离散元法研究岩石岩性对爆破荷载作用下岩质边坡波传播特性和动力响应的影响

Danqing Song¹, Xuerui Quang², Zhuo chen³ , Dakai Xu³, Chun Liu², Xiaoli Liu⁴, and Enzhi Wang⁴

¹State Key Laboratory of Subtropical Building and Urban Science, School of Civil Engineering and Transportation, South China University of Technology, Guangzhou, 510640, China 

²School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China 

³Sichuan Higher Education Engineering Research Center for Disaster Prevention and Mitigation of Village Construction, College of Civil Engineering, Sichuan Agricultural University, Dujiangyan, 611830, China ⁴State Key Laboratory of Hydroscience and Engineering, Tsinghua University, Beijing, 100084, China

Abstract:To investigate the dynamic response and attenuation law of rock slope sites subjected to blasting, three lithological numerical models, including slate (hard rock), tuff (relatively soft rock), and shale (soft rock), are established by using MatDEM. By analyzing the wave field, velocity, and acceleration response of the models and their Fourier spectrum, combined with stress and energy analysis, their dynamic response characteristics are investigated. The results show that blasting waves propagate from near field to far field in a circular arc, and the attenuation effect of waves in soft rock is less than that in hard rock. The influence of lithology on the dynamic response of the ground surface and bedrock is different. Blasting waves mainly affect the dynamic response in the near-field area of the blasting source. In addition, the dynamic amplification effect of slopes is as follows: hard rock > relatively soft rock > soft rock. The slope surface has an elevation attenuation effect. A dynamic amplification effect appears in the slope interior within the relative elevation (0.75, 1.0). The Fourier spectrum has an obvious predominant frequency, and that of the slope crest and interior is less than that of the slope surface. Moreover, the total energy generated by the rocky sites gradually changes into kinetic energy, gravitational potential energy, elastic potential energy, and heat. Energy-based analysis shows that the attenuation effect of blasting waves in hard rock is larger than that in soft rock overall. This work can provide a reference for revealing the blasting vibration effect of rock sites.

Figure 2: DEM model: (a) Model box; (b) DEM model (MatDEM) for the slope; (c) layout of measuring points; (d) blasting load application.

Figure 4: Distribution characteristics of the wave displacement field of the explosion source of Models 1–3: (a) slate slope (Model 1); (b) tuff slope (Model 2); (c) shale slope (Model 3).

Figure 6: Propagation characteristics of the horizontal acceleration wave in Models 1–3: (a) Right side of the explosion source; (b) left of the explosion source; (c) below the explosion source.

Figure 7: Characteristics of the dynamic amplifying effect of the slope area in Models 1–3: (a) PGV; (b) PGA.

Figure 11: Horizontal wave peak acceleration value (PGA) distribution of the explosion source: (a) Model 1; (b) Model 2; (c) Model 3.

Figure 12: Fourier spectrum of horizontal acceleration wave excitation from the explosion source in Models 1–3: (a) Right side of the explosion source; (b) left of the explosion source; (c) below the explosion source.

Figure 16: Distribution of the peak Fourier spectrum amplitude (PFSA) of acceleration wave excitation from the explosion source of Models 1–3.

Song D, Quan X, chen Z, et al. Influence of Lithology on the Characteristics of Wave Propagation and Dynamic Response in Rocky Slope Sites Subject to Blasting Load Via the Discrete Element Method[J]. Lithosphere, 2024, 2024(1): lithosphere_2023_302.