倾斜液化场地桩基地震响应离心机试验研究
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摘要
倾斜液化场地中群桩地震响应受液化土层侧向流动和桩土相互作用影响和控制,故倾斜液化场地中桩基抗震性能问题是一个极其复杂问题。基于动态土工离心机试验来探讨考虑倾斜液化土侧向流动特点的群桩地震响应规律。试验设计不同地震强度下2个50g典型土工离心模型试验,以研究倾斜液化场地中桩土加速度、位移、桩身弯矩和土体超孔隙水压力响应特性。试验提出倾斜饱和土层的制备方法,再现倾斜液化场地中桩基础在强震作用下的破坏程度、状态和机制,并进一步对比分析试验结果,取得较好的成果,此为倾斜液化场地桩基础的抗震设计提供可靠依据,对确保液化场地桩基础的抗震稳定性和安全性具有重要意义。
The problem of seismic performances of pile groups found on the inclined liquefiable soils is a nonlinear and complicated problem because the seismic responses of pile groups are influenced by the pile-soil interaction and lateral spread. Two cases of 50 g centrifuge tests are conducted to investigate acceleration, displacement,bending moment and excess pore water pressure responses of pile groups on the inclined liquefiable soils during earthquake. The scenario input motions with peak shaking amplitudes of 3.64 and 9.68 m/s2(at prototype scale) are adopted in centrifuge tests. A rectangular rigid container is used in two cases. The inclined soil profile is comprised of saturated silica sand resting on stiff bedrock. The fluid material is simulated by deaired motolose solution of 50 times of the viscosity of water such that the deposit has the prototype permeability of sand. The model of pile foundations consists of structure supported by a 2 row×2 row piles,10 times in diameter spacing pile group. Moreover,the results from centrifuge cases are compared. The failure mechanism of pile groups in laterally spreading soils during earthquake is also discussed;and a good result is achieved. It is found that the lateral displacement and bending moments of pile groups are much larger in laterally spreading soils than those in non-liquefiable soils. The location for the maximum bending moment during shaking and residual bending moment transfer further down with the liquefaction and lateral spread of soils. The proposed dynamic centrifuge test is applicable and reliable for simulating seismic performance of pile groups on the inclined liquefiable foundation. These results for insuring the aseismic stability and aseismic safety of pile group in the inclined liquefied soils are potentially very significant.
The problem of seismic performances of pile groups found on the inclined liquefiable soils is a nonlinear and complicated problem because the seismic responses of pile groups are influenced by the pile-soil interaction and lateral spread. Two cases of 50 g centrifuge tests are conducted to investigate acceleration, displacement,bending moment and excess pore water pressure responses of pile groups on the inclined liquefiable soils during earthquake. The scenario input motions with peak shaking amplitudes of 3.64 and 9.68 m/s2(at prototype scale) are adopted in centrifuge tests. A rectangular rigid container is used in two cases. The inclined soil profile is comprised of saturated silica sand resting on stiff bedrock. The fluid material is simulated by deaired motolose solution of 50 times of the viscosity of water such that the deposit has the prototype permeability of sand. The model of pile foundations consists of structure supported by a 2 row×2 row piles,10 times in diameter spacing pile group. Moreover,the results from centrifuge cases are compared. The failure mechanism of pile groups in laterally spreading soils during earthquake is also discussed;and a good result is achieved. It is found that the lateral displacement and bending moments of pile groups are much larger in laterally spreading soils than those in non-liquefiable soils. The location for the maximum bending moment during shaking and residual bending moment transfer further down with the liquefaction and lateral spread of soils. The proposed dynamic centrifuge test is applicable and reliable for simulating seismic performance of pile groups on the inclined liquefiable foundation. These results for insuring the aseismic stability and aseismic safety of pile group in the inclined liquefied soils are potentially very significant.
