新型预制管桩植桩工艺成果应用与静载试验

Application and Static Load Test of New Prefabricated Pipe Pile Driving Technology

摘要:

静钻根植桩、搅拌植入桩端后注浆管桩具有非挤土、机械化施工程度高、桩身质量可靠、节能环保、施工速度较快等优点，之前在桥梁中应用较少。军工路快速路新建工程试点将这2种新型预制管桩植桩工艺应用在桥梁工程中，并进行了静载试验。静载试验结果表明这2种桩单桩竖向极限承载力满足军工路新建工程桩基承载力要求。相同D600桩径下，搅拌植入桩端后注浆管桩极限承载能力高于静钻根植桩，沉降控制也好于静钻根植桩，但静钻根植桩对施工场地和设备要求比搅拌植入桩端后注浆管桩要低。这2种桩的上截桩直径多采用600 mm，单桩抗弯性能较弱。因此，在桥梁工程中应用这2种管桩时，需采用复合配筋先张法预应力混凝土管桩或增加桩数满足单个承台桩基抗弯需求。

Abstract:

The static drilling root driven pile and the stirring driven pile end post-grouting pipe pile have the advantages of non-soil squeezing, high degree of mechanized construction, reliable pile quality, energy conservation and environmental protection, and fast construction speed, which were less applied in bridges in the past. These two new prefabricated pile driving technologies have been applied in the bridge engineering in the pilot of the Jungong Road Expressway Project, and the static load tests are carried out. The test results show that the vertical ultimate bearing capacity of the single pile of these two piles meets the bearing capacity of pile foundation of this new project. Under the same D600 pile diameter, the ultimate bearing capacity of the stirring driven pile end post-grouting pipe pile is higher than that of the static drilling root driven pile, and its settlement control is also better than that of the static drilling root driven pile. However, the requirements for the construction site and equipment of the static drilling root driven piles are lower than those of the stirring driven pile end post-grouting pipe pile. The upper section diameter of these two types of piles is mostly 600 mm, and the bending resistance performance of a single pile is relatively weak. Therefore, when these two types of piles are applied in bridge engineering, it is necessary to adopt the composite reinforcement pre-tensioning method for prestressed concrete pipe piles or increase the number of piles to meet the bending resistance requirements of a base slab pile foundation.