砂土串囊式充气锚杆承载力的研究

Experimental study on group anchor effect of inflatable anchor with several airbags in sand stratum

在砂土地层中,串囊式充气锚杆的研究还比较少,其承载特性及受力机理尚不明确。本文基于莫尔-库仑模型和Vesic圆孔扩张理论法,分别对圆柱体、球体、组合体、椭球体假设下的串囊式充气锚杆的扩大段进行计算分析。并将计算结果与试验得到的实测值进行对比。结果表明:四种形状假设中椭球体的形状假设理论值与实测值的误差最小,仅为8.35%。通过拟合试验数据,并引入与端阻力和侧摩阻力有关的两个系数对承载力公式进行修正,得到了抗拔承载力的经验公式。

In the sandy soil layer, the research on the gas filled string bolt is still less, and its bearing characteristics and bearing mechanism are not clear. In this paper, based on the Mohr Coulomb model and the Vesic circular hole expansion theory, the expansion sections of the inflatable string anchor under the assumptions of cylinder, sphere, combination and ellipsoid are calculated and analyzed, respectively. The calculated results are compared with the measured values. The results show that among the 4 different assumptions, the error between the theoretical value and the measured value is the smallest, only 8.35%. By fitting the test data and introducing two coefficients related to end resistance and side friction resistance, the empirical formula of uplift bearing capacity is obtained.