摘要
爆破等动力扰动散射产生动应力集中是导致地下结构发生失稳破坏的重要因素。基于波函数展开法建立了平面P波入射下深埋管道的理论模型,引入傅里叶变换和Duhamel积分方法求解了深埋圆形输水管道周围的瞬态响应,分析了波长对瞬态响应的影响。考虑到地应力是深部结构失稳不可忽略的因素,而含初始应力的动力学方程无法有效解耦,因此借助LS-DYNA有限元软件建立数值模型,分析了初始应力作用下深埋管道的动力响应机制。研究结果表明:短波入射产生的压应力集中更大,长波入射导致的拉应力集中更大,沿入射方向极易出现拉应力集中。在初始应力的作用下,侧压系数越大,对动态应力集中响应的抑制作用愈发明显;另外,处于初始应力状态下的管道及周围岩体在受到动态冲击时,应力状态会发生较为剧烈的波动。这些研究现象揭示了地下管道的动态响应机制以及地应力环境产生的影响,对深部地下结构的抗震优化设计具有借鉴和指导意义。
Dynamic disturbance scattering such as blasting generates dynamic stress concentration which is an important factor resulting in instability and damage in underground structures.In this paper,a theoretical model of a deeply buried pipeline under plane P-wave incidence is developed based on the wave function expansion method.Fourier transforms and Duhamel integrals were introduced to solve the transient response around a deeply buried circular aqueduct,and the effect of wavelength on the transient response was analyzed.Considering that the ground stress is a non-negligible factor for the destabilization of deep structures,a numerical model was established with the help of LS-DYNA finite element software to analyze the dynamic response mechanism of deeply buried pipelines under the action of the initial stress.The results of the study show that the compressive stress concentration generated by short-wave incidence is greater,and the tensile stress concentration due to long-wave incidence is greater,and the tensile stress concentration is very easy to occur along the direction of incidence.The larger the lateral pressure coefficient,the more pronounced is the suppression of the dynamic response in the presence of initial stresses.In addition,the pipeline and the surrounding rock mass under the initial stress state will experience more drastic fluctuations in the stress state when subjected to dynamic loading.These research phenomena reveal that the dynamic response mechanism of underground pipelines and the impact of the in-situ stress environment,which can be used for the seismic optimization design of deep underground structures.
作者
丁三毛
DING San-mao(CRCC Harbour&CHANNEL Engineering BUREAU Group Co.,Ltd.,Zhuhai 519070,China)
出处
《爆破》
CSCD
北大核心
2023年第3期177-183,198,共8页
Blasting
关键词
动力响应
动态应力集中因子(DSCF)
数值模拟
初始应力
侧压系数
dynamic response
dynamic stress concentration factor(DSCF)
numerical simulation
initial stress
lateral pressure coefficient
