长大高耸结构的单桩基础振动台试验研究  

Shaking table test research of single piles with towering structures

作　　者：周永毅 张建经[1] 曹礼聪 欧阳芳 王志佳[3] 廖蔚茗[1] ZHOU Yongyi;ZHANG Jianjing;CAO Licong;OUYANG Fang;WANG Zhijia;LIAO Weiming(School of Civil Engineering,Southwest Jiaotong University,Chengdu 611756 China;Department of Architecture and Materials Engineering, Hubei University of Education,Wuhan 430000 China;School of Civil Engineering,Hainan University,Haikou 570228,China)

机构地区：[1]西南交通大学土木工程学院,四川成都611756 [2]湖北第二师范学院建筑与材料工程学院,湖北武汉430000 [3]海南大学土木工程学院,海南海口570228

出　　处：《自然灾害学报》2018年第6期133-141,共9页Journal of Natural Disasters

基　　金：国家重点研发计划(2017YFC0504901);国家重点基础研究发展计划(973)项目(2011CB013605-5)~~

摘　　要：横向地震响应是影响长大高耸结构(如风机、超高桥墩桥梁等)抗震稳定性的重要因素,开展此方面的研究对于此类结构的防震减灾具有积极意义。本文基于前期开展的单桩基础振动台试验,研究了地震激励下的桩基横向地震响应规律。首先使用加速度空采段数据对环境噪声进行了分析,为滤波器提供合理的截止频率,并将加速度响应结果与Gohl所开展试验进行了对比,以说明上部结构对桩基横向响应的影响。然后使用应变片数据转化得到了桩-土体系的p-y(土抗力-横向位移)数据,并通过不同传感器数据对同一物理量的记录情况对比,验证了试验数据质量,在此基础上研究桩基动力p-y响应规律。所得结果表明:(1)空采段数据所携带的噪声信息可以通过FFT变换后,利用信噪比为滤波器提供合理的截止频率;(2)上部结构对横向加速度响应影响显著,与Gohl试验相比,本文试验土面处加速度放大系数仅是其0. 59倍,而位移响应幅值是其10. 5倍;(3)桩基类型、场地条件对p-y响应影响显著,与Wilson试验结果相比,本试验p-y曲线的最大横向位移仅是其1/13;(4)地震作用下桩基一侧出现了明显的桩土间隙,而另一侧则不存在(刚度一侧加强,一侧减弱),这种两侧的差异性变化会严重影响结构的稳定性,但在其他非高耸结构的桩基振动台试验中少有记录和分析。The lateral seismic response of towering structures( wind turbines,bridges with high pier,et al.) is one of the main factors that influence the seismic stability,and it is meaningful to carry out the related research for the prevention and disaster mitigation of these structures. Lateral seismic response of pile foundations is studied in this paper basing on the shaking table test of single pile. Firstly,the pre-event memory of acceleration data is used to identify the noise component and determine the frequency edges for filter. Then the acceleration response is compared with Gohl’s shaking table test,so as to illustrate the influence of superstructure on lateral seismic response.Then test data recorded by different sensors are used to calculate the same physical quantity in order to evaluate the quality of test data. After that,dynamic p-y response of soil-pile is studied. The results show that:( 1) The pre-event memory can be used to frequency edges for filter combining with signal-to-noise ratio after FFT transformation.( 2) The superstructure has a great effect on the lateral acceleration response. In contrast to Gohl’s test,the acceleration amplification coefficient is only 0. 59 times,but the displacement response amplitude is 10. 5 times.( 3) The type of pile foundations and site conditions can influence the p-y response greatly. In contrast to Wilson’s test,the maximum lateral displacement of this test is 1/13 of it.( 4) there exists a great stiffness difference at different side of pile which has a negative effect on the stability of superstructures and is rarely mentioned in the test with usual superstructures.

关 键 词：振动台试验 单桩基础 高耸结构 横向地震响应 防震减灾 

分 类 号：X43[环境科学与工程—灾害防治] X93