底出料振冲碎石桩水下施工技术

Underwater Construction Technology of Vibro-replacement Stone Column of Bottom Discharge

振冲碎石桩加固水下软土地基的难点主要体现在成孔、定位及垂直度3方面。为了解决上述问题,采用导管底出料的方式将碎石料送到振冲器周围,并在振冲导杆外侧增加限位装置解,通过GPS实时对成桩过程进行跟踪定位,保证了碎石桩的成桩质量,并通过重型动力触探试验验证了底出料振冲碎石桩的加固效果。结果表明,底出料振冲碎石桩成桩均匀,密实度较高。

The difficulties for strengthening soft soil foundation reinforcement with vibro-replacement stone columns under water mainly reflected in three aspects. They are the drilling problem, positioning problem and verticality control. In order to solve the problems, the stone is sent to the vibrator around through the catheter, and limiting device is added on the outside of the vibrator rod, the piling process is tracking by GPS. In addition, these measures ensured the quality of vibro-replacement stone column. In order to verify the effect of reinforcement, dynamic penetration test is used to detect the density of the vibro- replacement stone column of bottom discharge. The test results show that the vibro-replacement stone column of bottom discharge has high density and homogeneity.