基于边坡稳定性的爆破振动控制标准确定方法

Determination method of control standard under blasting vibration based on stop stability

基于不良地质条件边坡开挖爆破振动控制的工程实践,通过对爆破作用下边坡沿控制性滑动面的稳定性进行极限平衡分析,提出了基于边坡稳定性的爆破振动控制标准确定方法,并对不同强度参数下爆破振动安全控制标准变化规律进行了分析。结果表明,爆破振动安全控制标准值[PPV]主要与边坡静态稳定性安全系数K j、动态稳定性安全系数设计值[K d]以及滑动面倾角、黏聚力和内摩擦角有关。[PPV]与K j和滑动面内摩擦角呈非线性正相关关系,且随内摩擦角增大,[PPV]增大越快;[PPV]与[K d]和滑动面倾角呈非线性负相关关系,一定范围内,随[K d]增大[PPV]降低得越迅速,而随倾角增大[PPV]降低速率减小;[PPV]存在极小值。[K d]越大,边坡对振动控制越严格。通过分析爆破作用角度可知,超过80%的情况下最大爆破作用力并非位于最不利方位。

The stability of slope is the key to success in blasting vibration control.Based on the vibration control practice in a slope excavation program under poor geological conditions,the slope stability along the slip plane is analyzed by using the limit equilibrium method.A determination method of blasting vibration control standard for slopes is proposed,and its change rule under different strength parameters is analyzed.The results show that the blasting vibration control standard or[PPV]is mainly related to the static stability safety factor of slope K j,the design dynamic stability safety factor[K d]and the inclination angle,cohesion and the internal friction angle of the sliding surface.[PPV]has a nonlinear positive relationship with both K j and the internal friction angle,and with the increase of internal friction angle,the[PPV]increased faster.[PPV]has a nonlinear negative relationship with[K d]and the inclination angle of the sliding surface.Within a certain range,with the increase of the inclination angle,[PPV]reduced faster,while with the increases of[K d],[PPV]reduced slower,and there is a minimum value of[PPV].The larger the dynamic stability design safety factor is,the stricter control of slope is required.The analysis shows that the maximum blasting forces are not located on the most unfavorable position in the cases of more than 80%.