【摘要】 结合矮寨悬索桥锚碇隧道的爆破施工,通过围岩的声波测试得到围岩损伤度和松动圈范围在不同等级的爆破冲击荷载作用下的发育规律,探讨围岩累积损伤程度和振动速度之间的对应关系,以及引起岩体损伤度累计效应的阈值,较为完整地描述了爆破冲击荷载作用下围岩损伤度和松动圈的发展过程。在此基础上得出合理的爆破振动速度的控制指标。结果表明:锚碇隧道的爆破施工不但要控制单次爆破对围岩的扰动,更重要的是,应考虑围岩在频繁的近距离爆破作用下产生的累计振动效应并加以控制。爆破振动速度控制在3～6cm/s时,最大围岩松动圈厚度约为2.3m,围岩平均损伤度约为0.15。当测点处围岩的振动速度小于2cm/s时,围岩的损伤度积累不明显,可视为爆破振动累积损伤阈值。更多还原

【Abstract】 Based on blasting excavation in anchorage tunnel of Aizhai suspension bridge,the development laws of damage degree and loose ring of surrounding rock under different blasting loads are obtained by acoustic wave testing method.The corresponding relation between the damage degree of surrounding rock and the peak particle velocity(PPV) of vibration is discussed.Moreover,the threshold which leads to accumulative damage to rock mass is discussed;and a comparatively complete description of the development of damage degree and loose ring of surrounding rock is given.On the basis of above-mentioned researches,a reasonable control index of blasting vibration velocity is obtained.It is shown that not only the disturbance of single blasting on the surrounding rock should be controlled during blasting construction of anchorage tunnel,but the emphasis should be put on the accumulative vibration effect of surrounding rock induced by frequent short-distance blasting;and the corresponding control measures should be taken.When the PPV of the surrounding rock is controlled in the range of 3-6 cm/s;the maximum thickness of the loose ring of the surrounding rock is about 2.3 m;and the average damage degree of the surrounding rock is 0.15.When the PPV of the surrounding rock is less than 2 cm/s,the accumulated damage degree of the surrounding rock is not obvious,which can be regarded as the threshold of blasting vibration accumulated damage in this project.更多还原