The Dynamic Response Of Subsurface Structures Under The Ground Explosion

International terrorism and chemical explosion accident occurred frequently, Subsurface structures such as subway and subsurface channels are the first places to be easily attacked, because of difficult evacuation and extensive influence in society. Anti-explosion and disaster mitigation, explosion protection for subsurface structures have became the most important research. On the basis of presult results at home and abroad, the dynamic response of subsurface structures under the ground explosion will be studied by using software ANSYS/LS-DYNA. The paper Includs the following aspects: the ground explosion stress wave transmission and distribution; the dynamic response of subsurface structures under explosion on the ground; the influence of buried depth, TNT equivalent, soil on the structural dynamic response. The main achievements and conclusions can be drawn as follows: the following conclusions can be draw from the research.(1) The law of the propagation and reflection of stress wave under the explosion on the ground is analyzed, and the theory calculation formula of pressure peak and the rise time is recommended, the calculation method of the pressure peak and the booster time on the underground structure is recommended under the explosion on the ground. The overpressure peak value and the rise time of stress wave in the soil and the dynamic peak on the underground protective structures of the example engineering is calculated and analysed by using the theoretical calculation formula.(2) Simulating the propagation and distribution of the ground blast stress wave field was simulated in clay and sandy soils by using ANSYS/LS-DYNA. the theoretical calculation results of pressure peak and the rise time are consistent with the results of numerical simulation; the accuracy of the numerical model was verified. The the ground blast stress wave field divided into surface area(near surface area and surface area) and the central area according to the result. The characteristics of stress wave and the effection of soil were analyzed.(3) The dynamic response of underground structures under the ground contact explosions in sandy soils was simulated by using ANSYS/LS-DYNA. The function influence between stress wave and structure was also studied. The stress, plastic strain, velocity and acceleration of the unit selected in damaged area were analyzed. The destruction form of underground structure and the location were discussed. The dynamic response of underground structures under the ground contact explosion in different of buried depth, TNT equivalent and the soil was simulated by using ANSYS/LS-DYNA. The influences of the parameter on the unit in damaged area are also analyzed, as well as the influence on the structure damage.