土塞效应对管桩低应变测试视波速的影响研究
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摘要
首先,基于附加质量模型建立了考虑环向波动效应的管桩纵向振动频域解析解,然后利用傅里叶逆变换得到半正弦脉冲激振力作用下时域响应半解析解,最后,基于建立的理论模型,研究了土塞效应对管桩视波速的影响,为管桩的低应变无损检测提供更加精确的管桩测试波速计算理论。本文解的理论反演曲线分别与现有理论解的反演曲线、模型试验和现场试验测试曲线进行了比较,验证了本文解的合理性和计算精度。分析表明:土塞效应对管桩视波速的衰减作用随着管桩壁厚和纵波波速的减小而增强;土塞的存在会导致桩端反射信号幅值到达时间随着桩顶接收角度的变化而变化;土塞效应会增大桩端反射信号的宽度。
First,the analytical solution in the frequency domain for the vertical dynamic response of pipe piles is established based on the additional mass model with the consideration of wave propagating both in the vertical and circumferential directions.Then,the corresponding quasi-analytical solution in the time domain for the pipe piles subjected to a vertical semi-sinusoidal impact force is obtained by utilizing the Fourier transform technique.Finally,based on the derived solutions,the influences of soil plug effect on the apparent wave velocity of pipe piles(AWVPP) are investigated.The proposed theory can provide a more precise AWVPP calculation basis for the low-strain integrity tests on pipe piles.The rationality and accuracy of the proposed solution are verified by comparing the fitted curves of the current solution with those based on previous theories and a series of model pipe pile experiments and field tests.The result shows that the reduction degree of AWVPP due to the soil plug effect increases with the decrease in wall thickness and vertical stress wave velocity of the pipe piles.Owing to the soil plug effect,the width of the reflected signal from pipe pile toe is widened,and its arrival time varies as the receiving acceleration transducer moves along the circumferential direction of pipe pile head.
First,the analytical solution in the frequency domain for the vertical dynamic response of pipe piles is established based on the additional mass model with the consideration of wave propagating both in the vertical and circumferential directions.Then,the corresponding quasi-analytical solution in the time domain for the pipe piles subjected to a vertical semi-sinusoidal impact force is obtained by utilizing the Fourier transform technique.Finally,based on the derived solutions,the influences of soil plug effect on the apparent wave velocity of pipe piles(AWVPP) are investigated.The proposed theory can provide a more precise AWVPP calculation basis for the low-strain integrity tests on pipe piles.The rationality and accuracy of the proposed solution are verified by comparing the fitted curves of the current solution with those based on previous theories and a series of model pipe pile experiments and field tests.The result shows that the reduction degree of AWVPP due to the soil plug effect increases with the decrease in wall thickness and vertical stress wave velocity of the pipe piles.Owing to the soil plug effect,the width of the reflected signal from pipe pile toe is widened,and its arrival time varies as the receiving acceleration transducer moves along the circumferential direction of pipe pile head.
引文
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[2]费康,刘汉龙,张霆.PCC桩低应变检测中的三维效应[J].岩土力学,2007,28(6):1095-1102.(FEI Kang,LIUHan-long,ZHANG Ting.Three-dimensional effects in low strain integrity test of PCC pile[J].Rock and Soil Mechanics,2007,28(6):1095-1102.(in Chinese))
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[5]胡新发,柳建新.基桩低应变检测中波速测不准问题的研究[J].岩石力学与工程学报,2013,32(增刊2):4183-4189.(HU Xin-fa,LIU Jian-xin.Study of inaccuracy of P-wave velocity in piles by low starin integrity testing[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(S2):4183-4189.(in Chinese))
[6]杨杰,沙晓东.尺寸效应对基桩动测的影响[C]//中国海岸工程学术研讨会.昆明,2005.(YANG Jie,SHAXiao-dong.Influence of size effect on dynamic testing of pile[C]//The 12th China Coastal Engineering Symposium,Kunming,2005.(in Chinese))
[7]吴文兵,蒋国盛,王奎华,等.土塞效应对管桩纵向动力特性的影响研究[J].岩土工程学报,2014,36(6):1129-1141.(WU Wen-bing,JIANG Guo-sheng,WANG Kui-hua,et al.Influence of soil plug effect on vertical dynamic response of pipe piles[J].Chinese Journal of Geotechnical Engineering,2014,36(6):1129-1141.(in Chinese))
[8]WU W B,EL NAGGAR M H,ABDLRAHEM M,et al.New interaction model for vertical dynamic response of pipe piles considering soil plug effect[J].Canadian Geotechnical Journal,2017,54(7):987-1001.
[9]WU W B,JIANG G S,HUANG S G,et al.A new analytical model to study the influence of weld on the vertical dynamic response of prestressed pipe pile[J].International Journal for Numerical and Analytical Methods in Geomechanics,2017,41(10):1247-1266.
