22层框架楼房定向爆破拆除倒塌过程分析

Analysis on Collapse Process of 22 Storey Frame Building Demolished by Directional Blasting

河源市龙川县远东花园4号楼为22层框架结构楼房,系违章建筑需爆破拆除。紧挨楼房5 m处有一栋3层别墅,别墅的围墙与待拆除楼房只有0.5 m,需防止楼房产生后座。根据周围环境条件,采用定向倾倒的方式爆破拆除,采用梯形爆破缺口,爆破高度13.5 m。为确定最佳延期时间,用ANSYS/LS-DYNA对排间延期时间300 ms、500 ms和800 ms三种方案进行了模拟,根据模拟结果,确定最佳延期时间为300 ms。起爆时,利用多台高级数码相机、无人机、高清摄像机等从不同方位和角度抓拍了楼房爆破运动及解体的全过程。通过数值模拟与爆破实际对比分析,发现二者在楼房倒塌姿态、观测点的运动轨迹、解体程度、爆堆形态和堆积范围都十分接近,数值模拟的结果的准确性和可靠性满足工程要求。

The No.4 Building of Yuandong Garden,Longchuan County,Heyuan City,a 22-story building with frame structure is an illegal building to be demolished by blasting.There is a three-story villa 5 m away from the building,whose fence is only 0.5 m away from the building.Therefore,it is necessary to prevent the building from generating backward sliding at bottom.According to the surrounding conditions,the directional collapse blasting demolition method was adopted,and the trapezoidal blasting cut with 13.5 in height was selected.In order to determine the best delay time,ANSYS/LS-DYNA was used to simulate the delay time of 300 ms,500 ms and 800 ms,and the simulation results showed that 300 ms was the best one.During the detonation,multiple advanced digital cameras,drones camera,high-definition cameras,etc.were used to capture the entire process of building blasting movement and disintegration from different positions and angles.Comparing the numerical simulation and actual blasting results,it was found that they were very close to each other in collapse posture,movement track of observation point,degree of disintegration,shape and range of blasting pile.The accuracy and reliability of the numerical simulation results meet the engineering requirements.