旋挖钻孔低粘降失水泥浆配制应用技术

在厚粘土、粉土、砂层进行旋挖钻孔灌注桩施工,通常由于泥浆孔口补给、泥浆不循环的工艺缺陷,导致塌孔、埋钻、卡钻、缩径、断桩事故频繁发生。在分析低粘、降失水、加速钻渣沉淀的解决机理的前提下,提出了配制低粘度、高降失水、防絮凝的铁铬盐-LV-CMC泥浆并同步孔底补浆工艺,可不需循环泥浆清孔,保证成孔质量,提高工作效率。

Application Technology of Preparation of Low Viscosity and Fluid Loss Control Mud for Rotary Drilling Borehole

For rotary drilling bored grouting pile construction in thick clay, silt and sand layer, borehole collapsing, drill rod burying, drill rod sticking, diameter shrinking and pile breaking often occur because of technical defects such as mud surpplying at borehole orifice and non-recirculation. On the premise of analysis on the mechanism in which low viscosity, fluid loss reduction and speed-up cuttings precipitation were solved, the formula of FCLS LV-CMC mud with low viscosity, high-level fluid loss reduction and anti-precipitation was put forward with simultaneous mud surpplying at hole bottom; hole cleaning by circulating mud was unnecessary to improve working efficiency.