摘要
桩基抗震设计与验算历来是工程建设中的难题,拟静力法与时程分析法是抗震设计中常用的两种计算方法。本文依托废黄河泛滥区江苏宿迁典型桩基工程实例,对比和分析了二者计算地震作用下桩基动态响应的异同。计算结果表明,二者的计算思路存在着明显差异,由于拟静力法未考虑土层变位对桩基的影响导致其计算结果偏小,而时程分析法因考虑了桩-土-结构之间的相互作用,其计算结果更加符合工程实际,但较拟静力法会消耗更多计算时间。根据时程分析法的计算结果,进一步对拟静力法的桩头弯矩计算公式进行了修正,并给出了修正系数。
Seismic design and calculation of piles has always been a difficult problem for construction project. Quasi-static method and time-history method are two methods which are commonly used in seismic design. Based on a construction project in Suqian,this paper compared and analyzed differences between the two methods in calculating dynamic response of piles. It shows that the result of time-history method corresponds more to the reality,but the result of quasi-static method is relatively small due to the ignorance of soil displacement. However,the timehistory method would cost more time compared to quasi-static method. According to the result of time-history method,a correction factor of the formula of calculating bending moment on pile tip in quasi-static method is proposed.
引文
[1]冯永,谢飞亚,李旭光.地震荷载下边坡抗滑桩桩土机理的三维模拟分析[J].地震工程学报,2017(1):32-38.FENG Yong,XIE Feiya,LI Xuguang. Three dimensional simulation of pile-soil interaction mechanism of anti-slide piles under seismic loads[J].China Earthquake Engineering Journal,2017,39(1):32-38.(in Chinese)
[2]黄明,付俊杰,陈福全,等.桩端荷载与地震耦合作用下溶洞顶板的破坏特征及安全厚度计算[J].岩土力学,2017,38(11):3154-3162.HUANG Ming,FU Junjie,CHEN Fuquan,et al. Damage characteristics of karst cave roof and its safety thickness calculation under the coupling effect of pile-tip load and seismic wave[J]. Rock and Soil Mechanics,2017,38(11):3154-3162.(in Chinese)
[3]李明广,陈锦剑,辛庆胜,等.考虑土体小应变特性的桩基动刚度拟静力计算方法[J].中国水利水电科学研究院学报,2015(3):217-221.LI Mingguang,CHEN Jinjian,XIN Qingsheng,et al. Quasi-static calculation method for dynamic stiffness of pile foundation considering the smallstrain stiffness behavior of soil[J]. Journal of China Institute of Water Resources and Hydropower Research,2015(3):217-221.(in Chinese)
[4]黄茂松,马昊,李森,等.软黏土中水平受荷桩的静力和循环p-y曲线[J].岩土工程学报,2017,39(增刊2):9-12.HUANG Maosong,MA Hao,LI Sen,et al. Static and cyclic p-y curves for laterally loaded piles in soft clay[J]. Chinese Journal of Geotechnical Engineering,2017,39(S2):9-12.(in Chinese)
[5] Zhang C,White D,Randolph M. Centrifuge modeling of the cyclic lateral response of a rigid pile in soft clay[J]. Journal of Geotechnical and Geoenvironmental Engineering,2010,137(7):717-29.
[6] GB 50011—2010建筑抗震设计规范[S].北京:中国建筑工业出版社,2010.GB 50011—2010 Code for Seismic Design of Buildings[S]. Beijing:China Architecture&Building Press,2010.(in Chinese)
[7] JGJ 94—2008建筑桩基技术规范[S].北京:中国建筑工业出版社,2008.JGJ 94—2008 Technical Code for Building Pile Foundations[S]. Beijing:China Architecture&Building Press,2008.(in Chinese)