论文部分内容阅读
为减少隧道爆破震动对初衬喷射混凝土的损伤,通过现场质点震速监测和信号分析,根据爆破动力学理论,探讨混凝土龄期对累积损伤的影响。综合考虑质点震速、初始损伤、混凝土强度和龄期等因素,提出单次爆破对混凝土的损伤增量及多次爆破对混凝土的累积损伤的计算方法。研究结果表明:混凝土的破坏是一个损伤的累积过程,单次爆破的损伤增量超过增量阈值并不一定造成材料的破坏;在混凝土中掺入早强剂有显著减震效果。将该方法应用于工程实例,提出新喷混凝土的爆破安全准则。
In order to reduce the damage to the shotcrete caused by tunnel blasting vibration, the influence of concrete age on the cumulative damage was discussed according to blasting dynamics theory through the monitoring and signal analysis of particle velocity in the site. Considering the velocity, initial damage, strength and age of the concrete mass, the calculation method of concrete damage caused by single blasting and the cumulative damage of multiple blasting are proposed. The results show that the damage of concrete is a cumulative process of damage. The damage increment of single blasting exceeds the increment threshold does not necessarily result in material damage. The early strength agent incorporated in concrete has a significant damping effect. Applying this method to engineering example, the blasting safety criterion of newly sprayed concrete is put forward.