关键词: 混凝土重力坝, 水下接触爆炸, 横缝, 模型试验, 动态响应

Abstract: In order to meet the requirements of construction, settlement and temperature control, concrete gravity dam is often divided into several dam sections along the dam axis, and transverse joints are set up between the sections. A 72 m-high concrete gravity dam is taken as a prototype for 1:100 scaling, and underwater contact explosion model tests of gravity dams with and without transverse joints are carried out. The pressure characteristics of the underwater explosion shock wave in front of the dam were collected and analyzed, and the damage modes of the concrete gravity dams with and without transverse joints under the underwater contact explosion were investigated. On this basis, the simulation model of underwater contact explosion of concrete gravity dam is established, and the reliability of the numerical model is verified by comparing and analyzing with the model test. Through numerical simulation, the effects of transverse joint on the damage characteristics and dynamic response of the concrete gravity dam under underwater explosion were further analyzed. The results show that the existence of transverse joints will weaken the stiffness of the dam under underwater contact explosion. The kinetic energy and acceleration response of the gravity dam with transverse joint is significantly larger than that of the gravity dam without transverse joint. The existence of the transverse joint avoids the penetration damage destruction mode of the dam neck, and the explosion crater formed at the dam body which is completely crushed directly to the explosives is mainly carried out along the longitudinal direction.

Key words: concrete gravity dam, underwater contact explosion, transverse joint, model test, dynamic response