基于Winkler模型,将弹性地基离散化为线性弹簧,建立长桩-弹簧动力相互作用模型试验系统,研究了桩顶横向简谐激励下桩基的非线性动力响应。通过两组共12种工况模型试验,分析了桩身参数、地基约束、桩顶配重和激励特征等对桩基动力响应幅值、共振和空间运动的影响。试验结果表明:随激励幅值增大,桩基动力响应的非线性特征显著;在特定的激励频率下,激振器与模型桩发生共振,在一定程度上改变桩-土系统的动力响应特征;若放松地基约束,桩基主共振响应呈软弹簧特性,表明土-结构相互作用对桩基的动力学特性有定性影响;改变桩顶配重,在小幅激励下桩基响应幅值的变化较大;由动力轨迹可知,桩顶有明显的面外运动。本文研究建立了理论分析与试验测试的直接关联,促进了基于Winkler模型开展的横向受荷长桩非线性动力学试验研究。
Abstract
Based on Winkler model, an elastic foundation was discretized as linear springs to establish a long pile-spring dynamic interaction model test system, and study nonlinear dynamic responses of pile foundation under a lateral simple harmonic excitation exerted on pile top. Through model tests under 12 working conditions in two groups, influences of pile parameters, foundation constraints, pile top counterweight and excitation characteristics on dynamic response amplitude, resonance and spatial motion of pile foundation were analyzed. The test results showed that nonlinear characteristics of pile foundation dynamic response are significant with increase in excitation amplitude; under a specific excitation frequency, the vibration exciter resonates with the model pile to change dynamic response characteristics of the pile-soil system to a certain extent; if foundation constraints are relaxed, the main resonance response of pile foundation is characterized by soft spring, so soil-structure interaction has a qualitative influence on dynamic characteristics of pile foundation; with the change of pile top counterweight, the response amplitude of pile foundation changes greatly under small amplitude excitation; observing the pile top’s dynamic trajectory, it has an obvious out of plane motion; here, the direct correlation between theoretical analysis and tests is established to promote nonlinear dynamic tests of laterally loaded long piles based on Winkler model.
关键词
横向受荷长桩 /
Winkler地基模型 /
离散线性弹簧 /
非线性动力响应 /
幅频响应曲线
{{custom_keyword}} /
Key words
laterally loaded long pile /
Winkler foundation model /
discrete linear spring /
nonlinear dynamic response /
frequency-response curve
{{custom_keyword}} /
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] MANNA B, BAIDYA D K. Nonlinear dynamic response of piles under horizontal excitation [J]. Journal of Geotechnical and Geoenvironmental Engineering, 2010, 136(12): 1600-1609.
[2] 吕建根, 韩强, 王荣辉. 地震作用下非弹性地基桩的3次超谐波共振[J]. 动力学与控制学报, 2015, 13(4): 278-282.
LV Jiangen, HAN Qiang, WANG Ronghui. Super-harmonic resonance of pile foundation under earthquake action [J]. Journal of Dynamic and Control, 2015, 13(4): 278-282.
[3] 凌贤长, 唐亮. 液化场地桩基侧向响应分析中p-y曲线模型研究进展[J]. 力学进展, 2010, 40(3): 250-262.
LING Xianchang, TANG Liang. Recent advance of p-y curve to model lateral response of pile foundation on liquefied ground [J]. Advances in Mechanics, 2010, 40(3): 250-262.
[4] KOJIMA K, FUJITA K, TAKEWAKI I. Unified analysis of kinematic and inertial earthquake pile responses via single-input response spectrum method [J]. Soil Dynamics and Earthquake Engineering, 2014, 63: 36-55.
[5] 胡伟, 孟建伟, 刘顺凯, 等. 单螺旋锚桩水平承载机理试验与理论研究[J]. 岩土工程学报, 2020, 42(1): 158-167.
HU Wei, MENG Jianwei, LIU Shunkai, et al. Experimental and theoretical researches on horizontal bearing mechansim of single screw anchor pile [J]. Chinese Journal of Geotechnical Engineering, 2020, 42(1): 158-167.
[6] EBEIDO A, EIGAMAL A, TOKIMATSU K, et al. Pile and pile-group response to liquefaction-induced lateral spreading in four large-scale shake-table experiments [J]. Journal of Geotechnical and Geoenvironmental Engineering, 2019, 145(10): 04019080.
[7] BISWAS S, MANNA B. Experimental and theoretical studies on the nonlinear characteristics of soil-pile systems under coupled vibrations [J]. Journal of Geotechnical and Geoenvironmental Engineering, 2018, 144(3): 04018007.
[8] XU D, XU X, LI W, et al. Field experiments on laterally loaded piles for an offshore wind farm [J]. Marine Structures, 2020, 69: 102684.
[9] 黄占芳, 王显耀, 吴植安, 等. 液化砂土中单桩地震响应振动台试验研究[J]. 振动与冲击, 2012, 31(20): 189-192.
HUANG Zhanfang, WANG Xianyao, WU Zhian, et al. Skaking table tests for single pile-soil dynamic interaction in liquefied foundation soil [J]. Journal of Vibration and Shock, 2012, 31(20): 189-192.
[10] 黄占芳, 白晓红. 可液化砂土中群桩基础地震响应的振动台试验研究[J]. 振动与冲击, 2013, 32(18): 153-158.
HUANG Zhanfang, BAI Xiaohong. Skaking table model test for seismic response of a pile group foundation with liquefiable sandy soil [J]. Journal of Vibration and Shock, 2013, 32(18): 153-158.
[11] BHOWMIK D, BAIDYA D K, DASGUPTA S P. A numerical and experimental study of hollow steel pile in layered soil subjected to lateral dynamic loading [J]. Soil Dynamics and Earthquake Engineering, 2013, 53: 119-129.
[12] ULLAH M S, KAJIWARA K, GOIT C S, et al. Frequency and intensity dependent dynamic responses of soil-steel pipe sheet pile (SPSP) foundation-superstructure system [J]. Soil Dynamics and Earthquake Engineering, 2019, 125: 105730.
[13] HE R, ZHU T. Model tests on the frequency responses of offshore monopiles [J]. Journal of Marine Science and Engineering, 2019, 7(12): 430.
[14] 张磊, 海维深, 甘浩, 等. 水平与上拔组合荷载下柔性单桩承载特性试验研究[J]. 岩土力学, 2020, 41(7): DOI 10.16285/j.rsm.2019.1522.
ZHANG Lei, HAI Weishen, GAN Hao, et al. On bearing behavior of a flexible single pile under combined horizontal and uplift load [J]. Rock and Soil Mechanics, 2020, 41(7): DOI 10.16285/j.rsm.2019.1522.
[15] MA J, GAO X, LIU F. Nonlinear lateral vibrations and two-to-one resonant responses of a single pile with soil-structure interaction [J]. Meccanica, 2017, 52(15): 3549-3562.
[16] GOIT C S, SAITOH M, MYLONAKIS G. Principle of superposition for assessing horizontal dynamic response of pile groups encompassing soil nonlinearity [J]. Soil Dynamics and Earthquake Engineering, 2016, 82: 73-83.
[17] COLEMAN R E, ALLEMANG R J. 试验结构动力学[M]. 刚宪约, 杨茂洪. 北京:清华大学出版社, 2012.
COLEMAN R E, ALLEMANG R J. Experimental Structural Dynamics [M]. GANG Xianyue, YANG Maohong. Beijing:Tsinghua University Press, 2012.
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}