地震作用下桩竖向抗震承载力的退化效应
|
摘要
在地震荷载作用下，由于土体振动孔隙水压力的产生，桩的竖向承载力将发生退化。基于桩的竖向承载机理以及地震作用下土的有效应力状态变化，提出了桩竖向抗震承载力退化效应的有效应力动力分析方法，分别建立了地震作用下极限桩侧阻力和极限桩端阻力的退化计算模型。最后应用该方法对液化砂土地基上的桩基进行了竖向抗震承载力退化计算。
When subjected to seismic loading pile vertical capacity undergoes significant degradation due to the buildup of pore－water pressure． On the basis of the mechanism of pile vertical capacity and the changes of effective stress state of soil an effective stress analysis method was presented in this paper which is capable of describing the vertical capacity behavior of pile during such an event． Two degradation models are respectively proposed for modeling ultimate shaft resistance and tip resistance of pile during earthquakes． Finally the proposed numerical method is applied to the calculation of the degradation for vertical seismic capacity of a pile foundation on liquefied sand．
When subjected to seismic loading pile vertical capacity undergoes significant degradation due to the buildup of pore－water pressure． On the basis of the mechanism of pile vertical capacity and the changes of effective stress state of soil an effective stress analysis method was presented in this paper which is capable of describing the vertical capacity behavior of pile during such an event． Two degradation models are respectively proposed for modeling ultimate shaft resistance and tip resistance of pile during earthquakes． Finally the proposed numerical method is applied to the calculation of the degradation for vertical seismic capacity of a pile foundation on liquefied sand．
引文
[1] 陈竹昌,徐和. 土类对轴向循环荷载下桩性状的影响[ J ]. 同济大学学报.1989,17(3):329-336.
[2] Chan S F Hanna T H. Repeated loading on single piles in sand[ J ]. Journal of the Geotechnical Engineering Division ASCE 1980 106(GT2):171-178.
[3] Bea R G. Pile capacity for axial cyclic loading[ J ]. Journal of Geotechnical Engineering. ASCE 1992118 (1): 34-50.
[4] Matlock H Foo S C. Axial analysis of piles using a hysteretic and degrading soil model[ A ]. Proc. Conf. Numerical Methods in Offshore Piling[ C ]. London: ICE. 1979, 165-185.
[5] Poulos H G. Cyclic axial loading analysis of piles in sand [ J ]. Journal of Geotechnical Engineering ASCE 1989 115(6): 836-852.
[6] Lee C Y Poulos H G. Effective stress dependence of pile shaft capacity in calcareous sand[ J ]. Journal of Geotechnical Engineering ASCE 1988 114(10): 1 189-1 193.
[7] 段云秦,郭耀堂.地基中动孔压的发展水平对桩承载力的影 响[ J ]. 工程抗震,1987(1):4-9.
[8] Yasuhara K. Postcyclic undrained strength for cohesive soils[ J ]. Journal of Geotechnical Engineering 1994 120(11): 1 961-1 979.
[9] Azzouz A S Malek A M Baligh M M. Cyclic behavior of clays in undrained simple shear[ J ]. Journal of Geotechnical Engineering ASCE 1989 115(5):637- 657.
[10] Sangrey D A Henkel D J Esrig M I. The effective stress response of a saturated clay soil to repeated loading[ J ]. Can. Geotech. J. 1969 6:241-252.
[11] 沈珠江.一个计算砂土液化变形的等价粘弹性模式[ A ]. 中 国土木工程学会第四届土力学及基础工程学术会议论文 选集[ C ]. 北京: 中国建筑工业出版社,1986:199～207.
[12] 黄雨,唐益群,叶为民等. 建筑桩基的有效应力地震反应分 析:Ⅱ-应用[ J ]. 水文地质工程地质.2000,27(6):20-23.
[13] 黄雨,陈竹昌,周红波. 上海软土的动力计算模型[ J ]. 同济 大学学报. 2000,28(3):359-363.
[2] Chan S F Hanna T H. Repeated loading on single piles in sand[ J ]. Journal of the Geotechnical Engineering Division ASCE 1980 106(GT2):171-178.
[3] Bea R G. Pile capacity for axial cyclic loading[ J ]. Journal of Geotechnical Engineering. ASCE 1992118 (1): 34-50.
[4] Matlock H Foo S C. Axial analysis of piles using a hysteretic and degrading soil model[ A ]. Proc. Conf. Numerical Methods in Offshore Piling[ C ]. London: ICE. 1979, 165-185.
[5] Poulos H G. Cyclic axial loading analysis of piles in sand [ J ]. Journal of Geotechnical Engineering ASCE 1989 115(6): 836-852.
[6] Lee C Y Poulos H G. Effective stress dependence of pile shaft capacity in calcareous sand[ J ]. Journal of Geotechnical Engineering ASCE 1988 114(10): 1 189-1 193.
[7] 段云秦,郭耀堂.地基中动孔压的发展水平对桩承载力的影 响[ J ]. 工程抗震,1987(1):4-9.
[8] Yasuhara K. Postcyclic undrained strength for cohesive soils[ J ]. Journal of Geotechnical Engineering 1994 120(11): 1 961-1 979.
[9] Azzouz A S Malek A M Baligh M M. Cyclic behavior of clays in undrained simple shear[ J ]. Journal of Geotechnical Engineering ASCE 1989 115(5):637- 657.
[10] Sangrey D A Henkel D J Esrig M I. The effective stress response of a saturated clay soil to repeated loading[ J ]. Can. Geotech. J. 1969 6:241-252.
[11] 沈珠江.一个计算砂土液化变形的等价粘弹性模式[ A ]. 中 国土木工程学会第四届土力学及基础工程学术会议论文 选集[ C ]. 北京: 中国建筑工业出版社,1986:199～207.
[12] 黄雨,唐益群,叶为民等. 建筑桩基的有效应力地震反应分 析:Ⅱ-应用[ J ]. 水文地质工程地质.2000,27(6):20-23.
[13] 黄雨,陈竹昌,周红波. 上海软土的动力计算模型[ J ]. 同济 大学学报. 2000,28(3):359-363.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心