|
|
|
| In-situ dynamic experimental study for simulating dynamic response of subgrades |
| LOU Shuang |
| (Department of Civil Engineering,Anhui Communications Vocational and Technical College,Hefei,Anhui 230000,China) |
|
|
|
|
Abstract The dynamic response rule of subgrades under dynamic loads is the basis for studying the long term dynamic stability of the subgrades. The self-developed separated variable frequency vibration exciter was used to carry out full-scale model tests to study the railway subgrade dynamic response. The dynamic response rules of the railway subgrade under different excitation frequencies and dynamic load levels were studied. The test results show that the resonance frequency of the railway subgrade which was filled with lime improved soil and silty clay is 25 Hz and the vibration acceleration and dynamic stress of the subgrade surface increase significantly with increasing the excitation frequency. The vibration acceleration and dynamic stress along the depth and horizontal direction were researched. It is revealed that the vibration acceleration and dynamic stress in the depth of 1.5m reduce by 90%,which indicates that the vibration acceleration and dynamic stress along the depth attenuates faster than those of the ballastless track subgrade. The changes of the vibration acceleration and dynamic stress in the horizontal direction are affected by the stress diffusion effect. To be specific,the vibration acceleration and dynamic stress decay rapidly in the shallow horizontal plane while keep relatively stable in the depth of 0.7m. The research results reveal the spatial variation characteristics of the subgrade dynamic response.
|
|
|
|
|
|
[1]龙万学,陈开圣,肖涛,等. 非饱和红黏土三轴试验研究[J]. 岩土力学,2009,30(增2):28–33.(LONG Wanxue,CHEN Kaisheng,XIAO Tao,et al. Research of general triaxial test for unsaturated red clay[J]. Rock and Soil Mechanics,2009,30(Supp.2):28–33.(in Chinese))
[2]聂庆科,李佩佩,王英辉,等. 三轴冲击荷载作用下红黏土力学性状[J]. 岩石力学与工程学报,2009,28(6):1 220–1 225.(NIE Qingke,LI Peipei,WANG Yinghui,et al. Mechanical Characteristics of Red Clay under Triaxial Impact Loading[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(6):1 220–1 225.(in Chinese))
[3]李 剑,陈善雄,姜领发,等. 应力历史对重塑红黏土动力特性影响的试验研究[J]. 岩土工程学报,2013,35(10):1 807–1 815.(LI Jian,CHEN Shanxiong,JIANG Lingfa,et al. Test study of the influence of stress history on the remolded red clay dynamic properties[J]. Chinese Journal of Geotechnical Engineering,2013,35(10):1 807–1 815.(in Chinese))
[4]姜领发,熊署丹,陈善雄,等. 列车荷载作用下高铁路基速度传递规律模型试验研究[J]. 岩土力学,2015,36(增1):265–269.(JIANG Lingfa,XIONG Shudan,CHEN Shanxiong,et al. Model test study of velocity transfer law of high-speed railway subgrade under train load[J]. Rock and Soil Mechanics,2015,36(Supp.1):265–269.(in Chinese))
[5]蒋红光,边学成,徐 翔,等. 列车移动荷载下高速铁路板式轨道路基动力性态的全比例尺物理模型试验[J]. 岩土工程学报,2014,36(2):354–362.(JIANG Hongguang,BIAN Xuecheng,XU Xiang,et al. Full scale model tests on dynamic performances of ballastless high-speed railways under moving train loads[J]. Chinese Journal of Geotechnical Engineering,2014,36(2):354–362.(in Chinese))
[6]苏 谦,蔡 英. 高速铁路级配碎石基床表层不同厚度动态大模型试验研究[J]. 铁道标准设计,2001,21(8):2–4.(SU Qian,CAI Ying. Dynamic model test on high speed railway grading macadam with different thickness[J]. Railway Standard Design,2001,21(8):2–4.(in Chinese))
[7]陈仁朋,赵 星,蒋红光,等. 水位变化对无砟轨道路基变形特性影响的研究[J]. 铁道学报,2014,36(3):87–93.(CHEN Renpeng,ZHAO Xing,JIANG Hongguang,et al. Model test on deformation characteristics of slab track-subgrade under changes of water level[J]. Journal of the China Railway Society,2014,36(3):87–93.(in Chinese))
[8]王亮亮,杨果林,房以河,等. 高速铁路膨胀土路堑全封闭基床动力特性现场试验[J]. 岩土工程学报,2014,36(4):640–645.(WANG Liangliang,YANG Guolin,FANG Yihe,et al. In-situ tests on dynamic character of fully-enclosed cutting subgrade of high-speed railways in expansive soil areas[J]. Chinese Journal of Geotechnical Engineering,2014,36(4):640–645.(in Chinese))
[9]陈尚勇,孙红林. 高速铁路浸水路基长期稳定性试验分析[J]. 铁道工程学报,2011,(12):40–44.(CHEN Shangyong,SUN Honglin. Experimental analysis of long-term stability of soaking subgrade for high speed railway[J]. Journal of Railway Engineering Society,2011,(12):40–44.(in Chinese))
[10]聂志红. 高速铁路路基结构竖向动力响应研究[博士学位论文][D]. 长沙:中南大学,2005.(NIE Zhihong. Study on structural vertical dynamic response of the high speed railway subgrade[Ph. D. Thesis] [D]. Changsha:Central South University,2005.(in Chinese))
[11]朱忠林,马伟斌,史存林. 合宁线试验段路堑基床地基动力特性试验研究[J]. 铁道建筑,2007,47(2):55–58.(ZHU Zhonglin,MA Weibin,SHI Cunlin. Test study on the dynamic characteristic of the cutting bedding foundation of the He-Ning Line test section[J]. Rail Engineering,2007,47(2):55–58.(in Chinese))
[12]卢 正. 交通荷作用下公路结构动力响应及路基动强度设计方法研究[博士学位论文] [D]. 武汉:中国科学院研究生院,2009.(LU Zheng. Study on the dynamic responses of highway structure layer under traffic loads and the design method of dynamic strength[Ph.D.Thesis][D]. Wuhan:Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,2009.(in Chinese))
[13]左 珅,徐林荣. 高速铁路建设对紧邻既有线路基服役状态影响的动力测试分析与对策[J]. 铁道学报. 2013,35:82–90.(ZUO Shen,XU Linrong. Dynamic analysis on influence of high speed railway construction on existing adjacent railway lines and countermeasures. Journal of the China Railway Society,2013,35:82–90.(in Chinese))
[14]崔文毅. 粉质土和黏质土的压实特性[J]. 施工技术,2001,(6):39–40.(CUI Wenyi. Compaction technology of silt soil and silt clay[J]. Construction Technology,2001,6:39–40.(in Chinese)) |
|
|
|