新浇筑基础混凝土爆破安全震动速度的确定

Determination of the Limit of the Safety Velocity for Young Foundation Concrete under Blasting Vibration Loading

针对以往完全依据工程经验来确定新浇筑混凝土爆破安全震动速度这一现状 ,通过爆破地震波(Rayleigh波 )作用下的新浇筑基础混凝土中的震动速度及动拉应变的分布计算并结合不同龄期下新浇筑混凝土的允许极限拉应变分析 ,提出了一种确定新浇筑基础混凝土安全震动速度的理论计算方法。理论分析结果和计算实例表明 ,所提出的理论计算方法是合理可行的 ,新浇筑基础混凝土的极限震动速度随混凝土龄期的缩短及基岩对新浇筑混凝土的基础约束程度的提高而降低。

Be aimed at the situation that the safety velocity of young concrete under blasting vibration loading was usually determined only by engineering experience, a theoretical method to determine safety velocity of young concrete under blasting vibration loading was proposed in this paper, through calculating of distribution of vibration velocity and dynamic strain in young foundation concrete caused by blasting seismic (Rayleigh wave) and analyzing of the ultimate tensile strain of young concrete. Results of theoretical analysis and calculated example show that the proposed method is both reasonable and feasible, the younger the concrete and the higher the degree of restraint from rock foundation are, the lower the safety vibration velocity of young concrete is permitted. The safety vibration velocity for young foundation concrete adopted in our country is of enough safety.