LABORATORY TESTS ON DYNAMIC MODULUS AND DAMPING RATIO OF CEMENT-STABILIZED EXPANSIVE SOIL AS SUBGRADE FILLING OF HEAVY HAUL RAILWAY
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摘要: 动弹模量与阻尼比是土动力学分析中的重要力学参数，考虑重载铁路荷载特征定量分析水泥改良膨胀土的动模量和阻尼比的较少。依托蒙西至华中地区铁路煤运通道(简称蒙-华铁路)工程为背景，采用南阳邓州市大山寨膨胀土，通过在不同频率、围压、固结比及动应力幅值下的持续振动三轴试验，研究了水泥掺量3%和5%水泥改良膨胀土的动弹模量及阻尼比，并与膨胀土素土进行对比分析。结果表明：水泥掺量3%和5%改良膨胀土的最大动弹模量约为膨胀土素土的3~4倍；在动弹模量-应变曲线中，动应变小于0.002时表现为陡降段，动弹模量随动应变增长降幅达70%，而动应变大于0.002时降幅较小，动弹模量随动应变增长趋于稳定；动弹模量随围压、频率、水泥掺量增加而增大，阻尼比随围压、固结比增加而减小；低应变水平下，固结比与动模量成正相关关系，高应变水平下，固结比与动弹模量成负相关关系。同时，对动弹模量及阻尼比进行了归一化分析，建立了估算动弹模量及阻尼比的经验公式。Abstract: Dynamic elastic modulus and damping ratio are important mechanical parameters in soil dynamics analysis. Considering the characteristics of heavy-duty railway loads, the dynamic modulus and damping ratio of cement-stabilized expansive soil are less. Based on the background of the railway coal transportation channel(hereinafter referred to as Meng-Hua Railway) in the central area of the city of Tolemon and the central China, the dynamic modulus and damping ratio of 3% and 5%cement reinforced expansive soils were studied and compared with the expanded soil from Dashanzhai expansive soil in Dengzhou City, Nanyang, under the consolidation with different frequencies, confining pressure, ratio and dynamic stress amplitude. The results were compared with expansive soils. The results show that the maximum dynamic modulus of cement modified with 3% and 5%modified expansive soil is about 3-4 times that of expansive soil. When the dynamic strain is less than 0.002, the dynamic elastic modulus has a steep drop and decreases by 70%. In the dynamic elastic modulus-strain curve, when the dynamic strain is greater than 0.002, the decrease is small, and the dynamic elastic modulus tends to be stable with the dynamic strain. The dynamic elastic modulus increases as the confining pressure, the frequency and the cement content increase. Damping ratio decreases as the confining pressure and consolidation ratio increase. At low strain levels, the consolidation ratio is positively correlated with the dynamic modulus. At high strain levels, the consolidation ratio is inversely related to the dynamic modulus. At the same time, the dynamic modulus and damping ratio are normalized and analyzed, and an empirical formula for estimating the dynamic modulus and damping ratio is established.
