摘要
杨泗港长江大桥沉井基底持力层为坚硬黏土层,施工中通过爆破辅助开挖实现沉井下沉。为确保黏土层能够顺利破坏和刃脚结构不发生损伤,需采用合理的爆破参数。对此,从爆破参数设计出发,应用ANSYS/LS-DYNA数值模拟软件,对不同爆破参数下黏土层和刃脚结构的应力变化和破坏效果进行了分析,并结合相应的动态破坏判据进行判断。最终确定合理的临空面高度、装药量分别为2 m和4.5~6 kg。施工过程中刃脚下临空面高度控制在2 m左右,装药量取4.5 kg,黏土层爆破效果和刃脚保护程度均达到了要求。最终经过3次循环爆破,1号塔沉井下沉到指定位置。
Bearing stratum of the Yangsigang Changjiang River Bridge is stiff clay layer. Blasting excavation was carried out as an auxiliary construction method during sinking of open caisson. To ensure clay layer to be destroyed smoothly and the cutting curb safely, it is crucial to adopt rational blasting parameters in the construction. On the ba- sis of corresponding dynamic destruction, numerical simulation software-ANSYS/LS-DYNA was applied to analyze the stress change and destructive effect of clay layer and cutting curb with different blasting parameters. The results show that rational free surface height was 2 m and charge amount was 4.5 - 6 kg, by which good blasting effect on clay layer and the protective degree of cutting curb was obtained. The open caisson of tower reached the specified po- sition with three blasting cycles.
出处
《爆破》
CSCD
北大核心
2017年第4期125-132,共8页
Blasting
基金
湖北省自然科学基金重点项目(No.2015CFA136)
中央高校基本科研业务费专项资金(No.20171136GX)
国家自然科学基金(No.51774220)
关键词
水下爆破
黏土
沉井
刃脚
参数设计
数值模拟
underwater blasting
clay
open caisson
cutting curb
design of parameters
numerical simulation