[10]吴文兵,邓国栋,张家生,等.考虑横向惯性效应时桩侧土-管桩-土塞纵向耦合振动特性研究[J].岩土力学,2017,38(4):993-1002.(WU Wen-bing,DENG Guo-dong,ZHANG Jia-sheng,et al.Vertical dynamic response of soil surrounding pile-pipe pile-soil plug by considering lateral inertial effect[J].Rock and Soil Mechanics,2017,38(4):993-1002.(in Chinese))
[11]刘浩,蒋国盛,梅国雄,等.基于附加质量模型的管桩扭转振动研究[J].岩土工程学报,2018,40(4):716-725.(LIU Hao,JIANG Guo-sheng,MEI Guo-xiong,et al.Torsional dynamic response of pipe pile based on the additional mass model[J].Chinese Journal of Geotechnical Engineering,2018,40(4):716-725.(in Chinese))
[12]ZHENG C J,LIU H L,DING X M,et al.Three-dimensional effects in low-strain integrity testing of large diameter pipe piles[J].Journal of Engineering Mechanics,2016,142(9):04016064.
[13]LYSMER J,RICHART F E.Dynamic response of footing to vertical load[J].Journal of the Soil Mechanics and Foundations Division,1966,2(1):65-91.
[14]DING X M,LIU H L,ZHANG B.High-frequency interference in low strain integrity testing of large-diameter pipe piles[J].Science China Technological Science,2011,54(2):420-430.
[2]费康,刘汉龙,张霆.PCC桩低应变检测中的三维效应[J].岩土力学,2007,28(6):1095-1102.(FEI Kang,LIUHan-long,ZHANG Ting.Three-dimensional effects in low strain integrity test of PCC pile[J].Rock and Soil Mechanics,2007,28(6):1095-1102.(in Chinese))
[3]卢志堂,王志亮,刘东甲,等.管桩低应变检测中的三维效应分析[J].同济大学学报(自然科学版),2012,40(11):1603-1607,1653.(LU Zhi-tang,WANG Zhi-liang,LIU Dong-jia,et al.Analysis of 3-D effects in low strain testing of pipe pile[J].Journal of Tongji University(Natural Science),2012,40(11):1603-1607,1653.(in Chinese))
[4]刘汉龙,丁选明.现浇薄壁管桩在低应变瞬态集中荷载作用下的动力响应解析解[J].岩土工程学报,2007,29(11):1611-1617.(LIU Han-long,DING Xuan-ming.Analytical solution of dynamic response of cast-in-situ concrete thin-wall pipe piles under transient concentrated load with low strain[J].Chinese Journal of Geotechnical Engineering,2007,29(11):1611-1617.(in Chinese))
[5]胡新发,柳建新.基桩低应变检测中波速测不准问题的研究[J].岩石力学与工程学报,2013,32(增刊2):4183-4189.(HU Xin-fa,LIU Jian-xin.Study of inaccuracy of P-wave velocity in piles by low starin integrity testing[J].Chinese Journal of Rock Mechanics and Engineering,2013,32(S2):4183-4189.(in Chinese))
[6]杨杰,沙晓东.尺寸效应对基桩动测的影响[C]//中国海岸工程学术研讨会.昆明,2005.(YANG Jie,SHAXiao-dong.Influence of size effect on dynamic testing of pile[C]//The 12th China Coastal Engineering Symposium,Kunming,2005.(in Chinese))
[7]吴文兵,蒋国盛,王奎华,等.土塞效应对管桩纵向动力特性的影响研究[J].岩土工程学报,2014,36(6):1129-1141.(WU Wen-bing,JIANG Guo-sheng,WANG Kui-hua,et al.Influence of soil plug effect on vertical dynamic response of pipe piles[J].Chinese Journal of Geotechnical Engineering,2014,36(6):1129-1141.(in Chinese))
[8]WU W B,EL NAGGAR M H,ABDLRAHEM M,et al.New interaction model for vertical dynamic response of pipe piles considering soil plug effect[J].Canadian Geotechnical Journal,2017,54(7):987-1001.
[9]WU W B,JIANG G S,HUANG S G,et al.A new analytical model to study the influence of weld on the vertical dynamic response of prestressed pipe pile[J].International Journal for Numerical and Analytical Methods in Geomechanics,2017,41(10):1247-1266.
[10]吴文兵,邓国栋,张家生,等.考虑横向惯性效应时桩侧土-管桩-土塞纵向耦合振动特性研究[J].岩土力学,2017,38(4):993-1002.(WU Wen-bing,DENG Guo-dong,ZHANG Jia-sheng,et al.Vertical dynamic response of soil surrounding pile-pipe pile-soil plug by considering lateral inertial effect[J].Rock and Soil Mechanics,2017,38(4):993-1002.(in Chinese))
[11]刘浩,蒋国盛,梅国雄,等.基于附加质量模型的管桩扭转振动研究[J].岩土工程学报,2018,40(4):716-725.(LIU Hao,JIANG Guo-sheng,MEI Guo-xiong,et al.Torsional dynamic response of pipe pile based on the additional mass model[J].Chinese Journal of Geotechnical Engineering,2018,40(4):716-725.(in Chinese))
[12]ZHENG C J,LIU H L,DING X M,et al.Three-dimensional effects in low-strain integrity testing of large diameter pipe piles[J].Journal of Engineering Mechanics,2016,142(9):04016064.
[13]LYSMER J,RICHART F E.Dynamic response of footing to vertical load[J].Journal of the Soil Mechanics and Foundations Division,1966,2(1):65-91.
[14]DING X M,LIU H L,ZHANG B.High-frequency interference in low strain integrity testing of large-diameter pipe piles[J].Science China Technological Science,2011,54(2):420-430.