## 1 Introduction  
Recently, enabled by advanced sensing technology [1; 2], the rapid development of structural health monitoring (SHM) [3; 4; 5; 6] and damage detection [7; 8; 9; 10] in many fields, especially in the field of civil infrastructure [11; 12; 13], has occurred. In particular, SHM of pipelines--a major form of infrastructure--has received much attention [14; 15; 16]. Representing a new trend in pipeline technology, the use of polyethylene (PE) pipelines has become increasingly widespread because of their corrosion resistance and low cost. However, compared with their metal counterparts, PE materials have much lower moduli and are prone to damage as a result of extreme events [17; 18; 19], such as explosions, which often accompany underground construction. Blasting technology is an economical and efficient type of construction technology that is commonly used in underground engineering. However, blasting operations inevitably trigger some negative effects. The impact and vibration effects of blast waves may cause potential safety hazards to surrounding underground pipelines. Therefore, the accurate calculation of the safety distance between an explosion source and a pipeline is essential for the rational design and safe construction of engineering blasting. Structures subject to high strain rate loads, such as explosion and impact, have received much attention [20; 21; 22; 23; 24]. To date, many experts and scholars have studied the allowable vibration velocity criterion of buried pipelines under the impact of blast waves. The recommended ground peak particle velocity (GPPV) safety criterion ranges from 2.0 cm/s to 15 cm/s with a wide span [25; 26; 27; 28; 29]. In actuality, the difference in the responses of different pipes subjected to the same blast wave may be very large due to varying materials and types of pipe. Moreover, the strength (yield) limit and impact resistance of individual pipes are also different, and the generation and attenuation of blast waves are very different under varying charge and site conditions. These distinctions are very important; however, such differences cannot be reflected by a single velocity criterion. Examples of representative research on buried pipelines subjected to the impact of blast waves include the following: [PERSON]'s calculation formula, which is derived from a plane wave with constant amplitude, whose calculation result can be used as the upper limit of the response of buried pipelines under far-field plane waves [30], and the empirical formulas proposed by [PERSON] et al. based on model and field test data, which require applicable site conditions and experimental environments [28]. There are also two typical semi-theoretical, semi-empirical formulas: One by [PERSON] et al., which is based on the harmonic assumption and uses a thin shell cylindrical model [31], and another by [PERSON] et al., which is based on the law of pressure attenuation of blast waves and uses the beam model on elastic foundation [29]. In these two formulas, the blast wave and pipe were simplified by different types, and therefore, their applications require further investigation and analysis. Thus, most of the existing criteria are based on their respective engineering cases, and current, in-depth research on the dynamic responses of pipelines subjected to blast waves is still lacking, especially with respect to PE pipelines. In this study, the dynamic response of a PE pipe situated near an explosive source was investigated. The pipe was directly buried in the soil, and measurements, including pipe dynamic strains, vibration velocities of the pipe, and ground vibrations were measured. The results revealed that a large hoop strain on the PE pipe was produced due to the local impact. Additionally, we found that peak hoop strain (PHS) or peak axial strain (PAS) has a power attenuation relationship with the scaled distance.