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Key words:
- Heavy haul railway /
- Cement-stabilized expansive soil /
- Dynamic modulus /
- Damping ratio
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图 2 水泥(3%)改良膨胀土(f=1，kc=1)
a. Ed~εd曲线；b. 1/Ed~εd曲线
Figure 2. Cement(3%)-stabilized expansive soil(f=1, kc=1)
图 3 水泥(5%)改良膨胀土(f=1，kc=1)
a. Ed~εd曲线；b. 1/Ed~εd曲线
Figure 3. Cement(5%)-stabilized expansive soil(f=1, kc=1)
图 4 阻尼比λ~εd变化曲线
a.素膨胀土(f=1，kc=1)；b.水泥掺量3%改良膨胀土(f=1，kc=1)；c.水泥掺量5%改良膨胀土(f=1，kc=1)
Figure 4. Damping ratio λ~εd curve
图 5 动弹性模量归一化曲线(膨胀土素土)
Figure 5. Dynamic modulus of elasticity normalized curve(expansive soil)
图 6 动弹性模量归一化变化曲线(3%水泥改良膨胀土)
Figure 6. Dynamic modulus of elasticity normalized curve (3% cement-stabilized expansive soil)
图 7 动弹性模量归一化变化曲线(5%水泥改良膨胀土)
Figure 7. Dynamic modulus of elasticity normalized curve (5% cement-stabilized expansive soil)
表 1 大山寨膨胀土基本物理力学参数
Table 1. Basic physical and mechanical parameters of expansive soil in Dashanzhai
天然含水率/% 天然密度/g·cm-3 液限/% 塑限/% 塑性指数 液性指数 内摩擦角/(°) 黏聚力/kPa 压缩系数/MPa-1 压缩模量/MPa 自由膨胀率/% 蒙脱石含量/% 阳离子交换量/mmol·kg-1 膨胀力/kPa 无荷膨胀量 20.0~27.5 1.75~2.01 36.9~50.3 23.7~27.9 13.2~21.4 0.04~0.31 18~22 38~46 0.19~0.23 7.22~9.01 55~73 22~28 276~390 27~129 15~30 
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表 2 水泥改良膨胀土基本物理力学参数(平均值)
Table 2. Basic physical and mechanical parameters of cement-stabilized expansive soil(average value)
掺量/% 最佳含水量/% 液限/% 塑限/% 内摩擦角/(°) 黏聚力/kPa 自由膨胀率/% 膨胀力/kPa 无侧限抗压强度/kPa 3 14.9 42.4 27.9 27.6 139 32 14 335(饱和样) 4 15.2 41.6 28.8 31.8 204 28 10 512(饱和样) 5 15.3 41.4 29.5 41.8 244 23 1 852(饱和样)
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表 3 试验参数
Table 3. Test parameters
试验工况 频率/Hz 固结比 固结围压/kPa 素膨胀土 1、5 1.0 15，30 2.0 15，30 3%水泥改良膨胀土 1、5 1.0 15，30，60 2.0 15，30，60 5%水泥改良膨胀土 1、5 1.0 15，30，60 2.0 15，30，60
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表 4 最大动弹性模量Edmax
Table 4. Maximum dynamic modulus Edmax
频率
/Hz固结比 围压
/kPa素膨胀土
/MPa3%改良土
/MPa5%改良土
/MPa1 1 15 68.68 184.84 243.90 30 84.53 207.47 270.27 60 / 234.74 285.71 1 2 15 78.99 235.29 338.98 30 117.51 239.23 347.22 60 / 280.11 357.14 5 1 15 79.11 215.05 270.27 30 102.25 238.10 297.62 60 / 242.72 322.58 5 2 15 95.60 289.02 358.42 30 141.64 320.51 398.41 60 / 336.70 454.55
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表 5 最大阻尼比λmax
Table 5. Maximum damping ratio λmax
频率/Hz 固结比 围压/kPa 素膨胀土 3%改良土 5%改良土 1 1 15 31.21 25.16 26.77 30 27.33 21.73 22.55 60 / 17.56 18.76 1 2 15 20.33 14.48 15.32 30 18.76 12.36 13.47 60 / 10.39 10.78 5 1 15 38.21 29.14 28.15 30 36，87 25.37 25.32 60 / 19.33 17.59 5 2 15 25.77 20.15 21.39 30 23.49 18.44 19.63 60 / 12.47 13.56
