季节性冻土区和多年冻土区桥梁结构地震反应分析
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摘要
冻土层的存在,对桥梁结构抗震安全性的影响是一个值得重视的问题。本文利用黏-弹性边界模拟波向无穷远辐射的结构-地基土一体化计算方法,对季节性冻土区和多年冻土区桥梁结构在不同地震波作用下的反应进行计算,分析冻土层的变化对桥梁结构地震反应的影响,总结在地震荷载作用下,不同场地、不同的冻土厚度、不同高度的桥墩和不同基础条件下桥墩应力分布的一般规律。分析结果表明:在II类场地上,冻土层对桥墩地震反应的影响十分显著,不同类型冻土场地上桥墩的最大反应差值可达1倍以上;墩高在10~22 m时,冻土层对桥墩地震反应的影响最为显著;不同类型的桥墩基础,对冬夏两季桥墩的地震反应的影响不大;在一般情况下,桥墩的地震反应与冻土性质、桥墩的动力特性以及地震波的性质均密切相关,按融土状态进行设计往往是不安全的,需要考虑桥墩与冻土层相互作用的影响。
It is worth attaching importance to the problem that the frozen earth layer has influence upon the aseismatic safety of bridges.Using the soil-structure interaction method that can simulate the radiant function of waves by use of the artificial viscidity-elasticity boundary,the responses of bridges under multifarious earthquakes in permafrost and seasonal frozen regions are calculated.The influence of the frozen earth layer change on the seismic responses of bridges is analyzed.The general distributing law of bridge pier stresses under seismic loading is summarized on condition of different sites,different frozen soil layer thicknesses,different heights of bridge piers and different bridge foundations.The analysis results are as follows: on sites type 2,frozen earth layers have marked influence on seismic responses of bridge piers and the maximum stress difference for different types of frozen earth layer sites may reach more than one time;when bridge piers are 10 to 22 m high,frozen earth layers have the most notable effects on pier seismic responses;the types of pier foundations may be neglected when the pier seismic responses are compared between winter and summer;in general,bridge pier seismic responses have close relationship with the frozen earth features,dynamic characteristics of bridge piers and seismic wave features.It needs to consider the interaction between bridge piers and frozen earth layers because it is not safe to apply thawy soil conditions to bridge design.
It is worth attaching importance to the problem that the frozen earth layer has influence upon the aseismatic safety of bridges.Using the soil-structure interaction method that can simulate the radiant function of waves by use of the artificial viscidity-elasticity boundary,the responses of bridges under multifarious earthquakes in permafrost and seasonal frozen regions are calculated.The influence of the frozen earth layer change on the seismic responses of bridges is analyzed.The general distributing law of bridge pier stresses under seismic loading is summarized on condition of different sites,different frozen soil layer thicknesses,different heights of bridge piers and different bridge foundations.The analysis results are as follows: on sites type 2,frozen earth layers have marked influence on seismic responses of bridge piers and the maximum stress difference for different types of frozen earth layer sites may reach more than one time;when bridge piers are 10 to 22 m high,frozen earth layers have the most notable effects on pier seismic responses;the types of pier foundations may be neglected when the pier seismic responses are compared between winter and summer;in general,bridge pier seismic responses have close relationship with the frozen earth features,dynamic characteristics of bridge piers and seismic wave features.It needs to consider the interaction between bridge piers and frozen earth layers because it is not safe to apply thawy soil conditions to bridge design.
引文
[1]王大雁,朱元林,等.超声波法测定冻土动弹性力学参数试验研究[J].岩土工程学报,2002,24(5):612—615.WANG Da-yan,ZHU Yuan-lin,et al.Study on Experi-mental Determination of the Dynamic Elastic MechanicalParameters of Frozen Soil by Ultrasonic Technique[J].Chinese Journal of Geotechnical Engineering,2002,24(5):612—615.
[2]徐学燕,仲丛利,陈亚明.冻土的动力特性研究及其参数确定[J].岩土工程学报,1998,20(5):77—81.XU Xue-yan,ZHONG Cong-li,CHEN Ya-ming.Researchon Dynamic Characters of Frozen Soil and Determination ofits Parameters[J].Chinese Journal of Geotechnical Engi-neering,1998,20(5),77—81.
[3]徐春华,徐学燕,邱明国,等.循环荷载下冻土的动阻尼比试验研究[J].哈尔滨建筑大学学报,2002,35(6):22—25.XU Chun-hua,XU Xue-yan,QIU Ming-guo,et al.Experi-mental Study on Dynamic Damping Ratio of Frozen SoilUnder Cyclic Loading.Journal of Harbin University of C.E.&Architecture.1998,20(5),77—81.
[4]徐学燕,徐春华,李晓稚.冻土场地地震加速度反应谱研究[J].岩土工程学报,2003,25(6):680—683.XU Xue-yan,XU Chun-hua,LI Xiao-zhi.Research onEarthquake Acceleration Response Spectrum of Frozen SoilGround[J].Chinese Journal of Geotechnical Engineering,2003,25(6):680—683.
