摘要
为研究不同爆距水下爆炸对重力坝的毁伤效应,并探讨是否存在“最优爆距”,基于离心模型试验建立了炸药-库水-空气-重力坝结构的全耦合数值模型,并设计了60组数值计算工况。不同工况水深均为600 mm,炸药量为2.2 g,重力坝模型几何比尺为1/80,包含5组爆深(50~250 mm),每组爆深对应12组爆距,爆距范围为10~200 mm,相应比例爆距范围为0.077~1.54 m/kg^(1/3)。对比分析了不同爆距水下爆炸对重力坝的毁伤程度,并定量比较了重力坝平均损伤、单元删除率、应力、应变等参数。结果表明,对于重力坝整体结构破坏,如重力坝整体弯曲导致的拉伸破坏,水下爆炸对重力坝的毁伤效应存在“最优爆距”,即随着爆距增加重力坝毁伤程度先增加后降低;与之类似,随着爆距的增加,重力坝上游坝面损伤区域的平均损伤、重力坝单元删除率、坝踵最大拉应力平均值和坝踵最大拉应变平均值先增加后降低且在40 mm爆距附近达到最大值。保持水深、炸药量和重力坝几何模型相同,5组不同爆深近水面水下爆炸对重力坝毁伤效应的“最优爆距”均在40 mm附近,表明近水面水下爆炸时爆深对“最优爆距”不存在显著影响。
To investigate the standoff distance of underwater explosions on the damage to gravity dams and to explore whether there is an“optimal standoff distance”,a numerical model of a fully-coupled explosive-water-air-gravity dam was established.The numerical model was validated by comparing it with centrifuge test results.The results demonstrated that the employed numerical model could predict the dam failures and the effect of bubble pulse well.Then,a numerical scheme including 60 numerical calculations was designed.In these calculations,the water depth is 600 mm,the explosive mass is 2.2 g,and the geometrical scaling factor of the gravity dam model is 1/80.The detonation depth ranges from 50 to 250 mm with five detonation depths.Each detonation depth corresponds to 12 standoff distances ranging from 10 to 200 mm,with the scaled standoff distance ranging from 0.077 to 1.54 m/kg^(1/3).The damage degrees to the gravity dam under underwater explosions with different standoff distances are compared.Quantitative comparisons of dam average damage,element erosion rate,stress,and strain are also presented.The results show that for the overall structural failure of the gravity dam,such as the structural bending-induced tensile failure,there is an“optimal standoff distance”for the damage effects of underwater explosions on gravity dams,that is,with the increase of standoff distance,the damage degree of gravity dam increases first and then decreases.The quantitative results also indicate that with the increase of standoff distance,the average damage of the damaged area in the dam upstream face,the element erosion rate,the average value of the maximum tensile stress of the dam heel,and the average value of the maximum tensile strain of the dam heel all increase first and then decrease,and reach their maximum values around a standoff distance of 40 mm.With identical water depth,explosive mass,and geometrical model of gravity dam,the“optimal standoff distances”for the damage effects of near-surface underwater explosions at five different detonation depths on the gravity dam are all near 40 mm.It suggests that for near-surface underwater explosions,the detonation depth owns limited influence on the“optimal standoff distance”.
作者
黄谢平
孔祥振
陈祖煜
方秦
HUANG Xieping;KONG Xiangzhen;CHEN Zuyu;FANG Qin(Institute of Geotechnical Engineering,Zhejiang University,Hangzhou 310058,Zhejiang,China;State Key Laboratory of Disaster Prevention&Mitigation of Explosion&Impact,Army Engineering University of PLA,Nanjing 210007,Jiangsu,China)
出处
《爆炸与冲击》
EI
CAS
CSCD
北大核心
2023年第5期18-33,共16页
Explosion and Shock Waves
基金
国家自然科学基金(52178515,52078133,51879283)。
关键词
水下爆炸
混凝土重力坝
最优爆距
数值计算
离心模型试验
underwater explosion
concrete gravity dam
optimal standoff distance
numerical simulation
centrifuge model test
作者简介
第一作者:黄谢平(1996-),男,博士研究生,huangxieping@zju.edu.cn;通信作者:孔祥振(1988-),男,博士,副教授,ouckxz@163.com。
