止水-加强型土钉墙在软弱土层基坑支护中的应用研究

Application of Reinforced Impervious Soil-nailing Wall in Soft-soil Foundation Pit Support

摘要:

止水-加强型土钉墙是由土钉墙和止水帷幕组成的一种新型支护体系，具有强度高、止水效果好和比较经济的特点，适用于淤泥和砂层等软弱地层基坑支护工程。结合广州地区某基坑特征，分析了止水-加强型土钉墙的支护机理和受力特点，指出止水-加强型土钉墙是通过压力注浆锚杆（管）、搅拌桩和钢管桩的共同作用，使加筋范围内具有近似于“重力式挡土墙”的特征。最后通过基坑监测数据表明此支护体系有足够的安全储备，可推广于类似地层基坑支护工程。

Abstract:

The reinforced impervious soil-nailing wall is a new type of supporting system composed of soil nail and impervious wall, which has high water impermeability with high strength but low cost, and is suitable to foundation pit supporting engineering in silt and sand formation. Analysis was made on supporting mechanism and stress characteristics of the reinforced impervious soil-nailing wall in combination with a case of foundation pit engineering in Guangzhou, and conclusion was drawn that the characteristics of reinforced impervious soil-nailing wall, which was similar to ‘gravity retaining wall’ in range of bolt, came from the interaction of pressed grouting bolt, mixing piles and steel pipe pile. The monitoring data show that this foundation supporting system has sufficient safety reservation, and can be extended to foundation pit supporting project in similar formation.