引文
[1]汪明武,金菊良,李丽.基于实码加速遗传算法的投影寻踪方法在砂土液化势评价中的应用[J].岩石力学与工程学报,2004,23(4):631–634.(WANG Mingwu,JIN Juliang,LI Li.Application of PPmethod based on RAGA to visualization assessment of sand liquefaction potential[J].Chinese Journal of Rock Mechanics and Engineering,2004,23(4):631–634.(in Chinese))
[2]汪明武,IAI S,TOBITA T.栈桥式构筑物抗震性能动态离心模型试验的数值模拟[J].岩土工程学报,2005,27(7):738–741.(WANG Mingwu,IAI S,TOBITA T.Numerical modeling for dynamic centrifuge model test of the seismic behaviors of pile-supported structure[J].Chinese Journal of Geotechnical Engineering,2005,27(7):738–741.(in Chinese))
[3]陈文化,门福录,景立平,等.有建筑物存在的饱和砂土地基液化振动台试验研究[J].地震工程与工程振动,1998,18(4):54–60.(CHEN Wenhua,MEN Fulu,JING Liping,et al.Shaking table test study of liquefaction of building subsoils[J].Earthquake Engineering and Engineering Vibration,1998,18(4):54–60.(in Chinese))
[4]楼梦麟,王文剑,马恒春,等.土–桩–结构相互作用体系的振动台模型试验[J].同济大学学报,2001,29(7):763–768.(LOU Menglin,WANG Wenjian,MA Hengchun,et al.Study of soil-pile-structure interaction system by shaking table model test[J]Journal of Tongji University,2001,29(7):763–768.(in Chinese))
[5]凌贤长,王东升.液化场地桩–土–桥梁结构动力相互作用振动台试验研究进展[J].地震工程与工程振动,2002,22(4):54–59.(LING Xianzhang,WANG Dongsheng.Study of shaking table test for seismic interaction of pile-soil-bridge structure in case of soil liquefaction caused by earthquake[J].Earthquake Engineering and Engineering Vibration,2002,22(4):54–59.(in Chinese))
[6]吕西林,陈跃庆,陈波,等.结构–地基动力相互作用体系振动台模拟试验研究[J].地震工程与工程振动,2000,20(4):20–29.(LU Xilin,CHEN Yueqing,CHEN Bo,et al.Shaking table testing of dynamic soil-structure interaction system[J].Earthquake Engineering and Engineering Vibration,2000,20(4):20–29.(in Chinese))
[7]王建华,冯士伦.桩土相互作用的振动台试验[J].岩土工程学报,2004,26(5):616–618.(WANG Jianhua,FENG Shilun.Shaking table test on soil-pile interaction[J].Chinese Journal of Geotechnical Engineering,2004,26(5):616–618.(in Chinese))
[8]包承纲.我国离心模拟试验技术发展现状和展望[J].岩土工程学报,1991,13(6):92–97.(BAO Chenggang.The state and prospect of centrifugal model test in China[J].Chinese Journal of Geotechnical Engineering,1991,13(6):92–97.(in Chinese))
[9]汪明武,IAI S,TOBITA T.液化场地堤坝地震响应动态土工离心试验及模拟[J].水利学报,2008,39(12):1346–1352.(WANG Mingwu,IAI S,TOBITA T.Centrifuge test and numerical analysis of seismic responses of dyke on liquefiable soils foundation[J].Journal of Hydraulic Engineering,2008,39(12):1346–1352.(in Chinese))
[10]KAGAWA T,SATO M,MINOWA C,et al.Centrifuge simulations of large-scale shaking table tests:case studies[J].Journal of Geotechnical and Geoenvironmental Engineering,2004,130(7):663–672.
[11]ABDOUN T,DOBRY R,O′ROURKE T D,et al.Pile response to lateral spreads:centrifuge case[J].Journal of Geotechnical and Geo-environmental Engineering,2003,129(10):869–878.
[12]侯瑜京,韩连兵,梁建辉.深水港码头围堤和群桩结构的离心模型试验[J].岩土工程学报,2004,26(5):594–600.(HOU Yujing,HAN Lianbing,LIANG Jianhui.Centrifuge modeling of sea dike and pile groups in a harbor[J].Chinese Journal of Geotechnical Engineering,2004,26(5):594–600.(in Chinese))
[13]苏栋,李相崧.可液化土中单桩地震响应的离心机试验研究[J].岩土工程学报,2006,28(4):423–427.(SU Dong,LI Xiangsong.Centrifuge investigation on seismic response of single pile in liquefiable soil[J].Chinese Journal of Geotechnical Engineering,2006,28(4):423–427.(in Chinese))
[14]于玉贞,邓丽军.抗滑桩加固边坡地震响应离心模型试验[J].岩土工程学报,2007,29(9):1320–1323.(YU Yuzhen,DENG Lijun.Centrifuge modeling of seismic behavior of slopes reinforced by stabilizing pile[J].Chinese Journal of Geotechnical Engineering,2007,29(9):1320–1323.(in Chinese))
[15]汪明武,TOBITA T,IAI S.强震动条件下的桩土相互作用动态土工离心试验研究[J].岩石力学与工程学报,2005,24(增2):5555–5560.(WANG Mingwu,TOBITA T,IAI S.Centrifuge modeling of soil-pile interaction in liquefiable soils subjected to strong motion[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(Supp.2):5555–5560.(in Chinese))
