黄土隧道锚杆锚固参数优化模型试验研究

Study on Anchorage Parameter Optimization by Model Test for the Loess Tunnel

为了研究不同锚杆直径、钻孔直径和浆液配比对黄土隧道锚杆锚固质量的影响,设计了简易锚杆拉拔试验台架.依托实际工程按照相似理论配置了围岩相似材料,运用正交试验法选取不同试验参数组合进行了锚杆拉拔模型试验.结果表明:所依托黄土隧道的最优锚固参数组合为锚杆直径22 mm,钻孔直径50 mm,注浆配合比0.38;注浆体厚度为14 mm时,因锚固体传力效果好且不易破坏或产生滑移变形,故锚固质量好;注浆配合比为0.38时注浆体与围岩能够很好地黏结,使得锚杆耐久性为最佳.试验所设计的简易锚杆拉拔试验台架可以在实际工程中推广,研究的方法及结果可为类似工程研究提供一定的指导和借鉴意义.

In order to study the selection of different bolt diameter, drilling diameter and mix ratio of grout, which affect the anchorage quality of loess tunnel, a simple equipment of bolt pullout test was designed. Accord- ing to the similar theory, the surrounding rock similar material was arranged based on the actual engineering. Using orthogonal experiment to choose different test parameters combination, the pull-out model tests were carried out in laboratory. It turns out that the optimal anchorage parameters combination of the loess tunnel are bolt 22mm diameter in bolt, 50mm diameter in drilling, mix ratio of grout is 0.38; when the thickness of grout is 14mm, the anchorage body transmits force well and it is uneasy to be damaged or slipped, so the anchorage quality is well; when the grout mix ratio is 0.38, the grouting body and the surrounding rock can be better cemented, which leads into even higher quality of durability. The simple equipment of bolt pullout test which was designed for the model test can be popularized in the actual engineering. The research methods and results can provide guidance and referential significance for similar engineering research.