[5]刘鸿绪,孙彦福,陈亚明,等.季节冻土层对房屋地震破坏的影响[J].冰川冻土,1998,20(1):46—50.LIU Hong-xu,SUN Yan-fu,CHEN Ya-ming,et al.Influ-ence of Seasonally Frozen Ground on the Seismic Damagesof Buildings[J].Journal of Glaciology and Gbocryllogy.1998,20(1):46—50.
[6]杨柏坡,孙平善,申杰.有冻土层场地上多层砖房的震害预测方法[J].地震工程与工程振动,1999,19(2):87—94.YANG Bai-po,SUN Ping-shan,SHEN Jie.Method ofDamage prediction for Multi-storeyed Brick Building on theSite With Frozen Layer[J].Earthquake Engineering andEngineering Vibration,1999,19(2):87—94.
[7]王旭、蒋代军.冻土动三轴试验及地基系数的测试报告[R].兰州:兰州交通大学土木工程学院岩土实验室,2003.
[8]陆鸣,等.青藏铁路四座主要桥梁工程场地地震安全性评价报告[D].中国地震局工程地震研究中心.2001.
[9]沈聚敏,周锡元,高小旺,等.抗震工程学[M].北京:中国建筑工业出版社,2000.
[10]廖振鹏.工程波动导引[M].北京:科学出版社,1996.
[11]潘昌实.隧道力学数值方法[M].北京:中国铁道出版社,1995.
[12]刘晶波,吕彦东.结构-地基动力相互作用问题分析的一种直接方法[J].土木工程学报.1998,31(3).55—64.LIU Jing-bo,LU Yan-dong.A Direct Method for Analy-sis of Dynamic Soil-structure Interaction[J].China CivilEngineering Journal,1998,31(3).55—64.
[2]徐学燕,仲丛利,陈亚明.冻土的动力特性研究及其参数确定[J].岩土工程学报,1998,20(5):77—81.XU Xue-yan,ZHONG Cong-li,CHEN Ya-ming.Researchon Dynamic Characters of Frozen Soil and Determination ofits Parameters[J].Chinese Journal of Geotechnical Engi-neering,1998,20(5),77—81.
[3]徐春华,徐学燕,邱明国,等.循环荷载下冻土的动阻尼比试验研究[J].哈尔滨建筑大学学报,2002,35(6):22—25.XU Chun-hua,XU Xue-yan,QIU Ming-guo,et al.Experi-mental Study on Dynamic Damping Ratio of Frozen SoilUnder Cyclic Loading.Journal of Harbin University of C.E.&Architecture.1998,20(5),77—81.
[4]徐学燕,徐春华,李晓稚.冻土场地地震加速度反应谱研究[J].岩土工程学报,2003,25(6):680—683.XU Xue-yan,XU Chun-hua,LI Xiao-zhi.Research onEarthquake Acceleration Response Spectrum of Frozen SoilGround[J].Chinese Journal of Geotechnical Engineering,2003,25(6):680—683.
[5]刘鸿绪,孙彦福,陈亚明,等.季节冻土层对房屋地震破坏的影响[J].冰川冻土,1998,20(1):46—50.LIU Hong-xu,SUN Yan-fu,CHEN Ya-ming,et al.Influ-ence of Seasonally Frozen Ground on the Seismic Damagesof Buildings[J].Journal of Glaciology and Gbocryllogy.1998,20(1):46—50.
[6]杨柏坡,孙平善,申杰.有冻土层场地上多层砖房的震害预测方法[J].地震工程与工程振动,1999,19(2):87—94.YANG Bai-po,SUN Ping-shan,SHEN Jie.Method ofDamage prediction for Multi-storeyed Brick Building on theSite With Frozen Layer[J].Earthquake Engineering andEngineering Vibration,1999,19(2):87—94.
[7]王旭、蒋代军.冻土动三轴试验及地基系数的测试报告[R].兰州:兰州交通大学土木工程学院岩土实验室,2003.
[8]陆鸣,等.青藏铁路四座主要桥梁工程场地地震安全性评价报告[D].中国地震局工程地震研究中心.2001.
[9]沈聚敏,周锡元,高小旺,等.抗震工程学[M].北京:中国建筑工业出版社,2000.
[10]廖振鹏.工程波动导引[M].北京:科学出版社,1996.
[11]潘昌实.隧道力学数值方法[M].北京:中国铁道出版社,1995.
[12]刘晶波,吕彦东.结构-地基动力相互作用问题分析的一种直接方法[J].土木工程学报.1998,31(3).55—64.LIU Jing-bo,LU Yan-dong.A Direct Method for Analy-sis of Dynamic Soil-structure Interaction[J].China CivilEngineering Journal,1998,31(3).55—64.
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