西安建筑科技大学学报(自然科学版)

针对现场采用静载法测试桩身内力和变形,往往不能得到破坏时真实数据这一问题.本文以银川市某工程为背景,现场静载试验采用锚桩法提供反力,滑动测微计测试桩身内力和变形,并与数值计算结果进行对比分析.结果表明:极限荷载作用下桩体压缩变形量接近桩顶沉降的一半; 在承载力特征值作用下可以忽略端阻力的贡献; 提出在极限荷载下桩身侧阻力和端阻力的建议值; 验证了数值模拟的可靠性并一定程度上弥补现场静载试验数据不足的问题.研究结论对银川地区桩基设计具有一定的参考价值.

In view of the problem that the real data of the damaged pile cannot be obtained when the static load method is used to test the internal force and deformation of the pile in the field,this study,based on the background of a project in Yinchuan,uses anchor pile method to provide reaction force in the field static load test,and sliding micrometer to test the internal force and deformation of the pile,and then the test results are compared with the numerical calculation results. The study shows that the compression deformation of pile under ultimate load is close to half of pile top settlement,and the contribution of end resistance can be ignored under the action of characteristic value of bearing capacity. The study also proposes the suggested values of pile side resistance and end resistance under ultimate load,verifies the reliability of numerical simulation and to a certain extent makes up for the lack of on-site static load test data. The research conclusion has a certain reference value for the design of pile foundation in Yinchuan area.

引言
1 工程概况
2 桩基内力现场试验研究
3 单桩静载数值模拟与分析
4 结论

图1 S1号试桩桩长范围内地层剖面图<br/>Fig.1 Cross-section of the stratum within the length of the S1 test pile

图1 S1号试桩桩长范围内地层剖面图
Fig.1 Cross-section of the stratum within the length of the S1 test pile

图2 滑动测微计测试原理<br/>Fig.2 Testing principle of slide micrometer

图2 滑动测微计测试原理
Fig.2 Testing principle of slide micrometer

图3 单桩静载试验成果图<br/>Fig.3 Static load test results of single pile

图3 单桩静载试验成果图
Fig.3 Static load test results of single pile

图4 桩身应变与桩顶荷载、深度关系曲线<br/>Fig.4 Relationship curve of pile strain with pile top load and depth

图4 桩身应变与桩顶荷载、深度关系曲线
Fig.4 Relationship curve of pile strain with pile top load and depth

图5 桩身轴力随桩深变化图<br/>Fig.5 Variation of pile shaft axial force with pile depth

图5 桩身轴力随桩深变化图
Fig.5 Variation of pile shaft axial force with pile depth

图6 桩身摩阻力随桩深变化图<br/>Fig.6 Variation of pile shaft friction resistance with pile depth

图6 桩身摩阻力随桩深变化图
Fig.6 Variation of pile shaft friction resistance with pile depth

图7 桩的侧摩阻力、端阻力与桩顶荷载关系曲线<br/>Fig.7 The curve of the relationship between the side friction and end resistance of pile and the load on the top of pile

图7 桩的侧摩阻力、端阻力与桩顶荷载关系曲线
Fig.7 The curve of the relationship between the side friction and end resistance of pile and the load on the top of pile

表1 桩端阻力占桩顶荷载的比例<br/>Tab.1 Proportion of pile end resistance to pile top load

表1 桩端阻力占桩顶荷载的比例
Tab.1 Proportion of pile end resistance to pile top load

表2 极限承载力下各层土的侧阻力综合取值表<br/>Tab.2 Comprehensive table of lateral resistance of each layer of soil under ultimate bearing capacity

表2 极限承载力下各层土的侧阻力综合取值表
Tab.2 Comprehensive table of lateral resistance of each layer of soil under ultimate bearing capacity

表3 试验桩S1力学参数<br/>Tab.3 Mechanical parameters of test pile S1

表3 试验桩S1力学参数
Tab.3 Mechanical parameters of test pile S1

表4 土层的岩土参数指标<br/>Tab.4 Geotechnical parameter Index of soil layer

表4 土层的岩土参数指标
Tab.4 Geotechnical parameter Index of soil layer

图8 计算模型和网格划分<br/>Fig.8 Calculation model and meshing diagram

图8 计算模型和网格划分
Fig.8 Calculation model and meshing diagram

图9 桩体位移和应力图<br/>Fig.9 Pile displacement and stress diagram

图9 桩体位移和应力图
Fig.9 Pile displacement and stress diagram

图10 土体竖向应力分布图<br/>Fig.10 Vertical stress distribution diagram of soil

图10 土体竖向应力分布图
Fig.10 Vertical stress distribution diagram of soil

图11 土体塑性区分布图<br/>Fig.11 Distribution map of soil plastic zone

图11 土体塑性区分布图
Fig.11 Distribution map of soil plastic zone

图12 荷载-沉降曲线对比图<br/>Fig.12 Load-settlement curve comparison chart

图12 荷载-沉降曲线对比图
Fig.12 Load-settlement curve comparison chart

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备注

引言

1 工程概况

2 桩基内力现场试验研究

3 单桩静载数值模拟与分析

4 结论

期刊信息