摘要
为研究近岸水下钻孔爆破能量波传播规律,评估地震波、水击波协同作用下水库大坝的毁伤效应及地震波对库岸基坑的毁伤效应,以桂林市第二水源工程-引水工程取水口水下钻孔爆破工程为背景,采用全耦合拉格朗日-欧拉算法开展近岸水下钻孔爆破数值模拟研究,分析爆破能量波传播形态变化及衰减规律、水库大坝及库岸基坑动力响应特征。研究结果表明:现场测试水击波峰值压力随距离比例药量(Q 1/3/R)的衰减特征、大坝振动速度时程曲线及峰值振动速度变化规律与数值模拟的结果具有较高的吻合性,且现场测试和数值模拟得到的水击波峰值压力衰减特征均与Cole经验公式有较高的拟合性,验证了水下钻孔爆破数值模拟模型的可靠性;基于水击波在水库库水、地震波在水库库底岩体中传播衰减特征的直观分析结果,将爆破能量波传播过程划分为三个阶段——爆炸阶段、扩散阶段及衰减阶段;爆破能量波传播引起介质振动速度v=0.1 cm/s的地震波、水击波的影响范围依次为270.00 m、206.28 m,均未传播至水库大坝坝脚;水击波峰值压力随爆心距、深度增加衰减显著,基于爆破相似类比法建立了同时考虑爆心距与水下深度的双因素水击波峰值压力经验计算公式,可用于可靠预测水域中任意位置的水击波峰值压力;爆破能量波在水库大坝中传播引起芯墙与坝体产生明显的动力响应,坝体迎爆面底部区域振动响应较为显著且坝脚区域产生损伤;坝体迎爆面坝底监测点峰值振动速度仅为0.17 cm/s,小于规范规定限值2.5 cm/s,初步判断水库大坝处于安全稳定状态;坝体迎爆面坝脚区域最大损伤比仅为25%,为确保大坝绝对安全,需要考虑对水库大坝采取适当的隔振及防护措施;爆破地震波在库岸岩体中传播,引起库岸基坑迎爆面、基坑坑底及坑侧、基坑背爆面依次出现动力响应,迎爆面库岸基坑坑顶的峰值应力与峰值振动速度最大,近距离大药量爆破会对库岸基坑的安全稳定造成不利影响,需要对库岸基坑采取严格的加固和隔振措施。研究成果也可为类似工程爆破施工能量波传播规律分析和不利影响评估提供参考。
To investigate the propagation of energy waves generated by nearshore underwater borehole blasting and to evaluate the destructive effects of seismic waves and water shock waves on reservoir dams,as well as to discuss the damaging effects of seismic waves on reservoir shore pits,the underwater borehole blasting project at the water intake of the Second Water Source Project in Guilin City was taken as an engineering background and research object.Using a fully coupled Lagrangian-Eulerian algorithm,numerical simulations of the nearshore underwater borehole blasting were carried out to analyze the changes in propagation patterns and the attenuation of blasting energy waves,as well as to investigate the dynamic response characteristics of the reservoir dam and shore pits.The results indicate that:the attenuation characteristics of the water shock wave peak pressure along with the variation of the scaled distance charge(Q 1/3/R),the dam vibration velocity time history curve and the variation pattern of dam peak vibration velocity observed in field tests show a high degree of consistency with the numerical simulation results.Both field tests and numerical simulations demonstrate that the attenuation characteristics of water shock wave peak pressure closely match the Cole’s empirical formula,confirming the reliability of the numerical simulation model for the underwater borehole blasting.Based on an intuitive analysis of the propagation and attenuation characteristics of water shock waves in the reservoir water and seismic waves in the reservoir bottom rock mass,the propagation process of blasting energy waves is divided into three stages:explosion stage,diffusion stage,and attenuation stage.The influence ranges of seismic waves and water shock waves caused by the propagation of energy waves,with a medium vibration velocity of v=0.1 cm/s,are 270 m and 206.28 m,respectively,and both of them do not reach the foot of the reservoir dam.The peak pressure of water shock waves significantly attenuate with the increase of the distance from the explosion center and also the increase of the depth.Based on the blast similarity analogy method,a dual-factor empirical calculation formula for water shock wave pressure,considering both the explosion center distance and underwater depth,was established,which can be used to reliably predict the peak pressure of water shock waves at any position in the water area.The propagation of blasting energy waves in the reservoir dam causes significant dynamic responses in the core wall and the dam body.The vibration response in the bottom region of the dam’s blast-facing side is intense,and localized damage occurs in the dam foot area.The peak vibration velocity at the monitoring point at the dam bottom is 0.17 cm/s,which is below the standard limit of 2.5 cm/s,indicating that the dam was preliminarily in a safe and stable state;the maximum damage ratio at the dam foot is only 25%.To ensure the absolute safety of the dam,appropriate vibration isolation and protective measures should be considered.The propagation of blast-induced seismic waves in the reservoir shore rock mass trigger sequentially dynamic responses on the blast-facing side,bottom,side,and back-blast side of the pit.The peak stress and peak vibration velocity are the highest at the top of the blast-facing side of the pit.Close-range high-charge blasting can adversely affect the safety and stability of the shore pit,necessitating strict reinforcement and vibration isolation measures in engineering practice.The findings provide a reference for analyzing the propagation laws of energy waves and assessing adverse impacts in similar engineering blasting projects.
作者
徐平
侯伟琦
乔世范
董辉
罗晓光
赵炜
XU Ping;HOU Weiqi;QIAO Shifan;DONG Hui;LUO Xiaoguang;ZHAO Wei(School of Civil Engineering,Xiangtan University,Xiangtan 411105,China;Key Laboratory of Geotechnical Mechanics and Engineering Safety of Hunan,Xiangtan University,Xiangtan 411105,China;School of Civil Engineering,Central South University,Changsha 410075,China)
出处
《振动与冲击》
北大核心
2025年第6期144-156,183,共14页
Journal of Vibration and Shock
基金
国家自然科学基金(42272304)
湖南省教育厅资助科学项目(22C0046,22C0071)
湘潭大学博士科研启动项目(21QDZ27)。
关键词
近岸水下钻孔爆破
数值模拟
地震波
水击波
传播规律
毁伤效应
nearshore underwater drilling blasting
numerical simulation
seismic wave
water shock wave
propagation law
damage effect
