端部加密锚固洞室在重复顶爆作用下的应力波传播及衰减规律

利用实验室抗爆模型试验装置，研究了端部加密和普通长密锚杆锚固洞室在重复顶爆作用下的应力波传播及衰减规律。端部加密锚固洞室和普通长密锚固洞室每一炮的拱顶压力峰值随着比例距离的增加呈幂函数逐渐衰减，并拟合出相应的幂函数曲线，前两炮拟合的应力波衰减指数均小于未受扰动岩石的衰减指数。两个洞室在爆炸应力波作用下，锚固区附近的岩石先被密实，然后不断损伤破坏。在相同的爆炸条件作用下，随着比例距离增加，两个洞室在相同比例距离时的压力差值逐渐减小；相同比例距离端部加密锚固洞室峰值压力比普通长密锚杆加固洞室峰值压力先大后小；端部加密锚杆加固洞室与普通长密锚杆加固洞室离加固范围最近测点的压应力峰值衰减规律比较相近，并且压应力峰值大小也比较相近。

Stress wave propagation and attenuation laws of underground openings reinforced by dense bolts at anchor top under repeated top explosions

Stress wave propagation and attenuation laws of underground openings reinforced by dense bolts at anchor top and long-dense bolts are studied by anti-explosion model tests under repeated top explosions. After each explosion, with the increase of scaled stance, peak pressure stresses on vault gradually decrease in the form of a power function, and the corresponding power functions to fit the curves are obtained, of which the indexes of fitting stress wave attenuation are smaller than those of undisturbed rock. Under the action of explosion stress waves, the rock near the anchorage zone is compacted firstly, and then damaged continuously. Under the same conditions of explosions, with the increase of scaled stance, the difference of pressure stresses with two underground openings is reduced gradually at the same scaled stance and peak pressure stress on vault of the underground opening reinforced by dense bolts at anchor top is greater than that of the underground opening reinforced by long-dense bolts firstly at the same scaled stance, and then smaller. Under the same conditions of explosions, the stress wave attenuation law and peak pressure stress of the nearest measuring points from two underground openings are similar.