摘要
新郑黄河公路特大桥6根试桩采用自平衡测试法进行静载荷试验。根据压浆前后及不同压浆方式得到的测试数据进行分析,钻孔灌注桩经压浆后,承载特性得到明显改善,且桩端与桩侧压浆并不是独立作用的,无论是桩侧压浆还是桩端压浆,均会改善整个桩土体系的承载特性。分析时,对无明显拐点的曲线采用双曲线函数进行拟合,并取s=15mm进行比较,进行侧压浆后,上段桩的平均摩阻力提高100%～104%,下段桩平均摩阻力采用等效的原桩身表面积进行计算,提高幅度分别达6 9倍和5 4倍,端阻力提高38%～45%。另外,压浆量存在一个合理的数值。
Static load tests were carried out with Osterberg method on six large diameter bored piles formed in Xin-zhen Yellow river bridge.In this paper,the test results from six piles were systematically processed in order to study the load transfer mechanism before and after grouting and the effects in different grouting methods.According to the analysis results,the bearing behavior were improved apparently despite base grouting or shaft grouted.In the process of analyzing the effect of grouting,hyperbolic models were fitted well with the τ-s curves,and displacement of 15mm was taken for comparison.According to the test results,after shaft grouting ,the average skin friction of upper shafts was increased by 100%～104%,the average skin friction of lower shafts was increased by 5.4～6.9 times,and the base bearing increased by 38%～45%.In addition,the grouting quantity has a reasonable value.
出处
《公路交通科技》
CAS
CSCD
北大核心
2004年第5期70-73,共4页
Journal of Highway and Transportation Research and Development
关键词
自平衡测试法
后压浆
摩阻力
端阻力
Osterberg method
Post grouting
Skin friction
Base bearing
