改性聚酯注浆新技术在控制基坑周边房屋沉降的运用

Application of PU grouting in settlements of structures induced by excavation

在短时间内以最小的扰动控制由于相邻基坑开挖引起的周边建筑物沉降是基坑周围环境保护首要解决的问题之一。介绍了一个减小基坑开挖对周围环境的影响实例,案例中对房屋基础采用改性聚酯注浆进行主动加固,设置隔离桩,在被动区压密注浆,增加浅层地基的承载能力和抗变形能力,减少基坑开挖对房屋的影响。改性聚酯注浆已被国内外广泛用作改善浅层地基和提升地面结构的有效方法。详细介绍了使用改性聚酯注浆材料的特点和采用该工艺进行房屋基础加固和沉降控制的关键技术。案例中,建筑物距离基坑开挖边线最近仅1.3 m,在不同阶段采用了改性聚酯注浆和跟踪注浆,提高了地基承载能力和变形能力。监测结果显示,房屋加固效果良好,沉降得到了有效控制。

It is of essence to solve, in short time and with the minimum effort, the problem of settlements of shallow foundations of the existing buildings/structures caused by the adjacent foundation excavation. A patent-pending methodology for reduce building settlements caused by foundation excavation is illustrated along with a case study. The PU grouting is adopted to minimize the negative impact on a historic building caused by foundation excavation, which is just 1.3 m away from the building. The PU grouting is conducted during different stages of construction, including the construction of diaphragm wall, the first and second layer bracing. The settlements of the neighboring building is minimized and controlled by the PU grouting.