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| Blasting analysis of tunnel surrounding rock with weak interlayers based on JHB-4D-LSM |
| MA Jianjun1,2, SHEN Kunyue1, ZHENG Nan3, HUANG Weizhen1*, XIAO Haihua4
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1. School of Civil Engineering, Sun Yat-sen University, Zhuhai 519082, Guangdong, China;
2. State Key Laboratory for Tunnel Engineering, Sun Yat-sen University, Zhuhai 519082, Guangdong, China;
3. National Key Laboratory of Intense Pulsed Radiation Simulation and Effect(NKLIPR), Xi'an 710024, Shaanxi, China;
4. Guangdong Expressway Co., Ltd., Guangzhou 510199, Guangdong, China;
5. WuhanYihetu Engineering Design Consulting Co., Ltd., Wuhan 430056, Hubei, China |
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Abstract As a typical unfavorable geological feature commonly encountered in tunnel construction, weak interlayers significantly affected the propagation characteristics of blasting-induced stress waves, thereby posing adverse impacts on construction safety and engineering quality. To accurately simulate blast stress wave propagation in tunnels containing weak interlayers, blasting-induced dynamic responses were modeled. A single-hole blasting numerical model was established using a continuous-discontinuous method—the Johnson-Holmquist-Beissel model within the four-dimensional lattice spring model(JHB-4D-LSM). The effects of blast-interlayer distance, interlayer thickness, and dip angles were investigated. Tunnel blasting stress wave propagation simulated by the JHB-4D-LSM model aligned well with prior LS-DYNA studies, validating the method's effectiveness. Localized stress concentration and increased peak stress were observed in the incident-wave-facing rock mass adjacent to the weak interlayer, while the peak stress decreased on the opposite side. This indicated the weak interlayer's dual role: enhancing stress on the incident-wave-facing side and attenuating stress on the transmission side. This effect intensified with greater interlayer thickness, showing a positive correlation. As the distance between the weak interlayer and the blast-hole decreased, stress concentration on the incident-wave-facing side became increasingly significant. When this distance exceeded 30 cm, the interlayer's influence on stress wave propagation was notably reduced. The dip angle's effect on stress wave propagation was governed primarily by the vertical distance between the blast-hole and the interlayer. Smaller vertical distances resulted in higher peak stresses, indicating a more pronounced stress wave impedance effect. This study provided valuable guidance for ensuring construction safety and offered a theoretical basis for optimizing blasting vibration control technology in tunnel engineering.
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Published: 19 September 2025
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