浅埋矩形RC结构物地震液化上浮有效应力分析
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摘要
场地地震液化可导致浅埋结构物上浮和破坏加大。应用基于多重剪切机构塑性模型的有效应力分析方法,以探讨液化场地中浅埋大断面矩形RC结构物的地震液化上浮特征,进而探索结构物与液化土间的动力相互作用机制。研究得出结构物液化上浮位移和侧向位移随着地震强度增强而增大,且场地液化模型的结构物上浮值和侧向位移值明显大于未发生液化模型相应的数值;对场地发生液化的模型,结构物的等效剪切变形小于土体剪切变形,顶底板与土层的相对侧向位移较大,而结构物侧壁与土层的相对垂直位移则较大,不同埋深处结构物与土层间的相对位移差随着场地液化发生而剧增,而对场地未液化模型中各数值则几乎相等且较小。
Liquefaction-induced uplift and serious damages of the shallow underground structures in liquefiable soils are observed among the earthquake history cases.Therefore,in order to insure the safety of underground structures in the liquefiable soils in the earthquake prone area,the analysis of uplift earthquake-induced is of prime importance.Based on the method of effective stress analysis using multi-spring model,liquefaction-induced uplift of shallow duct-type RC structures subjected to earthquake motions is discussed in this paper.Moreover,the dynamic interaction between the underground structures and liquefiable soils is further investigated.The results show that the values of uplifted displacements and lateral displacements increase with the level of input motions.And these values are much larger for the models,which the soils are liquefied,with peak amplitude of 8.352 3 or 4.941 1 m/s2,than for non-liquefied model with a lower input motion.For liquefied models,the value of global shear strain of RC structure is less than that of ground.The values of relative lateral displacement between the ground and the top and bottom slab are bigger,and the values of relative vertical displacements between the ground and sidewall are bigger.The values of relative displacement between ground and structure increase sharply up to a fixed value after the soils are liquefied during earthquakes.On the contrary,the both values for non-liquefied model with peak amplitude of 0.928 0 m/s2 are almost same and smaller.
Liquefaction-induced uplift and serious damages of the shallow underground structures in liquefiable soils are observed among the earthquake history cases.Therefore,in order to insure the safety of underground structures in the liquefiable soils in the earthquake prone area,the analysis of uplift earthquake-induced is of prime importance.Based on the method of effective stress analysis using multi-spring model,liquefaction-induced uplift of shallow duct-type RC structures subjected to earthquake motions is discussed in this paper.Moreover,the dynamic interaction between the underground structures and liquefiable soils is further investigated.The results show that the values of uplifted displacements and lateral displacements increase with the level of input motions.And these values are much larger for the models,which the soils are liquefied,with peak amplitude of 8.352 3 or 4.941 1 m/s2,than for non-liquefied model with a lower input motion.For liquefied models,the value of global shear strain of RC structure is less than that of ground.The values of relative lateral displacement between the ground and the top and bottom slab are bigger,and the values of relative vertical displacements between the ground and sidewall are bigger.The values of relative displacement between ground and structure increase sharply up to a fixed value after the soils are liquefied during earthquakes.On the contrary,the both values for non-liquefied model with peak amplitude of 0.928 0 m/s2 are almost same and smaller.
引文
[1]Tobita T,Iai S,Wang Ming-wu,et al.Preliminaryreport of Mid Niigata Prefecture,Japan,Earthquakein 2004[J].Journal of Japan Society for NaturalDisaster Science,2005,23(4):595—602.
[2]徐志英,施善云.土与地下结构动力相互作用的大型振动台试验与计算[J].岩土工程学报,1993,15(4):1—7.
[3]Krauthammer T,Chen Y.Soil-structure interfaceeffects on dynamic interaction analysis of reinforcedconcrete lifelines[J].Soil Dynamic and EarthquakeEngineering,1989,8(1):32—42.
[4]Wang Ming-wu,Iai S,Tobita T.Effective stressanalysis of underground RC structures duringearthquakes[J].Annuals of Disaster PreventionResearch Institute.Kyoto University,2005,47(B):371—382.
[5]Wang Ming-wu,Iai S,Tobiata T.Seismicperformances of underground RC structures inliquefiable soils in nuclear plants[J].GSP(152):Ground Modification and Seismic Mitigation,ASCE,2006:387—394.
[6]周键,董鹏,池永.软土地下结构的地震土压力分析研究[J].岩土力学,2004,25(4):554—559.
[7]车爱兰,岩敞广,葛修润.关于地铁地震响应的模型振动试验及数值分析[J].岩土力学,2006,27(8):1 293—1 298.
[8]林均岐,熊建国.液化场地土中埋设管线的上浮反应分析[J].地震工程与工程振动,2000,20(2):97—10.
[9]邹德高,孔宪京,Ling H I,等.地震饱和砂土地基中管线上浮机理及抗震措施试验研究[J].岩土工程学报,2002,24(3):323—326.
[10]刘华北,宋二祥.可液化土中地铁结构的地震液化响应[J].岩土力学,2005,26(3):381—386.
[11]Iai S,Matsunaga Y,Kameoka T.Strain spaceplasticity model for cyclic mobility[J].Soils andFoundations,1992,32(2):1—15.
[12]刘汉龙,井合进,一井康二.大型沉箱式码头岸壁地震反应分析[J].岩土工程学报,1998,20(2):26—30.
[2]徐志英,施善云.土与地下结构动力相互作用的大型振动台试验与计算[J].岩土工程学报,1993,15(4):1—7.
[3]Krauthammer T,Chen Y.Soil-structure interfaceeffects on dynamic interaction analysis of reinforcedconcrete lifelines[J].Soil Dynamic and EarthquakeEngineering,1989,8(1):32—42.
[4]Wang Ming-wu,Iai S,Tobita T.Effective stressanalysis of underground RC structures duringearthquakes[J].Annuals of Disaster PreventionResearch Institute.Kyoto University,2005,47(B):371—382.
[5]Wang Ming-wu,Iai S,Tobiata T.Seismicperformances of underground RC structures inliquefiable soils in nuclear plants[J].GSP(152):Ground Modification and Seismic Mitigation,ASCE,2006:387—394.
[6]周键,董鹏,池永.软土地下结构的地震土压力分析研究[J].岩土力学,2004,25(4):554—559.
[7]车爱兰,岩敞广,葛修润.关于地铁地震响应的模型振动试验及数值分析[J].岩土力学,2006,27(8):1 293—1 298.
[8]林均岐,熊建国.液化场地土中埋设管线的上浮反应分析[J].地震工程与工程振动,2000,20(2):97—10.
[9]邹德高,孔宪京,Ling H I,等.地震饱和砂土地基中管线上浮机理及抗震措施试验研究[J].岩土工程学报,2002,24(3):323—326.
[10]刘华北,宋二祥.可液化土中地铁结构的地震液化响应[J].岩土力学,2005,26(3):381—386.
[11]Iai S,Matsunaga Y,Kameoka T.Strain spaceplasticity model for cyclic mobility[J].Soils andFoundations,1992,32(2):1—15.
[12]刘汉龙,井合进,一井康二.大型沉箱式码头岸壁地震反应分析[J].岩土工程学报,1998,20(2):26—30.
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