爆炸载荷下水下隧道的压力分布和动力响应

Pressure distribution and dynamic response of a submerged tunnel under explosion loading

为了研究隧道结构在水中爆炸冲击下的荷载分布和动力响应,设计并制作了1/10缩尺隧道模型,进行了3次水下爆炸试验,对隧道模型的压力、冲量和位移进行了研究。研究结果表明:冲击波在浅水区会产生明显的水面截断效应,该效应会使近水面的冲量减小;自由场冲击波峰值压力的试验值与理论值吻合良好,误差在20%以内;圆形截面隧道迎爆面峰值压力为自由场峰值压力的1.626~1.716倍,顶面峰值压力为自由场峰值压力的54.3%~65.2%,背爆面峰值压力为自由场峰值压力的25.5%~31.3%;水中爆炸作用下的冲量时程曲线呈明显的阶梯状,每一次的气泡脉动都伴随着相应的冲量增加;水下爆炸会引起隧道结构产生振动,其振动过程可分为结构急速变形、结构大幅振动和结构颤振3个阶段,隧道结构的最大位移发生在结构大幅振动阶段。

In order to study the load distribution and dynamic response of tunnel structures under underwater explosion,a 1/10 scaled tunnel model was designed and manufactured,and underwater explosion tests were conducted for three times.The pressure,impulse,and displacement of the tunnel model were studied.The results show that the shock wave produces a significant water surface truncation effect in the shallow water area,which reduces the impulse near the water surface.The experimental value of the peak pressure of the free field shock wave is in good agreement with the theoretical value,and the error is within 20%.The peak pressure on the front surface of the circular cross-section tunnel is about 1.626-1.716 times that of the free field,the peak pressure on the top surface is about 55.4%-65.2%of the free field,and the peak pressure on the back surface is about 25.5%-31.3%of the free field.The impulse time history curve under the action of underwater explosion shows a clear step shape,and each bubble pulsation is accompanied by a corresponding increase in impulse.The displacement analysis shows that the underwater explosion causes the vibration of the tunnel structure.The vibration process can be divided into three stages:the rapid deformation of the tunnel structure,the large amplitude vibration of the tunnel structure,and the tremor of the tunnel structure.The maximum displacement of the tunnel structure occurs during the large amplitude vibration of the tunnel structure.