摘要
研究城市地下工程爆破施工地表振动衰减规律对邻近建筑保护具有重要意义。以武汉地铁8号线二期联络通道爆破开挖工程为例,运用现场监测与ANSYS/LS-DYNA三维有限元数值模拟计算相结合的方法,分析了联络通道爆破开挖作用下地表振动的空洞效应,并预测其衰减规律。研究表明:地表质点的峰值振速随着与掌子面距离的增大而不断减小,成洞区域上方地表振速明显大于未开挖区域;空洞效应放大系数随着与爆源纵向距离的增大先增大后缓慢减小,沿通道两侧随着距离的增大而不断减小,空洞效应的影响减弱;在距爆源8 m处(掌子面后方6 m),放大系数达到最大,应重点在距离爆源2~8 m即空洞效应较大的地表区域内开展振动监测。在开挖区域,与介质和爆破条件相关的系数、振动衰减系数和层介质吸收系数分别为58.52、1.43和0.019,而在未开挖区域,则分别为152.09、1.74和0.023。
The study of surface vibration attenuation law of urban underground engineering blasting construction is of great significance for the protection of adjacent buildings. This paper takes the Wuhan Metro Line 8 Phase Ⅱ liaison channel blasting excavation project as an example and uses a combination of field monitoring and ANSYS/LS-DYNA 3D finite element numerical simulation to analyze the characteristics of surface vibration hollow effect under the liaison channel blasting excavation and predict its attenuation law. The results indicate that where the surface vibration speed is significantly greater than the unexcavated area, there is a “cavity effect”;with the increase of the longitudinal distance between the mass point and the source of the explosion, the cavity effect amplification coefficient increases rapidly until the extreme value and then slowly decreases. Along both sides of the channel with the increase in distance, the amplification coefficient decreases, the effect of the cavity effect is weakened, at a distance of 8 m from the source(6 m behind the palm surface) to reach the maximum, 2-8 m from the source of the cavity effect should focus on vibration monitoring within the surface area. The excavation area with the blasting conditions is related to the coefficient of 58.52, and vibration attenuation coefficient of 1.43, while the unexcavated area of 152.09,and vibration attenuation coefficient of 1.74, the absorption coefficient of the layer media are 0.019, 0.023,respectively.
作者
董合费
朱斌
蒋楠
杨玉民
DONG Hefei;ZHU Bin;JIANG Nan;YANG Yumin(Wenzhou Oujiang River Diversion Development Co.,Ltd.,Wenzhou 325000,Zhejiang,China;Faculty of Engineering,China University of Geosciences,Wuhan 430074,Hubei,China)
出处
《高压物理学报》
CAS
CSCD
北大核心
2022年第5期181-189,共9页
Chinese Journal of High Pressure Physics
基金
国家自然科学基金(41972286,42072309)
爆破工程湖北省重点实验室开放基金(HKLBEF202001)。
关键词
联络通道
爆破开挖
空洞效应
振动速度
衰减预测
access tunnel
blasting excavation
cavity effect
vibration velocity
attenuation prediction
