value according to the standard formula, and the increase of bearing capacity of single pile is mainly due to the increase of pile side resistance. When the ratio of length to diameter increases, the coefficient of increase of side resistance of miniature CFG pile decreases, when the ratio of length to diameter is the same, the coefficient of increase of side resistance of single pile with small diameter is large.
【作者单位】：中南大学地球科学与信息物理学院有色资源与地质灾害探查湖南省重点实验室;中国有色桂林矿产地质研究院;湖南工业大学计算机与通信学院;
【基金】：国家自然科学基金资助项目(51108176)~~
【分类号】：TU473.1

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