充气锚杆加固砂土地基的研究进展

对充气锚杆的变形特性、承载特性及破坏形态进行了论述,总结了充气锚杆的一些力学规律:(1)充气压力越大,橡胶膜膨胀体体积就越大,膨胀体大致呈圆柱状。分析充气锚杆受力时,可将扩大头近似为等效圆柱体。向充气锚杆中高压注浆,能够有效地控制膨胀体的体积与形状,并为充气锚杆承载力的估算提供方便。(2)端部阻力与侧向阻力是充气锚杆扩大头极限承载力的主要组成部分,可用圆孔扩张理论更好地计算充气锚杆的端部阻力。(3)就充气锚杆的失效形态而言,多囊式充气锚杆与单囊充气锚杆相比,多囊式充气锚杆不会发生锚杆断裂破坏,因此,在实际砂土地基处理中,应优先选用多囊式充气锚杆。

Research progress of inflatable anchor for sandy soil foundation

Deformation properties, bearing behavior and failure modes of the inflatable anchor are discussed. The results show as follows: (1) The volume of rubber became larger with the increasing of air pressure, and inflatable is column. Enlarge head is as equivalent cylinder when discussing the force condition of inflatable anchor. At the same time, the column and shape of the inflatable anchor are controlled by high pressure grouting to provide convenience for the bearing force estimating of the inflatable anchor. (2) the main components of enlarge head ultimate bearing capacity of the inflatable anchor is tip resistance and lateral resistance, and the tip resistance would be better calculated by cavity expansion theory. (3) for the failure mode of the inflatable anchor, the anchor of polyclinic inflatable anchor could not be erupted than cystic inflatable anchor, so the polyclinic inflatable anchor should be preferred to use at practical engineering if the condition allowed.