【作者】 刘明武； 刘庭金； 周腾飞； 梁嘉明； 周志军；

【Author】 LIU Ming-wu;LIU Ting-jin;ZHOU Teng-fei;LIANG Jia-ming;ZHOU Zhi-jun;School of Civil Engineering and Transportation,South China University of Technology;State Key Laboratory of Subtropical Building Science,South China University of Technology;School of Civil Engineering and Architecture,Wuyi University;

【机构】 华南理工大学土木与交通学院； 华南理工大学亚热带建筑科学国家重点实验室； 五邑大学土木建筑学院；

【摘要】 近年来,城际列车高速行驶引发的环境振动问题日益突出,对于软土区的振动影响更为明显,水泥搅拌桩能有效加固软土地基,但其减振特性及对隧道周围土体振动响应影响的研究还有待深入。本文依托城际出入段线某软基加固工程开展了现场测试,从时域、频域以及振级三个方面深入探究了水泥搅拌桩加固的减振作用,然后通过建立隧道-土体三维有限元模型研究了水泥搅拌桩加固深度、动弹性模量及置换率等因素对减振特性的影响。研究结果表明:地基采用水泥搅拌桩加固时,水泥搅拌桩对地表40 Hz～80 Hz的主要频段具有较强的吸振作用。在离隧道中心线较近的范围内,加固深度的增加对加固区地表加速度的削弱较非加固区的明显。加固区地表的加速度对于水泥搅拌桩动弹模的变化更为敏感。加固区地表的加速度有效值随水泥搅拌桩置换率的增加整体上表现为逐渐减小,而非加固区地表的加速度有效值整体上表现为逐渐增大。本文研究结果可为类似工程的减隔振提供参考。更多还原

【Abstract】 In recent years,the environmental vibration problem caused by intercity trains running at high speed has become more and more prominent,and the vibration impact is more obvious for the soft soil area.Cement mixing piles can effectively strengthen the soft soil foundation,but the research on its vibration damping characteristics and the impact on the vibration response of the soil around the tunnel still needs to be deepened.In this paper,a soft foundation reinforcement project of intercity access line was tested in the field,and the vibration damping effect of cement mixing pile reinforcement was investigated in three aspects:time domain,frequency domain and vibration level,and then the effects of cement mixing pile reinforcement depth,dynamic elastic modulus and replacement ratio on the vibration damping characteristics were studied by establishing a three-dimensional finite element model of tunnel-soil.The results showed that when the foundation was reinforced by cement mixing pile,the cement mixing pile had a strong vibration absorption effect on the main frequency band of 40 Hz～80 Hz at the ground surface.In the range closer to the centerline of the tunnel,the increase of reinforcement depth weakened the ground acceleration in the reinforced area more significantly than that in the non-reinforced area.The acceleration of the ground surface in the reinforced area was more sensitive to the change of the dynamic-elastic mode of the cement mixing pile.The effective value of the acceleration in the reinforced area decreased gradually with the increase of cement mixing pile replacement ratio,while the effective value of the acceleration in the unreinforced area increased gradually.The results of this paper can provide reference for vibration reduction and isolation of similar projects.更多还原