[2]汪明武,IAI S,TOBITA T.栈桥式构筑物抗震性能动态离心模型试验的数值模拟[J].岩土工程学报,2005,27(7):738–741.(WANG Mingwu,IAI S,TOBITA T.Numerical modeling for dynamic centrifuge model test of the seismic behaviors of pile-supported structure[J].Chinese Journal of Geotechnical Engineering,2005,27(7):738–741.(in Chinese))
[3]陈文化,门福录,景立平,等.有建筑物存在的饱和砂土地基液化振动台试验研究[J].地震工程与工程振动,1998,18(4):54–60.(CHEN Wenhua,MEN Fulu,JING Liping,et al.Shaking table test study of liquefaction of building subsoils[J].Earthquake Engineering and Engineering Vibration,1998,18(4):54–60.(in Chinese))
[4]楼梦麟,王文剑,马恒春,等.土–桩–结构相互作用体系的振动台模型试验[J].同济大学学报,2001,29(7):763–768.(LOU Menglin,WANG Wenjian,MA Hengchun,et al.Study of soil-pile-structure interaction system by shaking table model test[J]Journal of Tongji University,2001,29(7):763–768.(in Chinese))
[5]凌贤长,王东升.液化场地桩–土–桥梁结构动力相互作用振动台试验研究进展[J].地震工程与工程振动,2002,22(4):54–59.(LING Xianzhang,WANG Dongsheng.Study of shaking table test for seismic interaction of pile-soil-bridge structure in case of soil liquefaction caused by earthquake[J].Earthquake Engineering and Engineering Vibration,2002,22(4):54–59.(in Chinese))
[6]吕西林,陈跃庆,陈波,等.结构–地基动力相互作用体系振动台模拟试验研究[J].地震工程与工程振动,2000,20(4):20–29.(LU Xilin,CHEN Yueqing,CHEN Bo,et al.Shaking table testing of dynamic soil-structure interaction system[J].Earthquake Engineering and Engineering Vibration,2000,20(4):20–29.(in Chinese))
[7]王建华,冯士伦.桩土相互作用的振动台试验[J].岩土工程学报,2004,26(5):616–618.(WANG Jianhua,FENG Shilun.Shaking table test on soil-pile interaction[J].Chinese Journal of Geotechnical Engineering,2004,26(5):616–618.(in Chinese))
[8]包承纲.我国离心模拟试验技术发展现状和展望[J].岩土工程学报,1991,13(6):92–97.(BAO Chenggang.The state and prospect of centrifugal model test in China[J].Chinese Journal of Geotechnical Engineering,1991,13(6):92–97.(in Chinese))
[9]汪明武,IAI S,TOBITA T.液化场地堤坝地震响应动态土工离心试验及模拟[J].水利学报,2008,39(12):1346–1352.(WANG Mingwu,IAI S,TOBITA T.Centrifuge test and numerical analysis of seismic responses of dyke on liquefiable soils foundation[J].Journal of Hydraulic Engineering,2008,39(12):1346–1352.(in Chinese))
[10]KAGAWA T,SATO M,MINOWA C,et al.Centrifuge simulations of large-scale shaking table tests:case studies[J].Journal of Geotechnical and Geoenvironmental Engineering,2004,130(7):663–672.
[11]ABDOUN T,DOBRY R,O′ROURKE T D,et al.Pile response to lateral spreads:centrifuge case[J].Journal of Geotechnical and Geo-environmental Engineering,2003,129(10):869–878.
[12]侯瑜京,韩连兵,梁建辉.深水港码头围堤和群桩结构的离心模型试验[J].岩土工程学报,2004,26(5):594–600.(HOU Yujing,HAN Lianbing,LIANG Jianhui.Centrifuge modeling of sea dike and pile groups in a harbor[J].Chinese Journal of Geotechnical Engineering,2004,26(5):594–600.(in Chinese))
[13]苏栋,李相崧.可液化土中单桩地震响应的离心机试验研究[J].岩土工程学报,2006,28(4):423–427.(SU Dong,LI Xiangsong.Centrifuge investigation on seismic response of single pile in liquefiable soil[J].Chinese Journal of Geotechnical Engineering,2006,28(4):423–427.(in Chinese))
[14]于玉贞,邓丽军.抗滑桩加固边坡地震响应离心模型试验[J].岩土工程学报,2007,29(9):1320–1323.(YU Yuzhen,DENG Lijun.Centrifuge modeling of seismic behavior of slopes reinforced by stabilizing pile[J].Chinese Journal of Geotechnical Engineering,2007,29(9):1320–1323.(in Chinese))
[15]汪明武,TOBITA T,IAI S.强震动条件下的桩土相互作用动态土工离心试验研究[J].岩石力学与工程学报,2005,24(增2):5555–5560.(WANG Mingwu,TOBITA T,IAI S.Centrifuge modeling of soil-pile interaction in liquefiable soils subjected to strong motion[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(Supp.2):5555–5560.(in Chinese))
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