爆破荷载在数值计算中的等效施加方法研究

针对目前爆破荷载数值模拟中施加荷载方法的不足,在分析了各种荷载施加方法的特点及不同爆破数值模拟的目的和要求,利用圣维南荷载等效原理,提出了爆破荷载的等效施加方法,即将作用在炮孔壁上的爆破荷载等效后,施加在同排炮孔联心线或者面上,以模拟爆炸作用。数值仿真结果表明,等效荷载施加方法在近区存在一定差异,但在中远区吻合得较好。利用该等效荷载施加方法,分析了某沉管隧道基槽爆破施工对既有堤岸稳定性影响,分析结果与现场实测结果进行了比较,结果表明,等效方法和现场试验结果的位移和振速在量上比较接近,进一步说明等效荷载施加分析方法是合理的,该方法为爆破振动动力问题数值分析提供了借鉴作用,可供类似工程参考。

An Equivalent Approach for Acting Blasting Load in Dynamic Numerical Simulation of Blasting Vibration

For the shortage of applying load in the current numerical simulation of blasting load,the characteristics of various load application and the purpose and requirements of different blasting numerical simulation are analyzed and an equivalent application method of blasting load is put forward on the basis of Saint-Venant principle,that is,applying the blasting load acting on the blast hole wall which is made equivalent on the line of centers or surface of the same blast hole row to simulate the blasting effects.The results for the numerical simulation of equivalent method show that the results are different in the vicinity but better fit in further zone.With this equivalent load application method,the influence of blasting construction of foundation trench of immersed tunnel on the stability of embankment is analyzed and the analysis results and site measurement results are compared.The results show that the equivalent method has a close value in the displacement and vibration speed with those by site test,which further proves that the analysis method of equivalent load application is reasonable,and this method provides a reference role for the numerical analysis of blast vibration motivation and can be referred by other similar projects.