单点动载下路基动应力状态及有效作用半径分析
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摘要
基于传统的Boussinesq课题解答,利用集中荷载作用下半无限空间弹性路基中不同空间位置,且满足一定限制条件的点的应力应变状态的集合来表征单次行车荷载下路基岩土体内某一点加载、卸载全过程的应力、应变等力学响应,将动力学问题转化为准静力学问题,建立着眼于简单与实用的路基动力学行为分析模型。借助建立的模型探讨路基一个加载、卸载全过程的应力状态及其有效作用半径。研究表明,(1)路基单元体动正应力差(σz?σx)和(σz?σy)曲线表现为脉冲状,而(σx?σy)曲线为双峰状;(2)最大主应力σ1绕z轴可能突发大角度旋转,但与z轴交角则连续旋转180°,最小主应力σ3整体旋转特征不甚明显,中间主应力σ2方向变化规律性较差;(3)单次交通荷载对路基路面系统的有效作用半径确定为10 m,影响范围确定为以荷载作用点为圆心,以10 m为半径的空间半球体。最后,利用原位监测数据对确定单次交通荷载的有效作用半径为10 m的合理性进行验证。
Based on the classical Boussinesq analytical solutions,a set defined by stress and strain state of points,when subjected to concentrated load,with varied spatial location in semi-infinite elastic subgrade and constrained by certain conditions,is employed to characterize the stress and strain state of a fixed point in the subgrade during the loading-unloading process induced by a single vehicle load.Dynamics,consequently,is transformed into quasi-statics,and analysis model,which is supposed to be convenient and practical for verifying subgrade dynamic behaviors,is established.Stress state and effective working radius are approached and determined during a loading—unloading process in subgrade.Results indicate:(1) curves of dynamic normal stress differences() and() are pulse shape,while() changes in a twin peak manner;(2) the maximum principal stress might whirl abruptly about z axis,and the angle intersected with z axis rotates gradually and continuously by 180°;the orientation of minimum principal stress turns in a relatively smooth pattern and its rotation features are less remarkably;while the intermediate principal stress direction alters elusively;(3) effective working radius,which represents the limit of impacts exerted by a single vehicle loads on subgrade,pavement system,is suggested to a length of 10 m,and the influenced area can be considered as a semi-sphere with a radius of 10 m and whose center sited at the point of load.At last,the validity of effective working radius,which is defined by 10 m under one vehicle loading,is specified by in situ monitoring data.
引文
[1]MOROZOV N,PETROV Y.Dynamics of fracture[M].Berlin:Springer-Verlag,2000.
    [2]LEONG E C,ANAND S,CHEONG H K,et al.Re-examination of peak stress and scaled distance due to ground shock[J].International Journal of Impact Engineering,2007,34(9):1 487–1 499.
    [3]QIAN Q H,QI C Z,WANG M Y.Dynamic strength of rocks and physical nature of rock strength[J].Journal of Rock Mechanics and Geotechnical Engineering,2009,1(1):1–10.
    [4]LI X B,ZHOU Z L,ZHAO F J,et al.Mechanical properties of rock under couple static-dynamic loads[J].Journal of Rock Mechanics and Geotechnical Engineering,2009,1(1):41–47.
    [5]LI X B,LOK T S,ZHAO J.Dynamic characteristics of granite subjected to intermediate loading rate[J].Rock Mechanics and Rock Engineering,2005,38(1):21–39.
    [6]YANG Y B,XIE X Y,WANG R L.Numerical simulation of dynamic第30卷增2汤连生等:单点动载下路基动应力状态及有效作用半径分析?4063?response of operating metro tunnel induced by ground explosion[J].Journal of Rock Mechanics and Geotechnical Engineering,2010,2(4):373–384.
    [7]朱颖,魏永幸.汶川地震铁路工程震害特征及工程抗震设计对策思考[J].岩石力学与工程学报,2010,29(增1):3378–3386.(ZHU Ying,WEI Yongxing.Earthquake and countermeasure considerations of engineering seismic design[J].Chinese Journal of Rock Mechanics and Engineering,2010,29(Supp.1):3 378–3 386.(in Chinese))
    [8]刘晋南,蒋鑫,邱延峻,等.水平地震荷载作用下斜坡路基动力稳定性分析[J].中外公路,2010,30(5):42–45.(LIU Jinnan,JIANG Xin,QIU Yanjun,et al.Analysis of dynamic stability of inclined subgrade under lateral earthquake shock[J].Journal of China and Foreign Highway,2010,30(5):42–45.(in Chinese))
    [9]杨桂通.弹塑性动力学基础[M].北京:科学出版社,2008.(YANG Guitong.Basic elasto-plastic dynamics[M].Beijing:Science Press,2008.(in Chinese))
    [10]凌建明,苏华才,谢华昌,等.路基土动态回弹模量的试验研究[J].地下空间与工程学报,2010,6(5):919–925.(LING Jianming,SU Huacai,XIE Huachang,et al.Laboratory research on dynamic resilient modulus of subgrade soil[J].Chinese Journal of Underground Space and Engineering,2010,6(5):919–925.(in Chinese))
    [11]SNEDDON I N.The stress produced by a pulse of pressure moving along the surface of a semi-infinite solid[J].Rendiconti del Circolo Matematico di Palermo,1952,1(1):57–62.