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Deng X. 2015. Dynamic characteristics of cement improved expansive soil under dry-wet cycling[D]. Chengdu: Southwest Jiaotong University. Gao M M, Zheng X L, Yang F. 2016. Dynamic performance study of track-bridge transition section for 30 t axle load heavy haul railway[J]. High Speed Railway Technology, 5 (7): 71-74, 79. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=gstljs201605016 Gong K, Xiang J, Mao J H, et al. 2017. Influence on freight train operation safety for ballasted and ballastless track[J]. Journal of Central South University(Science and Technology), 48(8): 2152-2161. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=zngydxxb201708024 Guo K M, Wang X D, Duan C L, et al. 2017. Thickness design of heavy haul railway subgrade bed based on strength control method[J]. Journal of Railway Science and Engineering, 14(1): 59-65. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=cstdxyxb201701010 Hardin B O, Black W L. 1969. Vibration modulus of normally consolidated clay(Clsure)[J]. Journal of the Soil Mechanics and Foudations Division, ASCE, 95(SM6): 1531-1537. He C R. 1997. Dynamic triaxial test on modulus and damping[J]. Chinese Journal of Geotechnical Engineering, 19(2): 39-48. http://d.old.wanfangdata.com.cn/Periodical/ytgcxb201504013 Hu Y D. 2015. Current status and development trend of technology system for railway heavy haul transport in China[J]. China Railway Science, 36(2): 1-10. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=zgtdkx201502001 Hu G, Zhao Q H, He Y S, et al. 2016. Elastic modulus's evolution law of plagiogranite under cyclic loading[J]. Journal of Engineering Geology, 24(5): 881-890. http://cn.bing.com/academic/profile?id=41387f9d65d9caa8afea5d9ef95bd89a&encoded=0&v=paper_preview&mkt=zh-cn Hu P. 2010. Dynamic experimental study and simulink analyis of closely spaced bridge-transition sections in for ballastless tracks on high speed railway[D]. Changsha: Central South University. Kumar S S, Krishna A M, Dey A. 2017. Evaluation of dynamic properties of sandy soil at high cyclic strains[J]. Soil Dynamics and Earthquake Engineering, 99 : 157-167. doi: 10.1016/j.soildyn.2017.05.016 Leng W M, Liu W J, Zhou W Q. 2015. Testing research on critical cyclical stress of coarse-grained soil filling in heavy haul railway subgrade[J]. Journal of Vibration and Shock, 34(16): 25-30. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=zdycj201516005 Li R K, Wu Z J, Liang Q G, et al. 2018. Influence factors of dynamic characteristics of loess considering the microstructure properties[J]. Journal of Engineering Geology, 26(4): 905-914. http://d.old.wanfangdata.com.cn/Periodical/gcdzxb201804014 Li R S, Chen L W, Yuan X M, et al. 2017. Experimental study on influences of different loading frequencies on dynamic modulus and damping ratio[J]. Chinese Journal of Geotechnical Engineering, 39(1): 71-80. http://d.old.wanfangdata.com.cn/Periodical/ytgcxb201701005 Mo W Y. 2015. Experimental study on the dynamic properties of lime-treated expansive soil affected by wetting-drying cycles[D]. Nanning: Guangxi University. Qiu M M, Yang G L, Shen Q, et al. 2017. Dynamic behavior of new cutting subgrade structure of expensive soil under train loads coupling with service environment[J]. Journal of Central South University, 24(4): 875-890. doi: 10.1007/s11771-017-3490-0 Seed H B, Idriss I M. 1970. Soil moduli and damping factors for dynamic response analyses(Report No. EERC 70-10)[R]. Berkeley: