中文摘要：

针对深基坑工程在开挖支护过程中遇到的难题,提出框架自钻胎串式锚杆新型支护结构,对其结构构成和工作机理进行了详细探讨。基于柱孔扩张理论,推导出极限抗拔承载力和胎体临界间距计算公式,采用非线性有限元软件ADINA模拟了该新型支护结构的特性、抗拔机理,进行了现场拉拔试验,并将理论值分别与数值模拟和现场拉拔试验结果作了对比分析。结果表明：①抗拔承载力理论计算值与模拟值和试验结果基本吻合,验证了理论分析和数值模拟的正确性。②自钻胎串式锚杆的轴力在胎体段大幅度提高,发生“突变”,呈“锯齿形”。③与普通框架锚杆支护结构相比,框架自钻胎串式锚杆能够使坡体水平位移明显减小,更有利于基坑稳定。（4）自钻胎串式锚杆的极限抗拔力、极限抗拔位移与胎体径向应变之间存在正相关性。

英文摘要：

Towards the challenging problems encountered during excavating and supporting process of deep foundation pit, a new supporting structure with the self-drilling tire tandem anchor is working mechanism of the structure are investigated in detail. Based on the proposed, and then the composition and theory of cylindrical cavity expansion, the calculation formula of uplift bearing capacity and critical spacing of tires are derived. The supporting characteristics and uplift mechanism of the new supporting structure is simulated by using the finite element software ADINA, and then the field uplift test is carried out. The comparison between theoretical results and simulation results shows that： ① The theoretical calculated values of ultimate bearing capacity basically agree with the simulated values and experimental values, validating the rationality of theoretical analysis and numerical simulation. ② For the tire segment, the distribution of axial force of the self-drilling tire tandem anchor is greatly improved, exhibiting a ＇ saltation＇ with a ＂jagged＂ shape. ③ Compared with the ordinary framed anchor bolt system, the horizontal displacement of slope can be greatly reduced by using the framed self-drilling tire tandem anchor, which shall be beneficial to the stability of foundation pit. bearing ④ For the self-drilling tire tandem anchor, there exist positive correlations between the ultimate uplift capacity or ultimate uplift displacement and the radial strain of tire .