优化复合锚固结构与单一锚固结构抗爆性能对比试验研究

Comparative test study of blast-resistance performance of optimal composite anchorage structure and single anchorage structure

优化复合锚固结构是由土钉和在土钉端部系统而规律地设置的一定长度的经特殊处理的空孔段群组成。空孔群在围岩介质中造成一个弱化区,弱化区介于支护结构与围岩介质之间,将原有的二介质系统(支护结构和围岩),改变为三介质系统(支护结构、弱化区和围岩)。爆炸条件下,优先由弱化区产生变形、破碎、压实或压密,同时大量吸收爆炸能,使支护结构的危机得以转移至弱化区而本身不受损。优化复合锚固结构对比单一锚固结构具有优异的抗动静载性能。因此进行对比试验,研究优化复合锚固结构及单一锚固结构的抗爆性能。试验结果表明,在支护结构产生临界破坏前后,单一锚固结构的质点加速度量值是优化复合锚固结构的2.22倍以上,前者的动应变量值是后者的5.30～4.50倍以上。在临界破坏条件下,优化复合锚固结构的抗力是单一锚固结构的5.10倍以上,在极限破坏状条件下,前者是后者的4.13～3.40倍以上。

The optimal composite anchorage structure is constituted by soil nail and groups of fixed-length empty holes that regular setting in the end of soil nail.Empty holes caused a weakened zone in the surrounding rock.The weakened zone is between the reinforced support structure and the surround rock.It changes the original two-medium system into three-medium system.Under the explosion condition,weakened zone is firstly deformed,cracked,crushed or densified;and at the same time,a great deal of blast energy is absorbed.Therefore,the crisis of the reinforced support structure is transferred into the weakened zone.The optimal composite anchorage structure has excellent blast-resistance.The test results of the compression test of optimal composite anchorage structure and single anchorage structure show that the particle acceleration of single anchorage structure is 2.22 times higher than that of the optimal composite anchorage structure.The dynamic strain of the former is 5.30-4.50 times higher than that of the latter.The blast-resistance of the optimal composite anchorage structure is 5.10 times higher than that of the single anchorage structure.Under the limit damage condition,the former is 4.13-3.40 times higher than that of the latter.