Earthquake Engineering Research Center, University of California. Tong F M. 2010. Analysis of mutual influence of dynamic response of subgrade in transition section between adjacent culverts of high speed railway[D]. Changsha: Central South University. Wang Q Y. 2013. Study on dynamic characteristics and paraneters of ballastless track-subgrade of high speed railway[D]. Changsha: Central South University. Xie J P, Shi Z J. 1973. Experimental study on dynamic performance of original saturated clay[R]. Beijing: Earthquake Engineering of Institute of Engineering Mechanics, Chinese Academy of Sciences. Yang G L, Qiu M M, He X, et al. 2016. Tests for working property of water-proof layer of cutting subgrade in expansive soil under vibrating load[J]. Journal of Vibrattion And Shock, 35 (5): 1-7, 20. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=zdycj201605001 Yang G Q. 2003. Study of dynamic performance of cement-improved soil[J]. Chinese Journal of Rock Mechanics and Engieering, 22(7): 1156-1160. http://d.old.wanfangdata.com.cn/Periodical/ytlx201812013 Zhang R G. 2017. Exploration of design technique on substructure for 400 km/h high-speed railway and 40 t axle-load heavy haul railway[D]. Chengdu: Southwest Jiaotong University. Zheng W, Wenbo X, Yao L, et al. 2019. Dynamic and static testing methods for shear modulus of oriented strand board[J]. Construction and Building Materials, 216 : 542-551. doi: 10.1016/j.conbuildmat.2019.05.004 邓稀. 2015.干湿循环下水泥掺入对膨胀土动力特性影响的试验研究[D].成都: 西南交通大学. 高芒芒, 郑晓龙, 杨飞. 2016.30t轴重重载铁路路桥过渡段动力性能研究[J].高速铁路技术5 (7): 71-74, 79. http://d.old.wanfangdata.com.cn/Periodical/gstljs201605016 龚凯, 向俊, 毛建红, 等. 2017.有砟及无砟轨道结构对货物列车运行安全性的影响[J].中南大学学报(自然科学版), 48(8): 2152-2161. http://d.old.wanfangdata.com.cn/Periodical/zngydxxb201708024 郭抗美, 王新单, 段辰铃, 等. 2017.基于强度控制法的重载铁路基床厚度设计研究[J].铁道科学与工程学报, 14(1): 59-65. doi: 10.3969/j.issn.1672-7029.2017.01.010 何昌荣. 1997.动模量和阻尼的动三轴试验研究[J].岩土工程学报, 19(2): 39-48. doi: 10.3321/j.issn:1000-4548.1997.02.006 胡广, 赵其华, 何云松, 等. 2016.循环荷载作用下斜长花岗岩弹性模量演化规律[J].工程地质学报24 (5): 881-890. doi: 10.13544/j.cnki.jeg.2016.05.018 胡萍. 2010.高速铁路无砟轨道密集过渡段路基动力试验与仿真分析[D].长沙: 中南大学. 胡亚东. 2015.我国铁路重载运输技术体系的现状与发展[J].中国铁道科学, 36(2): 1-10. doi: 10.3969/j.issn.1001-4632.2015.02.01 冷伍明, 刘文劼, 周文权. 2015.振动荷载作用下重载铁路路基粗颗粒土填料临界动应力试验研究[J].振动与冲击, 34(16): 25-30. http://d.old.wanfangdata.com.cn/Periodical/zdycj201516005 李瑞宽, 吴志坚, 梁庆国, 等. 2018.考虑微结构特征的黄土动力特性影响因素研究[J].工程地质学报, 26(4): 905-914. doi: 10.13544/j.cnki.jeg.2017-391 李瑞山, 陈龙伟, 袁晓铭, 等. 2017.荷载频率对动模量阻尼比影响的试验研究[J].岩土工程学报, 39(1): 71-80. http://d.old.wanfangdata.com.cn/Periodical/ytgcxb201701005 莫文瑜. 2015.干湿循环对石灰处治膨胀土动力特性影响试验研究[D].南宁: 广西大学. 童发明. 2010.高速铁路相邻涵洞间过渡段路基动力响应相互影响分析[D].长沙: 中南大学. 王启云. 2013.高速铁路无砟轨道路基动力特性及参数研究[D].长沙: 中南大学. 杨广庆. 2003.水泥改良土的动力特性试验研究[J].岩石力学与工程学报, 22(7): 1156-1160. doi: 10.3321/j.issn:1000-6915.2003.07.021 杨果林, 邱明明, 何旭, 等. 2016.膨胀土路堑基床新型防水层振动荷载下服役性能试验研究[J].振动与冲击, 35 (5): 1-7, 20. http://d.old.wanfangdata.com.cn/Periodical/zdycj201605001 张瑞国.2017.400 km/h高速铁路与轴重40 t重载铁路基床结构设计技术探讨[D].成都: 西南交通大学. -
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