    [12]COLE J,HUTH J.Stresses Produced in a half-plane by moving loads[J].Journal of Applied Mechanics,ASME,1958,25(1):433–436.
    [13]EASON G.The stresses produced in a semi-infinite solid by a moving surface force[J].International Journal of Engineering Science,1965,2(1):581–609.
    [14]凌建明,王伟,邬洪波.行车荷载作用下湿软路基残余变形的研究[J].同济大学学报:自然科学版,2002,30(11):1 315–1 320.(LING Jianming,WANG Wei,WU Hongbo.On residual deformation of saturated clay subgrade under vehicle load[J].Journal of Tongji University:Natural Science,2002,30(11):1 315–1 320.(in Chinese))
    [15]汤连生,林沛元,吴科,等.交通荷载下层状路基动附加应力的弹性计算模型[J].岩石力学与工程学报,2009,28(11):2 208–2 214.(TANG Liansheng,LIN Peiyuan,WU Ke,et al.Elastic calculation model for dynamic additional stresses in layered subgrade under traffic load[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(11):2 208–2 214.(in Chinese))
    [16]SHARP R W,BOOKER J R.Shakedown of pavements under moving surface loads[J].Journal of Transportation Engineering,1984,110(1):1–14.
    [17]郑颖人,沈珠江,龚晓南.岩土塑性力学原理:广义塑性力学[M].北京:中国建筑工业出版社,2002.(ZHENG Yingren,SHEN Zhujiang,GONG Xiaonan.Theory of plastic mechanics of rock and soil:generalized plastic mechanics[M].Beijing:China Architecture and Building Press,2002.(in Chinese))
    [18]廖化荣.交通荷载下路基软土动应力累积及塑性应变累积特性研究[博士学位论文][D].广州:中山大学,2008.(LIAO Huarong.Study of cumulative characteristics of dynamic stress and plastic strain in soil under traffic loading[Ph.D.Thesis][D].Guangzhou:Sun Yat-Sen University,2008.(in Chinese))
    [19]LEI X,NODA N A.Analyses of dynamic response of vehicle and track coupling system with random irregularity of track vertical profile[J].Journal of Sound and Vibration,2002,258(1):147–165.
    [20]SUBEI L M,SALAMA M,Bal Q M.A three-dimensional tunnel model for calculation of train-induced ground vibration[J].Journal of Sound and Vibration,2006,294(4/5):678–705.
    [21]董亮,赵成刚,蔡德钩,等.高速铁路路基的动力响应分析方法[J].工程力学,2008,25(11):231–236.(DONG Liang,ZHAO Chenggang,CAI Degou,et al.Method for dynamic response of subgrade subjected to high-speed moving load[J].Engineering Mechanics,2008,25(11):231–236.(in Chinese))
    [22]汤连生,徐通,林沛元,等.交通荷载下层状道路系统动应力特征分析[J].岩石力学与工程学报,2009,28(增1):3 876–3 884.(TANG Liansheng,XU Tong,LIN Peiyuan,et al.Studies on dynamic stress characters of layered road system under traffic loading[J].Chinese Journal of Rock Mechanics and Engineering,2009,28(Supp.1):3 876–3 884.(in Chinese))
    [23]徐鹏,蔡成标.列车–有砟轨道–路基空间耦合动力学模型[J].工程力学,2011,28(3):191–197.(XU Peng,CAI Chengbiao.Spatial dynamic model of train-ballast track-subgrade coupled system[J].Engineering Mechanics,2011,28(3):191–197.(in Chinese))
    [24]李广信.高等土力学[M].北京:清华大学出版社,2004:48–49.(LI Guangxin.Advanced soil mechanics[M].Beijing:Tsinghua University Press,2004:48–49.(in Chinese))
    [25]中华人民共和国国家标准编写组.GB50007—2002建筑地基基础设计规范[S].北京:中国建筑工业出版社,2002.(The National Standards Compilation Group of People′s Republic of China.GB50007—2002 Code for design of building foundation[S].Beijing:China Architecture and Building Press,2002.(in Chinese))
    [26]陈国兴,潘华.轨道交通振动作用引起的土单元应力路径特征及其在室内试验中的模拟[J].土木工程学报,2010,43(增):340–345.(CHEN Guoxin,PAN Hua.The characteristics and laboratory test simulation of stress path induced by traffic loading[J].China Civil Engineering Journal,2010,43(Supp.):340–345.(in Chinese))
    [27]王常晶,陈云敏.移动荷载引起的地基应力状态变化及主应力轴旋转[J].岩石力学与工程学报,2007,26(8):1 698–1 704.(WANG Changjing,CHEN Yunmin.Stress state variation and principal stress axes rotation of ground induced by moving loads[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(8):1 698–1 704.(in Chinese))
    [28]王常晶,温日琨,陈云敏.交通荷载引起的主应力轴旋转室内试验模拟探讨[J].岩土力学,2008,29(12):3 412–3 416.(WANG Changjing,WEN Rikun,CHEN Yunmin.Discussion on laboratory test simulation of principal stress axes rotation induced by traffic loading[J].Rock and Soil Mechanics,2008,29(12):3 412–3 416.(in Chinese))

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