复式注浆技术在宁波软土地区钻孔灌注桩中的应用

Application of Compound Grouting Technology in Bored Pile in Soft Soil Area of Ningbo

通过宁波软土地区一桩基工程实例,将复式注浆技术对超长大直径钻孔灌注桩单桩承载力的影响进行了静载荷试验研究和数据分析。试验表明,复式注浆显著增加了桩身回弹率。当钻孔灌注桩持力层为岩层且清渣到位时,桩端后注浆对桩基承载力影响不大。当注浆孔堵塞时可通过桩体体外注浆的方式进行补救。复式注浆技术影响因素众多,设计人员在参数选用过程中要结合现场实际条件,并通过对静载荷试验的科学分析合理选定,不可经验主义。

In this paper, the research of pile foundation engineering example is carried out in the soft soil area of Ningbo. The influence of compound grouting technology on the bearing capacity of super long large diameter bored pile is studied by static load test and data analysis. The test results show that the rebound rate of pile body is significantly increased by compound grouting. When the bearing stratum of cast-in-place bored pile is rock stratum and the slag is removed in place, the pile end post grouting has little effect on the bearing capacity of pile foundation. If the grouting hole is blocked, it can be remedied by grouting outside the pile. There are many factors influencing the technology of compound grouting. In the process of parameter selection, designers should combine with the actual conditions of the site and reasonably select the parameters through the scientific analysis of static load test.