Abstarct: Today, blasting operations are used to develop underground spaces and extract minerals in mines. Improper design of blasting operations in mines has always led to hazards such as fly rock, ground vibrations, etc. In mines that operate simultaneously in both surface and underground mines, severe ground vibrations resulting from explosions increase the likelihood of instability in adjacent underground spaces. Any instability in the underground space can lead to human and financial damage. Therefore, calculating the maximum allowable peak particle velocity in an explosion can help to increase the safety of underground structures. In order to investigate the effect of blast vibrations in an open pit mine on the underground structures, ANGOURAN lead and zinc mine has been selected as a case study. In this research, an attempt has been made to provide experimental relationships to calculate the peak particle velocity and determine the allowable value for this parameter by seismic surveys inside the main ramp of ANGOURAN mine during surface blasting operations, and also to modify the blast pattern if necessary. . A total of 19 seismic recordings of surface blasting events have been recorded. Among these, the maximum PPV recorded is 9.67 mm / s. According to the observations, no damage was visible in the underground space of this mine during the surface blasting operations, which shows the correctness of the open fire pattern of this mine. Finally, experimental equations for calculating the PPV using univariate regression with a scaled distance parameter are presented. These relationships are categorized baxsed on the impact of a fault on the eastern and western regions. The correlation coefficients for the eastern and western regions are 0.9544 and 0.7357, respectively. By comparing the obtained relations with the previously presented relations, it is concluded that the mentioned relations had higher correlation coefficients than the previous relations. By examining the fall occurred in this mine and using the provided relationships, a threshold for small local falls has been presented.