滨海复杂地层超深旋挖钻孔灌注桩质量问题改进技术

钻孔上部存在较厚的淤泥质软弱地层，旋挖钻孔灌注桩施工时应在孔口设置泥浆缓存池，始终保持钻孔内的泥浆面高度。护壁泥浆的性能是保证钻孔质量的基础，施工时必须加强对泥浆性能指标的监测，必要时应采用泥浆净化装置对泥浆进行净化。选择合理的护筒埋设长度和钻进参数，不仅可以保证施工质量，还可大幅降低施工成本。

Quality Improvement Technology for Ultra-deep Rotary Bored Grouting Pile in Complex Coastal Strata

Because of the thick soft silt layer in upper part of the borehole, a mud pool should be set up at the mouth in the construction of rotary bored grouting pile to keep the mud surface height in the borehole. The mud performance is the foundation to ensure the drilling quality, the performance indicators monitoring should be strengthened in the construction, and mud purifying device may be used if necessary. Reasonable selection of steel protective pipe embedding length and drilling parameters can not only ensure the construction quality, but also can greatly reduce the construction cost.