## 2 Materials and Methods
### Case Study and Data Collection  
In this study, in order to apply methods for PPV evaluation, four quarry blasting sites in Malaysia were selected. The names of these quarries and their latitudes and longitudes are presented in Table 1. In addition, geological map and locations of these quarries are shown in Figure 2. Generally in these quarries, the type of rock is granite, and blast operations are conducted in order to create aggregate to be used for construction purposes. In each site, roughly 30,000 tonnes of aggregate is produced per month. A value of 10 m was measured as the minimum bench height in the Kulai Quarry, while a value of 28 m was observed as maximum bench height in the Bukit Indah Quarry. Various weathering zones, ranging from moderately weathered to completely weathered, were observed in the studied sites based on the suggested method by ISRM [72], and as reported by [PERSON] et al. [73]. Results of the Schmidt hammer test (based on ISRM [72]) were measured in the range of 19-37. In addition, in these sites, rock quality designation (RQD) as an indicator of rock mass fracturing was measured as a minimum of 22.5% to a maximum of 61.25%. According to previous studies [74; 75], resistance parameters of the rock mass can have a deep impact on explosive operations. Figure 1: Flowchart of different steps in this study. The total number of conducted blasting operations which were investigated in these sites was 149 operations. In these operations, different blasting parameters, including burden (the shortest distance between the hole and the exposed bench face), spacing (the distance between blast-hole rows), stemming (the material which is placed on top of explosives in blast holes), maximum charge per delay (the maximum amount of explosive charge detonated on one delay within a blast with units defined as kg), powder factor (the amount of explosive needed to remove and a fragment of 1 m\({}^{3}\) of the rock mass with its unit defined as kg/m\({}^{3}\)) and distance from the blast face, were recorded. In all operations, a value of 115 mm was utilized for the blast-hole diameter. It is of a high importance to measure, evaluate and simulate PPV in the investigated sites, because blasting operations are carried out at a close distance to adjacent residential buildings. The nearest building is located 350 m away from the investigated sites; therefore, an area in a distance ranging from 65 m to 640 m to the blast face was determined for PPV measuring stations. All of the obtained PPV values were recorded opposite the quarry's bench, and almost perpendicular to it, and the maximum PPV levels in a variety of directions were taken into consideration. To effectively evaluate the PPV results, the parameters with the highest effects must be determined. As noted earlier, the two parameters of distance from the blast site and the maximum charge per delay have been widely taken into account by numerous scholars in the PPV prediction process. Furthermore, based on a number of studies available in the literature [7; 11; 22; 60; 76; 77], powder factor and blasting pattern parameters play an important role in determining the PPV value. Therefore, in this study, the burden-to-spacing ratio (BS), stemming (ST), powder factor (PF), maximum charge per delay (MC) and the distance from the blast face (D) were considered as predictors or model inputs. The average, maximum, minimum, unit and symbol of the measured parameters are shown in Table 2. It is important to note that in the case of parameters which had several values in a blast (such as stemming length), their average values were considered and used in the established database.