摘要
天津市某主塔楼桩基选用后压浆超长钻孔灌注桩,为了掌握超长后压浆钻孔灌注桩在该地层的工程特性,共设计了2组(共8根)试桩进行单桩竖向抗压静载试验。试桩中安装了振弦式钢筋计和分层沉降管以反映桩侧摩阻力和桩身分层沉降状态。对试验数据进行对比分析和计算结果表明,桩侧注浆可以明显提高超长桩的侧摩阻力;采用预压加载可以增强超长桩的弹性,减少桩顶的沉降;卸荷稳定后试桩具有桩侧阻力,桩身上段所受阻力为负摩阻力,下段为正摩阻力,同时具有的桩身轴力使试桩产生一定的压缩,其压缩量为残余变形量的重要组成部分。
The layers of a main tower construction site in Tianjin are mainly clay,silt and silt sand.Two groups of the super-long bored test piles with post pressure-grouting（a total of eight piles） are designed to take bearing behavior test using single pile vertical static load test of compression to master the engineering properties in the main tower construction site.Vibrating wire reinforcement meter and stratified settlement tube are installed to find out the pile side friction and the pile body layered settlement state.After the test,the results of the data analysis show that the pile side grouting can significantly improve the long pile side skin friction;pre-load pressure can enhance the flexibility of the super-long pile and reduce the settlement of the top of the pile in some degree.After unloaded stability,the test pile also has side resistance;the resistance of the upper segment is negative skin friction;and the lower segment is positive skin friction;and the pile body axial force causes the test pile to have some compression volume;that is an important part of the residual deformation.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2011年第9期2821-2826,共6页
Rock and Soil Mechanics
关键词
超长钻孔灌注桩
单桩承载性能
竖向抗压静载试验方法
桩侧摩阻力
super-long bored piles
bearing capacity of single pile
vertical static load test method of compression
pile shaft friction
