膨胀土地层扩底锚杆试验研究

文献与调查结果表明，膨胀土中水的浸入与反复胀缩性会导致该土层中粘结式锚杆锚固力降低。已有资料显示，扩底锚杆可以提高其锚固力。据此，作者自主研制了一套扩孔器，采用液（气）动式张拉系统，可适用于液、气循环两种成孔工艺。利用该仪器进行了膨胀土地层扩底锚杆试验，结果表明浇注完毕后未经降雨影响的试验锚杆，扩底比非扩底提高不多；但降雨浸泡后，非扩底锚杆锚固力会大幅度下降，扩底锚杆锚固力下降不明显，说明扩底锚杆在膨胀土地层中的应用是成功的。

Test Study on Anchored Bar with Expanding Ends in Expansive Soils

Investigation and literature information show that water immerging and the properties of swelling-shrinking to and fro of expansive soils will result in abating of anchorage force of anchored bar in such stratum. As recorded, the anchorage force can be increased for the anchor bar with expanding body. Hereby, a suit of expanding reamer was developed in this paper, whose expanding-retracting system was droved by liquid or air and that was available to liquid and air circulating boring. Some anchor bars with expanding ends were made by the expanding reamer. The conclusion can be drawn by uplift test on anchor bars aforesaid that the expanding ends were not obviously different from the non-expanding ends when the tests had been done before raining, but after raining the anchoring force of the non-expanding ends would decrease to a large extend, but the decrease of expanding ends was little. Such data indicate that the applications of anchored bars with expanding ends in expansive soils are successful.