澳门美高梅金殿扩底灌注桩施工泥浆技术

Mud Technology for Bottom-enlarged Grouting Pile Construction of MGM Grand Macao

在澳门美高梅金殿大直径扩底灌注桩工程中,为了减少钢护筒的入埋深度,确保其顺利回收,设计和实施了一套有效的泥浆技术,包括:用优质膨润土造浆,用具有降粘稀释和抑制地层水化分散的腐殖酸钾(KHm)处理剂,配制高抑制性低固相泥浆;应用气举反循环系统清洁钻孔,地表大循环系统调度泥浆、调整泥浆性能;强化重力沉淀和旋流除砂方法清除钻屑;把钻屑和废弃泥浆用低标号水泥硬化处理后外运,避免污染环境等。并通过泥浆损耗量的计算分析,提出了降低损耗和成本的措施。

A set of effective mud technology was designed and applied to reduce the burying depth of steel casing and en- sure the recovery in the large diameter bottom-enlarge grouting pile construction of MGM Grand Macao. The high inhibitive low solid mud was made with high quality bentonite and KHm treating agent which can reduce viscosity and inhibit hydration dispersion of formation. Air lift reverse circulation system was applied to clean the borehole, surface great circulation system to schedule mud and adjust mud property, intensified gravitative sedimentation and cyclone desanding to remove cuttings. The cuttings and wasted mud was carried away to avoid environment pollution after hardening treatment with low grade cement. The measures for reducing loss and cost were put forward by the calculation analysis on mud wastage.