水下分层爆破孔内延时电子雷管的抗冲击作用OA

Through the layered charge structure inside the blasting hole,water medium isolation layer,and diffe-rentiated delayed detonation design of upper and lower electronic detonators,underwater deep foundation trench blasting excavation was achieved.Aiming at the key issue that the explosion impact of the upper charge may cause misfiring of the lower electronic detonators,a blast wave testing system with an integrated pressure sensor array and an electronic detonator impact testing device inside the blasting hole were constructed based on the blasting conditions of a typicalϕ115 mm blas-ting hole underwater reef deep foundation trench.Viability test and shock wave overpressure test on electronic detonators at different distances inside the blasting hole under the same intensity of explosive source were conducted.At the same time,through finite element numerical calculations,the impact process of the lower electronic detonator after the explosion of the upper charge was simulated,and the overpressure of the water shock wave at different distances inside the blasting hole and the force state of the electronic detonator under different working conditions are obtained.The results indicate that in an unprotected state,when the peak overpressure of the shock wave in water inside the blasting hole exceeds 75.6 MPa,the electronic detonator of this model will be damaged.When adhesive strip is used as the protective material for detonators,it can effectively resist the impact of peak overpressure not exceeding 115.0 MPa.Considering a certain safety factor,the distance between the unprotected electronic detonator and the bottom of the upper charge should be greater than 1.89 m,and the minimum safety distance for protected electronic detonators is 1.69 m.